Show total transferred as part of throughput progress display

PATCH In review Shawn O. Pearce 2 participants 2 messages Jun 15, 2016

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Shawn O. Pearce

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2016-06-15 22:43 UTC #0 lore raw

PATCH 1/1 Show total transferred as part of throughput progress display

Right now it is infeasible to offer to the user a reasonable concept of when a clone will be complete as we aren't able to come up with the final pack size until after we have actually transferred the entire thing to the client. However in many cases users can work with a rough rule-of-thumb; for example it is somewhat well known that git.git is about 16 MiB today and that linux-2.6.git is over 120 MiB.

We now show the total amount of data we have transferred over the network as part of the throughput meter, organizing it in "human friendly" terms like ls -h would do. Users can glance at this, see that the total transferred size is about 3 MiB, see the throughput of X KiB/sec, and determine a reasonable figure of about when the clone will be complete, assuming they know the rough size of the source repository or are able to obtain it.

This is also a helpful indicator that there is progress being made even if we stall on a very large object. The thoughput meter may remain relatively constant and the percentage complete and object count won't be changing, but the total transferred will be increasing as additional data is received for this object.

Signed-off-by Shawn O. Pearce <[email protected]>

---

This follows on top of Nico's 5 patch series to add the thoughput meter. I think its a useful addition.

 progress.c |   32 +++++++++++++++++++++++++++++---
 1 files changed, 29 insertions(+), 3 deletions(-)

progress.c +29 -3

index 23ee9f3..5c95091 100644
@@ -11,7 +11,11 @@ struct throughput {
 	unsigned int avg_misecs;
 	unsigned int last_misecs[TP_IDX_MAX];
 	unsigned int idx;
-	char display[20];
+	unsigned int unit_size;
+	unsigned int unit_index;
+	unsigned int total_units;
+	unsigned int curr_bytes;
+	char display[40];
 };
 
 struct progress {

@@ -24,6 +28,7 @@ struct progress {
 	struct throughput *throughput;
 };
 
+static const char *units[] = {"bytes", "KiB", "MiB", "GiB"};
 static volatile sig_atomic_t progress_update;
 
 static void progress_interval(int signum)

@@ -113,12 +118,27 @@ void display_throughput(struct progress *progress, unsigned long n)
 
 	if (!tp) {
 		progress->throughput = tp = calloc(1, sizeof(*tp));
-		if (tp)
+		if (tp) {
 			tp->prev_tv = tv;
+			tp->unit_size = 1;
+		}
 		return;
 	}
 
 	tp->count += n;
+	tp->curr_bytes += n;
+	if (tp->curr_bytes > tp->unit_size) {
+		tp->total_units += tp->curr_bytes / tp->unit_size;
+		tp->curr_bytes = tp->curr_bytes % tp->unit_size;
+
+		while (tp->total_units >= 1024
+			&& tp->unit_index < ARRAY_SIZE(units)) {
+			tp->curr_bytes += (tp->total_units % 1024) * tp->unit_size;
+			tp->total_units = tp->total_units / 1024;
+			tp->unit_size *= 1024;
+			tp->unit_index++;
+		}
+	}
 
 	/*
 	 * We have x = bytes and y = microsecs.  We want z = KiB/s:

@@ -143,7 +163,13 @@ void display_throughput(struct progress *progress, unsigned long n)
 		tp->avg_bytes += tp->count;
 		tp->avg_misecs += misecs;
 		snprintf(tp->display, sizeof(tp->display),
-			 ", %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
+			 ", %3u.%2.2u %s     %lu KiB/s",
+			 tp->total_units,
+			 tp->unit_size > 1
+				? tp->curr_bytes / (tp->unit_size / 100)
+				: 0,
+			 units[tp->unit_index],
+			 tp->avg_bytes / tp->avg_misecs);
 		tp->avg_bytes -= tp->last_bytes[tp->idx];
 		tp->avg_misecs -= tp->last_misecs[tp->idx];
 		tp->last_bytes[tp->idx] = tp->count;

Signature · 1 line

1.5.3.4.1481.g854da

Nicolas Pitre

2016-06-15 22:43 UTC #1 lore raw

Quoted 7 lines · Shawn O. Pearce

We now show the total amount of data we have transferred over the network as part of the throughput meter, organizing it in "human friendly" terms like ls -h would do. Users can glance at this, see that the total transferred size is about 3 MiB, see the throughput of X KiB/sec, and determine a reasonable figure of about when the clone will be complete, assuming they know the rough size of the source repository or are able to obtain it.

Well, OK. But...

Quoted 5 lines

This is also a helpful indicator that there is progress being made even if we stall on a very large object. The thoughput meter may remain relatively constant and the percentage complete and object count won't be changing, but the total transferred will be increasing as additional data is received for this object.

Currently if the object count is unchanged for an extended period of time, the display_progress() function isn't called at all, so the updated byte count (and rate) won't be displayed either. This needs a fix, probably in a separate patch which I'll send right away.

Quoted 1 line

Signed-off-by Shawn O. Pearce <[email protected]>

Well, your patch has issues. Please see comments below.

Quoted 41 lines

progress.c +12 -2

index 23ee9f3..5c95091 100644
@@ -11,7 +11,11 @@ struct throughput {
 	unsigned int avg_misecs;
 	unsigned int last_misecs[TP_IDX_MAX];
 	unsigned int idx;
-	char display[20];
+	unsigned int unit_size;
+	unsigned int unit_index;
+	unsigned int total_units;
+	unsigned int curr_bytes;
+	char display[40];
 };
 
 struct progress {

@@ -24,6 +28,7 @@ struct progress {
 	struct throughput *throughput;
 };
 
+static const char *units[] = {"bytes", "KiB", "MiB", "GiB"};
 static volatile sig_atomic_t progress_update;
 
 static void progress_interval(int signum)

@@ -113,12 +118,27 @@ void display_throughput(struct progress *progress, unsigned long n)
 
 	if (!tp) {
 		progress->throughput = tp = calloc(1, sizeof(*tp));
-		if (tp)
+		if (tp) {
 			tp->prev_tv = tv;
+			tp->unit_size = 1;
+		}
 		return;
 	}
 
 	tp->count += n;
+	tp->curr_bytes += n;
+	if (tp->curr_bytes > tp->unit_size) {
+		tp->total_units += tp->curr_bytes / tp->unit_size;

progress.c void display_throughput(struct progress *progress, unsigned long n) · line 141

Quoted 10 lines

progress.c +10 -0

+		tp->curr_bytes = tp->curr_bytes % tp->unit_size;
+
+		while (tp->total_units >= 1024
+			&& tp->unit_index < ARRAY_SIZE(units)) {
+			tp->curr_bytes += (tp->total_units % 1024) * tp->unit_size;
+			tp->total_units = tp->total_units / 1024;
+			tp->unit_size *= 1024;
+			tp->unit_index++;
+		}
+	}

This whole block could be moved inside the "if (misecs > 512)" conditional. There is no point performing that computation over and over when the display isn't updated more than twice a second anyway.

progress.c void display_throughput(struct progress *progress, unsigned long n) · line 166

Quoted 6 lines

progress.c +1 -1

@@ -143,7 +163,13 @@ void display_throughput(struct progress *progress, unsigned long n)
 		tp->avg_bytes += tp->count;
 		tp->avg_misecs += misecs;
 		snprintf(tp->display, sizeof(tp->display),
-			 ", %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
+			 ", %3u.%2.2u %s     %lu KiB/s",

The line is becoming quite long already, and I'd prefer if remote messages like the pack-objects summary kept overwriting it entirely while this line is bumped to the next line on screen for a prettier display. So I'd prefer if there wasn't so many spaces inserted there. What about something like ", %u.%2.2u %s | %lu KiB/s" instead?

Also I think that displaying fractional bytes, even if it is always 0, is a bit weird.

progress.c void display_throughput(struct progress *progress, unsigned long n) · line 169

Quoted 3 lines

progress.c +3 -0

+			 tp->total_units,
+			 tp->unit_size > 1
+				? tp->curr_bytes / (tp->unit_size / 100)

This has integer truncation problems. Suppose tp->unit_size = 1024 and tp->curr_bytes = 1023. You get 1023 / (1024 / 100) = 102 while the desired result should be 99.

Overall I think your patch is also needlessly too complex. this could be implemented in a much simpler way, such as follows:

progress.c +26 -3

index 34a5961..1212be8 100644
@@ -15,13 +15,14 @@
 
 struct throughput {
 	struct timeval prev_tv;
+	size_t total;
 	unsigned long count;
 	unsigned long avg_bytes;
 	unsigned long last_bytes[TP_IDX_MAX];
 	unsigned int avg_misecs;
 	unsigned int last_misecs[TP_IDX_MAX];
 	unsigned int idx;
-	char display[20];
+	char display[32];
 };
 
 struct progress {

@@ -128,6 +129,7 @@ void display_throughput(struct progress *progress, unsigned long n)
 		return;
 	}
 
+	tp->total += n;
 	tp->count += n;
 
 	/*

@@ -149,11 +151,32 @@ void display_throughput(struct progress *progress, unsigned long n)
 	misecs += (int)(tv.tv_usec - tp->prev_tv.tv_usec) / 977;
 
 	if (misecs > 512) {
+		unsigned l = sizeof(tp->display);
 		tp->prev_tv = tv;
 		tp->avg_bytes += tp->count;
 		tp->avg_misecs += misecs;
-		snprintf(tp->display, sizeof(tp->display),
-			 ", %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
+
+		if (tp->total > 1 << 30) {
+			l -= snprintf(tp->display, l, ", %u.%2.2u GiB",
+				      (int)(tp->total >> 30),
+				      (int)(tp->total & ((1 << 30) - 1)) / 10737419);
+		} else if (tp->total > 1 << 20) {
+			l -= snprintf(tp->display, l, ", %u.%2.2u MiB",
+				      (int)(tp->total >> 20),
+				      ((int)(tp->total & ((1 << 20) - 1))
+				       * 100) >> 20);
+		} else if (tp->total > 1 << 10) {
+			l -= snprintf(tp->display, l, ", %u.%2.2u KiB",
+				      (int)(tp->total >> 10),
+				      ((int)(tp->total & ((1 << 10) - 1))
+				       * 100) >> 10);
+		} else {
+			l -= snprintf(tp->display, l, ", %u bytes",
+				      (int)tp->total);
+		}
+		snprintf(tp->display + sizeof(tp->display) - l, l,
+			 " | %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
+
 		tp->avg_bytes -= tp->last_bytes[tp->idx];
 		tp->avg_misecs -= tp->last_misecs[tp->idx];
 		tp->last_bytes[tp->idx] = tp->count;

Nicolas