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protocol version 2

PATCH Superseded Brandon Williams 6 participants 85 messages Mar 14, 2018 – Mar 30, 2018

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#0 lore raw

v5 cover protocol version 2

Changes in v5:

* Tweaked the API of the packet_read_with_status function so that it wrote the pktlen value even in the presence of non-normal reads (flush, delim, EOF).

* Changed the format of ref-patterns for the ls-refs server command. They are now ref-prefixes and matching is done as a simple prefix match against refnames.

* Tweaked the API for server commands. Instead of the server code dispatching the command and passing it an argv_array of keys and args, I changed it so that it passes it an argv_array of keys and then passes off the packet_reader so that the command can do the reading of the remainder of the input itself. This is to account for future commands (e.g. push) where the argument stream will include a packfile and doesn't make much sense to push into an argv_array.

* Various documentation changes, one of which calls out that the protocol is stateless by default and if state needs to be introduced at a later point, it must be hidden behind a capability which is only advertised when using transports which support state on the server side.

v4 found at:
https://public-inbox.org/git/[email protected]/

Brandon Williams (35):
pkt-line: introduce packet_read_with_status
pkt-line: allow peeking a packet line without consuming it
pkt-line: add delim packet support
upload-pack: convert to a builtin
upload-pack: factor out processing lines
transport: use get_refs_via_connect to get refs
connect: convert get_remote_heads to use struct packet_reader
connect: discover protocol version outside of get_remote_heads
transport: store protocol version
protocol: introduce enum protocol_version value protocol_v2
test-pkt-line: introduce a packet-line test helper
serve: introduce git-serve
ls-refs: introduce ls-refs server command
connect: request remote refs using v2
transport: convert get_refs_list to take a list of ref prefixes
transport: convert transport_get_remote_refs to take a list of ref
prefixes
ls-remote: pass ref prefixes when requesting a remote's refs
fetch: pass ref prefixes when fetching
push: pass ref prefixes when pushing
upload-pack: introduce fetch server command
fetch-pack: perform a fetch using v2
fetch-pack: support shallow requests
connect: refactor git_connect to only get the protocol version once
connect: don't request v2 when pushing
transport-helper: remove name parameter
transport-helper: refactor process_connect_service
transport-helper: introduce stateless-connect
pkt-line: add packet_buf_write_len function
remote-curl: create copy of the service name
remote-curl: store the protocol version the server responded with
http: allow providing extra headers for http requests
http: don't always add Git-Protocol header
http: eliminate "# service" line when using protocol v2
remote-curl: implement stateless-connect command
remote-curl: don't request v2 when pushing

 .gitignore                              |   1 +
 Documentation/Makefile                  |   1 +
 Documentation/gitremote-helpers.txt     |  32 ++
 Documentation/technical/protocol-v2.txt | 398 +++++++++++++++
 Makefile                                |   7 +-
 builtin.h                               |   2 +
 builtin/clone.c                         |   2 +-
 builtin/fetch-pack.c                    |  20 +-
 builtin/fetch.c                         |  21 +-
 builtin/ls-remote.c                     |  15 +-
 builtin/receive-pack.c                  |   6 +
 builtin/remote.c                        |   2 +-
 builtin/send-pack.c                     |  20 +-
 builtin/serve.c                         |  30 ++
 builtin/upload-pack.c                   |  74 +++
 connect.c                               | 364 ++++++++++----
 connect.h                               |   7 +
 fetch-pack.c                            | 339 ++++++++++++-
 fetch-pack.h                            |   4 +-
 git.c                                   |   2 +
 http-backend.c                          |   8 +-
 http.c                                  |  25 +-
 http.h                                  |   7 +
 ls-refs.c                               |  96 ++++
 ls-refs.h                               |  10 +
 pkt-line.c                              | 133 ++++-
 pkt-line.h                              |  78 +++
 protocol.c                              |   2 +
 protocol.h                              |   1 +
 refs.c                                  |  14 +
 refs.h                                  |   7 +
 remote-curl.c                           | 280 ++++++++++-
 remote.h                                |  11 +-
 serve.c                                 | 257 ++++++++++
 serve.h                                 |  15 +
 t/helper/test-pkt-line.c                |  64 +++
 t/t5701-git-serve.sh                    | 176 +++++++
 t/t5702-protocol-v2.sh                  | 273 +++++++++++
 transport-helper.c                      |  87 ++--
 transport-internal.h                    |  11 +-
 transport.c                             | 130 +++--
 transport.h                             |  18 +-
 upload-pack.c                           | 615 ++++++++++++++++++------
 upload-pack.h                           |  23 +
 44 files changed, 3320 insertions(+), 368 deletions(-)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 builtin/upload-pack.c
 create mode 100644 ls-refs.c
 create mode 100644 ls-refs.h
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100644 t/helper/test-pkt-line.c
 create mode 100755 t/t5701-git-serve.sh
 create mode 100755 t/t5702-protocol-v2.sh
 create mode 100644 upload-pack.h

base-commit: 5be1f00a9a701532232f57958efab4be8c959a29

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#1 lore raw

PATCH v5 1/35 pkt-line: introduce packet_read_with_status

The current pkt-line API encodes the status of a pkt-line read in the length of the read content. An error is indicated with '-1', a flush with '0' (which can be confusing since a return value of '0' can also indicate an empty pkt-line), and a positive integer for the length of the read content otherwise. This doesn't leave much room for allowing the addition of additional special packets in the future.

To solve this introduce 'packet_read_with_status()' which reads a packet and returns the status of the read encoded as an 'enum packet_status' type. This allows for easily identifying between special and normal packets as well as errors. It also enables easily adding a new special packet in the future.

---
 pkt-line.c | 51 +++++++++++++++++++++++++++++++++++++--------------
 pkt-line.h | 16 ++++++++++++++++
 2 files changed, 53 insertions(+), 14 deletions(-)
pkt-line.c +37 -14
index 2827ca772a..db2fb29ac3 100644
@@ -280,28 +280,39 @@ static int packet_length(const char *linelen)
 	return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 }
 
-int packet_read(int fd, char **src_buf, size_t *src_len,
-		char *buffer, unsigned size, int options)
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options)
 {
-	int len, ret;
+	int len;
 	char linelen[4];
 
-	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
-	if (ret < 0)
-		return ret;
+	if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
+	}
+
 	len = packet_length(linelen);
-	if (len < 0)
+
+	if (len < 0) {
 		die("protocol error: bad line length character: %.4s", linelen);
-	if (!len) {
+	} else if (!len) {
 		packet_trace("0000", 4, 0);
-		return 0;
+		*pktlen = 0;
+		return PACKET_READ_FLUSH;
+	} else if (len < 4) {
+		die("protocol error: bad line length %d", len);
 	}
+
 	len -= 4;
-	if (len >= size)
+	if ((unsigned)len >= size)
 		die("protocol error: bad line length %d", len);
-	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
-	if (ret < 0)
-		return ret;
+
+	if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
+	}
 
 	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 	    len && buffer[len-1] == '\n')
@@ -309,7 +320,19 @@ int packet_read(int fd, char **src_buf, size_t *src_len,
 
 	buffer[len] = 0;
 	packet_trace(buffer, len, 0);
-	return len;
+	*pktlen = len;
+	return PACKET_READ_NORMAL;
+}
+
+int packet_read(int fd, char **src_buffer, size_t *src_len,
+		char *buffer, unsigned size, int options)
+{
+	int pktlen = -1;
+
+	packet_read_with_status(fd, src_buffer, src_len, buffer, size,
+				&pktlen, options);
+
+	return pktlen;
 }
 
 static char *packet_read_line_generic(int fd,
pkt-line.h +16 -0
index 3dad583e2d..099b26b95f 100644
@@ -65,6 +65,22 @@ int write_packetized_from_buf(const char *src_in, size_t len, int fd_out);
 int packet_read(int fd, char **src_buffer, size_t *src_len, char
 		*buffer, unsigned size, int options);
 
+/*
+ * Read a packetized line into a buffer like the 'packet_read()' function but
+ * returns an 'enum packet_read_status' which indicates the status of the read.
+ * The number of bytes read will be assigined to *pktlen if the status of the
+ * read was 'PACKET_READ_NORMAL'.
+ */
+enum packet_read_status {
+	PACKET_READ_EOF,
+	PACKET_READ_NORMAL,
+	PACKET_READ_FLUSH,
+};
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options);
+
 /*
  * Convenience wrapper for packet_read that is not gentle, and sets the
  * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#2 lore raw

Re: [PATCH v5 01/35] pkt-line: introduce packet_read_with_status

pkt-line.h int write_packetized_from_buf(const char *src_in, size_t len, int fd_out); · line 78

Quoted 11 lines · Brandon Williams
pkt-line.h +11 -0
+/*
+ * Read a packetized line into a buffer like the 'packet_read()' function but
+ * returns an 'enum packet_read_status' which indicates the status of the read.
+ * The number of bytes read will be assigined to *pktlen if the status of the
+ * read was 'PACKET_READ_NORMAL'.
+ */
+enum packet_read_status {
+	PACKET_READ_EOF,
+	PACKET_READ_NORMAL,
+	PACKET_READ_FLUSH,
+};

EOF was -1 and NORMAL was 0 in the previous round; do we need to read through all the invocations of functions that return this type and make sure there is no "while (such_a_function())" that used to see if we read NORMAL that is left un-updated?

I just have gone thru all the hits from

 $ git grep -n -e packet_erad_with_status -e packet_reader_read -e packet_reader_peek

There are a few

switch (packet_reader_peek())

which by definition we do not have to worry about. Then majority of what could be problematic are of the form:

	while (packet_reader_read() == PACKET_READ_NORMAL)

and they were this way even in the previous version, so it seems quite alright.

Will replace. Thanks.

#3 lore raw

Re: [PATCH v5 01/35] pkt-line: introduce packet_read_with_status

Quoted 30 lines · Junio C Hamano

pkt-line.h int write_packetized_from_buf(const char *src_in, size_t len, int fd_out); · line 78

Quoted 11 lines · Brandon Williams
pkt-line.h +11 -0
+/*
+ * Read a packetized line into a buffer like the 'packet_read()' function but
+ * returns an 'enum packet_read_status' which indicates the status of the read.
+ * The number of bytes read will be assigined to *pktlen if the status of the
+ * read was 'PACKET_READ_NORMAL'.
+ */
+enum packet_read_status {
+	PACKET_READ_EOF,
+	PACKET_READ_NORMAL,
+	PACKET_READ_FLUSH,
+};

EOF was -1 and NORMAL was 0 in the previous round; do we need to read through all the invocations of functions that return this type and make sure there is no "while (such_a_function())" that used to see if we read NORMAL that is left un-updated?

I just have gone thru all the hits from

 $ git grep -n -e packet_erad_with_status -e packet_reader_read -e packet_reader_peek

There are a few

switch (packet_reader_peek())

which by definition we do not have to worry about. Then majority of what could be problematic are of the form:

Quoted 6 lines
	while (packet_reader_read() == PACKET_READ_NORMAL)

and they were this way even in the previous version, so it seems quite alright.

Will replace. Thanks.

A reviewer in the previous round found that it was unnecessary to have EOF start at -1, so per their comments I got rid of that.

Signature · 1 line
Brandon Williams
#4 lore raw

Re: [PATCH v5 01/35] pkt-line: introduce packet_read_with_status

Quoted 9 lines · Brandon Williams
Quoted 6 lines

EOF was -1 and NORMAL was 0 in the previous round; do we need to read through all the invocations of functions that return this type and make sure there is no "while (such_a_function())" that used to see if we read NORMAL that is left un-updated?
...
Will replace. Thanks.

A reviewer in the previous round found that it was unnecessary to have EOF start at -1, so per their comments I got rid of that.

Yes, I am aware of that exchange, and after vetting the callers I think it is "unnecessary" for EOF to be negative and NORMAL to be 0 with the current code (iow, any value can be used for these enums as long as they are distinct).

But that is different matter. If having negative EOF and/or zero NORMAL helps readability of the resulting code, then even if it is not "necessary" for EOF to be negative, it would still be "better".

#5 lore raw

PATCH v5 2/35 pkt-line: allow peeking a packet line without consuming it

In reply to Brandon Williams

Sometimes it is advantageous to be able to peek the next packet line without consuming it (e.g. to be able to determine the protocol version a server is speaking). In order to do that introduce 'struct packet_reader' which is an abstraction around the normal packet reading logic. This enables a caller to be able to peek a single line at a time using 'packet_reader_peek()' and having a caller consume a line by calling 'packet_reader_read()'.

---
 pkt-line.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 pkt-line.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+)
pkt-line.c +50 -0
index db2fb29ac3..1881dc8813 100644
@@ -400,3 +400,53 @@ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
 	}
 	return sb_out->len - orig_len;
 }
+
+/* Packet Reader Functions */
+void packet_reader_init(struct packet_reader *reader, int fd,
+			char *src_buffer, size_t src_len,
+			int options)
+{
+	memset(reader, 0, sizeof(*reader));
+
+	reader->fd = fd;
+	reader->src_buffer = src_buffer;
+	reader->src_len = src_len;
+	reader->buffer = packet_buffer;
+	reader->buffer_size = sizeof(packet_buffer);
+	reader->options = options;
+}
+
+enum packet_read_status packet_reader_read(struct packet_reader *reader)
+{
+	if (reader->line_peeked) {
+		reader->line_peeked = 0;
+		return reader->status;
+	}
+
+	reader->status = packet_read_with_status(reader->fd,
+						 &reader->src_buffer,
+						 &reader->src_len,
+						 reader->buffer,
+						 reader->buffer_size,
+						 &reader->pktlen,
+						 reader->options);
+
+	if (reader->status == PACKET_READ_NORMAL)
+		reader->line = reader->buffer;
+	else
+		reader->line = NULL;
+
+	return reader->status;
+}
+
+enum packet_read_status packet_reader_peek(struct packet_reader *reader)
+{
+	/* Only allow peeking a single line */
+	if (reader->line_peeked)
+		return reader->status;
+
+	/* Peek a line by reading it and setting peeked flag */
+	packet_reader_read(reader);
+	reader->line_peeked = 1;
+	return reader->status;
+}
pkt-line.h +58 -0

64 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#6 lore raw

PATCH v5 3/35 pkt-line: add delim packet support

In reply to Brandon Williams

One of the design goals of protocol-v2 is to improve the semantics of flush packets. Currently in protocol-v1, flush packets are used both to indicate a break in a list of packet lines as well as an indication that one side has finished speaking. This makes it particularly difficult to implement proxies as a proxy would need to completely understand git protocol instead of simply looking for a flush packet.

To do this, introduce the special deliminator packet '0001'. A delim packet can then be used as a deliminator between lists of packet lines while flush packets can be reserved to indicate the end of a response.

Documentation for how this packet will be used in protocol v2 will included in a future patch.

---
 pkt-line.c | 16 ++++++++++++++++
 pkt-line.h |  3 +++
 2 files changed, 19 insertions(+)
pkt-line.c +16 -0
index 1881dc8813..7296731cf3 100644
@@ -91,6 +91,12 @@ void packet_flush(int fd)
 	write_or_die(fd, "0000", 4);
 }
 
+void packet_delim(int fd)
+{
+	packet_trace("0001", 4, 1);
+	write_or_die(fd, "0001", 4);
+}
+
 int packet_flush_gently(int fd)
 {
 	packet_trace("0000", 4, 1);
@@ -105,6 +111,12 @@ void packet_buf_flush(struct strbuf *buf)
 	strbuf_add(buf, "0000", 4);
 }
 
+void packet_buf_delim(struct strbuf *buf)
+{
+	packet_trace("0001", 4, 1);
+	strbuf_add(buf, "0001", 4);
+}
+
 static void set_packet_header(char *buf, const int size)
 {
 	static char hexchar[] = "0123456789abcdef";
@@ -301,6 +313,10 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 		packet_trace("0000", 4, 0);
 		*pktlen = 0;
 		return PACKET_READ_FLUSH;
+	} else if (len == 1) {
+		packet_trace("0001", 4, 0);
+		*pktlen = 0;
+		return PACKET_READ_DELIM;
 	} else if (len < 4) {
 		die("protocol error: bad line length %d", len);
 	}
pkt-line.h +3 -0
index 11b04f026f..9570bd7a0a 100644
@@ -20,8 +20,10 @@
  * side can't, we stay with pure read/write interfaces.
  */
 void packet_flush(int fd);
+void packet_delim(int fd);
 void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 void packet_buf_flush(struct strbuf *buf);
+void packet_buf_delim(struct strbuf *buf);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int packet_flush_gently(int fd);
@@ -75,6 +77,7 @@ enum packet_read_status {
 	PACKET_READ_EOF,
 	PACKET_READ_NORMAL,
 	PACKET_READ_FLUSH,
+	PACKET_READ_DELIM,
 };
 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 						size_t *src_len, char *buffer,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#7 lore raw

PATCH v5 4/35 upload-pack: convert to a builtin

In reply to Brandon Williams

In order to allow for code sharing with the server-side of fetch in protocol-v2 convert upload-pack to be a builtin.

---
 Makefile              |   3 +-
 builtin.h             |   1 +
 builtin/upload-pack.c |  67 ++++++++++++++++++++++++++
 git.c                 |   1 +
 upload-pack.c         | 107 ++++++++++--------------------------------
 upload-pack.h         |  13 +++++
 6 files changed, 109 insertions(+), 83 deletions(-)
 create mode 100644 builtin/upload-pack.c
 create mode 100644 upload-pack.h
Makefile +2 -1
index 1a9b23b679..b7ccc05fac 100644
@@ -639,7 +639,6 @@ PROGRAM_OBJS += imap-send.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
 PROGRAM_OBJS += show-index.o
-PROGRAM_OBJS += upload-pack.o
 PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
@@ -909,6 +908,7 @@ LIB_OBJS += tree-diff.o
 LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
 LIB_OBJS += unpack-trees.o
+LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
 LIB_OBJS += urlmatch.o
 LIB_OBJS += usage.o
@@ -1026,6 +1026,7 @@ BUILTIN_OBJS += builtin/update-index.o
 BUILTIN_OBJS += builtin/update-ref.o
 BUILTIN_OBJS += builtin/update-server-info.o
 BUILTIN_OBJS += builtin/upload-archive.o
+BUILTIN_OBJS += builtin/upload-pack.o
 BUILTIN_OBJS += builtin/var.o
 BUILTIN_OBJS += builtin/verify-commit.o
 BUILTIN_OBJS += builtin/verify-pack.o
builtin.h +1 -0
index 42378f3aa4..f332a12574 100644
@@ -231,6 +231,7 @@ extern int cmd_update_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_update_server_info(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix);
+extern int cmd_upload_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_var(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_commit(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_tag(int argc, const char **argv, const char *prefix);
builtin/upload-pack.c new file +67 -0

67 lines not on this page · raw message

git.c +1 -0
index c870b9719c..f71073dc8d 100644
@@ -478,6 +478,7 @@ static struct cmd_struct commands[] = {
 	{ "update-server-info", cmd_update_server_info, RUN_SETUP },
 	{ "upload-archive", cmd_upload_archive },
 	{ "upload-archive--writer", cmd_upload_archive_writer },
+	{ "upload-pack", cmd_upload_pack },
 	{ "var", cmd_var, RUN_SETUP_GENTLY },
 	{ "verify-commit", cmd_verify_commit, RUN_SETUP },
 	{ "verify-pack", cmd_verify_pack },
upload-pack.c +25 -82

145 lines not on this page · raw message

upload-pack.h new file +13 -0
new file mode 100644
index 0000000000..a71e4dc7e2
@@ -0,0 +1,13 @@
+#ifndef UPLOAD_PACK_H
+#define UPLOAD_PACK_H
+
+struct upload_pack_options {
+	int stateless_rpc;
+	int advertise_refs;
+	unsigned int timeout;
+	int daemon_mode;
+};
+
+void upload_pack(struct upload_pack_options *options);
+
+#endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#8 lore raw

PATCH v5 5/35 upload-pack: factor out processing lines

In reply to Brandon Williams

Factor out the logic for processing shallow, deepen, deepen_since, and deepen_not lines into their own functions to simplify the 'receive_needs()' function in addition to making it easier to reuse some of this logic when implementing protocol_v2.

---
 upload-pack.c | 113 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 74 insertions(+), 39 deletions(-)
upload-pack.c +74 -39
index 2ad73a98b1..1e8a9e1caf 100644
@@ -724,6 +724,75 @@ static void deepen_by_rev_list(int ac, const char **av,
 	packet_flush(1);
 }
 
+static int process_shallow(const char *line, struct object_array *shallows)
+{
+	const char *arg;
+	if (skip_prefix(line, "shallow ", &arg)) {
+		struct object_id oid;
+		struct object *object;
+		if (get_oid_hex(arg, &oid))
+			die("invalid shallow line: %s", line);
+		object = parse_object(&oid);
+		if (!object)
+			return 1;
+		if (object->type != OBJ_COMMIT)
+			die("invalid shallow object %s", oid_to_hex(&oid));
+		if (!(object->flags & CLIENT_SHALLOW)) {
+			object->flags |= CLIENT_SHALLOW;
+			add_object_array(object, NULL, shallows);
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen(const char *line, int *depth)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen ", &arg)) {
+		char *end = NULL;
+		*depth = (int)strtol(arg, &end, 0);
+		if (!end || *end || *depth <= 0)
+			die("Invalid deepen: %s", line);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen_since(const char *line, timestamp_t *deepen_since, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-since ", &arg)) {
+		char *end = NULL;
+		*deepen_since = parse_timestamp(arg, &end, 0);
+		if (!end || *end || !deepen_since ||
+		    /* revisions.c's max_age -1 is special */
+		    *deepen_since == -1)
+			die("Invalid deepen-since: %s", line);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
+}
+
+static int process_deepen_not(const char *line, struct string_list *deepen_not, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-not ", &arg)) {
+		char *ref = NULL;
+		struct object_id oid;
+		if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
+			die("git upload-pack: ambiguous deepen-not: %s", line);
+		string_list_append(deepen_not, ref);
+		free(ref);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
+}
+
 static void receive_needs(void)
 {
 	struct object_array shallows = OBJECT_ARRAY_INIT;
@@ -745,49 +814,15 @@ static void receive_needs(void)
 		if (!line)
 			break;
 
-		if (skip_prefix(line, "shallow ", &arg)) {
-			struct object_id oid;
-			struct object *object;
-			if (get_oid_hex(arg, &oid))
-				die("invalid shallow line: %s", line);
-			object = parse_object(&oid);
-			if (!object)
-				continue;
-			if (object->type != OBJ_COMMIT)
-				die("invalid shallow object %s", oid_to_hex(&oid));
-			if (!(object->flags & CLIENT_SHALLOW)) {
-				object->flags |= CLIENT_SHALLOW;
-				add_object_array(object, NULL, &shallows);
-			}
+		if (process_shallow(line, &shallows))
 			continue;
-		}
-		if (skip_prefix(line, "deepen ", &arg)) {
-			char *end = NULL;
-			depth = strtol(arg, &end, 0);
-			if (!end || *end || depth <= 0)
-				die("Invalid deepen: %s", line);
+		if (process_deepen(line, &depth))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-since ", &arg)) {
-			char *end = NULL;
-			deepen_since = parse_timestamp(arg, &end, 0);
-			if (!end || *end || !deepen_since ||
-			    /* revisions.c's max_age -1 is special */
-			    deepen_since == -1)
-				die("Invalid deepen-since: %s", line);
-			deepen_rev_list = 1;
+		if (process_deepen_since(line, &deepen_since, &deepen_rev_list))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-not ", &arg)) {
-			char *ref = NULL;
-			struct object_id oid;
-			if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
-				die("git upload-pack: ambiguous deepen-not: %s", line);
-			string_list_append(&deepen_not, ref);
-			free(ref);
-			deepen_rev_list = 1;
+		if (process_deepen_not(line, &deepen_not, &deepen_rev_list))
 			continue;
-		}
+
 		if (!skip_prefix(line, "want ", &arg) ||
 		    get_oid_hex(arg, &oid_buf))
 			die("git upload-pack: protocol error, "
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#9 lore raw

PATCH v5 6/35 transport: use get_refs_via_connect to get refs

In reply to Brandon Williams

Remove code duplication and use the existing 'get_refs_via_connect()' function to retrieve a remote's heads in 'fetch_refs_via_pack()' and 'git_transport_push()'.

---
 transport.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)
transport.c +4 -14
index fc802260f6..8e87790962 100644
@@ -230,12 +230,8 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
 
-	if (!data->got_remote_heads) {
-		connect_setup(transport, 0);
-		get_remote_heads(data->fd[0], NULL, 0, &refs_tmp, 0,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
-	}
+	if (!data->got_remote_heads)
+		refs_tmp = get_refs_via_connect(transport, 0);
 
 	refs = fetch_pack(&args, data->fd, data->conn,
 			  refs_tmp ? refs_tmp : transport->remote_refs,
@@ -541,14 +537,8 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	struct send_pack_args args;
 	int ret;
 
-	if (!data->got_remote_heads) {
-		struct ref *tmp_refs;
-		connect_setup(transport, 1);
-
-		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
-	}
+	if (!data->got_remote_heads)
+		get_refs_via_connect(transport, 1);
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#10 lore raw

PATCH v5 7/35 connect: convert get_remote_heads to use struct packet_reader

In reply to Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced convert 'get_remote_heads()' to use 'struct packet_reader' to read packet lines. This enables a client to be able to peek the first line of a server's response (without consuming it) in order to determine the protocol version its speaking and then passing control to the appropriate handler.

This is needed because the initial response from a server speaking protocol_v0 includes the first ref, while subsequent protocol versions respond with a version line. We want to be able to read this first line without consuming the first ref sent in the protocol_v0 case so that the protocol version the server is speaking can be determined outside of 'get_remote_heads()' in a future patch.

---
 connect.c | 173 ++++++++++++++++++++++++++++++------------------------
 1 file changed, 95 insertions(+), 78 deletions(-)
connect.c +95 -78
index c3a014c5ba..c82c90b7c3 100644
@@ -48,6 +48,12 @@ int check_ref_type(const struct ref *ref, int flags)
 
 static void die_initial_contact(int unexpected)
 {
+	/*
+	 * A hang-up after seeing some response from the other end
+	 * means that it is unexpected, as we know the other end is
+	 * willing to talk to us.  A hang-up before seeing any
+	 * response does not necessarily mean an ACL problem, though.
+	 */
 	if (unexpected)
 		die(_("The remote end hung up upon initial contact"));
 	else
@@ -56,6 +62,40 @@ static void die_initial_contact(int unexpected)
 		      "and the repository exists."));
 }
 
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+	enum protocol_version version = protocol_unknown_version;
+
+	/*
+	 * Peek the first line of the server's response to
+	 * determine the protocol version the server is speaking.
+	 */
+	switch (packet_reader_peek(reader)) {
+	case PACKET_READ_EOF:
+		die_initial_contact(0);
+	case PACKET_READ_FLUSH:
+	case PACKET_READ_DELIM:
+		version = protocol_v0;
+		break;
+	case PACKET_READ_NORMAL:
+		version = determine_protocol_version_client(reader->line);
+		break;
+	}
+
+	switch (version) {
+	case protocol_v1:
+		/* Read the peeked version line */
+		packet_reader_read(reader);
+		break;
+	case protocol_v0:
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
+	return version;
+}
+
 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 {
 	char *sym, *target;
@@ -109,60 +149,21 @@ static void annotate_refs_with_symref_info(struct ref *ref)
 	string_list_clear(&symref, 0);
 }
 
-/*
- * Read one line of a server's ref advertisement into packet_buffer.
- */
-static int read_remote_ref(int in, char **src_buf, size_t *src_len,
-			   int *responded)
+static void process_capabilities(const char *line, int *len)
 {
-	int len = packet_read(in, src_buf, src_len,
-			      packet_buffer, sizeof(packet_buffer),
-			      PACKET_READ_GENTLE_ON_EOF |
-			      PACKET_READ_CHOMP_NEWLINE);
-	const char *arg;
-	if (len < 0)
-		die_initial_contact(*responded);
-	if (len > 4 && skip_prefix(packet_buffer, "ERR ", &arg))
-		die("remote error: %s", arg);
-
-	*responded = 1;
-
-	return len;
-}
-
-#define EXPECTING_PROTOCOL_VERSION 0
-#define EXPECTING_FIRST_REF 1
-#define EXPECTING_REF 2
-#define EXPECTING_SHALLOW 3
-
-/* Returns 1 if packet_buffer is a protocol version pkt-line, 0 otherwise. */
-static int process_protocol_version(void)
-{
-	switch (determine_protocol_version_client(packet_buffer)) {
-	case protocol_v1:
-		return 1;
-	case protocol_v0:
-		return 0;
-	default:
-		die("server is speaking an unknown protocol");
-	}
-}
-
-static void process_capabilities(int *len)
-{
-	int nul_location = strlen(packet_buffer);
+	int nul_location = strlen(line);
 	if (nul_location == *len)
 		return;
-	server_capabilities = xstrdup(packet_buffer + nul_location + 1);
+	server_capabilities = xstrdup(line + nul_location + 1);
 	*len = nul_location;
 }
 
-static int process_dummy_ref(void)
+static int process_dummy_ref(const char *line)
 {
 	struct object_id oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &oid, &name))
+	if (parse_oid_hex(line, &oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -171,20 +172,20 @@ static int process_dummy_ref(void)
 	return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 }
 
-static void check_no_capabilities(int len)
+static void check_no_capabilities(const char *line, int len)
 {
-	if (strlen(packet_buffer) != len)
+	if (strlen(line) != len)
 		warning("Ignoring capabilities after first line '%s'",
-			packet_buffer + strlen(packet_buffer));
+			line + strlen(line));
 }
 
-static int process_ref(int len, struct ref ***list, unsigned int flags,
-		       struct oid_array *extra_have)
+static int process_ref(const char *line, int len, struct ref ***list,
+		       unsigned int flags, struct oid_array *extra_have)
 {
 	struct object_id old_oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &old_oid, &name))
+	if (parse_oid_hex(line, &old_oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -200,16 +201,17 @@ static int process_ref(int len, struct ref ***list, unsigned int flags,
 		**list = ref;
 		*list = &ref->next;
 	}
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
-static int process_shallow(int len, struct oid_array *shallow_points)
+static int process_shallow(const char *line, int len,
+			   struct oid_array *shallow_points)
 {
 	const char *arg;
 	struct object_id old_oid;
 
-	if (!skip_prefix(packet_buffer, "shallow ", &arg))
+	if (!skip_prefix(line, "shallow ", &arg))
 		return 0;
 
 	if (get_oid_hex(arg, &old_oid))
@@ -217,10 +219,17 @@ static int process_shallow(int len, struct oid_array *shallow_points)
 	if (!shallow_points)
 		die("repository on the other end cannot be shallow");
 	oid_array_append(shallow_points, &old_oid);
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
+enum get_remote_heads_state {
+	EXPECTING_FIRST_REF = 0,
+	EXPECTING_REF,
+	EXPECTING_SHALLOW,
+	EXPECTING_DONE,
+};
+
 /*
  * Read all the refs from the other end
  */
@@ -230,47 +239,55 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 			      struct oid_array *shallow_points)
 {
 	struct ref **orig_list = list;
+	int len = 0;
+	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
+	struct packet_reader reader;
+	const char *arg;
 
-	/*
-	 * A hang-up after seeing some response from the other end
-	 * means that it is unexpected, as we know the other end is
-	 * willing to talk to us.  A hang-up before seeing any
-	 * response does not necessarily mean an ACL problem, though.
-	 */
-	int responded = 0;
-	int len;
-	int state = EXPECTING_PROTOCOL_VERSION;
+	packet_reader_init(&reader, in, src_buf, src_len,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	discover_version(&reader);
 
 	*list = NULL;
 
-	while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) {
+	while (state != EXPECTING_DONE) {
+		switch (packet_reader_read(&reader)) {
+		case PACKET_READ_EOF:
+			die_initial_contact(1);
+		case PACKET_READ_NORMAL:
+			len = reader.pktlen;
+			if (len > 4 && skip_prefix(reader.line, "ERR ", &arg))
+				die("remote error: %s", arg);
+			break;
+		case PACKET_READ_FLUSH:
+			state = EXPECTING_DONE;
+			break;
+		case PACKET_READ_DELIM:
+			die("invalid packet");
+		}
+
 		switch (state) {
-		case EXPECTING_PROTOCOL_VERSION:
-			if (process_protocol_version()) {
-				state = EXPECTING_FIRST_REF;
-				break;
-			}
-			state = EXPECTING_FIRST_REF;
-			/* fallthrough */
 		case EXPECTING_FIRST_REF:
-			process_capabilities(&len);
-			if (process_dummy_ref()) {
+			process_capabilities(reader.line, &len);
+			if (process_dummy_ref(reader.line)) {
 				state = EXPECTING_SHALLOW;
 				break;
 			}
 			state = EXPECTING_REF;
 			/* fallthrough */
 		case EXPECTING_REF:
-			if (process_ref(len, &list, flags, extra_have))
+			if (process_ref(reader.line, len, &list, flags, extra_have))
 				break;
 			state = EXPECTING_SHALLOW;
 			/* fallthrough */
 		case EXPECTING_SHALLOW:
-			if (process_shallow(len, shallow_points))
+			if (process_shallow(reader.line, len, shallow_points))
 				break;
-			die("protocol error: unexpected '%s'", packet_buffer);
-		default:
-			die("unexpected state %d", state);
+			die("protocol error: unexpected '%s'", reader.line);
+		case EXPECTING_DONE:
+			break;
 		}
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#11 lore raw

PATCH v5 8/35 connect: discover protocol version outside of get_remote_heads

In reply to Brandon Williams

In order to prepare for the addition of protocol_v2 push the protocol version discovery outside of 'get_remote_heads()'. This will allow for keeping the logic for processing the reference advertisement for protocol_v1 and protocol_v0 separate from the logic for protocol_v2.

---
 builtin/fetch-pack.c | 16 +++++++++++++++-
 builtin/send-pack.c  | 17 +++++++++++++++--
 connect.c            | 27 ++++++++++-----------------
 connect.h            |  3 +++
 remote-curl.c        | 20 ++++++++++++++++++--
 remote.h             |  5 +++--
 transport.c          | 24 +++++++++++++++++++-----
 7 files changed, 83 insertions(+), 29 deletions(-)
builtin/fetch-pack.c +15 -1
index 366b9d13f9..85d4faf76c 100644
@@ -4,6 +4,7 @@
 #include "remote.h"
 #include "connect.h"
 #include "sha1-array.h"
+#include "protocol.h"
 
 static const char fetch_pack_usage[] =
 "git fetch-pack [--all] [--stdin] [--quiet | -q] [--keep | -k] [--thin] "
@@ -52,6 +53,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	struct fetch_pack_args args;
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
+	struct packet_reader reader;
 
 	packet_trace_identity("fetch-pack");
 
@@ -193,7 +195,19 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 		if (!conn)
 			return args.diag_url ? 0 : 1;
 	}
-	get_remote_heads(fd[0], NULL, 0, &ref, 0, NULL, &shallow);
+
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
 			 &shallow, pack_lockfile_ptr);
builtin/send-pack.c +15 -2
index fc4f0bb5fb..83cb125a68 100644
@@ -14,6 +14,7 @@
 #include "sha1-array.h"
 #include "gpg-interface.h"
 #include "gettext.h"
+#include "protocol.h"
 
 static const char * const send_pack_usage[] = {
 	N_("git send-pack [--all | --mirror] [--dry-run] [--force] "
@@ -154,6 +155,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	int progress = -1;
 	int from_stdin = 0;
 	struct push_cas_option cas = {0};
+	struct packet_reader reader;
 
 	struct option options[] = {
 		OPT__VERBOSITY(&verbose),
@@ -256,8 +258,19 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 			args.verbose ? CONNECT_VERBOSE : 0);
 	}
 
-	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL,
-			 &extra_have, &shallow);
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &remote_refs, REF_NORMAL,
+				 &extra_have, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	transport_verify_remote_names(nr_refspecs, refspecs);
 
connect.c +10 -17
index c82c90b7c3..0b111e62d7 100644
@@ -62,7 +62,7 @@ static void die_initial_contact(int unexpected)
 		      "and the repository exists."));
 }
 
-static enum protocol_version discover_version(struct packet_reader *reader)
+enum protocol_version discover_version(struct packet_reader *reader)
 {
 	enum protocol_version version = protocol_unknown_version;
 
@@ -233,7 +233,7 @@ enum get_remote_heads_state {
 /*
  * Read all the refs from the other end
  */
-struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct ref **get_remote_heads(struct packet_reader *reader,
 			      struct ref **list, unsigned int flags,
 			      struct oid_array *extra_have,
 			      struct oid_array *shallow_points)
@@ -241,24 +241,17 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 	struct ref **orig_list = list;
 	int len = 0;
 	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
-	struct packet_reader reader;
 	const char *arg;
 
-	packet_reader_init(&reader, in, src_buf, src_len,
-			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
-
-	discover_version(&reader);
-
 	*list = NULL;
 
 	while (state != EXPECTING_DONE) {
-		switch (packet_reader_read(&reader)) {
+		switch (packet_reader_read(reader)) {
 		case PACKET_READ_EOF:
 			die_initial_contact(1);
 		case PACKET_READ_NORMAL:
-			len = reader.pktlen;
-			if (len > 4 && skip_prefix(reader.line, "ERR ", &arg))
+			len = reader->pktlen;
+			if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
 				die("remote error: %s", arg);
 			break;
 		case PACKET_READ_FLUSH:
@@ -270,22 +263,22 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 
 		switch (state) {
 		case EXPECTING_FIRST_REF:
-			process_capabilities(reader.line, &len);
-			if (process_dummy_ref(reader.line)) {
+			process_capabilities(reader->line, &len);
+			if (process_dummy_ref(reader->line)) {
 				state = EXPECTING_SHALLOW;
 				break;
 			}
 			state = EXPECTING_REF;
 			/* fallthrough */
 		case EXPECTING_REF:
-			if (process_ref(reader.line, len, &list, flags, extra_have))
+			if (process_ref(reader->line, len, &list, flags, extra_have))
 				break;
 			state = EXPECTING_SHALLOW;
 			/* fallthrough */
 		case EXPECTING_SHALLOW:
-			if (process_shallow(reader.line, len, shallow_points))
+			if (process_shallow(reader->line, len, shallow_points))
 				break;
-			die("protocol error: unexpected '%s'", reader.line);
+			die("protocol error: unexpected '%s'", reader->line);
 		case EXPECTING_DONE:
 			break;
 		}
connect.h +3 -0
index 01f14cdf3f..cdb8979dce 100644
@@ -13,4 +13,7 @@ extern int parse_feature_request(const char *features, const char *feature);
 extern const char *server_feature_value(const char *feature, int *len_ret);
 extern int url_is_local_not_ssh(const char *url);
 
+struct packet_reader;
+extern enum protocol_version discover_version(struct packet_reader *reader);
+
 #endif
remote-curl.c +18 -2
index 0053b09549..9f6d07683d 100644
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "config.h"
 #include "remote.h"
+#include "connect.h"
 #include "strbuf.h"
 #include "walker.h"
 #include "http.h"
@@ -13,6 +14,7 @@
 #include "credential.h"
 #include "sha1-array.h"
 #include "send-pack.h"
+#include "protocol.h"
 
 static struct remote *remote;
 /* always ends with a trailing slash */
@@ -176,8 +178,22 @@ static struct discovery *last_discovery;
 static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 {
 	struct ref *list = NULL;
-	get_remote_heads(-1, heads->buf, heads->len, &list,
-			 for_push ? REF_NORMAL : 0, NULL, &heads->shallow);
+	struct packet_reader reader;
+
+	packet_reader_init(&reader, -1, heads->buf, heads->len,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &list, for_push ? REF_NORMAL : 0,
+				 NULL, &heads->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
 	return list;
 }
 
remote.h +3 -2
index 1f6611be21..2016461df9 100644
@@ -150,10 +150,11 @@ int check_ref_type(const struct ref *ref, int flags);
 void free_refs(struct ref *ref);
 
 struct oid_array;
-extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct packet_reader;
+extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
-				     struct oid_array *shallow);
+				     struct oid_array *shallow_points);
 
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
transport.c +19 -5
index 8e87790962..63c3dbab94 100644
@@ -18,6 +18,7 @@
 #include "sha1-array.h"
 #include "sigchain.h"
 #include "transport-internal.h"
+#include "protocol.h"
 
 static void set_upstreams(struct transport *transport, struct ref *refs,
 	int pretend)
@@ -190,13 +191,26 @@ static int connect_setup(struct transport *transport, int for_push)
 static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
 {
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
+	struct packet_reader reader;
 
 	connect_setup(transport, for_push);
-	get_remote_heads(data->fd[0], NULL, 0, &refs,
-			 for_push ? REF_NORMAL : 0,
-			 &data->extra_have,
-			 &data->shallow);
+
+	packet_reader_init(&reader, data->fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &refs,
+				 for_push ? REF_NORMAL : 0,
+				 &data->extra_have,
+				 &data->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 	data->got_remote_heads = 1;
 
 	return refs;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#12 lore raw

PATCH v5 9/35 transport: store protocol version

In reply to Brandon Williams

Once protocol_v2 is introduced requesting a fetch or a push will need to be handled differently depending on the protocol version. Store the protocol version the server is speaking in 'struct git_transport_data' and use it to determine what to do in the case of a fetch or a push.

---
 transport.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)
transport.c +26 -9
index 63c3dbab94..2378dcb38c 100644
@@ -118,6 +118,7 @@ struct git_transport_data {
 	struct child_process *conn;
 	int fd[2];
 	unsigned got_remote_heads : 1;
+	enum protocol_version version;
 	struct oid_array extra_have;
 	struct oid_array shallow;
 };
@@ -200,7 +201,8 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_GENTLE_ON_EOF);
 
-	switch (discover_version(&reader)) {
+	data->version = discover_version(&reader);
+	switch (data->version) {
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &refs,
@@ -221,7 +223,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 {
 	int ret = 0;
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
 	char *dest = xstrdup(transport->url);
 	struct fetch_pack_args args;
 	struct ref *refs_tmp = NULL;
@@ -247,10 +249,18 @@ static int fetch_refs_via_pack(struct transport *transport,
 	if (!data->got_remote_heads)
 		refs_tmp = get_refs_via_connect(transport, 0);
 
-	refs = fetch_pack(&args, data->fd, data->conn,
-			  refs_tmp ? refs_tmp : transport->remote_refs,
-			  dest, to_fetch, nr_heads, &data->shallow,
-			  &transport->pack_lockfile);
+	switch (data->version) {
+	case protocol_v1:
+	case protocol_v0:
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
 	close(data->fd[0]);
 	close(data->fd[1]);
 	if (finish_connect(data->conn))
@@ -549,7 +559,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 {
 	struct git_transport_data *data = transport->data;
 	struct send_pack_args args;
-	int ret;
+	int ret = 0;
 
 	if (!data->got_remote_heads)
 		get_refs_via_connect(transport, 1);
@@ -574,8 +584,15 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	else
 		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
 
-	ret = send_pack(&args, data->fd, data->conn, remote_refs,
-			&data->extra_have);
+	switch (data->version) {
+	case protocol_v1:
+	case protocol_v0:
+		ret = send_pack(&args, data->fd, data->conn, remote_refs,
+				&data->extra_have);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	close(data->fd[1]);
 	close(data->fd[0]);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#13 lore raw

PATCH v5 10/35 protocol: introduce enum protocol_version value protocol_v2

In reply to Brandon Williams

Introduce protocol_v2, a new value for 'enum protocol_version'. Subsequent patches will fill in the implementation of protocol_v2.

---
 builtin/fetch-pack.c   | 2 ++
 builtin/receive-pack.c | 6 ++++++
 builtin/send-pack.c    | 3 +++
 builtin/upload-pack.c  | 7 +++++++
 connect.c              | 3 +++
 protocol.c             | 2 ++
 protocol.h             | 1 +
 remote-curl.c          | 3 +++
 transport.c            | 9 +++++++++
 9 files changed, 36 insertions(+)
builtin/fetch-pack.c +2 -0
index 85d4faf76c..b2374ddbbf 100644
@@ -201,6 +201,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
builtin/receive-pack.c +6 -0
index b7ce7c7f52..3656e94fdb 100644
@@ -1963,6 +1963,12 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		unpack_limit = receive_unpack_limit;
 
 	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		/*
+		 * push support for protocol v2 has not been implemented yet,
+		 * so ignore the request to use v2 and fallback to using v0.
+		 */
+		break;
 	case protocol_v1:
 		/*
 		 * v1 is just the original protocol with a version string,
builtin/send-pack.c +3 -0
index 83cb125a68..b5427f75e3 100644
@@ -263,6 +263,9 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &remote_refs, REF_NORMAL,
builtin/upload-pack.c +7 -0
index 2cb5cb35b0..8d53e9794b 100644
@@ -47,6 +47,13 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 		die("'%s' does not appear to be a git repository", dir);
 
 	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		/*
+		 * fetch support for protocol v2 has not been implemented yet,
+		 * so ignore the request to use v2 and fallback to using v0.
+		 */
+		upload_pack(&opts);
+		break;
 	case protocol_v1:
 		/*
 		 * v1 is just the original protocol with a version string,
connect.c +3 -0
index 0b111e62d7..4b89b984c4 100644
@@ -83,6 +83,9 @@ enum protocol_version discover_version(struct packet_reader *reader)
 	}
 
 	switch (version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 		/* Read the peeked version line */
 		packet_reader_read(reader);
protocol.c +2 -0
index 43012b7eb6..5e636785d1 100644
@@ -8,6 +8,8 @@ static enum protocol_version parse_protocol_version(const char *value)
 		return protocol_v0;
 	else if (!strcmp(value, "1"))
 		return protocol_v1;
+	else if (!strcmp(value, "2"))
+		return protocol_v2;
 	else
 		return protocol_unknown_version;
 }
protocol.h +1 -0
index 1b2bc94a8d..2ad35e433c 100644
@@ -5,6 +5,7 @@ enum protocol_version {
 	protocol_unknown_version = -1,
 	protocol_v0 = 0,
 	protocol_v1 = 1,
+	protocol_v2 = 2,
 };
 
 /*
remote-curl.c +3 -0
index 9f6d07683d..dae8a4a48d 100644
@@ -185,6 +185,9 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &list, for_push ? REF_NORMAL : 0,
transport.c +9 -0
index 2378dcb38c..83d9dd1df6 100644
@@ -203,6 +203,9 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 
 	data->version = discover_version(&reader);
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &refs,
@@ -250,6 +253,9 @@ static int fetch_refs_via_pack(struct transport *transport,
 		refs_tmp = get_refs_via_connect(transport, 0);
 
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		refs = fetch_pack(&args, data->fd, data->conn,
@@ -585,6 +591,9 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
 
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		ret = send_pack(&args, data->fd, data->conn, remote_refs,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#14 lore raw

PATCH v5 11/35 test-pkt-line: introduce a packet-line test helper

In reply to Brandon Williams

Introduce a packet-line test helper which can either pack or unpack an input stream into packet-lines and writes out the result to stdout.

---
 Makefile                 |  1 +
 t/helper/test-pkt-line.c | 64 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 t/helper/test-pkt-line.c
Makefile +1 -0
index b7ccc05fac..3b849c0607 100644
@@ -669,6 +669,7 @@ TEST_PROGRAMS_NEED_X += test-mktemp
 TEST_PROGRAMS_NEED_X += test-online-cpus
 TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-path-utils
+TEST_PROGRAMS_NEED_X += test-pkt-line
 TEST_PROGRAMS_NEED_X += test-prio-queue
 TEST_PROGRAMS_NEED_X += test-read-cache
 TEST_PROGRAMS_NEED_X += test-write-cache
t/helper/test-pkt-line.c new file +64 -0

64 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#15 lore raw

PATCH v5 12/35 serve: introduce git-serve

In reply to Brandon Williams

Introduce git-serve, the base server for protocol version 2.

Protocol version 2 is intended to be a replacement for Git's current wire protocol. The intention is that it will be a simpler, less wasteful protocol which can evolve over time.

Protocol version 2 improves upon version 1 by eliminating the initial ref advertisement. In its place a server will export a list of capabilities and commands which it supports in a capability advertisement. A client can then request that a particular command be executed by providing a number of capabilities and command specific parameters. At the completion of a command, a client can request that another command be executed or can terminate the connection by sending a flush packet.

---
 .gitignore                              |   1 +
 Documentation/Makefile                  |   1 +
 Documentation/technical/protocol-v2.txt | 174 +++++++++++++++++
 Makefile                                |   2 +
 builtin.h                               |   1 +
 builtin/serve.c                         |  30 +++
 git.c                                   |   1 +
 serve.c                                 | 247 ++++++++++++++++++++++++
 serve.h                                 |  15 ++
 t/t5701-git-serve.sh                    |  60 ++++++
 10 files changed, 532 insertions(+)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100755 t/t5701-git-serve.sh
.gitignore +1 -0
index 833ef3b0b7..2d0450c262 100644
@@ -140,6 +140,7 @@
 /git-rm
 /git-send-email
 /git-send-pack
+/git-serve
 /git-sh-i18n
 /git-sh-i18n--envsubst
 /git-sh-setup
Documentation/Makefile +1 -0
index 4ae9ba5c86..b105775acd 100644
@@ -77,6 +77,7 @@ TECH_DOCS += technical/pack-heuristics
 TECH_DOCS += technical/pack-protocol
 TECH_DOCS += technical/protocol-capabilities
 TECH_DOCS += technical/protocol-common
+TECH_DOCS += technical/protocol-v2
 TECH_DOCS += technical/racy-git
 TECH_DOCS += technical/send-pack-pipeline
 TECH_DOCS += technical/shallow
Documentation/technical/protocol-v2.txt new file +174 -0

174 lines not on this page · raw message

Makefile +2 -0
index 3b849c0607..18c255428a 100644
@@ -881,6 +881,7 @@ LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
 LIB_OBJS += send-pack.o
 LIB_OBJS += sequencer.o
+LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
@@ -1014,6 +1015,7 @@ BUILTIN_OBJS += builtin/rev-parse.o
 BUILTIN_OBJS += builtin/revert.o
 BUILTIN_OBJS += builtin/rm.o
 BUILTIN_OBJS += builtin/send-pack.o
+BUILTIN_OBJS += builtin/serve.o
 BUILTIN_OBJS += builtin/shortlog.o
 BUILTIN_OBJS += builtin/show-branch.o
 BUILTIN_OBJS += builtin/show-ref.o
builtin.h +1 -0
index f332a12574..3f3fdfc281 100644
@@ -215,6 +215,7 @@ extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
 extern int cmd_revert(int argc, const char **argv, const char *prefix);
 extern int cmd_rm(int argc, const char **argv, const char *prefix);
 extern int cmd_send_pack(int argc, const char **argv, const char *prefix);
+extern int cmd_serve(int argc, const char **argv, const char *prefix);
 extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
 extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
builtin/serve.c new file +30 -0
new file mode 100644
index 0000000000..d3fd240bb3
@@ -0,0 +1,30 @@
+#include "cache.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "serve.h"
+
+static char const * const serve_usage[] = {
+	N_("git serve [<options>]"),
+	NULL
+};
+
+int cmd_serve(int argc, const char **argv, const char *prefix)
+{
+	struct serve_options opts = SERVE_OPTIONS_INIT;
+
+	struct option options[] = {
+		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
+			 N_("quit after a single request/response exchange")),
+		OPT_BOOL(0, "advertise-capabilities", &opts.advertise_capabilities,
+			 N_("exit immediately after advertising capabilities")),
+		OPT_END()
+	};
+
+	/* ignore all unknown cmdline switches for now */
+	argc = parse_options(argc, argv, prefix, options, serve_usage,
+			     PARSE_OPT_KEEP_DASHDASH |
+			     PARSE_OPT_KEEP_UNKNOWN);
+	serve(&opts);
+
+	return 0;
+}
git.c +1 -0
index f71073dc8d..f85d682b62 100644
@@ -461,6 +461,7 @@ static struct cmd_struct commands[] = {
 	{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 	{ "rm", cmd_rm, RUN_SETUP },
 	{ "send-pack", cmd_send_pack, RUN_SETUP },
+	{ "serve", cmd_serve, RUN_SETUP },
 	{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 	{ "show", cmd_show, RUN_SETUP },
 	{ "show-branch", cmd_show_branch, RUN_SETUP },
serve.c new file +247 -0

247 lines not on this page · raw message

serve.h new file +15 -0
new file mode 100644
index 0000000000..fe65ba9f46
@@ -0,0 +1,15 @@
+#ifndef SERVE_H
+#define SERVE_H
+
+struct argv_array;
+extern int has_capability(const struct argv_array *keys, const char *capability,
+			  const char **value);
+
+struct serve_options {
+	unsigned advertise_capabilities;
+	unsigned stateless_rpc;
+};
+#define SERVE_OPTIONS_INIT { 0 }
+extern void serve(struct serve_options *options);
+
+#endif /* SERVE_H */
t/t5701-git-serve.sh new file +60 -0

60 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#16 lore raw

Re: [PATCH v5 12/35] serve: introduce git-serve

Quoted 4 lines · Brandon Williams

Introduce git-serve, the base server for protocol version 2.
...

 Documentation/Makefile                  |   1 +
 Documentation/technical/protocol-v2.txt | 174 +++++++++++++++++

asciidoc: ERROR: protocol-v2.txt: line 20: only book doctypes can contain level 0 sections
asciidoc: ERROR: protocol-v2.txt: line 374: [blockdef-listing] missing closing delimiter Makefile:368: recipe for target 'technical/protocol-v2.html' failed

I'll redo today's integration cycle to see if I can move this topic to a late part of 'pu', so that I can at least keep the part of 'pu' that is beyond what is in 'next' and still usable a bit larger. The bw/protocol-v2 topic has been merged immediately above the topics that are already in 'next' for the past week or so, but I cannot afford to leave the build broken for majority of merges of 'pu'.

#17 lore raw

Re: [PATCH v5 12/35] serve: introduce git-serve

Quoted 11 lines · Junio C Hamano
Quoted 4 lines · Brandon Williams

Introduce git-serve, the base server for protocol version 2.
...

 Documentation/Makefile                  |   1 +
 Documentation/technical/protocol-v2.txt | 174 +++++++++++++++++

asciidoc: ERROR: protocol-v2.txt: line 20: only book doctypes can contain level 0 sections
asciidoc: ERROR: protocol-v2.txt: line 374: [blockdef-listing] missing closing delimiter Makefile:368: recipe for target 'technical/protocol-v2.html' failed

Quoted 7 lines

I'll redo today's integration cycle to see if I can move this topic to a late part of 'pu', so that I can at least keep the part of 'pu' that is beyond what is in 'next' and still usable a bit larger. The bw/protocol-v2 topic has been merged immediately above the topics that are already in 'next' for the past week or so, but I cannot afford to leave the build broken for majority of merges of 'pu'.

Turns out I don't know how to write properly formed asciidocs, sorry about that. I fixed up the docs in my series locally and I'll send out a v5 in just a bit.

Signature · 1 line
Brandon Williams
#18 lore raw

PATCH v5 13/35 ls-refs: introduce ls-refs server command

In reply to Brandon Williams

Introduce the ls-refs server command. In protocol v2, the ls-refs command is used to request the ref advertisement from the server. Since it is a command which can be requested (as opposed to mandatory in v1), a client can sent a number of parameters in its request to limit the ref advertisement based on provided ref-prefixes.

---
 Documentation/technical/protocol-v2.txt |  31 +++++++
 Makefile                                |   1 +
 ls-refs.c                               |  96 ++++++++++++++++++++
 ls-refs.h                               |  10 +++
 serve.c                                 |   8 ++
 t/t5701-git-serve.sh                    | 115 ++++++++++++++++++++++++
 6 files changed, 261 insertions(+)
 create mode 100644 ls-refs.c
 create mode 100644 ls-refs.h
Documentation/technical/protocol-v2.txt +31 -0
index 3a671497b2..422edf870e 100644
@@ -172,3 +172,34 @@ printable ASCII characters except space (i.e., the byte range 32 < x <
 "git/1.8.3.1"). The agent strings are purely informative for statistics
 and debugging purposes, and MUST NOT be used to programmatically assume
 the presence or absence of particular features.
+
+ ls-refs
+---------
+
+`ls-refs` is the command used to request a reference advertisement in v2.
+Unlike the current reference advertisement, ls-refs takes in arguments
+which can be used to limit the refs sent from the server.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+ls-refs takes in the following arguments:
+
+    symrefs
+	In addition to the object pointed by it, show the underlying ref
+	pointed by it when showing a symbolic ref.
+    peel
+	Show peeled tags.
+    ref-prefix <prefix>
+	When specified, only references having a prefix matching one of
+	the provided prefixes are displayed.
+
+The output of ls-refs is as follows:
+
+    output = *ref
+	     flush-pkt
+    ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF)
+    ref-attribute = (symref | peeled)
+    symref = "symref-target:" symref-target
+    peeled = "peeled:" obj-id
Makefile +1 -0
index 18c255428a..e50927cfb3 100644
@@ -825,6 +825,7 @@ LIB_OBJS += list-objects-filter-options.o
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
+LIB_OBJS += ls-refs.o
 LIB_OBJS += mailinfo.o
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
ls-refs.c new file +96 -0

96 lines not on this page · raw message

ls-refs.h new file +10 -0
new file mode 100644
index 0000000000..b62877e8da
@@ -0,0 +1,10 @@
+#ifndef LS_REFS_H
+#define LS_REFS_H
+
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int ls_refs(struct repository *r, struct argv_array *keys,
+		   struct packet_reader *request);
+
+#endif /* LS_REFS_H */
serve.c +8 -0
index 7ddcba9003..1cb5fb9b5b 100644
@@ -4,8 +4,15 @@
 #include "pkt-line.h"
 #include "version.h"
 #include "argv-array.h"
+#include "ls-refs.h"
 #include "serve.h"
 
+static int always_advertise(struct repository *r,
+			    struct strbuf *value)
+{
+	return 1;
+}
+
 static int agent_advertise(struct repository *r,
 			   struct strbuf *value)
 {
@@ -46,6 +53,7 @@ struct protocol_capability {
 
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
+	{ "ls-refs", always_advertise, ls_refs },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +115 -0

125 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#19 lore raw

PATCH v5 14/35 connect: request remote refs using v2

In reply to Brandon Williams

Teach the client to be able to request a remote's refs using protocol v2. This is done by having a client issue a 'ls-refs' request to a v2 server.

---
 builtin/upload-pack.c  |  10 +--
 connect.c              | 138 +++++++++++++++++++++++++++++++++++++++--
 connect.h              |   2 +
 remote.h               |   6 ++
 t/t5702-protocol-v2.sh |  57 +++++++++++++++++
 transport.c            |   2 +-
 6 files changed, 204 insertions(+), 11 deletions(-)
 create mode 100755 t/t5702-protocol-v2.sh
builtin/upload-pack.c +5 -5
index 8d53e9794b..a757df8da0 100644
@@ -5,6 +5,7 @@
 #include "parse-options.h"
 #include "protocol.h"
 #include "upload-pack.h"
+#include "serve.h"
 
 static const char * const upload_pack_usage[] = {
 	N_("git upload-pack [<options>] <dir>"),
@@ -16,6 +17,7 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 	const char *dir;
 	int strict = 0;
 	struct upload_pack_options opts = { 0 };
+	struct serve_options serve_opts = SERVE_OPTIONS_INIT;
 	struct option options[] = {
 		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
 			 N_("quit after a single request/response exchange")),
@@ -48,11 +50,9 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 
 	switch (determine_protocol_version_server()) {
 	case protocol_v2:
-		/*
-		 * fetch support for protocol v2 has not been implemented yet,
-		 * so ignore the request to use v2 and fallback to using v0.
-		 */
-		upload_pack(&opts);
+		serve_opts.advertise_capabilities = opts.advertise_refs;
+		serve_opts.stateless_rpc = opts.stateless_rpc;
+		serve(&serve_opts);
 		break;
 	case protocol_v1:
 		/*
connect.c +133 -5

182 lines not on this page · raw message

connect.h +2 -0
index cdb8979dce..8898d44952 100644
@@ -16,4 +16,6 @@ extern int url_is_local_not_ssh(const char *url);
 struct packet_reader;
 extern enum protocol_version discover_version(struct packet_reader *reader);
 
+extern int server_supports_v2(const char *c, int die_on_error);
+
 #endif
remote.h +6 -0
index 2016461df9..368ba221cc 100644
@@ -151,11 +151,17 @@ void free_refs(struct ref *ref);
 
 struct oid_array;
 struct packet_reader;
+struct argv_array;
 extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
 				     struct oid_array *shallow_points);
 
+/* Used for protocol v2 in order to retrieve refs from a remote */
+extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+				    struct ref **list, int for_push,
+				    const struct argv_array *ref_prefixes);
+
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
 
t/t5702-protocol-v2.sh new file +57 -0

57 lines not on this page · raw message

transport.c +1 -1
index 83d9dd1df6..ffc6b2614f 100644
@@ -204,7 +204,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	data->version = discover_version(&reader);
 	switch (data->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		get_remote_refs(data->fd[1], &reader, &refs, for_push, NULL);
 		break;
 	case protocol_v1:
 	case protocol_v0:
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#20 lore raw

PATCH v5 15/35 transport: convert get_refs_list to take a list of ref prefixes

In reply to Brandon Williams

Convert the 'struct transport' virtual function 'get_refs_list()' to optionally take an argv_array of ref prefixes. When communicating with a server using protocol v2 these ref prefixes can be sent when requesting a listing of their refs allowing the server to filter the refs it sends based on the sent prefixes. This list will be ignored when not using protocol v2.

---
 transport-helper.c   |  5 +++--
 transport-internal.h | 11 ++++++++++-
 transport.c          | 18 +++++++++++-------
 3 files changed, 24 insertions(+), 10 deletions(-)
transport-helper.c +3 -2
index 5080150231..8774ab3013 100644
@@ -1026,7 +1026,8 @@ static int has_attribute(const char *attrs, const char *attr) {
 	}
 }
 
-static struct ref *get_refs_list(struct transport *transport, int for_push)
+static struct ref *get_refs_list(struct transport *transport, int for_push,
+				 const struct argv_array *ref_prefixes)
 {
 	struct helper_data *data = transport->data;
 	struct child_process *helper;
@@ -1039,7 +1040,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	if (process_connect(transport, for_push)) {
 		do_take_over(transport);
-		return transport->vtable->get_refs_list(transport, for_push);
+		return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
 	}
 
 	if (data->push && for_push)
transport-internal.h +10 -1
index 3c1a29d727..1cde6258a7 100644
@@ -3,6 +3,7 @@
 
 struct ref;
 struct transport;
+struct argv_array;
 
 struct transport_vtable {
 	/**
@@ -17,11 +18,19 @@ struct transport_vtable {
 	 * the transport to try to share connections, for_push is a
 	 * hint as to whether the ultimate operation is a push or a fetch.
 	 *
+	 * If communicating using protocol v2 a list of prefixes can be
+	 * provided to be sent to the server to enable it to limit the ref
+	 * advertisement.  Since ref filtering is done on the server's end, and
+	 * only when using protocol v2, this list will be ignored when not
+	 * using protocol v2 meaning this function can return refs which don't
+	 * match the provided ref_prefixes.
+	 *
 	 * If the transport is able to determine the remote hash for
 	 * the ref without a huge amount of effort, it should store it
 	 * in the ref's old_sha1 field; otherwise it should be all 0.
 	 **/
-	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
+	struct ref *(*get_refs_list)(struct transport *transport, int for_push,
+				     const struct argv_array *ref_prefixes);
 
 	/**
 	 * Fetch the objects for the given refs. Note that this gets
transport.c +11 -7
index ffc6b2614f..2e68010dd0 100644
@@ -72,7 +72,9 @@ struct bundle_transport_data {
 	struct bundle_header header;
 };
 
-static struct ref *get_refs_from_bundle(struct transport *transport, int for_push)
+static struct ref *get_refs_from_bundle(struct transport *transport,
+					int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct bundle_transport_data *data = transport->data;
 	struct ref *result = NULL;
@@ -189,7 +191,8 @@ static int connect_setup(struct transport *transport, int for_push)
 	return 0;
 }
 
-static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
+static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct git_transport_data *data = transport->data;
 	struct ref *refs = NULL;
@@ -204,7 +207,8 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	data->version = discover_version(&reader);
 	switch (data->version) {
 	case protocol_v2:
-		get_remote_refs(data->fd[1], &reader, &refs, for_push, NULL);
+		get_remote_refs(data->fd[1], &reader, &refs, for_push,
+				ref_prefixes);
 		break;
 	case protocol_v1:
 	case protocol_v0:
@@ -250,7 +254,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.update_shallow = data->options.update_shallow;
 
 	if (!data->got_remote_heads)
-		refs_tmp = get_refs_via_connect(transport, 0);
+		refs_tmp = get_refs_via_connect(transport, 0, NULL);
 
 	switch (data->version) {
 	case protocol_v2:
@@ -568,7 +572,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	int ret = 0;
 
 	if (!data->got_remote_heads)
-		get_refs_via_connect(transport, 1);
+		get_refs_via_connect(transport, 1, NULL);
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
@@ -1028,7 +1032,7 @@ int transport_push(struct transport *transport,
 		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
 			return -1;
 
-		remote_refs = transport->vtable->get_refs_list(transport, 1);
+		remote_refs = transport->vtable->get_refs_list(transport, 1, NULL);
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
@@ -1137,7 +1141,7 @@ int transport_push(struct transport *transport,
 const struct ref *transport_get_remote_refs(struct transport *transport)
 {
 	if (!transport->got_remote_refs) {
-		transport->remote_refs = transport->vtable->get_refs_list(transport, 0);
+		transport->remote_refs = transport->vtable->get_refs_list(transport, 0, NULL);
 		transport->got_remote_refs = 1;
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#21 lore raw

PATCH v5 16/35 transport: convert transport_get_remote_refs to take a list of ref prefixes

In reply to Brandon Williams

Teach transport_get_remote_refs() to accept a list of ref prefixes, which will be sent to the server for use in filtering when using protocol v2. (This list will be ignored when not using protocol v2.)

---
 builtin/clone.c     |  2 +-
 builtin/fetch.c     |  4 ++--
 builtin/ls-remote.c |  2 +-
 builtin/remote.c    |  2 +-
 transport.c         |  7 +++++--
 transport.h         | 12 +++++++++++-
 6 files changed, 21 insertions(+), 8 deletions(-)
builtin/clone.c +1 -1
index 284651797e..6e77d993fa 100644
@@ -1121,7 +1121,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (transport->smart_options && !deepen)
 		transport->smart_options->check_self_contained_and_connected = 1;
 
-	refs = transport_get_remote_refs(transport);
+	refs = transport_get_remote_refs(transport, NULL);
 
 	if (refs) {
 		mapped_refs = wanted_peer_refs(refs, refspec);
builtin/fetch.c +2 -2
index 7bbcd26faf..850382f559 100644
@@ -250,7 +250,7 @@ static void find_non_local_tags(struct transport *transport,
 	struct string_list_item *item = NULL;
 
 	for_each_ref(add_existing, &existing_refs);
-	for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
+	for (ref = transport_get_remote_refs(transport, NULL); ref; ref = ref->next) {
 		if (!starts_with(ref->name, "refs/tags/"))
 			continue;
 
@@ -336,7 +336,7 @@ static struct ref *get_ref_map(struct transport *transport,
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
-	const struct ref *remote_refs = transport_get_remote_refs(transport);
+	const struct ref *remote_refs = transport_get_remote_refs(transport, NULL);
 
 	if (refspec_count) {
 		struct refspec *fetch_refspec;
builtin/ls-remote.c +1 -1
index c4be98ab9e..c6e9847c5c 100644
@@ -96,7 +96,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
-	ref = transport_get_remote_refs(transport);
+	ref = transport_get_remote_refs(transport, NULL);
 	if (transport_disconnect(transport))
 		return 1;
 
builtin/remote.c +1 -1
index d95bf904c3..d0b6ff6e29 100644
@@ -862,7 +862,7 @@ static int get_remote_ref_states(const char *name,
 	if (query) {
 		transport = transport_get(states->remote, states->remote->url_nr > 0 ?
 			states->remote->url[0] : NULL);
-		remote_refs = transport_get_remote_refs(transport);
+		remote_refs = transport_get_remote_refs(transport, NULL);
 		transport_disconnect(transport);
 
 		states->queried = 1;
transport.c +5 -2
index 2e68010dd0..3f130518d2 100644
@@ -1138,10 +1138,13 @@ int transport_push(struct transport *transport,
 	return 1;
 }
 
-const struct ref *transport_get_remote_refs(struct transport *transport)
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes)
 {
 	if (!transport->got_remote_refs) {
-		transport->remote_refs = transport->vtable->get_refs_list(transport, 0, NULL);
+		transport->remote_refs =
+			transport->vtable->get_refs_list(transport, 0,
+							 ref_prefixes);
 		transport->got_remote_refs = 1;
 	}
 
transport.h +11 -1
index 731c78b679..83992a4257 100644
@@ -178,7 +178,17 @@ int transport_push(struct transport *connection,
 		   int refspec_nr, const char **refspec, int flags,
 		   unsigned int * reject_reasons);
 
-const struct ref *transport_get_remote_refs(struct transport *transport);
+/*
+ * Retrieve refs from a remote.
+ *
+ * Optionally a list of ref prefixes can be provided which can be sent to the
+ * server (when communicating using protocol v2) to enable it to limit the ref
+ * advertisement.  Since ref filtering is done on the server's end (and only
+ * when using protocol v2), this can return refs which don't match the provided
+ * ref_prefixes.
+ */
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes);
 
 int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#22 lore raw

PATCH v5 17/35 ls-remote: pass ref prefixes when requesting a remote's refs

In reply to Brandon Williams

Construct an argv_array of ref prefixes based on the patterns supplied via the command line and pass them to 'transport_get_remote_refs()' to be used when communicating protocol v2 so that the server can limit the ref advertisement based on those prefixes.

---
 builtin/ls-remote.c    | 15 +++++++++++++--
 refs.c                 | 14 ++++++++++++++
 refs.h                 |  7 +++++++
 t/t5702-protocol-v2.sh | 26 ++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 2 deletions(-)
builtin/ls-remote.c +13 -2
index c6e9847c5c..4276bf97d5 100644
@@ -2,6 +2,7 @@
 #include "cache.h"
 #include "transport.h"
 #include "remote.h"
+#include "refs.h"
 
 static const char * const ls_remote_usage[] = {
 	N_("git ls-remote [--heads] [--tags] [--refs] [--upload-pack=<exec>]\n"
@@ -43,6 +44,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	int show_symref_target = 0;
 	const char *uploadpack = NULL;
 	const char **pattern = NULL;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	struct remote *remote;
 	struct transport *transport;
@@ -74,8 +76,17 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (argc > 1) {
 		int i;
 		pattern = xcalloc(argc, sizeof(const char *));
-		for (i = 1; i < argc; i++)
+		for (i = 1; i < argc; i++) {
+			const char *glob;
 			pattern[i - 1] = xstrfmt("*/%s", argv[i]);
+
+			glob = strchr(argv[i], '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - argv[i]), argv[i]);
+			else
+				expand_ref_prefix(&ref_prefixes, argv[i]);
+		}
 	}
 
 	remote = remote_get(dest);
@@ -96,7 +107,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
-	ref = transport_get_remote_refs(transport, NULL);
+	ref = transport_get_remote_refs(transport, &ref_prefixes);
 	if (transport_disconnect(transport))
 		return 1;
 
refs.c +14 -0
index 20ba82b434..cefbad2076 100644
@@ -13,6 +13,7 @@
 #include "tag.h"
 #include "submodule.h"
 #include "worktree.h"
+#include "argv-array.h"
 
 /*
  * List of all available backends
@@ -501,6 +502,19 @@ int refname_match(const char *abbrev_name, const char *full_name)
 	return 0;
 }
 
+/*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
+{
+	const char **p;
+	int len = strlen(prefix);
+
+	for (p = ref_rev_parse_rules; *p; p++)
+		argv_array_pushf(prefixes, *p, len, prefix);
+}
+
 /*
  * *string and *len will only be substituted, and *string returned (for
  * later free()ing) if the string passed in is a magic short-hand form
refs.h +7 -0
index 01be5ae32f..93b6dce944 100644
@@ -139,6 +139,13 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
  */
 int refname_match(const char *abbrev_name, const char *full_name);
 
+/*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+struct argv_array;
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix);
+
 int expand_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_log(const char *str, int len, struct object_id *oid, char **ref);
t/t5702-protocol-v2.sh +26 -0
index dc5f813beb..562610fd25 100755
@@ -32,6 +32,19 @@ test_expect_success 'list refs with git:// using protocol v2' '
 	test_cmp actual expect
 '
 
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "$GIT_DAEMON_URL/parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C "$daemon_parent" rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
 stop_git_daemon
 
 # Test protocol v2 with 'file://' transport
@@ -54,4 +67,17 @@ test_expect_success 'list refs with file:// using protocol v2' '
 	test_cmp actual expect
 '
 
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "file://$(pwd)/file_parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C file_parent rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
 test_done
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#23 lore raw

PATCH v5 18/35 fetch: pass ref prefixes when fetching

In reply to Brandon Williams

Construct a list of ref prefixes to be passed to 'transport_get_remote_refs()' from the refspec to be used during the fetch. This list of ref prefixes will be used to allow the server to filter the ref advertisement when communicating using protocol v2.

---
 builtin/fetch.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)
builtin/fetch.c +18 -1
index 850382f559..8258bbf950 100644
@@ -332,11 +332,28 @@ static struct ref *get_ref_map(struct transport *transport,
 	struct ref *rm;
 	struct ref *ref_map = NULL;
 	struct ref **tail = &ref_map;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
-	const struct ref *remote_refs = transport_get_remote_refs(transport, NULL);
+	const struct ref *remote_refs;
+
+	for (i = 0; i < refspec_count; i++) {
+		if (!refspecs[i].exact_sha1) {
+			const char *glob = strchr(refspecs[i].src, '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - refspecs[i].src),
+						 refspecs[i].src);
+			else
+				expand_ref_prefix(&ref_prefixes, refspecs[i].src);
+		}
+	}
+
+	remote_refs = transport_get_remote_refs(transport, &ref_prefixes);
+
+	argv_array_clear(&ref_prefixes);
 
 	if (refspec_count) {
 		struct refspec *fetch_refspec;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#24 lore raw

PATCH v5 19/35 push: pass ref prefixes when pushing

In reply to Brandon Williams

Construct a list of ref prefixes to be passed to 'get_refs_list()' from the refspec to be used during the push. This list of ref prefixes will be used to allow the server to filter the ref advertisement when communicating using protocol v2.

---
 transport.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)
transport.c +28 -1
index 3f130518d2..57bdbb59bc 100644
@@ -1028,11 +1028,38 @@ int transport_push(struct transport *transport,
 		int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
 		int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
 		int push_ret, ret, err;
+		struct refspec *tmp_rs;
+		struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
+		int i;
 
 		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
 			return -1;
 
-		remote_refs = transport->vtable->get_refs_list(transport, 1, NULL);
+		tmp_rs = parse_push_refspec(refspec_nr, refspec);
+		for (i = 0; i < refspec_nr; i++) {
+			const char *prefix = NULL;
+
+			if (tmp_rs[i].dst)
+				prefix = tmp_rs[i].dst;
+			else if (tmp_rs[i].src && !tmp_rs[i].exact_sha1)
+				prefix = tmp_rs[i].src;
+
+			if (prefix) {
+				const char *glob = strchr(prefix, '*');
+				if (glob)
+					argv_array_pushf(&ref_prefixes, "%.*s",
+							 (int)(glob - prefix),
+							 prefix);
+				else
+					expand_ref_prefix(&ref_prefixes, prefix);
+			}
+		}
+
+		remote_refs = transport->vtable->get_refs_list(transport, 1,
+							       &ref_prefixes);
+
+		argv_array_clear(&ref_prefixes);
+		free_refspec(refspec_nr, tmp_rs);
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#25 lore raw

PATCH v5 20/35 upload-pack: introduce fetch server command

In reply to Brandon Williams

Introduce the 'fetch' server command.

---
 Documentation/technical/protocol-v2.txt | 127 +++++++++++
 serve.c                                 |   2 +
 t/t5701-git-serve.sh                    |   1 +
 upload-pack.c                           | 266 ++++++++++++++++++++++++
 upload-pack.h                           |   6 +
 5 files changed, 402 insertions(+)
Documentation/technical/protocol-v2.txt +127 -0
index 422edf870e..9ce91d7213 100644
@@ -203,3 +203,130 @@ The output of ls-refs is as follows:
     ref-attribute = (symref | peeled)
     symref = "symref-target:" symref-target
     peeled = "peeled:" obj-id
+
+ fetch
+-------
+
+`fetch` is the command used to fetch a packfile in v2.  It can be looked
+at as a modified version of the v1 fetch where the ref-advertisement is
+stripped out (since the `ls-refs` command fills that role) and the
+message format is tweaked to eliminate redundancies and permit easy
+addition of future extensions.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+A `fetch` request can take the following arguments:
+
+    want <oid>
+	Indicates to the server an object which the client wants to
+	retrieve.  Wants can be anything and are not limited to
+	advertised objects.
+
+    have <oid>
+	Indicates to the server an object which the client has locally.
+	This allows the server to make a packfile which only contains
+	the objects that the client needs. Multiple 'have' lines can be
+	supplied.
+
+    done
+	Indicates to the server that negotiation should terminate (or
+	not even begin if performing a clone) and that the server should
+	use the information supplied in the request to construct the
+	packfile.
+
+    thin-pack
+	Request that a thin pack be sent, which is a pack with deltas
+	which reference base objects not contained within the pack (but
+	are known to exist at the receiving end). This can reduce the
+	network traffic significantly, but it requires the receiving end
+	to know how to "thicken" these packs by adding the missing bases
+	to the pack.
+
+    no-progress
+	Request that progress information that would normally be sent on
+	side-band channel 2, during the packfile transfer, should not be
+	sent.  However, the side-band channel 3 is still used for error
+	responses.
+
+    include-tag
+	Request that annotated tags should be sent if the objects they
+	point to are being sent.
+
+    ofs-delta
+	Indicate that the client understands PACKv2 with delta referring
+	to its base by position in pack rather than by an oid.  That is,
+	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
+
+The response of `fetch` is broken into a number of sections separated by
+delimiter packets (0001), with each section beginning with its section
+header.
+
+    output = *section
+    section = (acknowledgments | packfile)
+	      (flush-pkt | delim-pkt)
+
+    acknowledgments = PKT-LINE("acknowledgments" LF)
+		      (nak | *ack)
+		      (ready)
+    ready = PKT-LINE("ready" LF)
+    nak = PKT-LINE("NAK" LF)
+    ack = PKT-LINE("ACK" SP obj-id LF)
+
+    packfile = PKT-LINE("packfile" LF)
+	       *PKT-LINE(%x01-03 *%x00-ff)
+
+----
+    acknowledgments section
+	* If the client determines that it is finished with negotiations
+	  by sending a "done" line, the acknowledgments sections MUST be
+	  omitted from the server's response.
+
+	* Always begins with the section header "acknowledgments"
+
+	* The server will respond with "NAK" if none of the object ids sent
+	  as have lines were common.
+
+	* The server will respond with "ACK obj-id" for all of the
+	  object ids sent as have lines which are common.
+
+	* A response cannot have both "ACK" lines as well as a "NAK"
+	  line.
+
+	* The server will respond with a "ready" line indicating that
+	  the server has found an acceptable common base and is ready to
+	  make and send a packfile (which will be found in the packfile
+	  section of the same response)
+
+	* If the server has found a suitable cut point and has decided
+	  to send a "ready" line, then the server can decide to (as an
+	  optimization) omit any "ACK" lines it would have sent during
+	  its response.  This is because the server will have already
+	  determined the objects it plans to send to the client and no
+	  further negotiation is needed.
+
+----
+    packfile section
+	* This section is only included if the client has sent 'want'
+	  lines in its request and either requested that no more
+	  negotiation be done by sending 'done' or if the server has
+	  decided it has found a sufficient cut point to produce a
+	  packfile.
+
+	* Always begins with the section header "packfile"
+
+	* The transmission of the packfile begins immediately after the
+	  section header
+
+	* The data transfer of the packfile is always multiplexed, using
+	  the same semantics of the 'side-band-64k' capability from
+	  protocol version 1.  This means that each packet, during the
+	  packfile data stream, is made up of a leading 4-byte pkt-line
+	  length (typical of the pkt-line format), followed by a 1-byte
+	  stream code, followed by the actual data.
+
+	  The stream code can be one of:
+		1 - pack data
+		2 - progress messages
+		3 - fatal error message just before stream aborts
serve.c +2 -0
index 1cb5fb9b5b..3692dda801 100644
@@ -6,6 +6,7 @@
 #include "argv-array.h"
 #include "ls-refs.h"
 #include "serve.h"
+#include "upload-pack.h"
 
 static int always_advertise(struct repository *r,
 			    struct strbuf *value)
@@ -54,6 +55,7 @@ struct protocol_capability {
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
 	{ "ls-refs", always_advertise, ls_refs },
+	{ "fetch", always_advertise, upload_pack_v2 },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +1 -0
index d03e08eebd..888a700443 100755
@@ -9,6 +9,7 @@ test_expect_success 'test capability advertisement' '
 	version 2
 	agent=git/$(git version | cut -d" " -f3)
 	ls-refs
+	fetch
 	0000
 	EOF
 
upload-pack.c +266 -0

275 lines not on this page · raw message

upload-pack.h +6 -0
index a71e4dc7e2..5bbdb7e445 100644
@@ -10,4 +10,10 @@ struct upload_pack_options {
 
 void upload_pack(struct upload_pack_options *options);
 
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
+			  struct packet_reader *request);
+
 #endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#26 lore raw

PATCH v5 21/35 fetch-pack: perform a fetch using v2

In reply to Brandon Williams

When communicating with a v2 server, perform a fetch by requesting the 'fetch' command.

---
 Documentation/technical/protocol-v2.txt |  68 +++++-
 builtin/fetch-pack.c                    |   2 +-
 fetch-pack.c                            | 270 +++++++++++++++++++++++-
 fetch-pack.h                            |   4 +-
 serve.c                                 |   2 +-
 t/t5701-git-serve.sh                    |   2 +-
 t/t5702-protocol-v2.sh                  |  97 +++++++++
 transport.c                             |   7 +-
 upload-pack.c                           | 141 ++++++++++---
 upload-pack.h                           |   4 +
 10 files changed, 549 insertions(+), 48 deletions(-)
Documentation/technical/protocol-v2.txt +67 -1
index 9ce91d7213..7b5a1d4000 100644
@@ -259,12 +259,43 @@ A `fetch` request can take the following arguments:
 	to its base by position in pack rather than by an oid.  That is,
 	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
 
+    shallow <oid>
+	A client must notify the server of all commits for which it only
+	has shallow copies (meaning that it doesn't have the parents of
+	a commit) by supplying a 'shallow <oid>' line for each such
+	object so that the server is aware of the limitations of the
+	client's history.  This is so that the server is aware that the
+	client may not have all objects reachable from such commits.
+
+    deepen <depth>
+	Requests that the fetch/clone should be shallow having a commit
+	depth of <depth> relative to the remote side.
+
+    deepen-relative
+	Requests that the semantics of the "deepen" command be changed
+	to indicate that the depth requested is relative to the client's
+	current shallow boundary, instead of relative to the requested
+	commits.
+
+    deepen-since <timestamp>
+	Requests that the shallow clone/fetch should be cut at a
+	specific time, instead of depth.  Internally it's equivalent to
+	doing "git rev-list --max-age=<timestamp>". Cannot be used with
+	"deepen".
+
+    deepen-not <rev>
+	Requests that the shallow clone/fetch should be cut at a
+	specific revision specified by '<rev>', instead of a depth.
+	Internally it's equivalent of doing "git rev-list --not <rev>".
+	Cannot be used with "deepen", but can be used with
+	"deepen-since".
+
 The response of `fetch` is broken into a number of sections separated by
 delimiter packets (0001), with each section beginning with its section
 header.
 
     output = *section
-    section = (acknowledgments | packfile)
+    section = (acknowledgments | shallow-info | packfile)
 	      (flush-pkt | delim-pkt)
 
     acknowledgments = PKT-LINE("acknowledgments" LF)
@@ -274,6 +305,11 @@ header.
     nak = PKT-LINE("NAK" LF)
     ack = PKT-LINE("ACK" SP obj-id LF)
 
+    shallow-info = PKT-LINE("shallow-info" LF)
+		   *PKT-LINE((shallow | unshallow) LF)
+    shallow = "shallow" SP obj-id
+    unshallow = "unshallow" SP obj-id
+
     packfile = PKT-LINE("packfile" LF)
 	       *PKT-LINE(%x01-03 *%x00-ff)
 
@@ -306,6 +342,36 @@ header.
 	  determined the objects it plans to send to the client and no
 	  further negotiation is needed.
 
+----
+    shallow-info section
+	If the client has requested a shallow fetch/clone, a shallow
+	client requests a fetch or the server is shallow then the
+	server's response may include a shallow-info section.  The
+	shallow-info section will be included if (due to one of the
+	above conditions) the server needs to inform the client of any
+	shallow boundaries or adjustments to the clients already
+	existing shallow boundaries.
+
+	* Always begins with the section header "shallow-info"
+
+	* If a positive depth is requested, the server will compute the
+	  set of commits which are no deeper than the desired depth.
+
+	* The server sends a "shallow obj-id" line for each commit whose
+	  parents will not be sent in the following packfile.
+
+	* The server sends an "unshallow obj-id" line for each commit
+	  which the client has indicated is shallow, but is no longer
+	  shallow as a result of the fetch (due to its parents being
+	  sent in the following packfile).
+
+	* The server MUST NOT send any "unshallow" lines for anything
+	  which the client has not indicated was shallow as a part of
+	  its request.
+
+	* This section is only included if a packfile section is also
+	  included in the response.
+
 ----
     packfile section
 	* This section is only included if the client has sent 'want'
builtin/fetch-pack.c +1 -1
index b2374ddbbf..f9d7d0b5a5 100644
@@ -212,7 +212,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
-			 &shallow, pack_lockfile_ptr);
+			 &shallow, pack_lockfile_ptr, protocol_v0);
 	if (pack_lockfile) {
 		printf("lock %s\n", pack_lockfile);
 		fflush(stdout);
fetch-pack.c +264 -6

301 lines not on this page · raw message

fetch-pack.h +3 -1
index b6aeb43a8e..7afca73056 100644
@@ -3,6 +3,7 @@
 
 #include "string-list.h"
 #include "run-command.h"
+#include "protocol.h"
 
 struct oid_array;
 
@@ -43,7 +44,8 @@ struct ref *fetch_pack(struct fetch_pack_args *args,
 		       struct ref **sought,
 		       int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile);
+		       char **pack_lockfile,
+		       enum protocol_version version);
 
 /*
  * Print an appropriate error message for each sought ref that wasn't
serve.c +1 -1
index 3692dda801..a5a7b2f7dd 100644
@@ -55,7 +55,7 @@ struct protocol_capability {
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
 	{ "ls-refs", always_advertise, ls_refs },
-	{ "fetch", always_advertise, upload_pack_v2 },
+	{ "fetch", upload_pack_advertise, upload_pack_v2 },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +1 -1
index 888a700443..72d7bc5628 100755
@@ -9,7 +9,7 @@ test_expect_success 'test capability advertisement' '
 	version 2
 	agent=git/$(git version | cut -d" " -f3)
 	ls-refs
-	fetch
+	fetch=shallow
 	0000
 	EOF
 
t/t5702-protocol-v2.sh +97 -0

107 lines not on this page · raw message

transport.c +5 -2
index 57bdbb59bc..9152a45b38 100644
@@ -258,14 +258,17 @@ static int fetch_refs_via_pack(struct transport *transport,
 
 	switch (data->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile, data->version);
 		break;
 	case protocol_v1:
 	case protocol_v0:
 		refs = fetch_pack(&args, data->fd, data->conn,
 				  refs_tmp ? refs_tmp : transport->remote_refs,
 				  dest, to_fetch, nr_heads, &data->shallow,
-				  &transport->pack_lockfile);
+				  &transport->pack_lockfile, data->version);
 		break;
 	case protocol_unknown_version:
 		BUG("unknown protocol version");
upload-pack.c +106 -35

203 lines not on this page · raw message

upload-pack.h +4 -0
index 5bbdb7e445..cab2178796 100644
@@ -16,4 +16,8 @@ struct packet_reader;
 extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
 			  struct packet_reader *request);
 
+struct strbuf;
+extern int upload_pack_advertise(struct repository *r,
+				 struct strbuf *value);
+
 #endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#27 lore raw

PATCH v5 22/35 fetch-pack: support shallow requests

In reply to Brandon Williams

Enable shallow clones and deepen requests using protocol version 2 if the server 'fetch' command supports the 'shallow' feature.

---
 connect.c    | 22 ++++++++++++++++
 connect.h    |  2 ++
 fetch-pack.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 94 insertions(+), 1 deletion(-)
connect.c +22 -0
index e42d779f71..5bb9d34844 100644
@@ -82,6 +82,28 @@ int server_supports_v2(const char *c, int die_on_error)
 	return 0;
 }
 
+int server_supports_feature(const char *c, const char *feature,
+			    int die_on_error)
+{
+	int i;
+
+	for (i = 0; i < server_capabilities_v2.argc; i++) {
+		const char *out;
+		if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+		    (!*out || *(out++) == '=')) {
+			if (parse_feature_request(out, feature))
+				return 1;
+			else
+				break;
+		}
+	}
+
+	if (die_on_error)
+		die("server doesn't support feature '%s'", feature);
+
+	return 0;
+}
+
 static void process_capabilities_v2(struct packet_reader *reader)
 {
 	while (packet_reader_read(reader) == PACKET_READ_NORMAL)
connect.h +2 -0
index 8898d44952..0e69c6709c 100644
@@ -17,5 +17,7 @@ struct packet_reader;
 extern enum protocol_version discover_version(struct packet_reader *reader);
 
 extern int server_supports_v2(const char *c, int die_on_error);
+extern int server_supports_feature(const char *c, const char *feature,
+				   int die_on_error);
 
 #endif
fetch-pack.c +70 -1

107 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#28 lore raw

PATCH v5 23/35 connect: refactor git_connect to only get the protocol version once

In reply to Brandon Williams

Instead of having each builtin transport asking for which protocol version the user has configured in 'protocol.version' by calling get_protocol_version_config() multiple times, factor this logic out so there is just a single call at the beginning of git_connect().

This will be helpful in the next patch where we can have centralized logic which determines if we need to request a different protocol version than what the user has configured.

---
 connect.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)
connect.c +15 -12
index 5bb9d34844..a57a060dc4 100644
@@ -1035,6 +1035,7 @@ static enum ssh_variant determine_ssh_variant(const char *ssh_command,
  */
 static struct child_process *git_connect_git(int fd[2], char *hostandport,
 					     const char *path, const char *prog,
+					     enum protocol_version version,
 					     int flags)
 {
 	struct child_process *conn;
@@ -1073,10 +1074,10 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
 		    target_host, 0);
 
 	/* If using a new version put that stuff here after a second null byte */
-	if (get_protocol_version_config() > 0) {
+	if (version > 0) {
 		strbuf_addch(&request, '\0');
 		strbuf_addf(&request, "version=%d%c",
-			    get_protocol_version_config(), '\0');
+			    version, '\0');
 	}
 
 	packet_write(fd[1], request.buf, request.len);
@@ -1092,14 +1093,14 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
  */
 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 			     enum ssh_variant variant, const char *port,
-			     int flags)
+			     enum protocol_version version, int flags)
 {
 	if (variant == VARIANT_SSH &&
-	    get_protocol_version_config() > 0) {
+	    version > 0) {
 		argv_array_push(args, "-o");
 		argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
 		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-				 get_protocol_version_config());
+				 version);
 	}
 
 	if (flags & CONNECT_IPV4) {
@@ -1152,7 +1153,8 @@ static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 
 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
-			  const char *port, int flags)
+			  const char *port, enum protocol_version version,
+			  int flags)
 {
 	const char *ssh;
 	enum ssh_variant variant;
@@ -1186,14 +1188,14 @@ static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
 		argv_array_push(&detect.args, ssh);
 		argv_array_push(&detect.args, "-G");
 		push_ssh_options(&detect.args, &detect.env_array,
-				 VARIANT_SSH, port, flags);
+				 VARIANT_SSH, port, version, flags);
 		argv_array_push(&detect.args, ssh_host);
 
 		variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
 	}
 
 	argv_array_push(&conn->args, ssh);
-	push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
+	push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
 	argv_array_push(&conn->args, ssh_host);
 }
 
@@ -1214,6 +1216,7 @@ struct child_process *git_connect(int fd[2], const char *url,
 	char *hostandport, *path;
 	struct child_process *conn;
 	enum protocol protocol;
+	enum protocol_version version = get_protocol_version_config();
 
 	/* Without this we cannot rely on waitpid() to tell
 	 * what happened to our children.
@@ -1228,7 +1231,7 @@ struct child_process *git_connect(int fd[2], const char *url,
 		printf("Diag: path=%s\n", path ? path : "NULL");
 		conn = NULL;
 	} else if (protocol == PROTO_GIT) {
-		conn = git_connect_git(fd, hostandport, path, prog, flags);
+		conn = git_connect_git(fd, hostandport, path, prog, version, flags);
 	} else {
 		struct strbuf cmd = STRBUF_INIT;
 		const char *const *var;
@@ -1271,12 +1274,12 @@ struct child_process *git_connect(int fd[2], const char *url,
 				strbuf_release(&cmd);
 				return NULL;
 			}
-			fill_ssh_args(conn, ssh_host, port, flags);
+			fill_ssh_args(conn, ssh_host, port, version, flags);
 		} else {
 			transport_check_allowed("file");
-			if (get_protocol_version_config() > 0) {
+			if (version > 0) {
 				argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-						 get_protocol_version_config());
+						 version);
 			}
 		}
 		argv_array_push(&conn->args, cmd.buf);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#29 lore raw

PATCH v5 24/35 connect: don't request v2 when pushing

In reply to Brandon Williams

In order to be able to ship protocol v2 with only supporting fetch, we need clients to not issue a request to use protocol v2 when pushing (since the client currently doesn't know how to push using protocol v2). This allows a client to have protocol v2 configured in protocol.version and take advantage of using v2 for fetch and falling back to using v0 when pushing while v2 for push is being designed.

We could run into issues if we didn't fall back to protocol v2 when pushing right now. This is because currently a server will ignore a request to use v2 when contacting the 'receive-pack' endpoint and fall back to using v0, but when push v2 is rolled out to servers, the 'receive-pack' endpoint will start responding using v2. So we don't want to get into a state where a client is requesting to push with v2 before they actually know how to push using v2.

---
 connect.c              |  8 ++++++++
 t/t5702-protocol-v2.sh | 24 ++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
connect.c +8 -0
index a57a060dc4..54971166ac 100644
@@ -1218,6 +1218,14 @@ struct child_process *git_connect(int fd[2], const char *url,
 	enum protocol protocol;
 	enum protocol_version version = get_protocol_version_config();
 
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
+		version = protocol_v0;
+
 	/* Without this we cannot rely on waitpid() to tell
 	 * what happened to our children.
 	 */
t/t5702-protocol-v2.sh +24 -0
index 4365ac2736..e3a7c09d4a 100755
@@ -95,6 +95,30 @@ test_expect_success 'pull with git:// using protocol v2' '
 	grep "fetch< version 2" log
 '
 
+test_expect_success 'push with git:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C daemon_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C daemon_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C daemon_child log -1 --format=%s >actual &&
+	git -C "$daemon_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	! grep "push> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	! grep "push< version 2" log
+'
+
 stop_git_daemon
 
 # Test protocol v2 with 'file://' transport
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#30 lore raw

PATCH v5 25/35 transport-helper: remove name parameter

In reply to Brandon Williams

Commit 266f1fdfa (transport-helper: be quiet on read errors from helpers, 2013-06-21) removed a call to 'die()' which printed the name of the remote helper passed in to the 'recvline_fh()' function using the 'name' parameter. Once the call to 'die()' was removed the parameter was no longer necessary but wasn't removed. Clean up 'recvline_fh()' parameter list by removing the 'name' parameter.

---
 transport-helper.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
transport-helper.c +3 -3
index 8774ab3013..9677ead426 100644
@@ -49,7 +49,7 @@ static void sendline(struct helper_data *helper, struct strbuf *buffer)
 		die_errno("Full write to remote helper failed");
 }
 
-static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
+static int recvline_fh(FILE *helper, struct strbuf *buffer)
 {
 	strbuf_reset(buffer);
 	if (debug)
@@ -67,7 +67,7 @@ static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
 
 static int recvline(struct helper_data *helper, struct strbuf *buffer)
 {
-	return recvline_fh(helper->out, buffer, helper->name);
+	return recvline_fh(helper->out, buffer);
 }
 
 static void write_constant(int fd, const char *str)
@@ -586,7 +586,7 @@ static int process_connect_service(struct transport *transport,
 		goto exit;
 
 	sendline(data, &cmdbuf);
-	if (recvline_fh(input, &cmdbuf, name))
+	if (recvline_fh(input, &cmdbuf))
 		exit(128);
 
 	if (!strcmp(cmdbuf.buf, "")) {
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#31 lore raw

PATCH v5 26/35 transport-helper: refactor process_connect_service

In reply to Brandon Williams

A future patch will need to take advantage of the logic which runs and processes the response of the connect command on a remote helper so factor out this logic from 'process_connect_service()' and place it into a helper function 'run_connect()'.

---
 transport-helper.c | 67 ++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 29 deletions(-)
transport-helper.c +38 -29
index 9677ead426..830f21f0a9 100644
@@ -545,14 +545,13 @@ static int fetch_with_import(struct transport *transport,
 	return 0;
 }
 
-static int process_connect_service(struct transport *transport,
-				   const char *name, const char *exec)
+static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 {
 	struct helper_data *data = transport->data;
-	struct strbuf cmdbuf = STRBUF_INIT;
-	struct child_process *helper;
-	int r, duped, ret = 0;
+	int ret = 0;
+	int duped;
 	FILE *input;
+	struct child_process *helper;
 
 	helper = get_helper(transport);
 
@@ -568,44 +567,54 @@ static int process_connect_service(struct transport *transport,
 	input = xfdopen(duped, "r");
 	setvbuf(input, NULL, _IONBF, 0);
 
+	sendline(data, cmdbuf);
+	if (recvline_fh(input, cmdbuf))
+		exit(128);
+
+	if (!strcmp(cmdbuf->buf, "")) {
+		data->no_disconnect_req = 1;
+		if (debug)
+			fprintf(stderr, "Debug: Smart transport connection "
+				"ready.\n");
+		ret = 1;
+	} else if (!strcmp(cmdbuf->buf, "fallback")) {
+		if (debug)
+			fprintf(stderr, "Debug: Falling back to dumb "
+				"transport.\n");
+	} else {
+		die("Unknown response to connect: %s",
+			cmdbuf->buf);
+	}
+
+	fclose(input);
+	return ret;
+}
+
+static int process_connect_service(struct transport *transport,
+				   const char *name, const char *exec)
+{
+	struct helper_data *data = transport->data;
+	struct strbuf cmdbuf = STRBUF_INIT;
+	int ret = 0;
+
 	/*
 	 * Handle --upload-pack and friends. This is fire and forget...
 	 * just warn if it fails.
 	 */
 	if (strcmp(name, exec)) {
-		r = set_helper_option(transport, "servpath", exec);
+		int r = set_helper_option(transport, "servpath", exec);
 		if (r > 0)
 			warning("Setting remote service path not supported by protocol.");
 		else if (r < 0)
 			warning("Invalid remote service path.");
 	}
 
-	if (data->connect)
+	if (data->connect) {
 		strbuf_addf(&cmdbuf, "connect %s\n", name);
-	else
-		goto exit;
-
-	sendline(data, &cmdbuf);
-	if (recvline_fh(input, &cmdbuf))
-		exit(128);
-
-	if (!strcmp(cmdbuf.buf, "")) {
-		data->no_disconnect_req = 1;
-		if (debug)
-			fprintf(stderr, "Debug: Smart transport connection "
-				"ready.\n");
-		ret = 1;
-	} else if (!strcmp(cmdbuf.buf, "fallback")) {
-		if (debug)
-			fprintf(stderr, "Debug: Falling back to dumb "
-				"transport.\n");
-	} else
-		die("Unknown response to connect: %s",
-			cmdbuf.buf);
+		ret = run_connect(transport, &cmdbuf);
+	}
 
-exit:
 	strbuf_release(&cmdbuf);
-	fclose(input);
 	return ret;
 }
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#32 lore raw

PATCH v5 27/35 transport-helper: introduce stateless-connect

In reply to Brandon Williams

Introduce the transport-helper capability 'stateless-connect'. This capability indicates that the transport-helper can be requested to run the 'stateless-connect' command which should attempt to make a stateless connection with a remote end. Once established, the connection can be used by the git client to communicate with the remote end natively in a stateless-rpc manner as supported by protocol v2. This means that the client must send everything the server needs in a single request as the client must not assume any state-storing on the part of the server or transport.

If a stateless connection cannot be established then the remote-helper will respond in the same manner as the 'connect' command indicating that the client should fallback to using the dumb remote-helper commands.

A future patch will implement the 'stateless-connect' capability in our http remote-helper (remote-curl) so that protocol v2 can be used using the http transport.

---
 Documentation/gitremote-helpers.txt | 32 +++++++++++++++++++++++++++++
 transport-helper.c                  | 11 ++++++++++
 transport.c                         |  1 +
 transport.h                         |  6 ++++++
 4 files changed, 50 insertions(+)
Documentation/gitremote-helpers.txt +32 -0
index 4a584f3c5d..cd9b34d230 100644
@@ -102,6 +102,14 @@ Capabilities for Pushing
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'push'::
 	Can discover remote refs and push local commits and the
 	history leading up to them to new or existing remote refs.
@@ -136,6 +144,14 @@ Capabilities for Fetching
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'fetch'::
 	Can discover remote refs and transfer objects reachable from
 	them to the local object store.
@@ -375,6 +391,22 @@ Supported if the helper has the "export" capability.
 +
 Supported if the helper has the "connect" capability.
 
+'stateless-connect' <service>::
+	Experimental; for internal use only.
+	Connects to the given remote service for communication using
+	git's wire-protocol version 2.  Valid replies to this command
+	are empty line (connection established), 'fallback' (no smart
+	transport support, fall back to dumb transports) and just
+	exiting with error message printed (can't connect, don't bother
+	trying to fall back).  After line feed terminating the positive
+	(empty) response, the output of the service starts.  Messages
+	(both request and response) must consist of zero or more
+	PKT-LINEs, terminating in a flush packet. The client must not
+	expect the server to store any state in between request-response
+	pairs.  After the connection ends, the remote helper exits.
++
+Supported if the helper has the "stateless-connect" capability.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without
transport-helper.c +11 -0
index 830f21f0a9..aecbc4a845 100644
@@ -12,6 +12,7 @@
 #include "argv-array.h"
 #include "refs.h"
 #include "transport-internal.h"
+#include "protocol.h"
 
 static int debug;
 
@@ -26,6 +27,7 @@ struct helper_data {
 		option : 1,
 		push : 1,
 		connect : 1,
+		stateless_connect : 1,
 		signed_tags : 1,
 		check_connectivity : 1,
 		no_disconnect_req : 1,
@@ -188,6 +190,8 @@ static struct child_process *get_helper(struct transport *transport)
 			refspecs[refspec_nr++] = xstrdup(arg);
 		} else if (!strcmp(capname, "connect")) {
 			data->connect = 1;
+		} else if (!strcmp(capname, "stateless-connect")) {
+			data->stateless_connect = 1;
 		} else if (!strcmp(capname, "signed-tags")) {
 			data->signed_tags = 1;
 		} else if (skip_prefix(capname, "export-marks ", &arg)) {
@@ -612,6 +616,13 @@ static int process_connect_service(struct transport *transport,
 	if (data->connect) {
 		strbuf_addf(&cmdbuf, "connect %s\n", name);
 		ret = run_connect(transport, &cmdbuf);
+	} else if (data->stateless_connect &&
+		   (get_protocol_version_config() == protocol_v2) &&
+		   !strcmp("git-upload-pack", name)) {
+		strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
+		ret = run_connect(transport, &cmdbuf);
+		if (ret)
+			transport->stateless_rpc = 1;
 	}
 
 	strbuf_release(&cmdbuf);
transport.c +1 -0
index 9152a45b38..342db492ca 100644
@@ -252,6 +252,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 		data->options.check_self_contained_and_connected;
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
+	args.stateless_rpc = transport->stateless_rpc;
 
 	if (!data->got_remote_heads)
 		refs_tmp = get_refs_via_connect(transport, 0, NULL);
transport.h +6 -0
index 83992a4257..0e602d4d47 100644
@@ -55,6 +55,12 @@ struct transport {
 	 */
 	unsigned cloning : 1;
 
+	/*
+	 * Indicates that the transport is connected via a half-duplex
+	 * connection and should operate in stateless-rpc mode.
+	 */
+	unsigned stateless_rpc : 1;
+
 	/*
 	 * These strings will be passed to the {pre, post}-receive hook,
 	 * on the remote side, if both sides support the push options capability.
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#33 lore raw

PATCH v5 28/35 pkt-line: add packet_buf_write_len function

In reply to Brandon Williams

Add the 'packet_buf_write_len()' function which allows for writing an arbitrary length buffer into a 'struct strbuf' and formatting it in packet-line format.

---
 pkt-line.c | 16 ++++++++++++++++
 pkt-line.h |  1 +
 2 files changed, 17 insertions(+)
pkt-line.c +16 -0
index 7296731cf3..555eb2a507 100644
@@ -215,6 +215,22 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	va_end(args);
 }
 
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
+{
+	size_t orig_len, n;
+
+	orig_len = buf->len;
+	strbuf_addstr(buf, "0000");
+	strbuf_add(buf, data, len);
+	n = buf->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
+		die("protocol error: impossibly long line");
+
+	set_packet_header(&buf->buf[orig_len], n);
+	packet_trace(data, len, 1);
+}
+
 int write_packetized_from_fd(int fd_in, int fd_out)
 {
 	static char buf[LARGE_PACKET_DATA_MAX];
pkt-line.h +1 -0
index 9570bd7a0a..5b28d43472 100644
@@ -26,6 +26,7 @@ void packet_buf_flush(struct strbuf *buf);
 void packet_buf_delim(struct strbuf *buf);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len);
 int packet_flush_gently(int fd);
 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int write_packetized_from_fd(int fd_in, int fd_out);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#34 lore raw

PATCH v5 29/35 remote-curl: create copy of the service name

In reply to Brandon Williams

Make a copy of the service name being requested instead of relying on the buffer pointed to by the passed in 'const char *' to remain unchanged.

Currently, all service names are string constants, but a subsequent patch will introduce service names from external sources.

---
 remote-curl.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
remote-curl.c +3 -2
index dae8a4a48d..4086aa733b 100644
@@ -165,7 +165,7 @@ static int set_option(const char *name, const char *value)
 }
 
 struct discovery {
-	const char *service;
+	char *service;
 	char *buf_alloc;
 	char *buf;
 	size_t len;
@@ -257,6 +257,7 @@ static void free_discovery(struct discovery *d)
 		free(d->shallow.oid);
 		free(d->buf_alloc);
 		free_refs(d->refs);
+		free(d->service);
 		free(d);
 	}
 }
@@ -343,7 +344,7 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		warning(_("redirecting to %s"), url.buf);
 
 	last= xcalloc(1, sizeof(*last_discovery));
-	last->service = service;
+	last->service = xstrdup(service);
 	last->buf_alloc = strbuf_detach(&buffer, &last->len);
 	last->buf = last->buf_alloc;
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#35 lore raw

PATCH v5 30/35 remote-curl: store the protocol version the server responded with

In reply to Brandon Williams

Store the protocol version the server responded with when performing discovery. This will be used in a future patch to either change the 'Git-Protocol' header sent in subsequent requests or to determine if a client needs to fallback to using a different protocol version.

---
 remote-curl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
remote-curl.c +3 -1
index 4086aa733b..c540358438 100644
@@ -171,6 +171,7 @@ struct discovery {
 	size_t len;
 	struct ref *refs;
 	struct oid_array shallow;
+	enum protocol_version version;
 	unsigned proto_git : 1;
 };
 static struct discovery *last_discovery;
@@ -184,7 +185,8 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_GENTLE_ON_EOF);
 
-	switch (discover_version(&reader)) {
+	heads->version = discover_version(&reader);
+	switch (heads->version) {
 	case protocol_v2:
 		die("support for protocol v2 not implemented yet");
 		break;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#36 lore raw

PATCH v5 31/35 http: allow providing extra headers for http requests

In reply to Brandon Williams

Add a way for callers to request that extra headers be included when making http requests.

---
 http.c | 8 ++++++++
 http.h | 7 +++++++
 2 files changed, 15 insertions(+)
http.c +8 -0
index 5977712712..e1757d62b2 100644
@@ -1723,6 +1723,14 @@ static int http_request(const char *url,
 
 	headers = curl_slist_append(headers, buf.buf);
 
+	/* Add additional headers here */
+	if (options && options->extra_headers) {
+		const struct string_list_item *item;
+		for_each_string_list_item(item, options->extra_headers) {
+			headers = curl_slist_append(headers, item->string);
+		}
+	}
+
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
http.h +7 -0
index f7bd3b26b0..4df4a25e1a 100644
@@ -172,6 +172,13 @@ struct http_get_options {
 	 * for details.
 	 */
 	struct strbuf *base_url;
+
+	/*
+	 * If not NULL, contains additional HTTP headers to be sent with the
+	 * request. The strings in the list must not be freed until after the
+	 * request has completed.
+	 */
+	struct string_list *extra_headers;
 };
 
 /* Return values for http_get_*() */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#37 lore raw

PATCH v5 32/35 http: don't always add Git-Protocol header

In reply to Brandon Williams

Instead of always sending the Git-Protocol header with the configured version with every http request, explicitly send it when discovering refs and then only send it on subsequent http requests if the server understood the version requested.

---
 http.c        | 17 -----------------
 remote-curl.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 17 deletions(-)
http.c +0 -17
index e1757d62b2..8f1129ac7c 100644
@@ -904,21 +904,6 @@ static void set_from_env(const char **var, const char *envname)
 		*var = val;
 }
 
-static void protocol_http_header(void)
-{
-	if (get_protocol_version_config() > 0) {
-		struct strbuf protocol_header = STRBUF_INIT;
-
-		strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
-			    get_protocol_version_config());
-
-
-		extra_http_headers = curl_slist_append(extra_http_headers,
-						       protocol_header.buf);
-		strbuf_release(&protocol_header);
-	}
-}
-
 void http_init(struct remote *remote, const char *url, int proactive_auth)
 {
 	char *low_speed_limit;
@@ -949,8 +934,6 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 	if (remote)
 		var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 
-	protocol_http_header();
-
 	pragma_header = curl_slist_append(http_copy_default_headers(),
 		"Pragma: no-cache");
 	no_pragma_header = curl_slist_append(http_copy_default_headers(),
remote-curl.c +33 -0
index c540358438..b4e9db85bb 100644
@@ -291,6 +291,19 @@ static int show_http_message(struct strbuf *type, struct strbuf *charset,
 	return 0;
 }
 
+static int get_protocol_http_header(enum protocol_version version,
+				    struct strbuf *header)
+{
+	if (version > 0) {
+		strbuf_addf(header, GIT_PROTOCOL_HEADER ": version=%d",
+			    version);
+
+		return 1;
+	}
+
+	return 0;
+}
+
 static struct discovery *discover_refs(const char *service, int for_push)
 {
 	struct strbuf exp = STRBUF_INIT;
@@ -299,6 +312,8 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	struct strbuf buffer = STRBUF_INIT;
 	struct strbuf refs_url = STRBUF_INIT;
 	struct strbuf effective_url = STRBUF_INIT;
+	struct strbuf protocol_header = STRBUF_INIT;
+	struct string_list extra_headers = STRING_LIST_INIT_DUP;
 	struct discovery *last = last_discovery;
 	int http_ret, maybe_smart = 0;
 	struct http_get_options http_options;
@@ -318,11 +333,16 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		strbuf_addf(&refs_url, "service=%s", service);
 	}
 
+	/* Add the extra Git-Protocol header */
+	if (get_protocol_http_header(get_protocol_version_config(), &protocol_header))
+		string_list_append(&extra_headers, protocol_header.buf);
+
 	memset(&http_options, 0, sizeof(http_options));
 	http_options.content_type = &type;
 	http_options.charset = &charset;
 	http_options.effective_url = &effective_url;
 	http_options.base_url = &url;
+	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
 	http_options.keep_error = 1;
@@ -389,6 +409,8 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	strbuf_release(&charset);
 	strbuf_release(&effective_url);
 	strbuf_release(&buffer);
+	strbuf_release(&protocol_header);
+	string_list_clear(&extra_headers, 0);
 	last_discovery = last;
 	return last;
 }
@@ -425,6 +447,7 @@ struct rpc_state {
 	char *service_url;
 	char *hdr_content_type;
 	char *hdr_accept;
+	char *protocol_header;
 	char *buf;
 	size_t alloc;
 	size_t len;
@@ -611,6 +634,10 @@ static int post_rpc(struct rpc_state *rpc)
 	headers = curl_slist_append(headers, needs_100_continue ?
 		"Expect: 100-continue" : "Expect:");
 
+	/* Add the extra Git-Protocol header */
+	if (rpc->protocol_header)
+		headers = curl_slist_append(headers, rpc->protocol_header);
+
 retry:
 	slot = get_active_slot();
 
@@ -751,6 +778,11 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 	strbuf_addf(&buf, "Accept: application/x-%s-result", svc);
 	rpc->hdr_accept = strbuf_detach(&buf, NULL);
 
+	if (get_protocol_http_header(heads->version, &buf))
+		rpc->protocol_header = strbuf_detach(&buf, NULL);
+	else
+		rpc->protocol_header = NULL;
+
 	while (!err) {
 		int n = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
 		if (!n)
@@ -778,6 +810,7 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 	free(rpc->service_url);
 	free(rpc->hdr_content_type);
 	free(rpc->hdr_accept);
+	free(rpc->protocol_header);
 	free(rpc->buf);
 	strbuf_release(&buf);
 	return err;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#38 lore raw

PATCH v5 33/35 http: eliminate "# service" line when using protocol v2

In reply to Brandon Williams

When an http info/refs request is made, requesting that protocol v2 be used, don't send a "# service" line since this line is not part of the v2 spec.

---
 http-backend.c | 8 ++++++--
 remote-curl.c  | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)
http-backend.c +6 -2
index f3dc218b2a..5d241e9109 100644
@@ -10,6 +10,7 @@
 #include "url.h"
 #include "argv-array.h"
 #include "packfile.h"
+#include "protocol.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
@@ -466,8 +467,11 @@ static void get_info_refs(struct strbuf *hdr, char *arg)
 		hdr_str(hdr, content_type, buf.buf);
 		end_headers(hdr);
 
-		packet_write_fmt(1, "# service=git-%s\n", svc->name);
-		packet_flush(1);
+
+		if (determine_protocol_version_server() != protocol_v2) {
+			packet_write_fmt(1, "# service=git-%s\n", svc->name);
+			packet_flush(1);
+		}
 
 		argv[0] = svc->name;
 		run_service(argv, 0);
remote-curl.c +3 -0
index b4e9db85bb..66a53f74bb 100644
@@ -396,6 +396,9 @@ static struct discovery *discover_refs(const char *service, int for_push)
 			;
 
 		last->proto_git = 1;
+	} else if (maybe_smart &&
+		   last->len > 5 && starts_with(last->buf + 4, "version 2")) {
+		last->proto_git = 1;
 	}
 
 	if (last->proto_git)
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#39 lore raw

PATCH v5 34/35 remote-curl: implement stateless-connect command

In reply to Brandon Williams

Teach remote-curl the 'stateless-connect' command which is used to establish a stateless connection with servers which support protocol version 2. This allows remote-curl to act as a proxy, allowing the git client to communicate natively with a remote end, simply using remote-curl as a pass through to convert requests to http.

---
 remote-curl.c          | 207 ++++++++++++++++++++++++++++++++++++++++-
 t/t5702-protocol-v2.sh |  45 +++++++++
 2 files changed, 251 insertions(+), 1 deletion(-)
remote-curl.c +206 -1
index 66a53f74bb..87f5b77b29 100644
@@ -188,7 +188,12 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 	heads->version = discover_version(&reader);
 	switch (heads->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		/*
+		 * Do nothing.  This isn't a list of refs but rather a
+		 * capability advertisement.  Client would have run
+		 * 'stateless-connect' so we'll dump this capability listing
+		 * and let them request the refs themselves.
+		 */
 		break;
 	case protocol_v1:
 	case protocol_v0:
@@ -1085,6 +1090,202 @@ static void parse_push(struct strbuf *buf)
 	free(specs);
 }
 
+/*
+ * Used to represent the state of a connection to an HTTP server when
+ * communicating using git's wire-protocol version 2.
+ */
+struct proxy_state {
+	char *service_name;
+	char *service_url;
+	struct curl_slist *headers;
+	struct strbuf request_buffer;
+	int in;
+	int out;
+	struct packet_reader reader;
+	size_t pos;
+	int seen_flush;
+};
+
+static void proxy_state_init(struct proxy_state *p, const char *service_name,
+			     enum protocol_version version)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	memset(p, 0, sizeof(*p));
+	p->service_name = xstrdup(service_name);
+
+	p->in = 0;
+	p->out = 1;
+	strbuf_init(&p->request_buffer, 0);
+
+	strbuf_addf(&buf, "%s%s", url.buf, p->service_name);
+	p->service_url = strbuf_detach(&buf, NULL);
+
+	p->headers = http_copy_default_headers();
+
+	strbuf_addf(&buf, "Content-Type: application/x-%s-request", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	strbuf_addf(&buf, "Accept: application/x-%s-result", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	p->headers = curl_slist_append(p->headers, "Transfer-Encoding: chunked");
+
+	/* Add the Git-Protocol header */
+	if (get_protocol_http_header(version, &buf))
+		p->headers = curl_slist_append(p->headers, buf.buf);
+
+	packet_reader_init(&p->reader, p->in, NULL, 0,
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	strbuf_release(&buf);
+}
+
+static void proxy_state_clear(struct proxy_state *p)
+{
+	free(p->service_name);
+	free(p->service_url);
+	curl_slist_free_all(p->headers);
+	strbuf_release(&p->request_buffer);
+}
+
+/*
+ * CURLOPT_READFUNCTION callback function.
+ * Attempts to copy over a single packet-line at a time into the
+ * curl provided buffer.
+ */
+static size_t proxy_in(char *buffer, size_t eltsize,
+		       size_t nmemb, void *userdata)
+{
+	size_t max;
+	struct proxy_state *p = userdata;
+	size_t avail = p->request_buffer.len - p->pos;
+
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	max = nmemb;
+
+	if (!avail) {
+		if (p->seen_flush) {
+			p->seen_flush = 0;
+			return 0;
+		}
+
+		strbuf_reset(&p->request_buffer);
+		switch (packet_reader_read(&p->reader)) {
+		case PACKET_READ_EOF:
+			die("unexpected EOF when reading from parent process");
+		case PACKET_READ_NORMAL:
+			packet_buf_write_len(&p->request_buffer, p->reader.line,
+					     p->reader.pktlen);
+			break;
+		case PACKET_READ_DELIM:
+			packet_buf_delim(&p->request_buffer);
+			break;
+		case PACKET_READ_FLUSH:
+			packet_buf_flush(&p->request_buffer);
+			p->seen_flush = 1;
+			break;
+		}
+		p->pos = 0;
+		avail = p->request_buffer.len;
+	}
+
+	if (max < avail)
+		avail = max;
+	memcpy(buffer, p->request_buffer.buf + p->pos, avail);
+	p->pos += avail;
+	return avail;
+}
+
+static size_t proxy_out(char *buffer, size_t eltsize,
+			size_t nmemb, void *userdata)
+{
+	size_t size;
+	struct proxy_state *p = userdata;
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	size = nmemb;
+
+	write_or_die(p->out, buffer, size);
+	return size;
+}
+
+/* Issues a request to the HTTP server configured in `p` */
+static int proxy_request(struct proxy_state *p)
+{
+	struct active_request_slot *slot;
+
+	slot = get_active_slot();
+
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, p->service_url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, p->headers);
+
+	/* Setup function to read request from client */
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, proxy_in);
+	curl_easy_setopt(slot->curl, CURLOPT_READDATA, p);
+
+	/* Setup function to write server response to client */
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, proxy_out);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, p);
+
+	if (run_slot(slot, NULL) != HTTP_OK)
+		return -1;
+
+	return 0;
+}
+
+static int stateless_connect(const char *service_name)
+{
+	struct discovery *discover;
+	struct proxy_state p;
+
+	/*
+	 * Run the info/refs request and see if the server supports protocol
+	 * v2.  If and only if the server supports v2 can we successfully
+	 * establish a stateless connection, otherwise we need to tell the
+	 * client to fallback to using other transport helper functions to
+	 * complete their request.
+	 */
+	discover = discover_refs(service_name, 0);
+	if (discover->version != protocol_v2) {
+		printf("fallback\n");
+		fflush(stdout);
+		return -1;
+	} else {
+		/* Stateless Connection established */
+		printf("\n");
+		fflush(stdout);
+	}
+
+	proxy_state_init(&p, service_name, discover->version);
+
+	/*
+	 * Dump the capability listing that we got from the server earlier
+	 * during the info/refs request.
+	 */
+	write_or_die(p.out, discover->buf, discover->len);
+
+	/* Peek the next packet line.  Until we see EOF keep sending POSTs */
+	while (packet_reader_peek(&p.reader) != PACKET_READ_EOF) {
+		if (proxy_request(&p)) {
+			/* We would have an err here */
+			break;
+		}
+	}
+
+	proxy_state_clear(&p);
+	return 0;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -1153,12 +1354,16 @@ int cmd_main(int argc, const char **argv)
 			fflush(stdout);
 
 		} else if (!strcmp(buf.buf, "capabilities")) {
+			printf("stateless-connect\n");
 			printf("fetch\n");
 			printf("option\n");
 			printf("push\n");
 			printf("check-connectivity\n");
 			printf("\n");
 			fflush(stdout);
+		} else if (skip_prefix(buf.buf, "stateless-connect ", &arg)) {
+			if (!stateless_connect(arg))
+				break;
 		} else {
 			error("remote-curl: unknown command '%s' from git", buf.buf);
 			return 1;
t/t5702-protocol-v2.sh +45 -0

49 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#40 lore raw

PATCH v5 35/35 remote-curl: don't request v2 when pushing

In reply to Brandon Williams

In order to be able to ship protocol v2 with only supporting fetch, we need clients to not issue a request to use protocol v2 when pushing (since the client currently doesn't know how to push using protocol v2). This allows a client to have protocol v2 configured in protocol.version and take advantage of using v2 for fetch and falling back to using v0 when pushing while v2 for push is being designed.

We could run into issues if we didn't fall back to protocol v2 when pushing right now. This is because currently a server will ignore a request to use v2 when contacting the 'receive-pack' endpoint and fall back to using v0, but when push v2 is rolled out to servers, the 'receive-pack' endpoint will start responding using v2. So we don't want to get into a state where a client is requesting to push with v2 before they actually know how to push using v2.

---
 remote-curl.c          | 11 ++++++++++-
 t/t5702-protocol-v2.sh | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)
remote-curl.c +10 -1
index 87f5b77b29..595447b16e 100644
@@ -322,6 +322,7 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	struct discovery *last = last_discovery;
 	int http_ret, maybe_smart = 0;
 	struct http_get_options http_options;
+	enum protocol_version version = get_protocol_version_config();
 
 	if (last && !strcmp(service, last->service))
 		return last;
@@ -338,8 +339,16 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		strbuf_addf(&refs_url, "service=%s", service);
 	}
 
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", service))
+		version = protocol_v0;
+
 	/* Add the extra Git-Protocol header */
-	if (get_protocol_http_header(get_protocol_version_config(), &protocol_header))
+	if (get_protocol_http_header(version, &protocol_header))
 		string_list_append(&extra_headers, protocol_header.buf);
 
 	memset(&http_options, 0, sizeof(http_options));
t/t5702-protocol-v2.sh +24 -0
index 124063c2c4..56f7c3c326 100755
@@ -244,6 +244,30 @@ test_expect_success 'fetch with http:// using protocol v2' '
 	grep "git< version 2" log
 '
 
+test_expect_success 'push with http:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C http_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C http_child log -1 --format=%s >actual &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client didnt request to use protocol v2
+	! grep "Git-Protocol: version=2" log &&
+	# Server didnt respond using protocol v2
+	! grep "git< version 2" log
+'
+
+
 stop_httpd
 
 test_done
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#41 lore raw

v6 cover protocol version 2

In reply to Brandon Williams

Fixed the protocol-v2.txt technical document so that it builds when running "make doc".

Brandon Williams (35):
pkt-line: introduce packet_read_with_status
pkt-line: allow peeking a packet line without consuming it
pkt-line: add delim packet support
upload-pack: convert to a builtin
upload-pack: factor out processing lines
transport: use get_refs_via_connect to get refs
connect: convert get_remote_heads to use struct packet_reader
connect: discover protocol version outside of get_remote_heads
transport: store protocol version
protocol: introduce enum protocol_version value protocol_v2
test-pkt-line: introduce a packet-line test helper
serve: introduce git-serve
ls-refs: introduce ls-refs server command
connect: request remote refs using v2
transport: convert get_refs_list to take a list of ref prefixes
transport: convert transport_get_remote_refs to take a list of ref
prefixes
ls-remote: pass ref prefixes when requesting a remote's refs
fetch: pass ref prefixes when fetching
push: pass ref prefixes when pushing
upload-pack: introduce fetch server command
fetch-pack: perform a fetch using v2
fetch-pack: support shallow requests
connect: refactor git_connect to only get the protocol version once
connect: don't request v2 when pushing
transport-helper: remove name parameter
transport-helper: refactor process_connect_service
transport-helper: introduce stateless-connect
pkt-line: add packet_buf_write_len function
remote-curl: create copy of the service name
remote-curl: store the protocol version the server responded with
http: allow providing extra headers for http requests
http: don't always add Git-Protocol header
http: eliminate "# service" line when using protocol v2
remote-curl: implement stateless-connect command
remote-curl: don't request v2 when pushing

 .gitignore                              |   1 +
 Documentation/Makefile                  |   1 +
 Documentation/gitremote-helpers.txt     |  32 ++
 Documentation/technical/protocol-v2.txt | 395 +++++++++++++++
 Makefile                                |   7 +-
 builtin.h                               |   2 +
 builtin/clone.c                         |   2 +-
 builtin/fetch-pack.c                    |  20 +-
 builtin/fetch.c                         |  21 +-
 builtin/ls-remote.c                     |  15 +-
 builtin/receive-pack.c                  |   6 +
 builtin/remote.c                        |   2 +-
 builtin/send-pack.c                     |  20 +-
 builtin/serve.c                         |  30 ++
 builtin/upload-pack.c                   |  74 +++
 connect.c                               | 364 ++++++++++----
 connect.h                               |   7 +
 fetch-pack.c                            | 339 ++++++++++++-
 fetch-pack.h                            |   4 +-
 git.c                                   |   2 +
 http-backend.c                          |   8 +-
 http.c                                  |  25 +-
 http.h                                  |   7 +
 ls-refs.c                               |  96 ++++
 ls-refs.h                               |  10 +
 pkt-line.c                              | 133 ++++-
 pkt-line.h                              |  78 +++
 protocol.c                              |   2 +
 protocol.h                              |   1 +
 refs.c                                  |  14 +
 refs.h                                  |   7 +
 remote-curl.c                           | 280 ++++++++++-
 remote.h                                |  11 +-
 serve.c                                 | 257 ++++++++++
 serve.h                                 |  15 +
 t/helper/test-pkt-line.c                |  64 +++
 t/t5701-git-serve.sh                    | 176 +++++++
 t/t5702-protocol-v2.sh                  | 273 +++++++++++
 transport-helper.c                      |  87 ++--
 transport-internal.h                    |  11 +-
 transport.c                             | 130 +++--
 transport.h                             |  18 +-
 upload-pack.c                           | 615 ++++++++++++++++++------
 upload-pack.h                           |  23 +
 44 files changed, 3317 insertions(+), 368 deletions(-)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 builtin/upload-pack.c
 create mode 100644 ls-refs.c
 create mode 100644 ls-refs.h
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100644 t/helper/test-pkt-line.c
 create mode 100755 t/t5701-git-serve.sh
 create mode 100755 t/t5702-protocol-v2.sh
 create mode 100644 upload-pack.h

base-commit: 5be1f00a9a701532232f57958efab4be8c959a29

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#42 lore raw

PATCH v6 1/35 pkt-line: introduce packet_read_with_status

The current pkt-line API encodes the status of a pkt-line read in the length of the read content. An error is indicated with '-1', a flush with '0' (which can be confusing since a return value of '0' can also indicate an empty pkt-line), and a positive integer for the length of the read content otherwise. This doesn't leave much room for allowing the addition of additional special packets in the future.

To solve this introduce 'packet_read_with_status()' which reads a packet and returns the status of the read encoded as an 'enum packet_status' type. This allows for easily identifying between special and normal packets as well as errors. It also enables easily adding a new special packet in the future.

---
 pkt-line.c | 51 +++++++++++++++++++++++++++++++++++++--------------
 pkt-line.h | 16 ++++++++++++++++
 2 files changed, 53 insertions(+), 14 deletions(-)
pkt-line.c +37 -14
index 2827ca772a..db2fb29ac3 100644
@@ -280,28 +280,39 @@ static int packet_length(const char *linelen)
 	return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 }
 
-int packet_read(int fd, char **src_buf, size_t *src_len,
-		char *buffer, unsigned size, int options)
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options)
 {
-	int len, ret;
+	int len;
 	char linelen[4];
 
-	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
-	if (ret < 0)
-		return ret;
+	if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
+	}
+
 	len = packet_length(linelen);
-	if (len < 0)
+
+	if (len < 0) {
 		die("protocol error: bad line length character: %.4s", linelen);
-	if (!len) {
+	} else if (!len) {
 		packet_trace("0000", 4, 0);
-		return 0;
+		*pktlen = 0;
+		return PACKET_READ_FLUSH;
+	} else if (len < 4) {
+		die("protocol error: bad line length %d", len);
 	}
+
 	len -= 4;
-	if (len >= size)
+	if ((unsigned)len >= size)
 		die("protocol error: bad line length %d", len);
-	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
-	if (ret < 0)
-		return ret;
+
+	if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
+		*pktlen = -1;
+		return PACKET_READ_EOF;
+	}
 
 	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 	    len && buffer[len-1] == '\n')
@@ -309,7 +320,19 @@ int packet_read(int fd, char **src_buf, size_t *src_len,
 
 	buffer[len] = 0;
 	packet_trace(buffer, len, 0);
-	return len;
+	*pktlen = len;
+	return PACKET_READ_NORMAL;
+}
+
+int packet_read(int fd, char **src_buffer, size_t *src_len,
+		char *buffer, unsigned size, int options)
+{
+	int pktlen = -1;
+
+	packet_read_with_status(fd, src_buffer, src_len, buffer, size,
+				&pktlen, options);
+
+	return pktlen;
 }
 
 static char *packet_read_line_generic(int fd,
pkt-line.h +16 -0
index 3dad583e2d..099b26b95f 100644
@@ -65,6 +65,22 @@ int write_packetized_from_buf(const char *src_in, size_t len, int fd_out);
 int packet_read(int fd, char **src_buffer, size_t *src_len, char
 		*buffer, unsigned size, int options);
 
+/*
+ * Read a packetized line into a buffer like the 'packet_read()' function but
+ * returns an 'enum packet_read_status' which indicates the status of the read.
+ * The number of bytes read will be assigined to *pktlen if the status of the
+ * read was 'PACKET_READ_NORMAL'.
+ */
+enum packet_read_status {
+	PACKET_READ_EOF,
+	PACKET_READ_NORMAL,
+	PACKET_READ_FLUSH,
+};
+enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
+						size_t *src_len, char *buffer,
+						unsigned size, int *pktlen,
+						int options);
+
 /*
  * Convenience wrapper for packet_read that is not gentle, and sets the
  * CHOMP_NEWLINE option. The return value is NULL for a flush packet,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#43 lore raw

PATCH v6 2/35 pkt-line: allow peeking a packet line without consuming it

In reply to Brandon Williams

Sometimes it is advantageous to be able to peek the next packet line without consuming it (e.g. to be able to determine the protocol version a server is speaking). In order to do that introduce 'struct packet_reader' which is an abstraction around the normal packet reading logic. This enables a caller to be able to peek a single line at a time using 'packet_reader_peek()' and having a caller consume a line by calling 'packet_reader_read()'.

---
 pkt-line.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 pkt-line.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+)
pkt-line.c +50 -0
index db2fb29ac3..1881dc8813 100644
@@ -400,3 +400,53 @@ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
 	}
 	return sb_out->len - orig_len;
 }
+
+/* Packet Reader Functions */
+void packet_reader_init(struct packet_reader *reader, int fd,
+			char *src_buffer, size_t src_len,
+			int options)
+{
+	memset(reader, 0, sizeof(*reader));
+
+	reader->fd = fd;
+	reader->src_buffer = src_buffer;
+	reader->src_len = src_len;
+	reader->buffer = packet_buffer;
+	reader->buffer_size = sizeof(packet_buffer);
+	reader->options = options;
+}
+
+enum packet_read_status packet_reader_read(struct packet_reader *reader)
+{
+	if (reader->line_peeked) {
+		reader->line_peeked = 0;
+		return reader->status;
+	}
+
+	reader->status = packet_read_with_status(reader->fd,
+						 &reader->src_buffer,
+						 &reader->src_len,
+						 reader->buffer,
+						 reader->buffer_size,
+						 &reader->pktlen,
+						 reader->options);
+
+	if (reader->status == PACKET_READ_NORMAL)
+		reader->line = reader->buffer;
+	else
+		reader->line = NULL;
+
+	return reader->status;
+}
+
+enum packet_read_status packet_reader_peek(struct packet_reader *reader)
+{
+	/* Only allow peeking a single line */
+	if (reader->line_peeked)
+		return reader->status;
+
+	/* Peek a line by reading it and setting peeked flag */
+	packet_reader_read(reader);
+	reader->line_peeked = 1;
+	return reader->status;
+}
pkt-line.h +58 -0

64 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#44 lore raw

PATCH v6 3/35 pkt-line: add delim packet support

In reply to Brandon Williams

One of the design goals of protocol-v2 is to improve the semantics of flush packets. Currently in protocol-v1, flush packets are used both to indicate a break in a list of packet lines as well as an indication that one side has finished speaking. This makes it particularly difficult to implement proxies as a proxy would need to completely understand git protocol instead of simply looking for a flush packet.

To do this, introduce the special deliminator packet '0001'. A delim packet can then be used as a deliminator between lists of packet lines while flush packets can be reserved to indicate the end of a response.

Documentation for how this packet will be used in protocol v2 will included in a future patch.

---
 pkt-line.c | 16 ++++++++++++++++
 pkt-line.h |  3 +++
 2 files changed, 19 insertions(+)
pkt-line.c +16 -0
index 1881dc8813..7296731cf3 100644
@@ -91,6 +91,12 @@ void packet_flush(int fd)
 	write_or_die(fd, "0000", 4);
 }
 
+void packet_delim(int fd)
+{
+	packet_trace("0001", 4, 1);
+	write_or_die(fd, "0001", 4);
+}
+
 int packet_flush_gently(int fd)
 {
 	packet_trace("0000", 4, 1);
@@ -105,6 +111,12 @@ void packet_buf_flush(struct strbuf *buf)
 	strbuf_add(buf, "0000", 4);
 }
 
+void packet_buf_delim(struct strbuf *buf)
+{
+	packet_trace("0001", 4, 1);
+	strbuf_add(buf, "0001", 4);
+}
+
 static void set_packet_header(char *buf, const int size)
 {
 	static char hexchar[] = "0123456789abcdef";
@@ -301,6 +313,10 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 		packet_trace("0000", 4, 0);
 		*pktlen = 0;
 		return PACKET_READ_FLUSH;
+	} else if (len == 1) {
+		packet_trace("0001", 4, 0);
+		*pktlen = 0;
+		return PACKET_READ_DELIM;
 	} else if (len < 4) {
 		die("protocol error: bad line length %d", len);
 	}
pkt-line.h +3 -0
index 11b04f026f..9570bd7a0a 100644
@@ -20,8 +20,10 @@
  * side can't, we stay with pure read/write interfaces.
  */
 void packet_flush(int fd);
+void packet_delim(int fd);
 void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 void packet_buf_flush(struct strbuf *buf);
+void packet_buf_delim(struct strbuf *buf);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int packet_flush_gently(int fd);
@@ -75,6 +77,7 @@ enum packet_read_status {
 	PACKET_READ_EOF,
 	PACKET_READ_NORMAL,
 	PACKET_READ_FLUSH,
+	PACKET_READ_DELIM,
 };
 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 						size_t *src_len, char *buffer,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#45 lore raw

PATCH v6 4/35 upload-pack: convert to a builtin

In reply to Brandon Williams

In order to allow for code sharing with the server-side of fetch in protocol-v2 convert upload-pack to be a builtin.

---
 Makefile              |   3 +-
 builtin.h             |   1 +
 builtin/upload-pack.c |  67 ++++++++++++++++++++++++++
 git.c                 |   1 +
 upload-pack.c         | 107 ++++++++++--------------------------------
 upload-pack.h         |  13 +++++
 6 files changed, 109 insertions(+), 83 deletions(-)
 create mode 100644 builtin/upload-pack.c
 create mode 100644 upload-pack.h
Makefile +2 -1
index 1a9b23b679..b7ccc05fac 100644
@@ -639,7 +639,6 @@ PROGRAM_OBJS += imap-send.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
 PROGRAM_OBJS += show-index.o
-PROGRAM_OBJS += upload-pack.o
 PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
@@ -909,6 +908,7 @@ LIB_OBJS += tree-diff.o
 LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
 LIB_OBJS += unpack-trees.o
+LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
 LIB_OBJS += urlmatch.o
 LIB_OBJS += usage.o
@@ -1026,6 +1026,7 @@ BUILTIN_OBJS += builtin/update-index.o
 BUILTIN_OBJS += builtin/update-ref.o
 BUILTIN_OBJS += builtin/update-server-info.o
 BUILTIN_OBJS += builtin/upload-archive.o
+BUILTIN_OBJS += builtin/upload-pack.o
 BUILTIN_OBJS += builtin/var.o
 BUILTIN_OBJS += builtin/verify-commit.o
 BUILTIN_OBJS += builtin/verify-pack.o
builtin.h +1 -0
index 42378f3aa4..f332a12574 100644
@@ -231,6 +231,7 @@ extern int cmd_update_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_update_server_info(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive(int argc, const char **argv, const char *prefix);
 extern int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix);
+extern int cmd_upload_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_var(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_commit(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_tag(int argc, const char **argv, const char *prefix);
builtin/upload-pack.c new file +67 -0

67 lines not on this page · raw message

git.c +1 -0
index c870b9719c..f71073dc8d 100644
@@ -478,6 +478,7 @@ static struct cmd_struct commands[] = {
 	{ "update-server-info", cmd_update_server_info, RUN_SETUP },
 	{ "upload-archive", cmd_upload_archive },
 	{ "upload-archive--writer", cmd_upload_archive_writer },
+	{ "upload-pack", cmd_upload_pack },
 	{ "var", cmd_var, RUN_SETUP_GENTLY },
 	{ "verify-commit", cmd_verify_commit, RUN_SETUP },
 	{ "verify-pack", cmd_verify_pack },
upload-pack.c +25 -82

145 lines not on this page · raw message

upload-pack.h new file +13 -0
new file mode 100644
index 0000000000..a71e4dc7e2
@@ -0,0 +1,13 @@
+#ifndef UPLOAD_PACK_H
+#define UPLOAD_PACK_H
+
+struct upload_pack_options {
+	int stateless_rpc;
+	int advertise_refs;
+	unsigned int timeout;
+	int daemon_mode;
+};
+
+void upload_pack(struct upload_pack_options *options);
+
+#endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#46 lore raw

PATCH v6 5/35 upload-pack: factor out processing lines

In reply to Brandon Williams

Factor out the logic for processing shallow, deepen, deepen_since, and deepen_not lines into their own functions to simplify the 'receive_needs()' function in addition to making it easier to reuse some of this logic when implementing protocol_v2.

---
 upload-pack.c | 113 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 74 insertions(+), 39 deletions(-)
upload-pack.c +74 -39
index 2ad73a98b1..1e8a9e1caf 100644
@@ -724,6 +724,75 @@ static void deepen_by_rev_list(int ac, const char **av,
 	packet_flush(1);
 }
 
+static int process_shallow(const char *line, struct object_array *shallows)
+{
+	const char *arg;
+	if (skip_prefix(line, "shallow ", &arg)) {
+		struct object_id oid;
+		struct object *object;
+		if (get_oid_hex(arg, &oid))
+			die("invalid shallow line: %s", line);
+		object = parse_object(&oid);
+		if (!object)
+			return 1;
+		if (object->type != OBJ_COMMIT)
+			die("invalid shallow object %s", oid_to_hex(&oid));
+		if (!(object->flags & CLIENT_SHALLOW)) {
+			object->flags |= CLIENT_SHALLOW;
+			add_object_array(object, NULL, shallows);
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen(const char *line, int *depth)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen ", &arg)) {
+		char *end = NULL;
+		*depth = (int)strtol(arg, &end, 0);
+		if (!end || *end || *depth <= 0)
+			die("Invalid deepen: %s", line);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int process_deepen_since(const char *line, timestamp_t *deepen_since, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-since ", &arg)) {
+		char *end = NULL;
+		*deepen_since = parse_timestamp(arg, &end, 0);
+		if (!end || *end || !deepen_since ||
+		    /* revisions.c's max_age -1 is special */
+		    *deepen_since == -1)
+			die("Invalid deepen-since: %s", line);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
+}
+
+static int process_deepen_not(const char *line, struct string_list *deepen_not, int *deepen_rev_list)
+{
+	const char *arg;
+	if (skip_prefix(line, "deepen-not ", &arg)) {
+		char *ref = NULL;
+		struct object_id oid;
+		if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
+			die("git upload-pack: ambiguous deepen-not: %s", line);
+		string_list_append(deepen_not, ref);
+		free(ref);
+		*deepen_rev_list = 1;
+		return 1;
+	}
+	return 0;
+}
+
 static void receive_needs(void)
 {
 	struct object_array shallows = OBJECT_ARRAY_INIT;
@@ -745,49 +814,15 @@ static void receive_needs(void)
 		if (!line)
 			break;
 
-		if (skip_prefix(line, "shallow ", &arg)) {
-			struct object_id oid;
-			struct object *object;
-			if (get_oid_hex(arg, &oid))
-				die("invalid shallow line: %s", line);
-			object = parse_object(&oid);
-			if (!object)
-				continue;
-			if (object->type != OBJ_COMMIT)
-				die("invalid shallow object %s", oid_to_hex(&oid));
-			if (!(object->flags & CLIENT_SHALLOW)) {
-				object->flags |= CLIENT_SHALLOW;
-				add_object_array(object, NULL, &shallows);
-			}
+		if (process_shallow(line, &shallows))
 			continue;
-		}
-		if (skip_prefix(line, "deepen ", &arg)) {
-			char *end = NULL;
-			depth = strtol(arg, &end, 0);
-			if (!end || *end || depth <= 0)
-				die("Invalid deepen: %s", line);
+		if (process_deepen(line, &depth))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-since ", &arg)) {
-			char *end = NULL;
-			deepen_since = parse_timestamp(arg, &end, 0);
-			if (!end || *end || !deepen_since ||
-			    /* revisions.c's max_age -1 is special */
-			    deepen_since == -1)
-				die("Invalid deepen-since: %s", line);
-			deepen_rev_list = 1;
+		if (process_deepen_since(line, &deepen_since, &deepen_rev_list))
 			continue;
-		}
-		if (skip_prefix(line, "deepen-not ", &arg)) {
-			char *ref = NULL;
-			struct object_id oid;
-			if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
-				die("git upload-pack: ambiguous deepen-not: %s", line);
-			string_list_append(&deepen_not, ref);
-			free(ref);
-			deepen_rev_list = 1;
+		if (process_deepen_not(line, &deepen_not, &deepen_rev_list))
 			continue;
-		}
+
 		if (!skip_prefix(line, "want ", &arg) ||
 		    get_oid_hex(arg, &oid_buf))
 			die("git upload-pack: protocol error, "
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#47 lore raw

PATCH v6 6/35 transport: use get_refs_via_connect to get refs

In reply to Brandon Williams

Remove code duplication and use the existing 'get_refs_via_connect()' function to retrieve a remote's heads in 'fetch_refs_via_pack()' and 'git_transport_push()'.

---
 transport.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)
transport.c +4 -14
index fc802260f6..8e87790962 100644
@@ -230,12 +230,8 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
 
-	if (!data->got_remote_heads) {
-		connect_setup(transport, 0);
-		get_remote_heads(data->fd[0], NULL, 0, &refs_tmp, 0,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
-	}
+	if (!data->got_remote_heads)
+		refs_tmp = get_refs_via_connect(transport, 0);
 
 	refs = fetch_pack(&args, data->fd, data->conn,
 			  refs_tmp ? refs_tmp : transport->remote_refs,
@@ -541,14 +537,8 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	struct send_pack_args args;
 	int ret;
 
-	if (!data->got_remote_heads) {
-		struct ref *tmp_refs;
-		connect_setup(transport, 1);
-
-		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL,
-				 NULL, &data->shallow);
-		data->got_remote_heads = 1;
-	}
+	if (!data->got_remote_heads)
+		get_refs_via_connect(transport, 1);
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#48 lore raw

PATCH v6 7/35 connect: convert get_remote_heads to use struct packet_reader

In reply to Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced convert 'get_remote_heads()' to use 'struct packet_reader' to read packet lines. This enables a client to be able to peek the first line of a server's response (without consuming it) in order to determine the protocol version its speaking and then passing control to the appropriate handler.

This is needed because the initial response from a server speaking protocol_v0 includes the first ref, while subsequent protocol versions respond with a version line. We want to be able to read this first line without consuming the first ref sent in the protocol_v0 case so that the protocol version the server is speaking can be determined outside of 'get_remote_heads()' in a future patch.

---
 connect.c | 173 ++++++++++++++++++++++++++++++------------------------
 1 file changed, 95 insertions(+), 78 deletions(-)
connect.c +95 -78
index c3a014c5ba..c82c90b7c3 100644
@@ -48,6 +48,12 @@ int check_ref_type(const struct ref *ref, int flags)
 
 static void die_initial_contact(int unexpected)
 {
+	/*
+	 * A hang-up after seeing some response from the other end
+	 * means that it is unexpected, as we know the other end is
+	 * willing to talk to us.  A hang-up before seeing any
+	 * response does not necessarily mean an ACL problem, though.
+	 */
 	if (unexpected)
 		die(_("The remote end hung up upon initial contact"));
 	else
@@ -56,6 +62,40 @@ static void die_initial_contact(int unexpected)
 		      "and the repository exists."));
 }
 
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+	enum protocol_version version = protocol_unknown_version;
+
+	/*
+	 * Peek the first line of the server's response to
+	 * determine the protocol version the server is speaking.
+	 */
+	switch (packet_reader_peek(reader)) {
+	case PACKET_READ_EOF:
+		die_initial_contact(0);
+	case PACKET_READ_FLUSH:
+	case PACKET_READ_DELIM:
+		version = protocol_v0;
+		break;
+	case PACKET_READ_NORMAL:
+		version = determine_protocol_version_client(reader->line);
+		break;
+	}
+
+	switch (version) {
+	case protocol_v1:
+		/* Read the peeked version line */
+		packet_reader_read(reader);
+		break;
+	case protocol_v0:
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
+	return version;
+}
+
 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 {
 	char *sym, *target;
@@ -109,60 +149,21 @@ static void annotate_refs_with_symref_info(struct ref *ref)
 	string_list_clear(&symref, 0);
 }
 
-/*
- * Read one line of a server's ref advertisement into packet_buffer.
- */
-static int read_remote_ref(int in, char **src_buf, size_t *src_len,
-			   int *responded)
+static void process_capabilities(const char *line, int *len)
 {
-	int len = packet_read(in, src_buf, src_len,
-			      packet_buffer, sizeof(packet_buffer),
-			      PACKET_READ_GENTLE_ON_EOF |
-			      PACKET_READ_CHOMP_NEWLINE);
-	const char *arg;
-	if (len < 0)
-		die_initial_contact(*responded);
-	if (len > 4 && skip_prefix(packet_buffer, "ERR ", &arg))
-		die("remote error: %s", arg);
-
-	*responded = 1;
-
-	return len;
-}
-
-#define EXPECTING_PROTOCOL_VERSION 0
-#define EXPECTING_FIRST_REF 1
-#define EXPECTING_REF 2
-#define EXPECTING_SHALLOW 3
-
-/* Returns 1 if packet_buffer is a protocol version pkt-line, 0 otherwise. */
-static int process_protocol_version(void)
-{
-	switch (determine_protocol_version_client(packet_buffer)) {
-	case protocol_v1:
-		return 1;
-	case protocol_v0:
-		return 0;
-	default:
-		die("server is speaking an unknown protocol");
-	}
-}
-
-static void process_capabilities(int *len)
-{
-	int nul_location = strlen(packet_buffer);
+	int nul_location = strlen(line);
 	if (nul_location == *len)
 		return;
-	server_capabilities = xstrdup(packet_buffer + nul_location + 1);
+	server_capabilities = xstrdup(line + nul_location + 1);
 	*len = nul_location;
 }
 
-static int process_dummy_ref(void)
+static int process_dummy_ref(const char *line)
 {
 	struct object_id oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &oid, &name))
+	if (parse_oid_hex(line, &oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -171,20 +172,20 @@ static int process_dummy_ref(void)
 	return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 }
 
-static void check_no_capabilities(int len)
+static void check_no_capabilities(const char *line, int len)
 {
-	if (strlen(packet_buffer) != len)
+	if (strlen(line) != len)
 		warning("Ignoring capabilities after first line '%s'",
-			packet_buffer + strlen(packet_buffer));
+			line + strlen(line));
 }
 
-static int process_ref(int len, struct ref ***list, unsigned int flags,
-		       struct oid_array *extra_have)
+static int process_ref(const char *line, int len, struct ref ***list,
+		       unsigned int flags, struct oid_array *extra_have)
 {
 	struct object_id old_oid;
 	const char *name;
 
-	if (parse_oid_hex(packet_buffer, &old_oid, &name))
+	if (parse_oid_hex(line, &old_oid, &name))
 		return 0;
 	if (*name != ' ')
 		return 0;
@@ -200,16 +201,17 @@ static int process_ref(int len, struct ref ***list, unsigned int flags,
 		**list = ref;
 		*list = &ref->next;
 	}
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
-static int process_shallow(int len, struct oid_array *shallow_points)
+static int process_shallow(const char *line, int len,
+			   struct oid_array *shallow_points)
 {
 	const char *arg;
 	struct object_id old_oid;
 
-	if (!skip_prefix(packet_buffer, "shallow ", &arg))
+	if (!skip_prefix(line, "shallow ", &arg))
 		return 0;
 
 	if (get_oid_hex(arg, &old_oid))
@@ -217,10 +219,17 @@ static int process_shallow(int len, struct oid_array *shallow_points)
 	if (!shallow_points)
 		die("repository on the other end cannot be shallow");
 	oid_array_append(shallow_points, &old_oid);
-	check_no_capabilities(len);
+	check_no_capabilities(line, len);
 	return 1;
 }
 
+enum get_remote_heads_state {
+	EXPECTING_FIRST_REF = 0,
+	EXPECTING_REF,
+	EXPECTING_SHALLOW,
+	EXPECTING_DONE,
+};
+
 /*
  * Read all the refs from the other end
  */
@@ -230,47 +239,55 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 			      struct oid_array *shallow_points)
 {
 	struct ref **orig_list = list;
+	int len = 0;
+	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
+	struct packet_reader reader;
+	const char *arg;
 
-	/*
-	 * A hang-up after seeing some response from the other end
-	 * means that it is unexpected, as we know the other end is
-	 * willing to talk to us.  A hang-up before seeing any
-	 * response does not necessarily mean an ACL problem, though.
-	 */
-	int responded = 0;
-	int len;
-	int state = EXPECTING_PROTOCOL_VERSION;
+	packet_reader_init(&reader, in, src_buf, src_len,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	discover_version(&reader);
 
 	*list = NULL;
 
-	while ((len = read_remote_ref(in, &src_buf, &src_len, &responded))) {
+	while (state != EXPECTING_DONE) {
+		switch (packet_reader_read(&reader)) {
+		case PACKET_READ_EOF:
+			die_initial_contact(1);
+		case PACKET_READ_NORMAL:
+			len = reader.pktlen;
+			if (len > 4 && skip_prefix(reader.line, "ERR ", &arg))
+				die("remote error: %s", arg);
+			break;
+		case PACKET_READ_FLUSH:
+			state = EXPECTING_DONE;
+			break;
+		case PACKET_READ_DELIM:
+			die("invalid packet");
+		}
+
 		switch (state) {
-		case EXPECTING_PROTOCOL_VERSION:
-			if (process_protocol_version()) {
-				state = EXPECTING_FIRST_REF;
-				break;
-			}
-			state = EXPECTING_FIRST_REF;
-			/* fallthrough */
 		case EXPECTING_FIRST_REF:
-			process_capabilities(&len);
-			if (process_dummy_ref()) {
+			process_capabilities(reader.line, &len);
+			if (process_dummy_ref(reader.line)) {
 				state = EXPECTING_SHALLOW;
 				break;
 			}
 			state = EXPECTING_REF;
 			/* fallthrough */
 		case EXPECTING_REF:
-			if (process_ref(len, &list, flags, extra_have))
+			if (process_ref(reader.line, len, &list, flags, extra_have))
 				break;
 			state = EXPECTING_SHALLOW;
 			/* fallthrough */
 		case EXPECTING_SHALLOW:
-			if (process_shallow(len, shallow_points))
+			if (process_shallow(reader.line, len, shallow_points))
 				break;
-			die("protocol error: unexpected '%s'", packet_buffer);
-		default:
-			die("unexpected state %d", state);
+			die("protocol error: unexpected '%s'", reader.line);
+		case EXPECTING_DONE:
+			break;
 		}
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#49 lore raw

Re: [PATCH v6 07/35] connect: convert get_remote_heads to use struct packet_reader

Review

Quoted 13 lines · Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced

(quoted diff) +12 -0
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+	enum protocol_version version = protocol_unknown_version;
+
+	/*
+	 * Peek the first line of the server's response to
+	 * determine the protocol version the server is speaking.
+	 */
+	switch (packet_reader_peek(reader)) {
+	case PACKET_READ_EOF:
+		die_initial_contact(0);
+	case PACKET_READ_FLUSH:

gcc is dumb. When -Werror and -Wimplicit-fallthrough are enabled (on at least gcc 7.x), it fails to realize that this die_initial_contact() will not fall through (even though we do tell it about die() not returning, but I guess that involves more flow analysis to realize die_initial_contact is in the same boat).

Since -Wimplicit-fallthrough may be useful to spot bugs elsewhere and there are only two places in this series that tick it off, is it possible to squash in something like this? On the off chance that we fail horribly to die, "break;" would stop the wrong code from executing even more.

This covers another patch too, but you get the idea.

connect.c +2 -0
index 54971166ac..847bf2f7d6 100644
@@ -124,6 +124,7 @@ enum protocol_version discover_version(struct packet_reader *reader)
 	switch (packet_reader_peek(reader)) {
 	case PACKET_READ_EOF:
 		die_initial_contact(0);
+		break;
 	case PACKET_READ_FLUSH:
 	case PACKET_READ_DELIM:
 		version = protocol_v0;
@@ -303,6 +304,7 @@ struct ref **get_remote_heads(struct packet_reader *reader,
 		switch (packet_reader_read(reader)) {
 		case PACKET_READ_EOF:
 			die_initial_contact(1);
+			break;
 		case PACKET_READ_NORMAL:
 			len = reader->pktlen;
 			if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))

--
Duy

#50 lore raw

Re: [PATCH v6 07/35] connect: convert get_remote_heads to use struct packet_reader

Quoted 22 lines · Duy Nguyen

Review

Quoted 13 lines · Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced

(quoted diff) +12 -0
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+	enum protocol_version version = protocol_unknown_version;
+
+	/*
+	 * Peek the first line of the server's response to
+	 * determine the protocol version the server is speaking.
+	 */
+	switch (packet_reader_peek(reader)) {
+	case PACKET_READ_EOF:
+		die_initial_contact(0);
+	case PACKET_READ_FLUSH:

gcc is dumb. When -Werror and -Wimplicit-fallthrough are enabled (on at least gcc 7.x), it fails to realize that this die_initial_contact() will not fall through (even though we do tell it about die() not returning, but I guess that involves more flow analysis to realize die_initial_contact is in the same boat).
[...]

Review enum protocol_version discover_version(struct packet_reader *reader) · line 127

Quoted 4 lines
(quoted diff) +1 -0
@@ -124,6 +124,7 @@ enum protocol_version discover_version(struct packet_reader *reader)
 	switch (packet_reader_peek(reader)) {
 	case PACKET_READ_EOF:
 		die_initial_contact(0);
+		break;

Would it make sense just to annotate that function to help the flow analysis? Like:

connect.c +1 -1
index c3a014c5ba..49eca46462 100644
@@ -46,7 +46,7 @@ int check_ref_type(const struct ref *ref, int flags)
 	return check_ref(ref->name, flags);
 }
 
-static void die_initial_contact(int unexpected)
+static NORETURN void die_initial_contact(int unexpected)
 {
 	if (unexpected)
 		die(_("The remote end hung up upon initial contact"));

That should let the callers know what's going on, and inside the function itself, the compiler should confirm that all code paths hit another NORETURN function.

-Peff

#51 lore raw

Re: [PATCH v6 07/35] connect: convert get_remote_heads to use struct packet_reader

Quoted 23 lines · Jeff King
Quoted 21 lines · Duy Nguyen

Review

Quoted 13 lines · Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced

(quoted diff) +12 -0
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+   enum protocol_version version = protocol_unknown_version;
+
+   /*
+    * Peek the first line of the server's response to
+    * determine the protocol version the server is speaking.
+    */
+   switch (packet_reader_peek(reader)) {
+   case PACKET_READ_EOF:
+           die_initial_contact(0);
+   case PACKET_READ_FLUSH:

gcc is dumb. When -Werror and -Wimplicit-fallthrough are enabled (on at least gcc 7.x), it fails to realize that this die_initial_contact() will not fall through (even though we do tell it about die() not returning, but I guess that involves more flow analysis to realize die_initial_contact is in the same boat).
[...]

Quoted 8 lines

Review enum protocol_version discover_version(struct packet_reader *reader) · line 127

Quoted 5 lines
(quoted diff) +1 -0
@@ -124,6 +124,7 @@ enum protocol_version discover_version(struct packet_reader *reader)
      switch (packet_reader_peek(reader)) {
      case PACKET_READ_EOF:
              die_initial_contact(0);
+             break;

Would it make sense just to annotate that function to help the flow analysis?

Yes that works wonderfully with my gcc-7.3.0

Quoted 21 lines

Like:

connect.c +1 -1
index c3a014c5ba..49eca46462 100644
@@ -46,7 +46,7 @@ int check_ref_type(const struct ref *ref, int flags)
        return check_ref(ref->name, flags);
 }
 
-static void die_initial_contact(int unexpected)
+static NORETURN void die_initial_contact(int unexpected)
 {
        if (unexpected)
                die(_("The remote end hung up upon initial contact"));

That should let the callers know what's going on, and inside the function itself, the compiler should confirm that all code paths hit another NORETURN function.

-Peff

Signature · 1 line
Duy
#52 lore raw

Re: [PATCH v6 07/35] connect: convert get_remote_heads to use struct packet_reader

Quoted 33 lines · Duy Nguyen
Quoted 23 lines · Jeff King
Quoted 21 lines · Duy Nguyen

Review

Quoted 13 lines · Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced

(quoted diff) +12 -0
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+   enum protocol_version version = protocol_unknown_version;
+
+   /*
+    * Peek the first line of the server's response to
+    * determine the protocol version the server is speaking.
+    */
+   switch (packet_reader_peek(reader)) {
+   case PACKET_READ_EOF:
+           die_initial_contact(0);
+   case PACKET_READ_FLUSH:

gcc is dumb. When -Werror and -Wimplicit-fallthrough are enabled (on at least gcc 7.x), it fails to realize that this die_initial_contact() will not fall through (even though we do tell it about die() not returning, but I guess that involves more flow analysis to realize die_initial_contact is in the same boat).
[...]

Quoted 8 lines

Review enum protocol_version discover_version(struct packet_reader *reader) · line 127

Quoted 5 lines
(quoted diff) +1 -0
@@ -124,6 +124,7 @@ enum protocol_version discover_version(struct packet_reader *reader)
      switch (packet_reader_peek(reader)) {
      case PACKET_READ_EOF:
              die_initial_contact(0);
+             break;

Would it make sense just to annotate that function to help the flow analysis?

Quoted 1 line

Yes that works wonderfully with my gcc-7.3.0

And this changes things. Since this series is 35 patches and there's no sign of reroll needed, I'm going to make this change separately. Don't reroll just because of this

Signature · 1 line
Duy
#53 lore raw

Re: [PATCH v6 07/35] connect: convert get_remote_heads to use struct packet_reader

Quoted 34 lines · Duy Nguyen
Quoted 33 lines · Duy Nguyen
Quoted 31 lines · Jeff King
Quoted 22 lines · Duy Nguyen

Review

Quoted 13 lines · Brandon Williams

In order to allow for better control flow when protocol_v2 is introduced

(quoted diff) +12 -0
+static enum protocol_version discover_version(struct packet_reader *reader)
+{
+   enum protocol_version version = protocol_unknown_version;
+
+   /*
+    * Peek the first line of the server's response to
+    * determine the protocol version the server is speaking.
+    */
+   switch (packet_reader_peek(reader)) {
+   case PACKET_READ_EOF:
+           die_initial_contact(0);
+   case PACKET_READ_FLUSH:

gcc is dumb. When -Werror and -Wimplicit-fallthrough are enabled (on at least gcc 7.x), it fails to realize that this die_initial_contact() will not fall through (even though we do tell it about die() not returning, but I guess that involves more flow analysis to realize die_initial_contact is in the same boat).
[...]

Review enum protocol_version discover_version(struct packet_reader *reader) · line 127

Quoted 4 lines
(quoted diff) +1 -0
@@ -124,6 +124,7 @@ enum protocol_version discover_version(struct packet_reader *reader)
      switch (packet_reader_peek(reader)) {
      case PACKET_READ_EOF:
              die_initial_contact(0);
+             break;

Would it make sense just to annotate that function to help the flow analysis?

Quoted 7 lines
Quoted 1 line

Yes that works wonderfully with my gcc-7.3.0

And this changes things. Since this series is 35 patches and there's no sign of reroll needed, I'm going to make this change separately. Don't reroll just because of this

Signature · 1 line
Duy

Looks like a good change, but yes, it should work fine as a patch on top.

Signature · 1 line
Brandon Williams
#54 lore raw

PATCH v6 8/35 connect: discover protocol version outside of get_remote_heads

In reply to Brandon Williams

In order to prepare for the addition of protocol_v2 push the protocol version discovery outside of 'get_remote_heads()'. This will allow for keeping the logic for processing the reference advertisement for protocol_v1 and protocol_v0 separate from the logic for protocol_v2.

---
 builtin/fetch-pack.c | 16 +++++++++++++++-
 builtin/send-pack.c  | 17 +++++++++++++++--
 connect.c            | 27 ++++++++++-----------------
 connect.h            |  3 +++
 remote-curl.c        | 20 ++++++++++++++++++--
 remote.h             |  5 +++--
 transport.c          | 24 +++++++++++++++++++-----
 7 files changed, 83 insertions(+), 29 deletions(-)
builtin/fetch-pack.c +15 -1
index 366b9d13f9..85d4faf76c 100644
@@ -4,6 +4,7 @@
 #include "remote.h"
 #include "connect.h"
 #include "sha1-array.h"
+#include "protocol.h"
 
 static const char fetch_pack_usage[] =
 "git fetch-pack [--all] [--stdin] [--quiet | -q] [--keep | -k] [--thin] "
@@ -52,6 +53,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	struct fetch_pack_args args;
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
+	struct packet_reader reader;
 
 	packet_trace_identity("fetch-pack");
 
@@ -193,7 +195,19 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 		if (!conn)
 			return args.diag_url ? 0 : 1;
 	}
-	get_remote_heads(fd[0], NULL, 0, &ref, 0, NULL, &shallow);
+
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
 			 &shallow, pack_lockfile_ptr);
builtin/send-pack.c +15 -2
index fc4f0bb5fb..83cb125a68 100644
@@ -14,6 +14,7 @@
 #include "sha1-array.h"
 #include "gpg-interface.h"
 #include "gettext.h"
+#include "protocol.h"
 
 static const char * const send_pack_usage[] = {
 	N_("git send-pack [--all | --mirror] [--dry-run] [--force] "
@@ -154,6 +155,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	int progress = -1;
 	int from_stdin = 0;
 	struct push_cas_option cas = {0};
+	struct packet_reader reader;
 
 	struct option options[] = {
 		OPT__VERBOSITY(&verbose),
@@ -256,8 +258,19 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 			args.verbose ? CONNECT_VERBOSE : 0);
 	}
 
-	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL,
-			 &extra_have, &shallow);
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &remote_refs, REF_NORMAL,
+				 &extra_have, &shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	transport_verify_remote_names(nr_refspecs, refspecs);
 
connect.c +10 -17
index c82c90b7c3..0b111e62d7 100644
@@ -62,7 +62,7 @@ static void die_initial_contact(int unexpected)
 		      "and the repository exists."));
 }
 
-static enum protocol_version discover_version(struct packet_reader *reader)
+enum protocol_version discover_version(struct packet_reader *reader)
 {
 	enum protocol_version version = protocol_unknown_version;
 
@@ -233,7 +233,7 @@ enum get_remote_heads_state {
 /*
  * Read all the refs from the other end
  */
-struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct ref **get_remote_heads(struct packet_reader *reader,
 			      struct ref **list, unsigned int flags,
 			      struct oid_array *extra_have,
 			      struct oid_array *shallow_points)
@@ -241,24 +241,17 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 	struct ref **orig_list = list;
 	int len = 0;
 	enum get_remote_heads_state state = EXPECTING_FIRST_REF;
-	struct packet_reader reader;
 	const char *arg;
 
-	packet_reader_init(&reader, in, src_buf, src_len,
-			   PACKET_READ_CHOMP_NEWLINE |
-			   PACKET_READ_GENTLE_ON_EOF);
-
-	discover_version(&reader);
-
 	*list = NULL;
 
 	while (state != EXPECTING_DONE) {
-		switch (packet_reader_read(&reader)) {
+		switch (packet_reader_read(reader)) {
 		case PACKET_READ_EOF:
 			die_initial_contact(1);
 		case PACKET_READ_NORMAL:
-			len = reader.pktlen;
-			if (len > 4 && skip_prefix(reader.line, "ERR ", &arg))
+			len = reader->pktlen;
+			if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
 				die("remote error: %s", arg);
 			break;
 		case PACKET_READ_FLUSH:
@@ -270,22 +263,22 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 
 		switch (state) {
 		case EXPECTING_FIRST_REF:
-			process_capabilities(reader.line, &len);
-			if (process_dummy_ref(reader.line)) {
+			process_capabilities(reader->line, &len);
+			if (process_dummy_ref(reader->line)) {
 				state = EXPECTING_SHALLOW;
 				break;
 			}
 			state = EXPECTING_REF;
 			/* fallthrough */
 		case EXPECTING_REF:
-			if (process_ref(reader.line, len, &list, flags, extra_have))
+			if (process_ref(reader->line, len, &list, flags, extra_have))
 				break;
 			state = EXPECTING_SHALLOW;
 			/* fallthrough */
 		case EXPECTING_SHALLOW:
-			if (process_shallow(reader.line, len, shallow_points))
+			if (process_shallow(reader->line, len, shallow_points))
 				break;
-			die("protocol error: unexpected '%s'", reader.line);
+			die("protocol error: unexpected '%s'", reader->line);
 		case EXPECTING_DONE:
 			break;
 		}
connect.h +3 -0
index 01f14cdf3f..cdb8979dce 100644
@@ -13,4 +13,7 @@ extern int parse_feature_request(const char *features, const char *feature);
 extern const char *server_feature_value(const char *feature, int *len_ret);
 extern int url_is_local_not_ssh(const char *url);
 
+struct packet_reader;
+extern enum protocol_version discover_version(struct packet_reader *reader);
+
 #endif
remote-curl.c +18 -2
index 0053b09549..9f6d07683d 100644
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "config.h"
 #include "remote.h"
+#include "connect.h"
 #include "strbuf.h"
 #include "walker.h"
 #include "http.h"
@@ -13,6 +14,7 @@
 #include "credential.h"
 #include "sha1-array.h"
 #include "send-pack.h"
+#include "protocol.h"
 
 static struct remote *remote;
 /* always ends with a trailing slash */
@@ -176,8 +178,22 @@ static struct discovery *last_discovery;
 static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 {
 	struct ref *list = NULL;
-	get_remote_heads(-1, heads->buf, heads->len, &list,
-			 for_push ? REF_NORMAL : 0, NULL, &heads->shallow);
+	struct packet_reader reader;
+
+	packet_reader_init(&reader, -1, heads->buf, heads->len,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &list, for_push ? REF_NORMAL : 0,
+				 NULL, &heads->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
 	return list;
 }
 
remote.h +3 -2
index 1f6611be21..2016461df9 100644
@@ -150,10 +150,11 @@ int check_ref_type(const struct ref *ref, int flags);
 void free_refs(struct ref *ref);
 
 struct oid_array;
-extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+struct packet_reader;
+extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
-				     struct oid_array *shallow);
+				     struct oid_array *shallow_points);
 
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
transport.c +19 -5
index 8e87790962..63c3dbab94 100644
@@ -18,6 +18,7 @@
 #include "sha1-array.h"
 #include "sigchain.h"
 #include "transport-internal.h"
+#include "protocol.h"
 
 static void set_upstreams(struct transport *transport, struct ref *refs,
 	int pretend)
@@ -190,13 +191,26 @@ static int connect_setup(struct transport *transport, int for_push)
 static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
 {
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
+	struct packet_reader reader;
 
 	connect_setup(transport, for_push);
-	get_remote_heads(data->fd[0], NULL, 0, &refs,
-			 for_push ? REF_NORMAL : 0,
-			 &data->extra_have,
-			 &data->shallow);
+
+	packet_reader_init(&reader, data->fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	switch (discover_version(&reader)) {
+	case protocol_v1:
+	case protocol_v0:
+		get_remote_heads(&reader, &refs,
+				 for_push ? REF_NORMAL : 0,
+				 &data->extra_have,
+				 &data->shallow);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 	data->got_remote_heads = 1;
 
 	return refs;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#55 lore raw

PATCH v6 9/35 transport: store protocol version

In reply to Brandon Williams

Once protocol_v2 is introduced requesting a fetch or a push will need to be handled differently depending on the protocol version. Store the protocol version the server is speaking in 'struct git_transport_data' and use it to determine what to do in the case of a fetch or a push.

---
 transport.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)
transport.c +26 -9
index 63c3dbab94..2378dcb38c 100644
@@ -118,6 +118,7 @@ struct git_transport_data {
 	struct child_process *conn;
 	int fd[2];
 	unsigned got_remote_heads : 1;
+	enum protocol_version version;
 	struct oid_array extra_have;
 	struct oid_array shallow;
 };
@@ -200,7 +201,8 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_GENTLE_ON_EOF);
 
-	switch (discover_version(&reader)) {
+	data->version = discover_version(&reader);
+	switch (data->version) {
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &refs,
@@ -221,7 +223,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 {
 	int ret = 0;
 	struct git_transport_data *data = transport->data;
-	struct ref *refs;
+	struct ref *refs = NULL;
 	char *dest = xstrdup(transport->url);
 	struct fetch_pack_args args;
 	struct ref *refs_tmp = NULL;
@@ -247,10 +249,18 @@ static int fetch_refs_via_pack(struct transport *transport,
 	if (!data->got_remote_heads)
 		refs_tmp = get_refs_via_connect(transport, 0);
 
-	refs = fetch_pack(&args, data->fd, data->conn,
-			  refs_tmp ? refs_tmp : transport->remote_refs,
-			  dest, to_fetch, nr_heads, &data->shallow,
-			  &transport->pack_lockfile);
+	switch (data->version) {
+	case protocol_v1:
+	case protocol_v0:
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
 	close(data->fd[0]);
 	close(data->fd[1]);
 	if (finish_connect(data->conn))
@@ -549,7 +559,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 {
 	struct git_transport_data *data = transport->data;
 	struct send_pack_args args;
-	int ret;
+	int ret = 0;
 
 	if (!data->got_remote_heads)
 		get_refs_via_connect(transport, 1);
@@ -574,8 +584,15 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	else
 		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
 
-	ret = send_pack(&args, data->fd, data->conn, remote_refs,
-			&data->extra_have);
+	switch (data->version) {
+	case protocol_v1:
+	case protocol_v0:
+		ret = send_pack(&args, data->fd, data->conn, remote_refs,
+				&data->extra_have);
+		break;
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
 
 	close(data->fd[1]);
 	close(data->fd[0]);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#56 lore raw

PATCH v6 10/35 protocol: introduce enum protocol_version value protocol_v2

In reply to Brandon Williams

Introduce protocol_v2, a new value for 'enum protocol_version'. Subsequent patches will fill in the implementation of protocol_v2.

---
 builtin/fetch-pack.c   | 2 ++
 builtin/receive-pack.c | 6 ++++++
 builtin/send-pack.c    | 3 +++
 builtin/upload-pack.c  | 7 +++++++
 connect.c              | 3 +++
 protocol.c             | 2 ++
 protocol.h             | 1 +
 remote-curl.c          | 3 +++
 transport.c            | 9 +++++++++
 9 files changed, 36 insertions(+)
builtin/fetch-pack.c +2 -0
index 85d4faf76c..b2374ddbbf 100644
@@ -201,6 +201,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &ref, 0, NULL, &shallow);
builtin/receive-pack.c +6 -0
index b7ce7c7f52..3656e94fdb 100644
@@ -1963,6 +1963,12 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 		unpack_limit = receive_unpack_limit;
 
 	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		/*
+		 * push support for protocol v2 has not been implemented yet,
+		 * so ignore the request to use v2 and fallback to using v0.
+		 */
+		break;
 	case protocol_v1:
 		/*
 		 * v1 is just the original protocol with a version string,
builtin/send-pack.c +3 -0
index 83cb125a68..b5427f75e3 100644
@@ -263,6 +263,9 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &remote_refs, REF_NORMAL,
builtin/upload-pack.c +7 -0
index 2cb5cb35b0..8d53e9794b 100644
@@ -47,6 +47,13 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 		die("'%s' does not appear to be a git repository", dir);
 
 	switch (determine_protocol_version_server()) {
+	case protocol_v2:
+		/*
+		 * fetch support for protocol v2 has not been implemented yet,
+		 * so ignore the request to use v2 and fallback to using v0.
+		 */
+		upload_pack(&opts);
+		break;
 	case protocol_v1:
 		/*
 		 * v1 is just the original protocol with a version string,
connect.c +3 -0
index 0b111e62d7..4b89b984c4 100644
@@ -83,6 +83,9 @@ enum protocol_version discover_version(struct packet_reader *reader)
 	}
 
 	switch (version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 		/* Read the peeked version line */
 		packet_reader_read(reader);
protocol.c +2 -0
index 43012b7eb6..5e636785d1 100644
@@ -8,6 +8,8 @@ static enum protocol_version parse_protocol_version(const char *value)
 		return protocol_v0;
 	else if (!strcmp(value, "1"))
 		return protocol_v1;
+	else if (!strcmp(value, "2"))
+		return protocol_v2;
 	else
 		return protocol_unknown_version;
 }
protocol.h +1 -0
index 1b2bc94a8d..2ad35e433c 100644
@@ -5,6 +5,7 @@ enum protocol_version {
 	protocol_unknown_version = -1,
 	protocol_v0 = 0,
 	protocol_v1 = 1,
+	protocol_v2 = 2,
 };
 
 /*
remote-curl.c +3 -0
index 9f6d07683d..dae8a4a48d 100644
@@ -185,6 +185,9 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 			   PACKET_READ_GENTLE_ON_EOF);
 
 	switch (discover_version(&reader)) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &list, for_push ? REF_NORMAL : 0,
transport.c +9 -0
index 2378dcb38c..83d9dd1df6 100644
@@ -203,6 +203,9 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 
 	data->version = discover_version(&reader);
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		get_remote_heads(&reader, &refs,
@@ -250,6 +253,9 @@ static int fetch_refs_via_pack(struct transport *transport,
 		refs_tmp = get_refs_via_connect(transport, 0);
 
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		refs = fetch_pack(&args, data->fd, data->conn,
@@ -585,6 +591,9 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 		args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
 
 	switch (data->version) {
+	case protocol_v2:
+		die("support for protocol v2 not implemented yet");
+		break;
 	case protocol_v1:
 	case protocol_v0:
 		ret = send_pack(&args, data->fd, data->conn, remote_refs,
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#57 lore raw

PATCH v6 11/35 test-pkt-line: introduce a packet-line test helper

In reply to Brandon Williams

Introduce a packet-line test helper which can either pack or unpack an input stream into packet-lines and writes out the result to stdout.

---
 Makefile                 |  1 +
 t/helper/test-pkt-line.c | 64 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 t/helper/test-pkt-line.c
Makefile +1 -0
index b7ccc05fac..3b849c0607 100644
@@ -669,6 +669,7 @@ TEST_PROGRAMS_NEED_X += test-mktemp
 TEST_PROGRAMS_NEED_X += test-online-cpus
 TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-path-utils
+TEST_PROGRAMS_NEED_X += test-pkt-line
 TEST_PROGRAMS_NEED_X += test-prio-queue
 TEST_PROGRAMS_NEED_X += test-read-cache
 TEST_PROGRAMS_NEED_X += test-write-cache
t/helper/test-pkt-line.c new file +64 -0

64 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#58 lore raw

PATCH v6 12/35 serve: introduce git-serve

In reply to Brandon Williams

Introduce git-serve, the base server for protocol version 2.

Protocol version 2 is intended to be a replacement for Git's current wire protocol. The intention is that it will be a simpler, less wasteful protocol which can evolve over time.

Protocol version 2 improves upon version 1 by eliminating the initial ref advertisement. In its place a server will export a list of capabilities and commands which it supports in a capability advertisement. A client can then request that a particular command be executed by providing a number of capabilities and command specific parameters. At the completion of a command, a client can request that another command be executed or can terminate the connection by sending a flush packet.

---
 .gitignore                              |   1 +
 Documentation/Makefile                  |   1 +
 Documentation/technical/protocol-v2.txt | 170 ++++++++++++++++
 Makefile                                |   2 +
 builtin.h                               |   1 +
 builtin/serve.c                         |  30 +++
 git.c                                   |   1 +
 serve.c                                 | 247 ++++++++++++++++++++++++
 serve.h                                 |  15 ++
 t/t5701-git-serve.sh                    |  60 ++++++
 10 files changed, 528 insertions(+)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100755 t/t5701-git-serve.sh
.gitignore +1 -0
index 833ef3b0b7..2d0450c262 100644
@@ -140,6 +140,7 @@
 /git-rm
 /git-send-email
 /git-send-pack
+/git-serve
 /git-sh-i18n
 /git-sh-i18n--envsubst
 /git-sh-setup
Documentation/Makefile +1 -0
index 4ae9ba5c86..b105775acd 100644
@@ -77,6 +77,7 @@ TECH_DOCS += technical/pack-heuristics
 TECH_DOCS += technical/pack-protocol
 TECH_DOCS += technical/protocol-capabilities
 TECH_DOCS += technical/protocol-common
+TECH_DOCS += technical/protocol-v2
 TECH_DOCS += technical/racy-git
 TECH_DOCS += technical/send-pack-pipeline
 TECH_DOCS += technical/shallow
Documentation/technical/protocol-v2.txt new file +170 -0

170 lines not on this page · raw message

Makefile +2 -0
index 3b849c0607..18c255428a 100644
@@ -881,6 +881,7 @@ LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
 LIB_OBJS += send-pack.o
 LIB_OBJS += sequencer.o
+LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
@@ -1014,6 +1015,7 @@ BUILTIN_OBJS += builtin/rev-parse.o
 BUILTIN_OBJS += builtin/revert.o
 BUILTIN_OBJS += builtin/rm.o
 BUILTIN_OBJS += builtin/send-pack.o
+BUILTIN_OBJS += builtin/serve.o
 BUILTIN_OBJS += builtin/shortlog.o
 BUILTIN_OBJS += builtin/show-branch.o
 BUILTIN_OBJS += builtin/show-ref.o
builtin.h +1 -0
index f332a12574..3f3fdfc281 100644
@@ -215,6 +215,7 @@ extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
 extern int cmd_revert(int argc, const char **argv, const char *prefix);
 extern int cmd_rm(int argc, const char **argv, const char *prefix);
 extern int cmd_send_pack(int argc, const char **argv, const char *prefix);
+extern int cmd_serve(int argc, const char **argv, const char *prefix);
 extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
 extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
builtin/serve.c new file +30 -0
new file mode 100644
index 0000000000..d3fd240bb3
@@ -0,0 +1,30 @@
+#include "cache.h"
+#include "builtin.h"
+#include "parse-options.h"
+#include "serve.h"
+
+static char const * const serve_usage[] = {
+	N_("git serve [<options>]"),
+	NULL
+};
+
+int cmd_serve(int argc, const char **argv, const char *prefix)
+{
+	struct serve_options opts = SERVE_OPTIONS_INIT;
+
+	struct option options[] = {
+		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
+			 N_("quit after a single request/response exchange")),
+		OPT_BOOL(0, "advertise-capabilities", &opts.advertise_capabilities,
+			 N_("exit immediately after advertising capabilities")),
+		OPT_END()
+	};
+
+	/* ignore all unknown cmdline switches for now */
+	argc = parse_options(argc, argv, prefix, options, serve_usage,
+			     PARSE_OPT_KEEP_DASHDASH |
+			     PARSE_OPT_KEEP_UNKNOWN);
+	serve(&opts);
+
+	return 0;
+}
git.c +1 -0
index f71073dc8d..f85d682b62 100644
@@ -461,6 +461,7 @@ static struct cmd_struct commands[] = {
 	{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 	{ "rm", cmd_rm, RUN_SETUP },
 	{ "send-pack", cmd_send_pack, RUN_SETUP },
+	{ "serve", cmd_serve, RUN_SETUP },
 	{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 	{ "show", cmd_show, RUN_SETUP },
 	{ "show-branch", cmd_show_branch, RUN_SETUP },
serve.c new file +247 -0

247 lines not on this page · raw message

serve.h new file +15 -0
new file mode 100644
index 0000000000..fe65ba9f46
@@ -0,0 +1,15 @@
+#ifndef SERVE_H
+#define SERVE_H
+
+struct argv_array;
+extern int has_capability(const struct argv_array *keys, const char *capability,
+			  const char **value);
+
+struct serve_options {
+	unsigned advertise_capabilities;
+	unsigned stateless_rpc;
+};
+#define SERVE_OPTIONS_INIT { 0 }
+extern void serve(struct serve_options *options);
+
+#endif /* SERVE_H */
t/t5701-git-serve.sh new file +60 -0

60 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#59 lore raw

PATCH v6 13/35 ls-refs: introduce ls-refs server command

In reply to Brandon Williams

Introduce the ls-refs server command. In protocol v2, the ls-refs command is used to request the ref advertisement from the server. Since it is a command which can be requested (as opposed to mandatory in v1), a client can sent a number of parameters in its request to limit the ref advertisement based on provided ref-prefixes.

---
 Documentation/technical/protocol-v2.txt |  31 +++++++
 Makefile                                |   1 +
 ls-refs.c                               |  96 ++++++++++++++++++++
 ls-refs.h                               |  10 +++
 serve.c                                 |   8 ++
 t/t5701-git-serve.sh                    | 115 ++++++++++++++++++++++++
 6 files changed, 261 insertions(+)
 create mode 100644 ls-refs.c
 create mode 100644 ls-refs.h
Documentation/technical/protocol-v2.txt +31 -0
index 270b28f364..bbb8b14d27 100644
@@ -168,3 +168,34 @@ printable ASCII characters except space (i.e., the byte range 32 < x <
 "git/1.8.3.1"). The agent strings are purely informative for statistics
 and debugging purposes, and MUST NOT be used to programmatically assume
 the presence or absence of particular features.
+
+ ls-refs
+~~~~~~~~~
+
+`ls-refs` is the command used to request a reference advertisement in v2.
+Unlike the current reference advertisement, ls-refs takes in arguments
+which can be used to limit the refs sent from the server.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+ls-refs takes in the following arguments:
+
+    symrefs
+	In addition to the object pointed by it, show the underlying ref
+	pointed by it when showing a symbolic ref.
+    peel
+	Show peeled tags.
+    ref-prefix <prefix>
+	When specified, only references having a prefix matching one of
+	the provided prefixes are displayed.
+
+The output of ls-refs is as follows:
+
+    output = *ref
+	     flush-pkt
+    ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF)
+    ref-attribute = (symref | peeled)
+    symref = "symref-target:" symref-target
+    peeled = "peeled:" obj-id
Makefile +1 -0
index 18c255428a..e50927cfb3 100644
@@ -825,6 +825,7 @@ LIB_OBJS += list-objects-filter-options.o
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
+LIB_OBJS += ls-refs.o
 LIB_OBJS += mailinfo.o
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
ls-refs.c new file +96 -0

96 lines not on this page · raw message

ls-refs.h new file +10 -0
new file mode 100644
index 0000000000..b62877e8da
@@ -0,0 +1,10 @@
+#ifndef LS_REFS_H
+#define LS_REFS_H
+
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int ls_refs(struct repository *r, struct argv_array *keys,
+		   struct packet_reader *request);
+
+#endif /* LS_REFS_H */
serve.c +8 -0
index 7ddcba9003..1cb5fb9b5b 100644
@@ -4,8 +4,15 @@
 #include "pkt-line.h"
 #include "version.h"
 #include "argv-array.h"
+#include "ls-refs.h"
 #include "serve.h"
 
+static int always_advertise(struct repository *r,
+			    struct strbuf *value)
+{
+	return 1;
+}
+
 static int agent_advertise(struct repository *r,
 			   struct strbuf *value)
 {
@@ -46,6 +53,7 @@ struct protocol_capability {
 
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
+	{ "ls-refs", always_advertise, ls_refs },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +115 -0

125 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#60 lore raw

PATCH v6 14/35 connect: request remote refs using v2

In reply to Brandon Williams

Teach the client to be able to request a remote's refs using protocol v2. This is done by having a client issue a 'ls-refs' request to a v2 server.

---
 builtin/upload-pack.c  |  10 +--
 connect.c              | 138 +++++++++++++++++++++++++++++++++++++++--
 connect.h              |   2 +
 remote.h               |   6 ++
 t/t5702-protocol-v2.sh |  57 +++++++++++++++++
 transport.c            |   2 +-
 6 files changed, 204 insertions(+), 11 deletions(-)
 create mode 100755 t/t5702-protocol-v2.sh
builtin/upload-pack.c +5 -5
index 8d53e9794b..a757df8da0 100644
@@ -5,6 +5,7 @@
 #include "parse-options.h"
 #include "protocol.h"
 #include "upload-pack.h"
+#include "serve.h"
 
 static const char * const upload_pack_usage[] = {
 	N_("git upload-pack [<options>] <dir>"),
@@ -16,6 +17,7 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 	const char *dir;
 	int strict = 0;
 	struct upload_pack_options opts = { 0 };
+	struct serve_options serve_opts = SERVE_OPTIONS_INIT;
 	struct option options[] = {
 		OPT_BOOL(0, "stateless-rpc", &opts.stateless_rpc,
 			 N_("quit after a single request/response exchange")),
@@ -48,11 +50,9 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 
 	switch (determine_protocol_version_server()) {
 	case protocol_v2:
-		/*
-		 * fetch support for protocol v2 has not been implemented yet,
-		 * so ignore the request to use v2 and fallback to using v0.
-		 */
-		upload_pack(&opts);
+		serve_opts.advertise_capabilities = opts.advertise_refs;
+		serve_opts.stateless_rpc = opts.stateless_rpc;
+		serve(&serve_opts);
 		break;
 	case protocol_v1:
 		/*
connect.c +133 -5

182 lines not on this page · raw message

connect.h +2 -0
index cdb8979dce..8898d44952 100644
@@ -16,4 +16,6 @@ extern int url_is_local_not_ssh(const char *url);
 struct packet_reader;
 extern enum protocol_version discover_version(struct packet_reader *reader);
 
+extern int server_supports_v2(const char *c, int die_on_error);
+
 #endif
remote.h +6 -0
index 2016461df9..368ba221cc 100644
@@ -151,11 +151,17 @@ void free_refs(struct ref *ref);
 
 struct oid_array;
 struct packet_reader;
+struct argv_array;
 extern struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
 				     struct oid_array *shallow_points);
 
+/* Used for protocol v2 in order to retrieve refs from a remote */
+extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+				    struct ref **list, int for_push,
+				    const struct argv_array *ref_prefixes);
+
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
 
t/t5702-protocol-v2.sh new file +57 -0

57 lines not on this page · raw message

transport.c +1 -1
index 83d9dd1df6..ffc6b2614f 100644
@@ -204,7 +204,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	data->version = discover_version(&reader);
 	switch (data->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		get_remote_refs(data->fd[1], &reader, &refs, for_push, NULL);
 		break;
 	case protocol_v1:
 	case protocol_v0:
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#61 lore raw

PATCH v6 15/35 transport: convert get_refs_list to take a list of ref prefixes

In reply to Brandon Williams

Convert the 'struct transport' virtual function 'get_refs_list()' to optionally take an argv_array of ref prefixes. When communicating with a server using protocol v2 these ref prefixes can be sent when requesting a listing of their refs allowing the server to filter the refs it sends based on the sent prefixes. This list will be ignored when not using protocol v2.

---
 transport-helper.c   |  5 +++--
 transport-internal.h | 11 ++++++++++-
 transport.c          | 18 +++++++++++-------
 3 files changed, 24 insertions(+), 10 deletions(-)
transport-helper.c +3 -2
index 5080150231..8774ab3013 100644
@@ -1026,7 +1026,8 @@ static int has_attribute(const char *attrs, const char *attr) {
 	}
 }
 
-static struct ref *get_refs_list(struct transport *transport, int for_push)
+static struct ref *get_refs_list(struct transport *transport, int for_push,
+				 const struct argv_array *ref_prefixes)
 {
 	struct helper_data *data = transport->data;
 	struct child_process *helper;
@@ -1039,7 +1040,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	if (process_connect(transport, for_push)) {
 		do_take_over(transport);
-		return transport->vtable->get_refs_list(transport, for_push);
+		return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
 	}
 
 	if (data->push && for_push)
transport-internal.h +10 -1
index 3c1a29d727..1cde6258a7 100644
@@ -3,6 +3,7 @@
 
 struct ref;
 struct transport;
+struct argv_array;
 
 struct transport_vtable {
 	/**
@@ -17,11 +18,19 @@ struct transport_vtable {
 	 * the transport to try to share connections, for_push is a
 	 * hint as to whether the ultimate operation is a push or a fetch.
 	 *
+	 * If communicating using protocol v2 a list of prefixes can be
+	 * provided to be sent to the server to enable it to limit the ref
+	 * advertisement.  Since ref filtering is done on the server's end, and
+	 * only when using protocol v2, this list will be ignored when not
+	 * using protocol v2 meaning this function can return refs which don't
+	 * match the provided ref_prefixes.
+	 *
 	 * If the transport is able to determine the remote hash for
 	 * the ref without a huge amount of effort, it should store it
 	 * in the ref's old_sha1 field; otherwise it should be all 0.
 	 **/
-	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
+	struct ref *(*get_refs_list)(struct transport *transport, int for_push,
+				     const struct argv_array *ref_prefixes);
 
 	/**
 	 * Fetch the objects for the given refs. Note that this gets
transport.c +11 -7
index ffc6b2614f..2e68010dd0 100644
@@ -72,7 +72,9 @@ struct bundle_transport_data {
 	struct bundle_header header;
 };
 
-static struct ref *get_refs_from_bundle(struct transport *transport, int for_push)
+static struct ref *get_refs_from_bundle(struct transport *transport,
+					int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct bundle_transport_data *data = transport->data;
 	struct ref *result = NULL;
@@ -189,7 +191,8 @@ static int connect_setup(struct transport *transport, int for_push)
 	return 0;
 }
 
-static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
+static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
+					const struct argv_array *ref_prefixes)
 {
 	struct git_transport_data *data = transport->data;
 	struct ref *refs = NULL;
@@ -204,7 +207,8 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 	data->version = discover_version(&reader);
 	switch (data->version) {
 	case protocol_v2:
-		get_remote_refs(data->fd[1], &reader, &refs, for_push, NULL);
+		get_remote_refs(data->fd[1], &reader, &refs, for_push,
+				ref_prefixes);
 		break;
 	case protocol_v1:
 	case protocol_v0:
@@ -250,7 +254,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.update_shallow = data->options.update_shallow;
 
 	if (!data->got_remote_heads)
-		refs_tmp = get_refs_via_connect(transport, 0);
+		refs_tmp = get_refs_via_connect(transport, 0, NULL);
 
 	switch (data->version) {
 	case protocol_v2:
@@ -568,7 +572,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	int ret = 0;
 
 	if (!data->got_remote_heads)
-		get_refs_via_connect(transport, 1);
+		get_refs_via_connect(transport, 1, NULL);
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
@@ -1028,7 +1032,7 @@ int transport_push(struct transport *transport,
 		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
 			return -1;
 
-		remote_refs = transport->vtable->get_refs_list(transport, 1);
+		remote_refs = transport->vtable->get_refs_list(transport, 1, NULL);
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
@@ -1137,7 +1141,7 @@ int transport_push(struct transport *transport,
 const struct ref *transport_get_remote_refs(struct transport *transport)
 {
 	if (!transport->got_remote_refs) {
-		transport->remote_refs = transport->vtable->get_refs_list(transport, 0);
+		transport->remote_refs = transport->vtable->get_refs_list(transport, 0, NULL);
 		transport->got_remote_refs = 1;
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#62 lore raw

PATCH v6 16/35 transport: convert transport_get_remote_refs to take a list of ref prefixes

In reply to Brandon Williams

Teach transport_get_remote_refs() to accept a list of ref prefixes, which will be sent to the server for use in filtering when using protocol v2. (This list will be ignored when not using protocol v2.)

---
 builtin/clone.c     |  2 +-
 builtin/fetch.c     |  4 ++--
 builtin/ls-remote.c |  2 +-
 builtin/remote.c    |  2 +-
 transport.c         |  7 +++++--
 transport.h         | 12 +++++++++++-
 6 files changed, 21 insertions(+), 8 deletions(-)
builtin/clone.c +1 -1
index 284651797e..6e77d993fa 100644
@@ -1121,7 +1121,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (transport->smart_options && !deepen)
 		transport->smart_options->check_self_contained_and_connected = 1;
 
-	refs = transport_get_remote_refs(transport);
+	refs = transport_get_remote_refs(transport, NULL);
 
 	if (refs) {
 		mapped_refs = wanted_peer_refs(refs, refspec);
builtin/fetch.c +2 -2
index 7bbcd26faf..850382f559 100644
@@ -250,7 +250,7 @@ static void find_non_local_tags(struct transport *transport,
 	struct string_list_item *item = NULL;
 
 	for_each_ref(add_existing, &existing_refs);
-	for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
+	for (ref = transport_get_remote_refs(transport, NULL); ref; ref = ref->next) {
 		if (!starts_with(ref->name, "refs/tags/"))
 			continue;
 
@@ -336,7 +336,7 @@ static struct ref *get_ref_map(struct transport *transport,
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
-	const struct ref *remote_refs = transport_get_remote_refs(transport);
+	const struct ref *remote_refs = transport_get_remote_refs(transport, NULL);
 
 	if (refspec_count) {
 		struct refspec *fetch_refspec;
builtin/ls-remote.c +1 -1
index c4be98ab9e..c6e9847c5c 100644
@@ -96,7 +96,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
-	ref = transport_get_remote_refs(transport);
+	ref = transport_get_remote_refs(transport, NULL);
 	if (transport_disconnect(transport))
 		return 1;
 
builtin/remote.c +1 -1
index d95bf904c3..d0b6ff6e29 100644
@@ -862,7 +862,7 @@ static int get_remote_ref_states(const char *name,
 	if (query) {
 		transport = transport_get(states->remote, states->remote->url_nr > 0 ?
 			states->remote->url[0] : NULL);
-		remote_refs = transport_get_remote_refs(transport);
+		remote_refs = transport_get_remote_refs(transport, NULL);
 		transport_disconnect(transport);
 
 		states->queried = 1;
transport.c +5 -2
index 2e68010dd0..3f130518d2 100644
@@ -1138,10 +1138,13 @@ int transport_push(struct transport *transport,
 	return 1;
 }
 
-const struct ref *transport_get_remote_refs(struct transport *transport)
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes)
 {
 	if (!transport->got_remote_refs) {
-		transport->remote_refs = transport->vtable->get_refs_list(transport, 0, NULL);
+		transport->remote_refs =
+			transport->vtable->get_refs_list(transport, 0,
+							 ref_prefixes);
 		transport->got_remote_refs = 1;
 	}
 
transport.h +11 -1
index 731c78b679..83992a4257 100644
@@ -178,7 +178,17 @@ int transport_push(struct transport *connection,
 		   int refspec_nr, const char **refspec, int flags,
 		   unsigned int * reject_reasons);
 
-const struct ref *transport_get_remote_refs(struct transport *transport);
+/*
+ * Retrieve refs from a remote.
+ *
+ * Optionally a list of ref prefixes can be provided which can be sent to the
+ * server (when communicating using protocol v2) to enable it to limit the ref
+ * advertisement.  Since ref filtering is done on the server's end (and only
+ * when using protocol v2), this can return refs which don't match the provided
+ * ref_prefixes.
+ */
+const struct ref *transport_get_remote_refs(struct transport *transport,
+					    const struct argv_array *ref_prefixes);
 
 int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#63 lore raw

PATCH v6 17/35 ls-remote: pass ref prefixes when requesting a remote's refs

In reply to Brandon Williams

Construct an argv_array of ref prefixes based on the patterns supplied via the command line and pass them to 'transport_get_remote_refs()' to be used when communicating protocol v2 so that the server can limit the ref advertisement based on those prefixes.

---
 builtin/ls-remote.c    | 15 +++++++++++++--
 refs.c                 | 14 ++++++++++++++
 refs.h                 |  7 +++++++
 t/t5702-protocol-v2.sh | 26 ++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 2 deletions(-)
builtin/ls-remote.c +13 -2
index c6e9847c5c..4276bf97d5 100644
@@ -2,6 +2,7 @@
 #include "cache.h"
 #include "transport.h"
 #include "remote.h"
+#include "refs.h"
 
 static const char * const ls_remote_usage[] = {
 	N_("git ls-remote [--heads] [--tags] [--refs] [--upload-pack=<exec>]\n"
@@ -43,6 +44,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	int show_symref_target = 0;
 	const char *uploadpack = NULL;
 	const char **pattern = NULL;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	struct remote *remote;
 	struct transport *transport;
@@ -74,8 +76,17 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (argc > 1) {
 		int i;
 		pattern = xcalloc(argc, sizeof(const char *));
-		for (i = 1; i < argc; i++)
+		for (i = 1; i < argc; i++) {
+			const char *glob;
 			pattern[i - 1] = xstrfmt("*/%s", argv[i]);
+
+			glob = strchr(argv[i], '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - argv[i]), argv[i]);
+			else
+				expand_ref_prefix(&ref_prefixes, argv[i]);
+		}
 	}
 
 	remote = remote_get(dest);
@@ -96,7 +107,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
 	if (uploadpack != NULL)
 		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
 
-	ref = transport_get_remote_refs(transport, NULL);
+	ref = transport_get_remote_refs(transport, &ref_prefixes);
 	if (transport_disconnect(transport))
 		return 1;
 
refs.c +14 -0
index 20ba82b434..cefbad2076 100644
@@ -13,6 +13,7 @@
 #include "tag.h"
 #include "submodule.h"
 #include "worktree.h"
+#include "argv-array.h"
 
 /*
  * List of all available backends
@@ -501,6 +502,19 @@ int refname_match(const char *abbrev_name, const char *full_name)
 	return 0;
 }
 
+/*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
+{
+	const char **p;
+	int len = strlen(prefix);
+
+	for (p = ref_rev_parse_rules; *p; p++)
+		argv_array_pushf(prefixes, *p, len, prefix);
+}
+
 /*
  * *string and *len will only be substituted, and *string returned (for
  * later free()ing) if the string passed in is a magic short-hand form
refs.h +7 -0
index 01be5ae32f..93b6dce944 100644
@@ -139,6 +139,13 @@ int resolve_gitlink_ref(const char *submodule, const char *refname,
  */
 int refname_match(const char *abbrev_name, const char *full_name);
 
+/*
+ * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
+ * the results to 'prefixes'
+ */
+struct argv_array;
+void expand_ref_prefix(struct argv_array *prefixes, const char *prefix);
+
 int expand_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref);
 int dwim_log(const char *str, int len, struct object_id *oid, char **ref);
t/t5702-protocol-v2.sh +26 -0
index dc5f813beb..562610fd25 100755
@@ -32,6 +32,19 @@ test_expect_success 'list refs with git:// using protocol v2' '
 	test_cmp actual expect
 '
 
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "$GIT_DAEMON_URL/parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C "$daemon_parent" rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
 stop_git_daemon
 
 # Test protocol v2 with 'file://' transport
@@ -54,4 +67,17 @@ test_expect_success 'list refs with file:// using protocol v2' '
 	test_cmp actual expect
 '
 
+test_expect_success 'ref advertisment is filtered with ls-remote using protocol v2' '
+	test_when_finished "rm -f log" &&
+
+	GIT_TRACE_PACKET="$(pwd)/log" git -c protocol.version=2 \
+		ls-remote "file://$(pwd)/file_parent" master >actual &&
+
+	cat >expect <<-EOF &&
+	$(git -C file_parent rev-parse refs/heads/master)$(printf "\t")refs/heads/master
+	EOF
+
+	test_cmp actual expect
+'
+
 test_done
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#64 lore raw

PATCH v6 18/35 fetch: pass ref prefixes when fetching

In reply to Brandon Williams

Construct a list of ref prefixes to be passed to 'transport_get_remote_refs()' from the refspec to be used during the fetch. This list of ref prefixes will be used to allow the server to filter the ref advertisement when communicating using protocol v2.

---
 builtin/fetch.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)
builtin/fetch.c +18 -1
index 850382f559..8258bbf950 100644
@@ -332,11 +332,28 @@ static struct ref *get_ref_map(struct transport *transport,
 	struct ref *rm;
 	struct ref *ref_map = NULL;
 	struct ref **tail = &ref_map;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
-	const struct ref *remote_refs = transport_get_remote_refs(transport, NULL);
+	const struct ref *remote_refs;
+
+	for (i = 0; i < refspec_count; i++) {
+		if (!refspecs[i].exact_sha1) {
+			const char *glob = strchr(refspecs[i].src, '*');
+			if (glob)
+				argv_array_pushf(&ref_prefixes, "%.*s",
+						 (int)(glob - refspecs[i].src),
+						 refspecs[i].src);
+			else
+				expand_ref_prefix(&ref_prefixes, refspecs[i].src);
+		}
+	}
+
+	remote_refs = transport_get_remote_refs(transport, &ref_prefixes);
+
+	argv_array_clear(&ref_prefixes);
 
 	if (refspec_count) {
 		struct refspec *fetch_refspec;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#65 lore raw

PATCH v6 19/35 push: pass ref prefixes when pushing

In reply to Brandon Williams

Construct a list of ref prefixes to be passed to 'get_refs_list()' from the refspec to be used during the push. This list of ref prefixes will be used to allow the server to filter the ref advertisement when communicating using protocol v2.

---
 transport.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)
transport.c +28 -1
index 3f130518d2..57bdbb59bc 100644
@@ -1028,11 +1028,38 @@ int transport_push(struct transport *transport,
 		int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
 		int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
 		int push_ret, ret, err;
+		struct refspec *tmp_rs;
+		struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
+		int i;
 
 		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
 			return -1;
 
-		remote_refs = transport->vtable->get_refs_list(transport, 1, NULL);
+		tmp_rs = parse_push_refspec(refspec_nr, refspec);
+		for (i = 0; i < refspec_nr; i++) {
+			const char *prefix = NULL;
+
+			if (tmp_rs[i].dst)
+				prefix = tmp_rs[i].dst;
+			else if (tmp_rs[i].src && !tmp_rs[i].exact_sha1)
+				prefix = tmp_rs[i].src;
+
+			if (prefix) {
+				const char *glob = strchr(prefix, '*');
+				if (glob)
+					argv_array_pushf(&ref_prefixes, "%.*s",
+							 (int)(glob - prefix),
+							 prefix);
+				else
+					expand_ref_prefix(&ref_prefixes, prefix);
+			}
+		}
+
+		remote_refs = transport->vtable->get_refs_list(transport, 1,
+							       &ref_prefixes);
+
+		argv_array_clear(&ref_prefixes);
+		free_refspec(refspec_nr, tmp_rs);
 
 		if (flags & TRANSPORT_PUSH_ALL)
 			match_flags |= MATCH_REFS_ALL;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#66 lore raw

PATCH v6 20/35 upload-pack: introduce fetch server command

In reply to Brandon Williams

Introduce the 'fetch' server command.

---
 Documentation/technical/protocol-v2.txt | 125 +++++++++++
 serve.c                                 |   2 +
 t/t5701-git-serve.sh                    |   1 +
 upload-pack.c                           | 266 ++++++++++++++++++++++++
 upload-pack.h                           |   6 +
 5 files changed, 400 insertions(+)
Documentation/technical/protocol-v2.txt +125 -0
index bbb8b14d27..307dc1489b 100644
@@ -199,3 +199,128 @@ The output of ls-refs is as follows:
     ref-attribute = (symref | peeled)
     symref = "symref-target:" symref-target
     peeled = "peeled:" obj-id
+
+ fetch
+~~~~~~~
+
+`fetch` is the command used to fetch a packfile in v2.  It can be looked
+at as a modified version of the v1 fetch where the ref-advertisement is
+stripped out (since the `ls-refs` command fills that role) and the
+message format is tweaked to eliminate redundancies and permit easy
+addition of future extensions.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+A `fetch` request can take the following arguments:
+
+    want <oid>
+	Indicates to the server an object which the client wants to
+	retrieve.  Wants can be anything and are not limited to
+	advertised objects.
+
+    have <oid>
+	Indicates to the server an object which the client has locally.
+	This allows the server to make a packfile which only contains
+	the objects that the client needs. Multiple 'have' lines can be
+	supplied.
+
+    done
+	Indicates to the server that negotiation should terminate (or
+	not even begin if performing a clone) and that the server should
+	use the information supplied in the request to construct the
+	packfile.
+
+    thin-pack
+	Request that a thin pack be sent, which is a pack with deltas
+	which reference base objects not contained within the pack (but
+	are known to exist at the receiving end). This can reduce the
+	network traffic significantly, but it requires the receiving end
+	to know how to "thicken" these packs by adding the missing bases
+	to the pack.
+
+    no-progress
+	Request that progress information that would normally be sent on
+	side-band channel 2, during the packfile transfer, should not be
+	sent.  However, the side-band channel 3 is still used for error
+	responses.
+
+    include-tag
+	Request that annotated tags should be sent if the objects they
+	point to are being sent.
+
+    ofs-delta
+	Indicate that the client understands PACKv2 with delta referring
+	to its base by position in pack rather than by an oid.  That is,
+	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
+
+The response of `fetch` is broken into a number of sections separated by
+delimiter packets (0001), with each section beginning with its section
+header.
+
+    output = *section
+    section = (acknowledgments | packfile)
+	      (flush-pkt | delim-pkt)
+
+    acknowledgments = PKT-LINE("acknowledgments" LF)
+		      (nak | *ack)
+		      (ready)
+    ready = PKT-LINE("ready" LF)
+    nak = PKT-LINE("NAK" LF)
+    ack = PKT-LINE("ACK" SP obj-id LF)
+
+    packfile = PKT-LINE("packfile" LF)
+	       *PKT-LINE(%x01-03 *%x00-ff)
+
+    acknowledgments section
+	* If the client determines that it is finished with negotiations
+	  by sending a "done" line, the acknowledgments sections MUST be
+	  omitted from the server's response.
+
+	* Always begins with the section header "acknowledgments"
+
+	* The server will respond with "NAK" if none of the object ids sent
+	  as have lines were common.
+
+	* The server will respond with "ACK obj-id" for all of the
+	  object ids sent as have lines which are common.
+
+	* A response cannot have both "ACK" lines as well as a "NAK"
+	  line.
+
+	* The server will respond with a "ready" line indicating that
+	  the server has found an acceptable common base and is ready to
+	  make and send a packfile (which will be found in the packfile
+	  section of the same response)
+
+	* If the server has found a suitable cut point and has decided
+	  to send a "ready" line, then the server can decide to (as an
+	  optimization) omit any "ACK" lines it would have sent during
+	  its response.  This is because the server will have already
+	  determined the objects it plans to send to the client and no
+	  further negotiation is needed.
+
+    packfile section
+	* This section is only included if the client has sent 'want'
+	  lines in its request and either requested that no more
+	  negotiation be done by sending 'done' or if the server has
+	  decided it has found a sufficient cut point to produce a
+	  packfile.
+
+	* Always begins with the section header "packfile"
+
+	* The transmission of the packfile begins immediately after the
+	  section header
+
+	* The data transfer of the packfile is always multiplexed, using
+	  the same semantics of the 'side-band-64k' capability from
+	  protocol version 1.  This means that each packet, during the
+	  packfile data stream, is made up of a leading 4-byte pkt-line
+	  length (typical of the pkt-line format), followed by a 1-byte
+	  stream code, followed by the actual data.
+
+	  The stream code can be one of:
+		1 - pack data
+		2 - progress messages
+		3 - fatal error message just before stream aborts
serve.c +2 -0
index 1cb5fb9b5b..3692dda801 100644
@@ -6,6 +6,7 @@
 #include "argv-array.h"
 #include "ls-refs.h"
 #include "serve.h"
+#include "upload-pack.h"
 
 static int always_advertise(struct repository *r,
 			    struct strbuf *value)
@@ -54,6 +55,7 @@ struct protocol_capability {
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
 	{ "ls-refs", always_advertise, ls_refs },
+	{ "fetch", always_advertise, upload_pack_v2 },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +1 -0
index d03e08eebd..888a700443 100755
@@ -9,6 +9,7 @@ test_expect_success 'test capability advertisement' '
 	version 2
 	agent=git/$(git version | cut -d" " -f3)
 	ls-refs
+	fetch
 	0000
 	EOF
 
upload-pack.c +266 -0

275 lines not on this page · raw message

upload-pack.h +6 -0
index a71e4dc7e2..5bbdb7e445 100644
@@ -10,4 +10,10 @@ struct upload_pack_options {
 
 void upload_pack(struct upload_pack_options *options);
 
+struct repository;
+struct argv_array;
+struct packet_reader;
+extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
+			  struct packet_reader *request);
+
 #endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#67 lore raw

PATCH v6 21/35 fetch-pack: perform a fetch using v2

In reply to Brandon Williams

When communicating with a v2 server, perform a fetch by requesting the 'fetch' command.

---
 Documentation/technical/protocol-v2.txt |  67 +++++-
 builtin/fetch-pack.c                    |   2 +-
 fetch-pack.c                            | 270 +++++++++++++++++++++++-
 fetch-pack.h                            |   4 +-
 serve.c                                 |   2 +-
 t/t5701-git-serve.sh                    |   2 +-
 t/t5702-protocol-v2.sh                  |  97 +++++++++
 transport.c                             |   7 +-
 upload-pack.c                           | 141 ++++++++++---
 upload-pack.h                           |   4 +
 10 files changed, 548 insertions(+), 48 deletions(-)
Documentation/technical/protocol-v2.txt +66 -1
index 307dc1489b..4f7f251569 100644
@@ -255,12 +255,43 @@ A `fetch` request can take the following arguments:
 	to its base by position in pack rather than by an oid.  That is,
 	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
 
+    shallow <oid>
+	A client must notify the server of all commits for which it only
+	has shallow copies (meaning that it doesn't have the parents of
+	a commit) by supplying a 'shallow <oid>' line for each such
+	object so that the server is aware of the limitations of the
+	client's history.  This is so that the server is aware that the
+	client may not have all objects reachable from such commits.
+
+    deepen <depth>
+	Requests that the fetch/clone should be shallow having a commit
+	depth of <depth> relative to the remote side.
+
+    deepen-relative
+	Requests that the semantics of the "deepen" command be changed
+	to indicate that the depth requested is relative to the client's
+	current shallow boundary, instead of relative to the requested
+	commits.
+
+    deepen-since <timestamp>
+	Requests that the shallow clone/fetch should be cut at a
+	specific time, instead of depth.  Internally it's equivalent to
+	doing "git rev-list --max-age=<timestamp>". Cannot be used with
+	"deepen".
+
+    deepen-not <rev>
+	Requests that the shallow clone/fetch should be cut at a
+	specific revision specified by '<rev>', instead of a depth.
+	Internally it's equivalent of doing "git rev-list --not <rev>".
+	Cannot be used with "deepen", but can be used with
+	"deepen-since".
+
 The response of `fetch` is broken into a number of sections separated by
 delimiter packets (0001), with each section beginning with its section
 header.
 
     output = *section
-    section = (acknowledgments | packfile)
+    section = (acknowledgments | shallow-info | packfile)
 	      (flush-pkt | delim-pkt)
 
     acknowledgments = PKT-LINE("acknowledgments" LF)
@@ -270,6 +301,11 @@ header.
     nak = PKT-LINE("NAK" LF)
     ack = PKT-LINE("ACK" SP obj-id LF)
 
+    shallow-info = PKT-LINE("shallow-info" LF)
+		   *PKT-LINE((shallow | unshallow) LF)
+    shallow = "shallow" SP obj-id
+    unshallow = "unshallow" SP obj-id
+
     packfile = PKT-LINE("packfile" LF)
 	       *PKT-LINE(%x01-03 *%x00-ff)
 
@@ -301,6 +337,35 @@ header.
 	  determined the objects it plans to send to the client and no
 	  further negotiation is needed.
 
+    shallow-info section
+	If the client has requested a shallow fetch/clone, a shallow
+	client requests a fetch or the server is shallow then the
+	server's response may include a shallow-info section.  The
+	shallow-info section will be included if (due to one of the
+	above conditions) the server needs to inform the client of any
+	shallow boundaries or adjustments to the clients already
+	existing shallow boundaries.
+
+	* Always begins with the section header "shallow-info"
+
+	* If a positive depth is requested, the server will compute the
+	  set of commits which are no deeper than the desired depth.
+
+	* The server sends a "shallow obj-id" line for each commit whose
+	  parents will not be sent in the following packfile.
+
+	* The server sends an "unshallow obj-id" line for each commit
+	  which the client has indicated is shallow, but is no longer
+	  shallow as a result of the fetch (due to its parents being
+	  sent in the following packfile).
+
+	* The server MUST NOT send any "unshallow" lines for anything
+	  which the client has not indicated was shallow as a part of
+	  its request.
+
+	* This section is only included if a packfile section is also
+	  included in the response.
+
     packfile section
 	* This section is only included if the client has sent 'want'
 	  lines in its request and either requested that no more
builtin/fetch-pack.c +1 -1
index b2374ddbbf..f9d7d0b5a5 100644
@@ -212,7 +212,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	}
 
 	ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
-			 &shallow, pack_lockfile_ptr);
+			 &shallow, pack_lockfile_ptr, protocol_v0);
 	if (pack_lockfile) {
 		printf("lock %s\n", pack_lockfile);
 		fflush(stdout);
fetch-pack.c +264 -6

301 lines not on this page · raw message

fetch-pack.h +3 -1
index b6aeb43a8e..7afca73056 100644
@@ -3,6 +3,7 @@
 
 #include "string-list.h"
 #include "run-command.h"
+#include "protocol.h"
 
 struct oid_array;
 
@@ -43,7 +44,8 @@ struct ref *fetch_pack(struct fetch_pack_args *args,
 		       struct ref **sought,
 		       int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile);
+		       char **pack_lockfile,
+		       enum protocol_version version);
 
 /*
  * Print an appropriate error message for each sought ref that wasn't
serve.c +1 -1
index 3692dda801..a5a7b2f7dd 100644
@@ -55,7 +55,7 @@ struct protocol_capability {
 static struct protocol_capability capabilities[] = {
 	{ "agent", agent_advertise, NULL },
 	{ "ls-refs", always_advertise, ls_refs },
-	{ "fetch", always_advertise, upload_pack_v2 },
+	{ "fetch", upload_pack_advertise, upload_pack_v2 },
 };
 
 static void advertise_capabilities(void)
t/t5701-git-serve.sh +1 -1
index 888a700443..72d7bc5628 100755
@@ -9,7 +9,7 @@ test_expect_success 'test capability advertisement' '
 	version 2
 	agent=git/$(git version | cut -d" " -f3)
 	ls-refs
-	fetch
+	fetch=shallow
 	0000
 	EOF
 
t/t5702-protocol-v2.sh +97 -0

107 lines not on this page · raw message

transport.c +5 -2
index 57bdbb59bc..9152a45b38 100644
@@ -258,14 +258,17 @@ static int fetch_refs_via_pack(struct transport *transport,
 
 	switch (data->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		refs = fetch_pack(&args, data->fd, data->conn,
+				  refs_tmp ? refs_tmp : transport->remote_refs,
+				  dest, to_fetch, nr_heads, &data->shallow,
+				  &transport->pack_lockfile, data->version);
 		break;
 	case protocol_v1:
 	case protocol_v0:
 		refs = fetch_pack(&args, data->fd, data->conn,
 				  refs_tmp ? refs_tmp : transport->remote_refs,
 				  dest, to_fetch, nr_heads, &data->shallow,
-				  &transport->pack_lockfile);
+				  &transport->pack_lockfile, data->version);
 		break;
 	case protocol_unknown_version:
 		BUG("unknown protocol version");
upload-pack.c +106 -35

203 lines not on this page · raw message

upload-pack.h +4 -0
index 5bbdb7e445..cab2178796 100644
@@ -16,4 +16,8 @@ struct packet_reader;
 extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
 			  struct packet_reader *request);
 
+struct strbuf;
+extern int upload_pack_advertise(struct repository *r,
+				 struct strbuf *value);
+
 #endif /* UPLOAD_PACK_H */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#68 lore raw

PATCH v6 22/35 fetch-pack: support shallow requests

In reply to Brandon Williams

Enable shallow clones and deepen requests using protocol version 2 if the server 'fetch' command supports the 'shallow' feature.

---
 Documentation/technical/protocol-v2.txt | 18 ++++---
 connect.c                               | 22 ++++++++
 connect.h                               |  2 +
 fetch-pack.c                            | 71 ++++++++++++++++++++++++-
 4 files changed, 105 insertions(+), 8 deletions(-)
Documentation/technical/protocol-v2.txt +11 -7
index 4f7f251569..136179d7d8 100644
@@ -255,6 +255,10 @@ A `fetch` request can take the following arguments:
 	to its base by position in pack rather than by an oid.  That is,
 	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
 
+If the 'shallow' feature is advertised the following arguments can be
+included in the clients request as well as the potential addition of the
+'shallow-info' section in the server's response as explained below.
+
     shallow <oid>
 	A client must notify the server of all commits for which it only
 	has shallow copies (meaning that it doesn't have the parents of
@@ -338,13 +342,13 @@ header.
 	  further negotiation is needed.
 
     shallow-info section
-	If the client has requested a shallow fetch/clone, a shallow
-	client requests a fetch or the server is shallow then the
-	server's response may include a shallow-info section.  The
-	shallow-info section will be included if (due to one of the
-	above conditions) the server needs to inform the client of any
-	shallow boundaries or adjustments to the clients already
-	existing shallow boundaries.
+	* If the client has requested a shallow fetch/clone, a shallow
+	  client requests a fetch or the server is shallow then the
+	  server's response may include a shallow-info section.  The
+	  shallow-info section will be included if (due to one of the
+	  above conditions) the server needs to inform the client of any
+	  shallow boundaries or adjustments to the clients already
+	  existing shallow boundaries.
 
 	* Always begins with the section header "shallow-info"
 
connect.c +22 -0
index e42d779f71..5bb9d34844 100644
@@ -82,6 +82,28 @@ int server_supports_v2(const char *c, int die_on_error)
 	return 0;
 }
 
+int server_supports_feature(const char *c, const char *feature,
+			    int die_on_error)
+{
+	int i;
+
+	for (i = 0; i < server_capabilities_v2.argc; i++) {
+		const char *out;
+		if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
+		    (!*out || *(out++) == '=')) {
+			if (parse_feature_request(out, feature))
+				return 1;
+			else
+				break;
+		}
+	}
+
+	if (die_on_error)
+		die("server doesn't support feature '%s'", feature);
+
+	return 0;
+}
+
 static void process_capabilities_v2(struct packet_reader *reader)
 {
 	while (packet_reader_read(reader) == PACKET_READ_NORMAL)
connect.h +2 -0
index 8898d44952..0e69c6709c 100644
@@ -17,5 +17,7 @@ struct packet_reader;
 extern enum protocol_version discover_version(struct packet_reader *reader);
 
 extern int server_supports_v2(const char *c, int die_on_error);
+extern int server_supports_feature(const char *c, const char *feature,
+				   int die_on_error);
 
 #endif
fetch-pack.c +70 -1

107 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#69 lore raw

PATCH v6 23/35 connect: refactor git_connect to only get the protocol version once

In reply to Brandon Williams

Instead of having each builtin transport asking for which protocol version the user has configured in 'protocol.version' by calling get_protocol_version_config() multiple times, factor this logic out so there is just a single call at the beginning of git_connect().

This will be helpful in the next patch where we can have centralized logic which determines if we need to request a different protocol version than what the user has configured.

---
 connect.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)
connect.c +15 -12
index 5bb9d34844..a57a060dc4 100644
@@ -1035,6 +1035,7 @@ static enum ssh_variant determine_ssh_variant(const char *ssh_command,
  */
 static struct child_process *git_connect_git(int fd[2], char *hostandport,
 					     const char *path, const char *prog,
+					     enum protocol_version version,
 					     int flags)
 {
 	struct child_process *conn;
@@ -1073,10 +1074,10 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
 		    target_host, 0);
 
 	/* If using a new version put that stuff here after a second null byte */
-	if (get_protocol_version_config() > 0) {
+	if (version > 0) {
 		strbuf_addch(&request, '\0');
 		strbuf_addf(&request, "version=%d%c",
-			    get_protocol_version_config(), '\0');
+			    version, '\0');
 	}
 
 	packet_write(fd[1], request.buf, request.len);
@@ -1092,14 +1093,14 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
  */
 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 			     enum ssh_variant variant, const char *port,
-			     int flags)
+			     enum protocol_version version, int flags)
 {
 	if (variant == VARIANT_SSH &&
-	    get_protocol_version_config() > 0) {
+	    version > 0) {
 		argv_array_push(args, "-o");
 		argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
 		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-				 get_protocol_version_config());
+				 version);
 	}
 
 	if (flags & CONNECT_IPV4) {
@@ -1152,7 +1153,8 @@ static void push_ssh_options(struct argv_array *args, struct argv_array *env,
 
 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
-			  const char *port, int flags)
+			  const char *port, enum protocol_version version,
+			  int flags)
 {
 	const char *ssh;
 	enum ssh_variant variant;
@@ -1186,14 +1188,14 @@ static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
 		argv_array_push(&detect.args, ssh);
 		argv_array_push(&detect.args, "-G");
 		push_ssh_options(&detect.args, &detect.env_array,
-				 VARIANT_SSH, port, flags);
+				 VARIANT_SSH, port, version, flags);
 		argv_array_push(&detect.args, ssh_host);
 
 		variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
 	}
 
 	argv_array_push(&conn->args, ssh);
-	push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
+	push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
 	argv_array_push(&conn->args, ssh_host);
 }
 
@@ -1214,6 +1216,7 @@ struct child_process *git_connect(int fd[2], const char *url,
 	char *hostandport, *path;
 	struct child_process *conn;
 	enum protocol protocol;
+	enum protocol_version version = get_protocol_version_config();
 
 	/* Without this we cannot rely on waitpid() to tell
 	 * what happened to our children.
@@ -1228,7 +1231,7 @@ struct child_process *git_connect(int fd[2], const char *url,
 		printf("Diag: path=%s\n", path ? path : "NULL");
 		conn = NULL;
 	} else if (protocol == PROTO_GIT) {
-		conn = git_connect_git(fd, hostandport, path, prog, flags);
+		conn = git_connect_git(fd, hostandport, path, prog, version, flags);
 	} else {
 		struct strbuf cmd = STRBUF_INIT;
 		const char *const *var;
@@ -1271,12 +1274,12 @@ struct child_process *git_connect(int fd[2], const char *url,
 				strbuf_release(&cmd);
 				return NULL;
 			}
-			fill_ssh_args(conn, ssh_host, port, flags);
+			fill_ssh_args(conn, ssh_host, port, version, flags);
 		} else {
 			transport_check_allowed("file");
-			if (get_protocol_version_config() > 0) {
+			if (version > 0) {
 				argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-						 get_protocol_version_config());
+						 version);
 			}
 		}
 		argv_array_push(&conn->args, cmd.buf);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#70 lore raw

PATCH v6 24/35 connect: don't request v2 when pushing

In reply to Brandon Williams

In order to be able to ship protocol v2 with only supporting fetch, we need clients to not issue a request to use protocol v2 when pushing (since the client currently doesn't know how to push using protocol v2). This allows a client to have protocol v2 configured in protocol.version and take advantage of using v2 for fetch and falling back to using v0 when pushing while v2 for push is being designed.

We could run into issues if we didn't fall back to protocol v2 when pushing right now. This is because currently a server will ignore a request to use v2 when contacting the 'receive-pack' endpoint and fall back to using v0, but when push v2 is rolled out to servers, the 'receive-pack' endpoint will start responding using v2. So we don't want to get into a state where a client is requesting to push with v2 before they actually know how to push using v2.

---
 connect.c              |  8 ++++++++
 t/t5702-protocol-v2.sh | 24 ++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
connect.c +8 -0
index a57a060dc4..54971166ac 100644
@@ -1218,6 +1218,14 @@ struct child_process *git_connect(int fd[2], const char *url,
 	enum protocol protocol;
 	enum protocol_version version = get_protocol_version_config();
 
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
+		version = protocol_v0;
+
 	/* Without this we cannot rely on waitpid() to tell
 	 * what happened to our children.
 	 */
t/t5702-protocol-v2.sh +24 -0
index 4365ac2736..e3a7c09d4a 100755
@@ -95,6 +95,30 @@ test_expect_success 'pull with git:// using protocol v2' '
 	grep "fetch< version 2" log
 '
 
+test_expect_success 'push with git:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C daemon_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C daemon_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C daemon_child log -1 --format=%s >actual &&
+	git -C "$daemon_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v2
+	! grep "push> .*\\\0\\\0version=2\\\0$" log &&
+	# Server responded using protocol v2
+	! grep "push< version 2" log
+'
+
 stop_git_daemon
 
 # Test protocol v2 with 'file://' transport
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#71 lore raw

PATCH v6 25/35 transport-helper: remove name parameter

In reply to Brandon Williams

Commit 266f1fdfa (transport-helper: be quiet on read errors from helpers, 2013-06-21) removed a call to 'die()' which printed the name of the remote helper passed in to the 'recvline_fh()' function using the 'name' parameter. Once the call to 'die()' was removed the parameter was no longer necessary but wasn't removed. Clean up 'recvline_fh()' parameter list by removing the 'name' parameter.

---
 transport-helper.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
transport-helper.c +3 -3
index 8774ab3013..9677ead426 100644
@@ -49,7 +49,7 @@ static void sendline(struct helper_data *helper, struct strbuf *buffer)
 		die_errno("Full write to remote helper failed");
 }
 
-static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
+static int recvline_fh(FILE *helper, struct strbuf *buffer)
 {
 	strbuf_reset(buffer);
 	if (debug)
@@ -67,7 +67,7 @@ static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
 
 static int recvline(struct helper_data *helper, struct strbuf *buffer)
 {
-	return recvline_fh(helper->out, buffer, helper->name);
+	return recvline_fh(helper->out, buffer);
 }
 
 static void write_constant(int fd, const char *str)
@@ -586,7 +586,7 @@ static int process_connect_service(struct transport *transport,
 		goto exit;
 
 	sendline(data, &cmdbuf);
-	if (recvline_fh(input, &cmdbuf, name))
+	if (recvline_fh(input, &cmdbuf))
 		exit(128);
 
 	if (!strcmp(cmdbuf.buf, "")) {
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#72 lore raw

PATCH v6 26/35 transport-helper: refactor process_connect_service

In reply to Brandon Williams

A future patch will need to take advantage of the logic which runs and processes the response of the connect command on a remote helper so factor out this logic from 'process_connect_service()' and place it into a helper function 'run_connect()'.

---
 transport-helper.c | 67 ++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 29 deletions(-)
transport-helper.c +38 -29
index 9677ead426..830f21f0a9 100644
@@ -545,14 +545,13 @@ static int fetch_with_import(struct transport *transport,
 	return 0;
 }
 
-static int process_connect_service(struct transport *transport,
-				   const char *name, const char *exec)
+static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 {
 	struct helper_data *data = transport->data;
-	struct strbuf cmdbuf = STRBUF_INIT;
-	struct child_process *helper;
-	int r, duped, ret = 0;
+	int ret = 0;
+	int duped;
 	FILE *input;
+	struct child_process *helper;
 
 	helper = get_helper(transport);
 
@@ -568,44 +567,54 @@ static int process_connect_service(struct transport *transport,
 	input = xfdopen(duped, "r");
 	setvbuf(input, NULL, _IONBF, 0);
 
+	sendline(data, cmdbuf);
+	if (recvline_fh(input, cmdbuf))
+		exit(128);
+
+	if (!strcmp(cmdbuf->buf, "")) {
+		data->no_disconnect_req = 1;
+		if (debug)
+			fprintf(stderr, "Debug: Smart transport connection "
+				"ready.\n");
+		ret = 1;
+	} else if (!strcmp(cmdbuf->buf, "fallback")) {
+		if (debug)
+			fprintf(stderr, "Debug: Falling back to dumb "
+				"transport.\n");
+	} else {
+		die("Unknown response to connect: %s",
+			cmdbuf->buf);
+	}
+
+	fclose(input);
+	return ret;
+}
+
+static int process_connect_service(struct transport *transport,
+				   const char *name, const char *exec)
+{
+	struct helper_data *data = transport->data;
+	struct strbuf cmdbuf = STRBUF_INIT;
+	int ret = 0;
+
 	/*
 	 * Handle --upload-pack and friends. This is fire and forget...
 	 * just warn if it fails.
 	 */
 	if (strcmp(name, exec)) {
-		r = set_helper_option(transport, "servpath", exec);
+		int r = set_helper_option(transport, "servpath", exec);
 		if (r > 0)
 			warning("Setting remote service path not supported by protocol.");
 		else if (r < 0)
 			warning("Invalid remote service path.");
 	}
 
-	if (data->connect)
+	if (data->connect) {
 		strbuf_addf(&cmdbuf, "connect %s\n", name);
-	else
-		goto exit;
-
-	sendline(data, &cmdbuf);
-	if (recvline_fh(input, &cmdbuf))
-		exit(128);
-
-	if (!strcmp(cmdbuf.buf, "")) {
-		data->no_disconnect_req = 1;
-		if (debug)
-			fprintf(stderr, "Debug: Smart transport connection "
-				"ready.\n");
-		ret = 1;
-	} else if (!strcmp(cmdbuf.buf, "fallback")) {
-		if (debug)
-			fprintf(stderr, "Debug: Falling back to dumb "
-				"transport.\n");
-	} else
-		die("Unknown response to connect: %s",
-			cmdbuf.buf);
+		ret = run_connect(transport, &cmdbuf);
+	}
 
-exit:
 	strbuf_release(&cmdbuf);
-	fclose(input);
 	return ret;
 }
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#73 lore raw

PATCH v6 27/35 transport-helper: introduce stateless-connect

In reply to Brandon Williams

Introduce the transport-helper capability 'stateless-connect'. This capability indicates that the transport-helper can be requested to run the 'stateless-connect' command which should attempt to make a stateless connection with a remote end. Once established, the connection can be used by the git client to communicate with the remote end natively in a stateless-rpc manner as supported by protocol v2. This means that the client must send everything the server needs in a single request as the client must not assume any state-storing on the part of the server or transport.

If a stateless connection cannot be established then the remote-helper will respond in the same manner as the 'connect' command indicating that the client should fallback to using the dumb remote-helper commands.

A future patch will implement the 'stateless-connect' capability in our http remote-helper (remote-curl) so that protocol v2 can be used using the http transport.

---
 Documentation/gitremote-helpers.txt | 32 +++++++++++++++++++++++++++++
 transport-helper.c                  | 11 ++++++++++
 transport.c                         |  1 +
 transport.h                         |  6 ++++++
 4 files changed, 50 insertions(+)
Documentation/gitremote-helpers.txt +32 -0
index 4a584f3c5d..cd9b34d230 100644
@@ -102,6 +102,14 @@ Capabilities for Pushing
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'push'::
 	Can discover remote refs and push local commits and the
 	history leading up to them to new or existing remote refs.
@@ -136,6 +144,14 @@ Capabilities for Fetching
 +
 Supported commands: 'connect'.
 
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
 'fetch'::
 	Can discover remote refs and transfer objects reachable from
 	them to the local object store.
@@ -375,6 +391,22 @@ Supported if the helper has the "export" capability.
 +
 Supported if the helper has the "connect" capability.
 
+'stateless-connect' <service>::
+	Experimental; for internal use only.
+	Connects to the given remote service for communication using
+	git's wire-protocol version 2.  Valid replies to this command
+	are empty line (connection established), 'fallback' (no smart
+	transport support, fall back to dumb transports) and just
+	exiting with error message printed (can't connect, don't bother
+	trying to fall back).  After line feed terminating the positive
+	(empty) response, the output of the service starts.  Messages
+	(both request and response) must consist of zero or more
+	PKT-LINEs, terminating in a flush packet. The client must not
+	expect the server to store any state in between request-response
+	pairs.  After the connection ends, the remote helper exits.
++
+Supported if the helper has the "stateless-connect" capability.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without
transport-helper.c +11 -0
index 830f21f0a9..aecbc4a845 100644
@@ -12,6 +12,7 @@
 #include "argv-array.h"
 #include "refs.h"
 #include "transport-internal.h"
+#include "protocol.h"
 
 static int debug;
 
@@ -26,6 +27,7 @@ struct helper_data {
 		option : 1,
 		push : 1,
 		connect : 1,
+		stateless_connect : 1,
 		signed_tags : 1,
 		check_connectivity : 1,
 		no_disconnect_req : 1,
@@ -188,6 +190,8 @@ static struct child_process *get_helper(struct transport *transport)
 			refspecs[refspec_nr++] = xstrdup(arg);
 		} else if (!strcmp(capname, "connect")) {
 			data->connect = 1;
+		} else if (!strcmp(capname, "stateless-connect")) {
+			data->stateless_connect = 1;
 		} else if (!strcmp(capname, "signed-tags")) {
 			data->signed_tags = 1;
 		} else if (skip_prefix(capname, "export-marks ", &arg)) {
@@ -612,6 +616,13 @@ static int process_connect_service(struct transport *transport,
 	if (data->connect) {
 		strbuf_addf(&cmdbuf, "connect %s\n", name);
 		ret = run_connect(transport, &cmdbuf);
+	} else if (data->stateless_connect &&
+		   (get_protocol_version_config() == protocol_v2) &&
+		   !strcmp("git-upload-pack", name)) {
+		strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
+		ret = run_connect(transport, &cmdbuf);
+		if (ret)
+			transport->stateless_rpc = 1;
 	}
 
 	strbuf_release(&cmdbuf);
transport.c +1 -0
index 9152a45b38..342db492ca 100644
@@ -252,6 +252,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 		data->options.check_self_contained_and_connected;
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
+	args.stateless_rpc = transport->stateless_rpc;
 
 	if (!data->got_remote_heads)
 		refs_tmp = get_refs_via_connect(transport, 0, NULL);
transport.h +6 -0
index 83992a4257..0e602d4d47 100644
@@ -55,6 +55,12 @@ struct transport {
 	 */
 	unsigned cloning : 1;
 
+	/*
+	 * Indicates that the transport is connected via a half-duplex
+	 * connection and should operate in stateless-rpc mode.
+	 */
+	unsigned stateless_rpc : 1;
+
 	/*
 	 * These strings will be passed to the {pre, post}-receive hook,
 	 * on the remote side, if both sides support the push options capability.
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#74 lore raw

PATCH v6 28/35 pkt-line: add packet_buf_write_len function

In reply to Brandon Williams

Add the 'packet_buf_write_len()' function which allows for writing an arbitrary length buffer into a 'struct strbuf' and formatting it in packet-line format.

---
 pkt-line.c | 16 ++++++++++++++++
 pkt-line.h |  1 +
 2 files changed, 17 insertions(+)
pkt-line.c +16 -0
index 7296731cf3..555eb2a507 100644
@@ -215,6 +215,22 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	va_end(args);
 }
 
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
+{
+	size_t orig_len, n;
+
+	orig_len = buf->len;
+	strbuf_addstr(buf, "0000");
+	strbuf_add(buf, data, len);
+	n = buf->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
+		die("protocol error: impossibly long line");
+
+	set_packet_header(&buf->buf[orig_len], n);
+	packet_trace(data, len, 1);
+}
+
 int write_packetized_from_fd(int fd_in, int fd_out)
 {
 	static char buf[LARGE_PACKET_DATA_MAX];
pkt-line.h +1 -0
index 9570bd7a0a..5b28d43472 100644
@@ -26,6 +26,7 @@ void packet_buf_flush(struct strbuf *buf);
 void packet_buf_delim(struct strbuf *buf);
 void packet_write(int fd_out, const char *buf, size_t size);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len);
 int packet_flush_gently(int fd);
 int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 int write_packetized_from_fd(int fd_in, int fd_out);
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#75 lore raw

PATCH v6 29/35 remote-curl: create copy of the service name

In reply to Brandon Williams

Make a copy of the service name being requested instead of relying on the buffer pointed to by the passed in 'const char *' to remain unchanged.

Currently, all service names are string constants, but a subsequent patch will introduce service names from external sources.

---
 remote-curl.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
remote-curl.c +3 -2
index dae8a4a48d..4086aa733b 100644
@@ -165,7 +165,7 @@ static int set_option(const char *name, const char *value)
 }
 
 struct discovery {
-	const char *service;
+	char *service;
 	char *buf_alloc;
 	char *buf;
 	size_t len;
@@ -257,6 +257,7 @@ static void free_discovery(struct discovery *d)
 		free(d->shallow.oid);
 		free(d->buf_alloc);
 		free_refs(d->refs);
+		free(d->service);
 		free(d);
 	}
 }
@@ -343,7 +344,7 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		warning(_("redirecting to %s"), url.buf);
 
 	last= xcalloc(1, sizeof(*last_discovery));
-	last->service = service;
+	last->service = xstrdup(service);
 	last->buf_alloc = strbuf_detach(&buffer, &last->len);
 	last->buf = last->buf_alloc;
 
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#76 lore raw

PATCH v6 30/35 remote-curl: store the protocol version the server responded with

In reply to Brandon Williams

Store the protocol version the server responded with when performing discovery. This will be used in a future patch to either change the 'Git-Protocol' header sent in subsequent requests or to determine if a client needs to fallback to using a different protocol version.

---
 remote-curl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
remote-curl.c +3 -1
index 4086aa733b..c540358438 100644
@@ -171,6 +171,7 @@ struct discovery {
 	size_t len;
 	struct ref *refs;
 	struct oid_array shallow;
+	enum protocol_version version;
 	unsigned proto_git : 1;
 };
 static struct discovery *last_discovery;
@@ -184,7 +185,8 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_GENTLE_ON_EOF);
 
-	switch (discover_version(&reader)) {
+	heads->version = discover_version(&reader);
+	switch (heads->version) {
 	case protocol_v2:
 		die("support for protocol v2 not implemented yet");
 		break;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#77 lore raw

PATCH v6 31/35 http: allow providing extra headers for http requests

In reply to Brandon Williams

Add a way for callers to request that extra headers be included when making http requests.

---
 http.c | 8 ++++++++
 http.h | 7 +++++++
 2 files changed, 15 insertions(+)
http.c +8 -0
index 5977712712..e1757d62b2 100644
@@ -1723,6 +1723,14 @@ static int http_request(const char *url,
 
 	headers = curl_slist_append(headers, buf.buf);
 
+	/* Add additional headers here */
+	if (options && options->extra_headers) {
+		const struct string_list_item *item;
+		for_each_string_list_item(item, options->extra_headers) {
+			headers = curl_slist_append(headers, item->string);
+		}
+	}
+
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
http.h +7 -0
index f7bd3b26b0..4df4a25e1a 100644
@@ -172,6 +172,13 @@ struct http_get_options {
 	 * for details.
 	 */
 	struct strbuf *base_url;
+
+	/*
+	 * If not NULL, contains additional HTTP headers to be sent with the
+	 * request. The strings in the list must not be freed until after the
+	 * request has completed.
+	 */
+	struct string_list *extra_headers;
 };
 
 /* Return values for http_get_*() */
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#78 lore raw

PATCH v6 32/35 http: don't always add Git-Protocol header

In reply to Brandon Williams

Instead of always sending the Git-Protocol header with the configured version with every http request, explicitly send it when discovering refs and then only send it on subsequent http requests if the server understood the version requested.

---
 http.c        | 17 -----------------
 remote-curl.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 17 deletions(-)
http.c +0 -17
index e1757d62b2..8f1129ac7c 100644
@@ -904,21 +904,6 @@ static void set_from_env(const char **var, const char *envname)
 		*var = val;
 }
 
-static void protocol_http_header(void)
-{
-	if (get_protocol_version_config() > 0) {
-		struct strbuf protocol_header = STRBUF_INIT;
-
-		strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
-			    get_protocol_version_config());
-
-
-		extra_http_headers = curl_slist_append(extra_http_headers,
-						       protocol_header.buf);
-		strbuf_release(&protocol_header);
-	}
-}
-
 void http_init(struct remote *remote, const char *url, int proactive_auth)
 {
 	char *low_speed_limit;
@@ -949,8 +934,6 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 	if (remote)
 		var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 
-	protocol_http_header();
-
 	pragma_header = curl_slist_append(http_copy_default_headers(),
 		"Pragma: no-cache");
 	no_pragma_header = curl_slist_append(http_copy_default_headers(),
remote-curl.c +33 -0
index c540358438..b4e9db85bb 100644
@@ -291,6 +291,19 @@ static int show_http_message(struct strbuf *type, struct strbuf *charset,
 	return 0;
 }
 
+static int get_protocol_http_header(enum protocol_version version,
+				    struct strbuf *header)
+{
+	if (version > 0) {
+		strbuf_addf(header, GIT_PROTOCOL_HEADER ": version=%d",
+			    version);
+
+		return 1;
+	}
+
+	return 0;
+}
+
 static struct discovery *discover_refs(const char *service, int for_push)
 {
 	struct strbuf exp = STRBUF_INIT;
@@ -299,6 +312,8 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	struct strbuf buffer = STRBUF_INIT;
 	struct strbuf refs_url = STRBUF_INIT;
 	struct strbuf effective_url = STRBUF_INIT;
+	struct strbuf protocol_header = STRBUF_INIT;
+	struct string_list extra_headers = STRING_LIST_INIT_DUP;
 	struct discovery *last = last_discovery;
 	int http_ret, maybe_smart = 0;
 	struct http_get_options http_options;
@@ -318,11 +333,16 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		strbuf_addf(&refs_url, "service=%s", service);
 	}
 
+	/* Add the extra Git-Protocol header */
+	if (get_protocol_http_header(get_protocol_version_config(), &protocol_header))
+		string_list_append(&extra_headers, protocol_header.buf);
+
 	memset(&http_options, 0, sizeof(http_options));
 	http_options.content_type = &type;
 	http_options.charset = &charset;
 	http_options.effective_url = &effective_url;
 	http_options.base_url = &url;
+	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
 	http_options.keep_error = 1;
@@ -389,6 +409,8 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	strbuf_release(&charset);
 	strbuf_release(&effective_url);
 	strbuf_release(&buffer);
+	strbuf_release(&protocol_header);
+	string_list_clear(&extra_headers, 0);
 	last_discovery = last;
 	return last;
 }
@@ -425,6 +447,7 @@ struct rpc_state {
 	char *service_url;
 	char *hdr_content_type;
 	char *hdr_accept;
+	char *protocol_header;
 	char *buf;
 	size_t alloc;
 	size_t len;
@@ -611,6 +634,10 @@ static int post_rpc(struct rpc_state *rpc)
 	headers = curl_slist_append(headers, needs_100_continue ?
 		"Expect: 100-continue" : "Expect:");
 
+	/* Add the extra Git-Protocol header */
+	if (rpc->protocol_header)
+		headers = curl_slist_append(headers, rpc->protocol_header);
+
 retry:
 	slot = get_active_slot();
 
@@ -751,6 +778,11 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 	strbuf_addf(&buf, "Accept: application/x-%s-result", svc);
 	rpc->hdr_accept = strbuf_detach(&buf, NULL);
 
+	if (get_protocol_http_header(heads->version, &buf))
+		rpc->protocol_header = strbuf_detach(&buf, NULL);
+	else
+		rpc->protocol_header = NULL;
+
 	while (!err) {
 		int n = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
 		if (!n)
@@ -778,6 +810,7 @@ static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
 	free(rpc->service_url);
 	free(rpc->hdr_content_type);
 	free(rpc->hdr_accept);
+	free(rpc->protocol_header);
 	free(rpc->buf);
 	strbuf_release(&buf);
 	return err;
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#79 lore raw

PATCH v6 33/35 http: eliminate "# service" line when using protocol v2

In reply to Brandon Williams

When an http info/refs request is made, requesting that protocol v2 be used, don't send a "# service" line since this line is not part of the v2 spec.

---
 http-backend.c | 8 ++++++--
 remote-curl.c  | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)
http-backend.c +6 -2
index f3dc218b2a..5d241e9109 100644
@@ -10,6 +10,7 @@
 #include "url.h"
 #include "argv-array.h"
 #include "packfile.h"
+#include "protocol.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
@@ -466,8 +467,11 @@ static void get_info_refs(struct strbuf *hdr, char *arg)
 		hdr_str(hdr, content_type, buf.buf);
 		end_headers(hdr);
 
-		packet_write_fmt(1, "# service=git-%s\n", svc->name);
-		packet_flush(1);
+
+		if (determine_protocol_version_server() != protocol_v2) {
+			packet_write_fmt(1, "# service=git-%s\n", svc->name);
+			packet_flush(1);
+		}
 
 		argv[0] = svc->name;
 		run_service(argv, 0);
remote-curl.c +3 -0
index b4e9db85bb..66a53f74bb 100644
@@ -396,6 +396,9 @@ static struct discovery *discover_refs(const char *service, int for_push)
 			;
 
 		last->proto_git = 1;
+	} else if (maybe_smart &&
+		   last->len > 5 && starts_with(last->buf + 4, "version 2")) {
+		last->proto_git = 1;
 	}
 
 	if (last->proto_git)
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#80 lore raw

PATCH v6 34/35 remote-curl: implement stateless-connect command

In reply to Brandon Williams

Teach remote-curl the 'stateless-connect' command which is used to establish a stateless connection with servers which support protocol version 2. This allows remote-curl to act as a proxy, allowing the git client to communicate natively with a remote end, simply using remote-curl as a pass through to convert requests to http.

---
 remote-curl.c          | 207 ++++++++++++++++++++++++++++++++++++++++-
 t/t5702-protocol-v2.sh |  45 +++++++++
 2 files changed, 251 insertions(+), 1 deletion(-)
remote-curl.c +206 -1
index 66a53f74bb..87f5b77b29 100644
@@ -188,7 +188,12 @@ static struct ref *parse_git_refs(struct discovery *heads, int for_push)
 	heads->version = discover_version(&reader);
 	switch (heads->version) {
 	case protocol_v2:
-		die("support for protocol v2 not implemented yet");
+		/*
+		 * Do nothing.  This isn't a list of refs but rather a
+		 * capability advertisement.  Client would have run
+		 * 'stateless-connect' so we'll dump this capability listing
+		 * and let them request the refs themselves.
+		 */
 		break;
 	case protocol_v1:
 	case protocol_v0:
@@ -1085,6 +1090,202 @@ static void parse_push(struct strbuf *buf)
 	free(specs);
 }
 
+/*
+ * Used to represent the state of a connection to an HTTP server when
+ * communicating using git's wire-protocol version 2.
+ */
+struct proxy_state {
+	char *service_name;
+	char *service_url;
+	struct curl_slist *headers;
+	struct strbuf request_buffer;
+	int in;
+	int out;
+	struct packet_reader reader;
+	size_t pos;
+	int seen_flush;
+};
+
+static void proxy_state_init(struct proxy_state *p, const char *service_name,
+			     enum protocol_version version)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	memset(p, 0, sizeof(*p));
+	p->service_name = xstrdup(service_name);
+
+	p->in = 0;
+	p->out = 1;
+	strbuf_init(&p->request_buffer, 0);
+
+	strbuf_addf(&buf, "%s%s", url.buf, p->service_name);
+	p->service_url = strbuf_detach(&buf, NULL);
+
+	p->headers = http_copy_default_headers();
+
+	strbuf_addf(&buf, "Content-Type: application/x-%s-request", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	strbuf_addf(&buf, "Accept: application/x-%s-result", p->service_name);
+	p->headers = curl_slist_append(p->headers, buf.buf);
+	strbuf_reset(&buf);
+
+	p->headers = curl_slist_append(p->headers, "Transfer-Encoding: chunked");
+
+	/* Add the Git-Protocol header */
+	if (get_protocol_http_header(version, &buf))
+		p->headers = curl_slist_append(p->headers, buf.buf);
+
+	packet_reader_init(&p->reader, p->in, NULL, 0,
+			   PACKET_READ_GENTLE_ON_EOF);
+
+	strbuf_release(&buf);
+}
+
+static void proxy_state_clear(struct proxy_state *p)
+{
+	free(p->service_name);
+	free(p->service_url);
+	curl_slist_free_all(p->headers);
+	strbuf_release(&p->request_buffer);
+}
+
+/*
+ * CURLOPT_READFUNCTION callback function.
+ * Attempts to copy over a single packet-line at a time into the
+ * curl provided buffer.
+ */
+static size_t proxy_in(char *buffer, size_t eltsize,
+		       size_t nmemb, void *userdata)
+{
+	size_t max;
+	struct proxy_state *p = userdata;
+	size_t avail = p->request_buffer.len - p->pos;
+
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	max = nmemb;
+
+	if (!avail) {
+		if (p->seen_flush) {
+			p->seen_flush = 0;
+			return 0;
+		}
+
+		strbuf_reset(&p->request_buffer);
+		switch (packet_reader_read(&p->reader)) {
+		case PACKET_READ_EOF:
+			die("unexpected EOF when reading from parent process");
+		case PACKET_READ_NORMAL:
+			packet_buf_write_len(&p->request_buffer, p->reader.line,
+					     p->reader.pktlen);
+			break;
+		case PACKET_READ_DELIM:
+			packet_buf_delim(&p->request_buffer);
+			break;
+		case PACKET_READ_FLUSH:
+			packet_buf_flush(&p->request_buffer);
+			p->seen_flush = 1;
+			break;
+		}
+		p->pos = 0;
+		avail = p->request_buffer.len;
+	}
+
+	if (max < avail)
+		avail = max;
+	memcpy(buffer, p->request_buffer.buf + p->pos, avail);
+	p->pos += avail;
+	return avail;
+}
+
+static size_t proxy_out(char *buffer, size_t eltsize,
+			size_t nmemb, void *userdata)
+{
+	size_t size;
+	struct proxy_state *p = userdata;
+
+	if (eltsize != 1)
+		BUG("curl read callback called with size = %"PRIuMAX" != 1",
+		    (uintmax_t)eltsize);
+	size = nmemb;
+
+	write_or_die(p->out, buffer, size);
+	return size;
+}
+
+/* Issues a request to the HTTP server configured in `p` */
+static int proxy_request(struct proxy_state *p)
+{
+	struct active_request_slot *slot;
+
+	slot = get_active_slot();
+
+	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
+	curl_easy_setopt(slot->curl, CURLOPT_URL, p->service_url);
+	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, p->headers);
+
+	/* Setup function to read request from client */
+	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, proxy_in);
+	curl_easy_setopt(slot->curl, CURLOPT_READDATA, p);
+
+	/* Setup function to write server response to client */
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, proxy_out);
+	curl_easy_setopt(slot->curl, CURLOPT_WRITEDATA, p);
+
+	if (run_slot(slot, NULL) != HTTP_OK)
+		return -1;
+
+	return 0;
+}
+
+static int stateless_connect(const char *service_name)
+{
+	struct discovery *discover;
+	struct proxy_state p;
+
+	/*
+	 * Run the info/refs request and see if the server supports protocol
+	 * v2.  If and only if the server supports v2 can we successfully
+	 * establish a stateless connection, otherwise we need to tell the
+	 * client to fallback to using other transport helper functions to
+	 * complete their request.
+	 */
+	discover = discover_refs(service_name, 0);
+	if (discover->version != protocol_v2) {
+		printf("fallback\n");
+		fflush(stdout);
+		return -1;
+	} else {
+		/* Stateless Connection established */
+		printf("\n");
+		fflush(stdout);
+	}
+
+	proxy_state_init(&p, service_name, discover->version);
+
+	/*
+	 * Dump the capability listing that we got from the server earlier
+	 * during the info/refs request.
+	 */
+	write_or_die(p.out, discover->buf, discover->len);
+
+	/* Peek the next packet line.  Until we see EOF keep sending POSTs */
+	while (packet_reader_peek(&p.reader) != PACKET_READ_EOF) {
+		if (proxy_request(&p)) {
+			/* We would have an err here */
+			break;
+		}
+	}
+
+	proxy_state_clear(&p);
+	return 0;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -1153,12 +1354,16 @@ int cmd_main(int argc, const char **argv)
 			fflush(stdout);
 
 		} else if (!strcmp(buf.buf, "capabilities")) {
+			printf("stateless-connect\n");
 			printf("fetch\n");
 			printf("option\n");
 			printf("push\n");
 			printf("check-connectivity\n");
 			printf("\n");
 			fflush(stdout);
+		} else if (skip_prefix(buf.buf, "stateless-connect ", &arg)) {
+			if (!stateless_connect(arg))
+				break;
 		} else {
 			error("remote-curl: unknown command '%s' from git", buf.buf);
 			return 1;
t/t5702-protocol-v2.sh +45 -0

49 lines not on this page · raw message

Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#81 lore raw

PATCH v6 35/35 remote-curl: don't request v2 when pushing

In reply to Brandon Williams

In order to be able to ship protocol v2 with only supporting fetch, we need clients to not issue a request to use protocol v2 when pushing (since the client currently doesn't know how to push using protocol v2). This allows a client to have protocol v2 configured in protocol.version and take advantage of using v2 for fetch and falling back to using v0 when pushing while v2 for push is being designed.

We could run into issues if we didn't fall back to protocol v2 when pushing right now. This is because currently a server will ignore a request to use v2 when contacting the 'receive-pack' endpoint and fall back to using v0, but when push v2 is rolled out to servers, the 'receive-pack' endpoint will start responding using v2. So we don't want to get into a state where a client is requesting to push with v2 before they actually know how to push using v2.

---
 remote-curl.c          | 11 ++++++++++-
 t/t5702-protocol-v2.sh | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)
remote-curl.c +10 -1
index 87f5b77b29..595447b16e 100644
@@ -322,6 +322,7 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	struct discovery *last = last_discovery;
 	int http_ret, maybe_smart = 0;
 	struct http_get_options http_options;
+	enum protocol_version version = get_protocol_version_config();
 
 	if (last && !strcmp(service, last->service))
 		return last;
@@ -338,8 +339,16 @@ static struct discovery *discover_refs(const char *service, int for_push)
 		strbuf_addf(&refs_url, "service=%s", service);
 	}
 
+	/*
+	 * NEEDSWORK: If we are trying to use protocol v2 and we are planning
+	 * to perform a push, then fallback to v0 since the client doesn't know
+	 * how to push yet using v2.
+	 */
+	if (version == protocol_v2 && !strcmp("git-receive-pack", service))
+		version = protocol_v0;
+
 	/* Add the extra Git-Protocol header */
-	if (get_protocol_http_header(get_protocol_version_config(), &protocol_header))
+	if (get_protocol_http_header(version, &protocol_header))
 		string_list_append(&extra_headers, protocol_header.buf);
 
 	memset(&http_options, 0, sizeof(http_options));
t/t5702-protocol-v2.sh +24 -0
index 124063c2c4..56f7c3c326 100755
@@ -244,6 +244,30 @@ test_expect_success 'fetch with http:// using protocol v2' '
 	grep "git< version 2" log
 '
 
+test_expect_success 'push with http:// and a config of v2 does not request v2' '
+	test_when_finished "rm -f log" &&
+	# Till v2 for push is designed, make sure that if a client has
+	# protocol.version configured to use v2, that the client instead falls
+	# back and uses v0.
+
+	test_commit -C http_child three &&
+
+	# Push to another branch, as the target repository has the
+	# master branch checked out and we cannot push into it.
+	GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \
+		push origin HEAD:client_branch &&
+
+	git -C http_child log -1 --format=%s >actual &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" log -1 --format=%s client_branch >expect &&
+	test_cmp expect actual &&
+
+	# Client didnt request to use protocol v2
+	! grep "Git-Protocol: version=2" log &&
+	# Server didnt respond using protocol v2
+	! grep "git< version 2" log
+'
+
+
 stop_httpd
 
 test_done
Signature · 1 line
2.16.2.804.g6dcf76e118-goog
#82 lore raw

PATCH 1/1 {fetch,upload}-pack: clearly mark unreachable v2 code

In reply to Brandon Williams

Change the switch statement driving upload_pack_v2() and do_fetch_pack_v2() to clearly indicate that the FETCH_DONE case is being handled implicitly by other code, instead of giving the reader the impression that the "continue" statement is needed.

This issue was flagged as DEADCODE by Coverity[1]. Simply removing the "case FETCH_DONE" would make -Wswitch warn. Instead implement the same solution discussed for my "[PATCH v2 18/29] grep: catch a missing enum in switch statement" patch[2] (which never made it into git.git).

1. https://public-inbox.org/git/CAGZ79kbAOcwaRzjuMtZ_HVsYvUr_7UAPbOcnrmPgsdE19q=PrQ@mail.gmail.com/
2. https://public-inbox.org/git/[email protected]/

---
 fetch-pack.c  | 4 ++--
 upload-pack.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
fetch-pack.c +2 -2
index 216d1368be..3a16b4bc1a 100644
@@ -1393,8 +1393,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 
 			state = FETCH_DONE;
 			break;
-		case FETCH_DONE:
-			continue;
+		default:
+			BUG("Added a new fetch_state without updating switch");
 		}
 	}
 
upload-pack.c +2 -2
index 87b4d32a6e..b7a7601c83 100644
@@ -1416,8 +1416,8 @@ int upload_pack_v2(struct repository *r, struct argv_array *keys,
 			create_pack_file();
 			state = FETCH_DONE;
 			break;
-		case FETCH_DONE:
-			continue;
+		default:
+			BUG("Added a new fetch_state without updating switch");
 		}
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118
#83 lore raw

Re: [PATCH] {fetch,upload}-pack: clearly mark unreachable v2 code

Quoted 5 lines · Ævar Arnfjörð Bjarmason

Change the switch statement driving upload_pack_v2() and do_fetch_pack_v2() to clearly indicate that the FETCH_DONE case is being handled implicitly by other code, instead of giving the reader the impression that the "continue" statement is needed.

Quoted 7 lines

This issue was flagged as DEADCODE by Coverity[1]. Simply removing the "case FETCH_DONE" would make -Wswitch warn. Instead implement the same solution discussed for my "[PATCH v2 18/29] grep: catch a missing enum in switch statement" patch[2] (which never made it into git.git).

1. https://public-inbox.org/git/CAGZ79kbAOcwaRzjuMtZ_HVsYvUr_7UAPbOcnrmPgsdE19q=PrQ@mail.gmail.com/
2. https://public-inbox.org/git/[email protected]/

I understand why you want this change, but I dislike it because it removes the ability to have the compiler tell you that your switch statements are exhaustive. Of course it should be noticed rather quickly by the addition of those BUG statements :)

Quoted 40 lines
---
 fetch-pack.c  | 4 ++--
 upload-pack.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
fetch-pack.c +2 -2
index 216d1368be..3a16b4bc1a 100644
@@ -1393,8 +1393,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 
 			state = FETCH_DONE;
 			break;
-		case FETCH_DONE:
-			continue;
+		default:
+			BUG("Added a new fetch_state without updating switch");
 		}
 	}
 
upload-pack.c +2 -2
index 87b4d32a6e..b7a7601c83 100644
@@ -1416,8 +1416,8 @@ int upload_pack_v2(struct repository *r, struct argv_array *keys,
 			create_pack_file();
 			state = FETCH_DONE;
 			break;
-		case FETCH_DONE:
-			continue;
+		default:
+			BUG("Added a new fetch_state without updating switch");
 		}
 	}
 
Signature · 1 line
2.16.2.804.g6dcf76e118
Signature · 1 line
Brandon Williams
#84 lore raw

Re: [PATCH] {fetch,upload}-pack: clearly mark unreachable v2 code

Quoted 11 lines · Brandon Williams
Quoted 10 lines · Ævar Arnfjörð Bjarmason

Change the switch statement driving upload_pack_v2() and do_fetch_pack_v2() to clearly indicate that the FETCH_DONE case is being handled implicitly by other code, instead of giving the reader the impression that the "continue" statement is needed.

This issue was flagged as DEADCODE by Coverity[1]. Simply removing the "case FETCH_DONE" would make -Wswitch warn. Instead implement the same solution discussed for my "[PATCH v2 18/29] grep: catch a missing enum in switch statement" patch[2] (which never made it into git.git).

Quoted 7 lines
Quoted 2 lines

1. https://public-inbox.org/git/CAGZ79kbAOcwaRzjuMtZ_HVsYvUr_7UAPbOcnrmPgsdE19q=PrQ@mail.gmail.com/
2. https://public-inbox.org/git/[email protected]/

I understand why you want this change, but I dislike it because it removes the ability to have the compiler tell you that your switch statements are exhaustive. Of course it should be noticed rather quickly by the addition of those BUG statements :)

I think coverity doesn't flag empty sections, i.e.

    case FETCH_DONE:
    default:
        BUG(...)

would do for coverity. Not sure if we want to add a /*fall thru */ comment, that would aid other compilers to not warn about it.

This would cover both the compiler as well as coverity.

Stefan