btrfs: Add zstd support to btrfs

Import xxhash and zstd from the upstream kernel as-is. This will not compile. The next patch in the series contains all the changes needed to make zstd compile in grub. Only the files needed for decompression are imported from zstd.

The files are copied from these locations:
include/linux/{xxhash,zstd}.h
lib/xxhash.c
lib/zstd/

Signed-off-by Nick Terrell <[email protected]>

---
 grub-core/lib/zstd/bitstream.h      |  374 ++++++
 grub-core/lib/zstd/decompress.c     | 2528 +++++++++++++++++++++++++++++++++++
 grub-core/lib/zstd/entropy_common.c |  243 ++++
 grub-core/lib/zstd/error_private.h  |   53 +
 grub-core/lib/zstd/fse.h            |  575 ++++++++
 grub-core/lib/zstd/fse_decompress.c |  332 +++++
 grub-core/lib/zstd/huf.h            |  212 +++
 grub-core/lib/zstd/huf_decompress.c |  960 +++++++++++++
 grub-core/lib/zstd/mem.h            |  151 +++
 grub-core/lib/zstd/xxhash.c         |  500 +++++++
 grub-core/lib/zstd/xxhash.h         |  236 ++++
 grub-core/lib/zstd/zstd.h           | 1157 ++++++++++++++++
 grub-core/lib/zstd/zstd_common.c    |   75 ++
 grub-core/lib/zstd/zstd_internal.h  |  263 ++++
 14 files changed, 7659 insertions(+)
 create mode 100644 grub-core/lib/zstd/bitstream.h
 create mode 100644 grub-core/lib/zstd/decompress.c
 create mode 100644 grub-core/lib/zstd/entropy_common.c
 create mode 100644 grub-core/lib/zstd/error_private.h
 create mode 100644 grub-core/lib/zstd/fse.h
 create mode 100644 grub-core/lib/zstd/fse_decompress.c
 create mode 100644 grub-core/lib/zstd/huf.h
 create mode 100644 grub-core/lib/zstd/huf_decompress.c
 create mode 100644 grub-core/lib/zstd/mem.h
 create mode 100644 grub-core/lib/zstd/xxhash.c
 create mode 100644 grub-core/lib/zstd/xxhash.h
 create mode 100644 grub-core/lib/zstd/zstd.h
 create mode 100644 grub-core/lib/zstd/zstd_common.c
 create mode 100644 grub-core/lib/zstd/zstd_internal.h

grub-core/lib/zstd/bitstream.h new file +374 -0

new file mode 100644
index 000000000..a826b99e1
@@ -0,0 +1,374 @@
+/*
+ * bitstream
+ * Part of FSE library
+ * header file (to include)
+ * Copyright (C) 2013-2016, Yann Collet.
+ *
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ *
+ * You can contact the author at :
+ * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ */
+#ifndef BITSTREAM_H_MODULE
+#define BITSTREAM_H_MODULE
+
+/*
+*  This API consists of small unitary functions, which must be inlined for best performance.
+*  Since link-time-optimization is not available for all compilers,
+*  these functions are defined into a .h to be included.
+*/
+
+/*-****************************************
+*  Dependencies
+******************************************/
+#include "error_private.h" /* error codes and messages */
+#include "mem.h"          /* unaligned access routines */
+
+/*=========================================
+*  Target specific
+=========================================*/
+#define STREAM_ACCUMULATOR_MIN_32 25
+#define STREAM_ACCUMULATOR_MIN_64 57
+#define STREAM_ACCUMULATOR_MIN ((U32)(ZSTD_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))
+
+/*-******************************************
+*  bitStream encoding API (write forward)
+********************************************/
+/* bitStream can mix input from multiple sources.
+*  A critical property of these streams is that they encode and decode in **reverse** direction.
+*  So the first bit sequence you add will be the last to be read, like a LIFO stack.
+*/
+typedef struct {
+       size_t bitContainer;
+       int bitPos;
+       char *startPtr;
+       char *ptr;
+       char *endPtr;
+} BIT_CStream_t;
+
+ZSTD_STATIC size_t BIT_initCStream(BIT_CStream_t *bitC, void *dstBuffer, size_t dstCapacity);
+ZSTD_STATIC void BIT_addBits(BIT_CStream_t *bitC, size_t value, unsigned nbBits);
+ZSTD_STATIC void BIT_flushBits(BIT_CStream_t *bitC);
+ZSTD_STATIC size_t BIT_closeCStream(BIT_CStream_t *bitC);
+
+/* Start with initCStream, providing the size of buffer to write into.
+*  bitStream will never write outside of this buffer.
+*  `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
+*
+*  bits are first added to a local register.
+*  Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
+*  Writing data into memory is an explicit operation, performed by the flushBits function.
+*  Hence keep track how many bits are potentially stored into local register to avoid register overflow.
+*  After a flushBits, a maximum of 7 bits might still be stored into local register.
+*
+*  Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
+*
+*  Last operation is to close the bitStream.
+*  The function returns the final size of CStream in bytes.
+*  If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
+*/
+
+/*-********************************************
+*  bitStream decoding API (read backward)
+**********************************************/
+typedef struct {
+       size_t bitContainer;
+       unsigned bitsConsumed;
+       const char *ptr;
+       const char *start;
+} BIT_DStream_t;
+
+typedef enum {
+       BIT_DStream_unfinished = 0,
+       BIT_DStream_endOfBuffer = 1,
+       BIT_DStream_completed = 2,
+       BIT_DStream_overflow = 3
+} BIT_DStream_status; /* result of BIT_reloadDStream() */
+/* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
+
+ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, size_t srcSize);
+ZSTD_STATIC size_t BIT_readBits(BIT_DStream_t *bitD, unsigned nbBits);
+ZSTD_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t *bitD);
+ZSTD_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t *bitD);
+
+/* Start by invoking BIT_initDStream().
+*  A chunk of the bitStream is then stored into a local register.
+*  Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
+*  You can then retrieve bitFields stored into the local register, **in reverse order**.
+*  Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
+*  A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
+*  Otherwise, it can be less than that, so proceed accordingly.
+*  Checking if DStream has reached its end can be performed with BIT_endOfDStream().
+*/
+
+/*-****************************************
+*  unsafe API
+******************************************/
+ZSTD_STATIC void BIT_addBitsFast(BIT_CStream_t *bitC, size_t value, unsigned nbBits);
+/* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */
+
+ZSTD_STATIC void BIT_flushBitsFast(BIT_CStream_t *bitC);
+/* unsafe version; does not check buffer overflow */
+
+ZSTD_STATIC size_t BIT_readBitsFast(BIT_DStream_t *bitD, unsigned nbBits);
+/* faster, but works only if nbBits >= 1 */
+
+/*-**************************************************************
+*  Internal functions
+****************************************************************/
+ZSTD_STATIC unsigned BIT_highbit32(register U32 val) { return 31 - __builtin_clz(val); }
+
+/*=====    Local Constants   =====*/
+static const unsigned BIT_mask[] = {0,       1,       3,       7,      0xF,      0x1F,     0x3F,     0x7F,      0xFF,
+                                   0x1FF,   0x3FF,   0x7FF,   0xFFF,    0x1FFF,   0x3FFF,   0x7FFF,   0xFFFF,    0x1FFFF,
+                                   0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF, 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF}; /* up to 26 bits */
+
+/*-**************************************************************
+*  bitStream encoding
+****************************************************************/
+/*! BIT_initCStream() :
+ *  `dstCapacity` must be > sizeof(void*)
+ *  @return : 0 if success,
+                         otherwise an error code (can be tested using ERR_isError() ) */
+ZSTD_STATIC size_t BIT_initCStream(BIT_CStream_t *bitC, void *startPtr, size_t dstCapacity)
+{
+       bitC->bitContainer = 0;
+       bitC->bitPos = 0;
+       bitC->startPtr = (char *)startPtr;
+       bitC->ptr = bitC->startPtr;
+       bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->ptr);
+       if (dstCapacity <= sizeof(bitC->ptr))
+               return ERROR(dstSize_tooSmall);
+       return 0;
+}
+
+/*! BIT_addBits() :
+       can add up to 26 bits into `bitC`.
+       Does not check for register overflow ! */
+ZSTD_STATIC void BIT_addBits(BIT_CStream_t *bitC, size_t value, unsigned nbBits)
+{
+       bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
+       bitC->bitPos += nbBits;
+}
+
+/*! BIT_addBitsFast() :
+ *  works only if `value` is _clean_, meaning all high bits above nbBits are 0 */
+ZSTD_STATIC void BIT_addBitsFast(BIT_CStream_t *bitC, size_t value, unsigned nbBits)
+{
+       bitC->bitContainer |= value << bitC->bitPos;
+       bitC->bitPos += nbBits;
+}
+
+/*! BIT_flushBitsFast() :
+ *  unsafe version; does not check buffer overflow */
+ZSTD_STATIC void BIT_flushBitsFast(BIT_CStream_t *bitC)
+{
+       size_t const nbBytes = bitC->bitPos >> 3;
+       ZSTD_writeLEST(bitC->ptr, bitC->bitContainer);
+       bitC->ptr += nbBytes;
+       bitC->bitPos &= 7;
+       bitC->bitContainer >>= nbBytes * 8; /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+}
+
+/*! BIT_flushBits() :
+ *  safe version; check for buffer overflow, and prevents it.
+ *  note : does not signal buffer overflow. This will be revealed later on using BIT_closeCStream() */
+ZSTD_STATIC void BIT_flushBits(BIT_CStream_t *bitC)
+{
+       size_t const nbBytes = bitC->bitPos >> 3;
+       ZSTD_writeLEST(bitC->ptr, bitC->bitContainer);
+       bitC->ptr += nbBytes;
+       if (bitC->ptr > bitC->endPtr)
+               bitC->ptr = bitC->endPtr;
+       bitC->bitPos &= 7;
+       bitC->bitContainer >>= nbBytes * 8; /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+}
+
+/*! BIT_closeCStream() :
+ *  @return : size of CStream, in bytes,
+                         or 0 if it could not fit into dstBuffer */
+ZSTD_STATIC size_t BIT_closeCStream(BIT_CStream_t *bitC)
+{
+       BIT_addBitsFast(bitC, 1, 1); /* endMark */
+       BIT_flushBits(bitC);
+
+       if (bitC->ptr >= bitC->endPtr)
+               return 0; /* doesn't fit within authorized budget : cancel */
+
+       return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
+}
+
+/*-********************************************************
+* bitStream decoding
+**********************************************************/
+/*! BIT_initDStream() :
+*   Initialize a BIT_DStream_t.
+*   `bitD` : a pointer to an already allocated BIT_DStream_t structure.
+*   `srcSize` must be the *exact* size of the bitStream, in bytes.
+*   @return : size of stream (== srcSize) or an errorCode if a problem is detected
+*/
+ZSTD_STATIC size_t BIT_initDStream(BIT_DStream_t *bitD, const void *srcBuffer, size_t srcSize)
+{
+       if (srcSize < 1) {
+               memset(bitD, 0, sizeof(*bitD));
+               return ERROR(srcSize_wrong);
+       }
+
+       if (srcSize >= sizeof(bitD->bitContainer)) { /* normal case */
+               bitD->start = (const char *)srcBuffer;
+               bitD->ptr = (const char *)srcBuffer + srcSize - sizeof(bitD->bitContainer);
+               bitD->bitContainer = ZSTD_readLEST(bitD->ptr);
+               {
+                       BYTE const lastByte = ((const BYTE *)srcBuffer)[srcSize - 1];
+                       bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0; /* ensures bitsConsumed is always set */
+                       if (lastByte == 0)
+                               return ERROR(GENERIC); /* endMark not present */
+               }
+       } else {
+               bitD->start = (const char *)srcBuffer;
+               bitD->ptr = bitD->start;
+               bitD->bitContainer = *(const BYTE *)(bitD->start);
+               switch (srcSize) {
+               case 7: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[6]) << (sizeof(bitD->bitContainer) * 8 - 16);
+               case 6: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[5]) << (sizeof(bitD->bitContainer) * 8 - 24);
+               case 5: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[4]) << (sizeof(bitD->bitContainer) * 8 - 32);
+               case 4: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[3]) << 24;
+               case 3: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[2]) << 16;
+               case 2: bitD->bitContainer += (size_t)(((const BYTE *)(srcBuffer))[1]) << 8;
+               default:;
+               }
+               {
+                       BYTE const lastByte = ((const BYTE *)srcBuffer)[srcSize - 1];
+                       bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
+                       if (lastByte == 0)
+                               return ERROR(GENERIC); /* endMark not present */
+               }
+               bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize) * 8;
+       }
+
+       return srcSize;
+}
+
+ZSTD_STATIC size_t BIT_getUpperBits(size_t bitContainer, U32 const start) { return bitContainer >> start; }
+
+ZSTD_STATIC size_t BIT_getMiddleBits(size_t bitContainer, U32 const start, U32 const nbBits) { return (bitContainer >> start) & BIT_mask[nbBits]; }
+
+ZSTD_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits) { return bitContainer & BIT_mask[nbBits]; }
+
+/*! BIT_lookBits() :
+ *  Provides next n bits from local register.
+ *  local register is not modified.
+ *  On 32-bits, maxNbBits==24.
+ *  On 64-bits, maxNbBits==56.
+ *  @return : value extracted
+ */
+ZSTD_STATIC size_t BIT_lookBits(const BIT_DStream_t *bitD, U32 nbBits)
+{
+       U32 const bitMask = sizeof(bitD->bitContainer) * 8 - 1;
+       return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask - nbBits) & bitMask);
+}
+
+/*! BIT_lookBitsFast() :
+*   unsafe version; only works only if nbBits >= 1 */
+ZSTD_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t *bitD, U32 nbBits)
+{
+       U32 const bitMask = sizeof(bitD->bitContainer) * 8 - 1;
+       return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask + 1) - nbBits) & bitMask);
+}
+
+ZSTD_STATIC void BIT_skipBits(BIT_DStream_t *bitD, U32 nbBits) { bitD->bitsConsumed += nbBits; }
+
+/*! BIT_readBits() :
+ *  Read (consume) next n bits from local register and update.
+ *  Pay attention to not read more than nbBits contained into local register.
+ *  @return : extracted value.
+ */
+ZSTD_STATIC size_t BIT_readBits(BIT_DStream_t *bitD, U32 nbBits)
+{
+       size_t const value = BIT_lookBits(bitD, nbBits);
+       BIT_skipBits(bitD, nbBits);
+       return value;
+}
+
+/*! BIT_readBitsFast() :
+*   unsafe version; only works only if nbBits >= 1 */
+ZSTD_STATIC size_t BIT_readBitsFast(BIT_DStream_t *bitD, U32 nbBits)
+{
+       size_t const value = BIT_lookBitsFast(bitD, nbBits);
+       BIT_skipBits(bitD, nbBits);
+       return value;
+}
+
+/*! BIT_reloadDStream() :
+*   Refill `bitD` from buffer previously set in BIT_initDStream() .
+*   This function is safe, it guarantees it will not read beyond src buffer.
+*   @return : status of `BIT_DStream_t` internal register.
+                         if status == BIT_DStream_unfinished, internal register is filled with >= (sizeof(bitD->bitContainer)*8 - 7) bits */
+ZSTD_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t *bitD)
+{
+       if (bitD->bitsConsumed > (sizeof(bitD->bitContainer) * 8)) /* should not happen => corruption detected */
+               return BIT_DStream_overflow;
+
+       if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer)) {
+               bitD->ptr -= bitD->bitsConsumed >> 3;
+               bitD->bitsConsumed &= 7;
+               bitD->bitContainer = ZSTD_readLEST(bitD->ptr);
+               return BIT_DStream_unfinished;
+       }
+       if (bitD->ptr == bitD->start) {
+               if (bitD->bitsConsumed < sizeof(bitD->bitContainer) * 8)
+                       return BIT_DStream_endOfBuffer;
+               return BIT_DStream_completed;
+       }
+       {
+               U32 nbBytes = bitD->bitsConsumed >> 3;
+               BIT_DStream_status result = BIT_DStream_unfinished;
+               if (bitD->ptr - nbBytes < bitD->start) {
+                       nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */
+                       result = BIT_DStream_endOfBuffer;
+               }
+               bitD->ptr -= nbBytes;
+               bitD->bitsConsumed -= nbBytes * 8;
+               bitD->bitContainer = ZSTD_readLEST(bitD->ptr); /* reminder : srcSize > sizeof(bitD) */
+               return result;
+       }
+}
+
+/*! BIT_endOfDStream() :
+*   @return Tells if DStream has exactly reached its end (all bits consumed).
+*/
+ZSTD_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t *DStream)
+{
+       return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer) * 8));
+}
+
+#endif /* BITSTREAM_H_MODULE */

grub-core/lib/zstd/decompress.c new file +2528 -0

new file mode 100644
index 000000000..b17846725
@@ -0,0 +1,2528 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of https://github.com/facebook/zstd.
+ * An additional grant of patent rights can be found in the PATENTS file in the
+ * same directory.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ */
+
+/* ***************************************************************
+*  Tuning parameters
+*****************************************************************/
+/*!
+*  MAXWINDOWSIZE_DEFAULT :
+*  maximum window size accepted by DStream, by default.
+*  Frames requiring more memory will be rejected.
+*/
+#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
+#define ZSTD_MAXWINDOWSIZE_DEFAULT ((1 << ZSTD_WINDOWLOG_MAX) + 1) /* defined within zstd.h */
+#endif
+
+/*-*******************************************************
+*  Dependencies
+*********************************************************/
+#include "fse.h"
+#include "huf.h"
+#include "mem.h" /* low level memory routines */
+#include "zstd_internal.h"
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h> /* memcpy, memmove, memset */
+
+#define ZSTD_PREFETCH(ptr) __builtin_prefetch(ptr, 0, 0)
+
+/*-*************************************
+*  Macros
+***************************************/
+#define ZSTD_isError ERR_isError /* for inlining */
+#define FSE_isError ERR_isError
+#define HUF_isError ERR_isError
+
+/*_*******************************************************
+*  Memory operations
+**********************************************************/
+static void ZSTD_copy4(void *dst, const void *src) { memcpy(dst, src, 4); }
+
+/*-*************************************************************
+*   Context management
+***************************************************************/
+typedef enum {
+       ZSTDds_getFrameHeaderSize,
+       ZSTDds_decodeFrameHeader,
+       ZSTDds_decodeBlockHeader,
+       ZSTDds_decompressBlock,
+       ZSTDds_decompressLastBlock,
+       ZSTDds_checkChecksum,
+       ZSTDds_decodeSkippableHeader,
+       ZSTDds_skipFrame
+} ZSTD_dStage;
+
+typedef struct {
+       FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
+       FSE_DTable OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
+       FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
+       HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */
+       U64 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32 / 2];
+       U32 rep[ZSTD_REP_NUM];
+} ZSTD_entropyTables_t;
+
+struct ZSTD_DCtx_s {
+       const FSE_DTable *LLTptr;
+       const FSE_DTable *MLTptr;
+       const FSE_DTable *OFTptr;
+       const HUF_DTable *HUFptr;
+       ZSTD_entropyTables_t entropy;
+       const void *previousDstEnd; /* detect continuity */
+       const void *base;          /* start of curr segment */
+       const void *vBase;        /* virtual start of previous segment if it was just before curr one */
+       const void *dictEnd;    /* end of previous segment */
+       size_t expected;
+       ZSTD_frameParams fParams;
+       blockType_e bType; /* used in ZSTD_decompressContinue(), to transfer blockType between header decoding and block decoding stages */
+       ZSTD_dStage stage;
+       U32 litEntropy;
+       U32 fseEntropy;
+       struct xxh64_state xxhState;
+       size_t headerSize;
+       U32 dictID;
+       const BYTE *litPtr;
+       ZSTD_customMem customMem;
+       size_t litSize;
+       size_t rleSize;
+       BYTE litBuffer[ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
+       BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
+}; /* typedef'd to ZSTD_DCtx within "zstd.h" */
+
+size_t ZSTD_DCtxWorkspaceBound(void) { return ZSTD_ALIGN(sizeof(ZSTD_stack)) + ZSTD_ALIGN(sizeof(ZSTD_DCtx)); }
+
+size_t ZSTD_decompressBegin(ZSTD_DCtx *dctx)
+{
+       dctx->expected = ZSTD_frameHeaderSize_prefix;
+       dctx->stage = ZSTDds_getFrameHeaderSize;
+       dctx->previousDstEnd = NULL;
+       dctx->base = NULL;
+       dctx->vBase = NULL;
+       dctx->dictEnd = NULL;
+       dctx->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */
+       dctx->litEntropy = dctx->fseEntropy = 0;
+       dctx->dictID = 0;
+       ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
+       memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */
+       dctx->LLTptr = dctx->entropy.LLTable;
+       dctx->MLTptr = dctx->entropy.MLTable;
+       dctx->OFTptr = dctx->entropy.OFTable;
+       dctx->HUFptr = dctx->entropy.hufTable;
+       return 0;
+}
+
+ZSTD_DCtx *ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
+{
+       ZSTD_DCtx *dctx;
+
+       if (!customMem.customAlloc || !customMem.customFree)
+               return NULL;
+
+       dctx = (ZSTD_DCtx *)ZSTD_malloc(sizeof(ZSTD_DCtx), customMem);
+       if (!dctx)
+               return NULL;
+       memcpy(&dctx->customMem, &customMem, sizeof(customMem));
+       ZSTD_decompressBegin(dctx);
+       return dctx;
+}
+
+ZSTD_DCtx *ZSTD_initDCtx(void *workspace, size_t workspaceSize)
+{
+       ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize);
+       return ZSTD_createDCtx_advanced(stackMem);
+}
+
+size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx)
+{
+       if (dctx == NULL)
+               return 0; /* support free on NULL */
+       ZSTD_free(dctx, dctx->customMem);
+       return 0; /* reserved as a potential error code in the future */
+}
+
+void ZSTD_copyDCtx(ZSTD_DCtx *dstDCtx, const ZSTD_DCtx *srcDCtx)
+{
+       size_t const workSpaceSize = (ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH) + ZSTD_frameHeaderSize_max;
+       memcpy(dstDCtx, srcDCtx, sizeof(ZSTD_DCtx) - workSpaceSize); /* no need to copy workspace */
+}
+
+static void ZSTD_refDDict(ZSTD_DCtx *dstDCtx, const ZSTD_DDict *ddict);
+
+/*-*************************************************************
+*   Decompression section
+***************************************************************/
+
+/*! ZSTD_isFrame() :
+ *  Tells if the content of `buffer` starts with a valid Frame Identifier.
+ *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
+ *  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
+ *  Note 3 : Skippable Frame Identifiers are considered valid. */
+unsigned ZSTD_isFrame(const void *buffer, size_t size)
+{
+       if (size < 4)
+               return 0;
+       {
+               U32 const magic = ZSTD_readLE32(buffer);
+               if (magic == ZSTD_MAGICNUMBER)
+                       return 1;
+               if ((magic & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START)
+                       return 1;
+       }
+       return 0;
+}
+
+/** ZSTD_frameHeaderSize() :
+*   srcSize must be >= ZSTD_frameHeaderSize_prefix.
+*   @return : size of the Frame Header */
+static size_t ZSTD_frameHeaderSize(const void *src, size_t srcSize)
+{
+       if (srcSize < ZSTD_frameHeaderSize_prefix)
+               return ERROR(srcSize_wrong);
+       {
+               BYTE const fhd = ((const BYTE *)src)[4];
+               U32 const dictID = fhd & 3;
+               U32 const singleSegment = (fhd >> 5) & 1;
+               U32 const fcsId = fhd >> 6;
+               return ZSTD_frameHeaderSize_prefix + !singleSegment + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId] + (singleSegment && !fcsId);
+       }
+}
+
+/** ZSTD_getFrameParams() :
+*   decode Frame Header, or require larger `srcSize`.
+*   @return : 0, `fparamsPtr` is correctly filled,
+*            >0, `srcSize` is too small, result is expected `srcSize`,
+*             or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_getFrameParams(ZSTD_frameParams *fparamsPtr, const void *src, size_t srcSize)
+{
+       const BYTE *ip = (const BYTE *)src;
+
+       if (srcSize < ZSTD_frameHeaderSize_prefix)
+               return ZSTD_frameHeaderSize_prefix;
+       if (ZSTD_readLE32(src) != ZSTD_MAGICNUMBER) {
+               if ((ZSTD_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+                       if (srcSize < ZSTD_skippableHeaderSize)
+                               return ZSTD_skippableHeaderSize; /* magic number + skippable frame length */
+                       memset(fparamsPtr, 0, sizeof(*fparamsPtr));
+                       fparamsPtr->frameContentSize = ZSTD_readLE32((const char *)src + 4);
+                       fparamsPtr->windowSize = 0; /* windowSize==0 means a frame is skippable */
+                       return 0;
+               }
+               return ERROR(prefix_unknown);
+       }
+
+       /* ensure there is enough `srcSize` to fully read/decode frame header */
+       {
+               size_t const fhsize = ZSTD_frameHeaderSize(src, srcSize);
+               if (srcSize < fhsize)
+                       return fhsize;
+       }
+
+       {
+               BYTE const fhdByte = ip[4];
+               size_t pos = 5;
+               U32 const dictIDSizeCode = fhdByte & 3;
+               U32 const checksumFlag = (fhdByte >> 2) & 1;
+               U32 const singleSegment = (fhdByte >> 5) & 1;
+               U32 const fcsID = fhdByte >> 6;
+               U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;
+               U32 windowSize = 0;
+               U32 dictID = 0;
+               U64 frameContentSize = 0;
+               if ((fhdByte & 0x08) != 0)
+                       return ERROR(frameParameter_unsupported); /* reserved bits, which must be zero */
+               if (!singleSegment) {
+                       BYTE const wlByte = ip[pos++];
+                       U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
+                       if (windowLog > ZSTD_WINDOWLOG_MAX)
+                               return ERROR(frameParameter_windowTooLarge); /* avoids issue with 1 << windowLog */
+                       windowSize = (1U << windowLog);
+                       windowSize += (windowSize >> 3) * (wlByte & 7);
+               }
+
+               switch (dictIDSizeCode) {
+               default: /* impossible */
+               case 0: break;
+               case 1:
+                       dictID = ip[pos];
+                       pos++;
+                       break;
+               case 2:
+                       dictID = ZSTD_readLE16(ip + pos);
+                       pos += 2;
+                       break;
+               case 3:
+                       dictID = ZSTD_readLE32(ip + pos);
+                       pos += 4;
+                       break;
+               }
+               switch (fcsID) {
+               default: /* impossible */
+               case 0:
+                       if (singleSegment)
+                               frameContentSize = ip[pos];
+                       break;
+               case 1: frameContentSize = ZSTD_readLE16(ip + pos) + 256; break;
+               case 2: frameContentSize = ZSTD_readLE32(ip + pos); break;
+               case 3: frameContentSize = ZSTD_readLE64(ip + pos); break;
+               }
+               if (!windowSize)
+                       windowSize = (U32)frameContentSize;
+               if (windowSize > windowSizeMax)
+                       return ERROR(frameParameter_windowTooLarge);
+               fparamsPtr->frameContentSize = frameContentSize;
+               fparamsPtr->windowSize = windowSize;
+               fparamsPtr->dictID = dictID;
+               fparamsPtr->checksumFlag = checksumFlag;
+       }
+       return 0;
+}
+
+/** ZSTD_getFrameContentSize() :
+*   compatible with legacy mode
+*   @return : decompressed size of the single frame pointed to be `src` if known, otherwise
+*             - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
+*             - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
+unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
+{
+       {
+               ZSTD_frameParams fParams;
+               if (ZSTD_getFrameParams(&fParams, src, srcSize) != 0)
+                       return ZSTD_CONTENTSIZE_ERROR;
+               if (fParams.windowSize == 0) {
+                       /* Either skippable or empty frame, size == 0 either way */
+                       return 0;
+               } else if (fParams.frameContentSize != 0) {
+                       return fParams.frameContentSize;
+               } else {
+                       return ZSTD_CONTENTSIZE_UNKNOWN;
+               }
+       }
+}
+
+/** ZSTD_findDecompressedSize() :
+ *  compatible with legacy mode
+ *  `srcSize` must be the exact length of some number of ZSTD compressed and/or
+ *      skippable frames
+ *  @return : decompressed size of the frames contained */
+unsigned long long ZSTD_findDecompressedSize(const void *src, size_t srcSize)
+{
+       {
+               unsigned long long totalDstSize = 0;
+               while (srcSize >= ZSTD_frameHeaderSize_prefix) {
+                       const U32 magicNumber = ZSTD_readLE32(src);
+
+                       if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+                               size_t skippableSize;
+                               if (srcSize < ZSTD_skippableHeaderSize)
+                                       return ERROR(srcSize_wrong);
+                               skippableSize = ZSTD_readLE32((const BYTE *)src + 4) + ZSTD_skippableHeaderSize;
+                               if (srcSize < skippableSize) {
+                                       return ZSTD_CONTENTSIZE_ERROR;
+                               }
+
+                               src = (const BYTE *)src + skippableSize;
+                               srcSize -= skippableSize;
+                               continue;
+                       }
+
+                       {
+                               unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
+                               if (ret >= ZSTD_CONTENTSIZE_ERROR)
+                                       return ret;
+
+                               /* check for overflow */
+                               if (totalDstSize + ret < totalDstSize)
+                                       return ZSTD_CONTENTSIZE_ERROR;
+                               totalDstSize += ret;
+                       }
+                       {
+                               size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
+                               if (ZSTD_isError(frameSrcSize)) {
+                                       return ZSTD_CONTENTSIZE_ERROR;
+                               }
+
+                               src = (const BYTE *)src + frameSrcSize;
+                               srcSize -= frameSrcSize;
+                       }
+               }
+
+               if (srcSize) {
+                       return ZSTD_CONTENTSIZE_ERROR;
+               }
+
+               return totalDstSize;
+       }
+}
+
+/** ZSTD_decodeFrameHeader() :
+*   `headerSize` must be the size provided by ZSTD_frameHeaderSize().
+*   @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
+static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx *dctx, const void *src, size_t headerSize)
+{
+       size_t const result = ZSTD_getFrameParams(&(dctx->fParams), src, headerSize);
+       if (ZSTD_isError(result))
+               return result; /* invalid header */
+       if (result > 0)
+               return ERROR(srcSize_wrong); /* headerSize too small */
+       if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID))
+               return ERROR(dictionary_wrong);
+       if (dctx->fParams.checksumFlag)
+               xxh64_reset(&dctx->xxhState, 0);
+       return 0;
+}
+
+typedef struct {
+       blockType_e blockType;
+       U32 lastBlock;
+       U32 origSize;
+} blockProperties_t;
+
+/*! ZSTD_getcBlockSize() :
+*   Provides the size of compressed block from block header `src` */
+size_t ZSTD_getcBlockSize(const void *src, size_t srcSize, blockProperties_t *bpPtr)
+{
+       if (srcSize < ZSTD_blockHeaderSize)
+               return ERROR(srcSize_wrong);
+       {
+               U32 const cBlockHeader = ZSTD_readLE24(src);
+               U32 const cSize = cBlockHeader >> 3;
+               bpPtr->lastBlock = cBlockHeader & 1;
+               bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
+               bpPtr->origSize = cSize; /* only useful for RLE */
+               if (bpPtr->blockType == bt_rle)
+                       return 1;
+               if (bpPtr->blockType == bt_reserved)
+                       return ERROR(corruption_detected);
+               return cSize;
+       }
+}
+
+static size_t ZSTD_copyRawBlock(void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{
+       if (srcSize > dstCapacity)
+               return ERROR(dstSize_tooSmall);
+       memcpy(dst, src, srcSize);
+       return srcSize;
+}
+
+static size_t ZSTD_setRleBlock(void *dst, size_t dstCapacity, const void *src, size_t srcSize, size_t regenSize)
+{
+       if (srcSize != 1)
+               return ERROR(srcSize_wrong);
+       if (regenSize > dstCapacity)
+               return ERROR(dstSize_tooSmall);
+       memset(dst, *(const BYTE *)src, regenSize);
+       return regenSize;
+}
+
+/*! ZSTD_decodeLiteralsBlock() :
+       @return : nb of bytes read from src (< srcSize ) */
+size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx *dctx, const void *src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
+{
+       if (srcSize < MIN_CBLOCK_SIZE)
+               return ERROR(corruption_detected);
+
+       {
+               const BYTE *const istart = (const BYTE *)src;
+               symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
+
+               switch (litEncType) {
+               case set_repeat:
+                       if (dctx->litEntropy == 0)
+                               return ERROR(dictionary_corrupted);
+               /* fall-through */
+               case set_compressed:
+                       if (srcSize < 5)
+                               return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3 */
+                       {
+                               size_t lhSize, litSize, litCSize;
+                               U32 singleStream = 0;
+                               U32 const lhlCode = (istart[0] >> 2) & 3;
+                               U32 const lhc = ZSTD_readLE32(istart);
+                               switch (lhlCode) {
+                               case 0:
+                               case 1:
+                               default: /* note : default is impossible, since lhlCode into [0..3] */
+                                       /* 2 - 2 - 10 - 10 */
+                                       singleStream = !lhlCode;
+                                       lhSize = 3;
+                                       litSize = (lhc >> 4) & 0x3FF;
+                                       litCSize = (lhc >> 14) & 0x3FF;
+                                       break;
+                               case 2:
+                                       /* 2 - 2 - 14 - 14 */
+                                       lhSize = 4;
+                                       litSize = (lhc >> 4) & 0x3FFF;
+                                       litCSize = lhc >> 18;
+                                       break;
+                               case 3:
+                                       /* 2 - 2 - 18 - 18 */
+                                       lhSize = 5;
+                                       litSize = (lhc >> 4) & 0x3FFFF;
+                                       litCSize = (lhc >> 22) + (istart[4] << 10);
+                                       break;
+                               }
+                               if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX)
+                                       return ERROR(corruption_detected);
+                               if (litCSize + lhSize > srcSize)
+                                       return ERROR(corruption_detected);
+
+                               if (HUF_isError(
+                                       (litEncType == set_repeat)
+                                           ? (singleStream ? HUF_decompress1X_usingDTable(dctx->litBuffer, litSize, istart + lhSize, litCSize, dctx->HUFptr)
+                                                           : HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart + lhSize, litCSize, dctx->HUFptr))
+                                           : (singleStream
+                                                  ? HUF_decompress1X2_DCtx_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart + lhSize, litCSize,
+                                                                                dctx->entropy.workspace, sizeof(dctx->entropy.workspace))
+                                                  : HUF_decompress4X_hufOnly_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart + lhSize, litCSize,
+                                                                                  dctx->entropy.workspace, sizeof(dctx->entropy.workspace)))))
+                                       return ERROR(corruption_detected);
+
+                               dctx->litPtr = dctx->litBuffer;
+                               dctx->litSize = litSize;
+                               dctx->litEntropy = 1;
+                               if (litEncType == set_compressed)
+                                       dctx->HUFptr = dctx->entropy.hufTable;
+                               memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
+                               return litCSize + lhSize;
+                       }
+
+               case set_basic: {
+                       size_t litSize, lhSize;
+                       U32 const lhlCode = ((istart[0]) >> 2) & 3;
+                       switch (lhlCode) {
+                       case 0:
+                       case 2:
+                       default: /* note : default is impossible, since lhlCode into [0..3] */
+                               lhSize = 1;
+                               litSize = istart[0] >> 3;
+                               break;
+                       case 1:
+                               lhSize = 2;
+                               litSize = ZSTD_readLE16(istart) >> 4;
+                               break;
+                       case 3:
+                               lhSize = 3;
+                               litSize = ZSTD_readLE24(istart) >> 4;
+                               break;
+                       }
+
+                       if (lhSize + litSize + WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */
+                               if (litSize + lhSize > srcSize)
+                                       return ERROR(corruption_detected);
+                               memcpy(dctx->litBuffer, istart + lhSize, litSize);
+                               dctx->litPtr = dctx->litBuffer;
+                               dctx->litSize = litSize;
+                               memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
+                               return lhSize + litSize;
+                       }
+                       /* direct reference into compressed stream */
+                       dctx->litPtr = istart + lhSize;
+                       dctx->litSize = litSize;
+                       return lhSize + litSize;
+               }
+
+               case set_rle: {
+                       U32 const lhlCode = ((istart[0]) >> 2) & 3;
+                       size_t litSize, lhSize;
+                       switch (lhlCode) {
+                       case 0:
+                       case 2:
+                       default: /* note : default is impossible, since lhlCode into [0..3] */
+                               lhSize = 1;
+                               litSize = istart[0] >> 3;
+                               break;
+                       case 1:
+                               lhSize = 2;
+                               litSize = ZSTD_readLE16(istart) >> 4;
+                               break;
+                       case 3:
+                               lhSize = 3;
+                               litSize = ZSTD_readLE24(istart) >> 4;
+                               if (srcSize < 4)
+                                       return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
+                               break;
+                       }
+                       if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX)
+                               return ERROR(corruption_detected);
+                       memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH);
+                       dctx->litPtr = dctx->litBuffer;
+                       dctx->litSize = litSize;
+                       return lhSize + 1;
+               }
+               default:
+                       return ERROR(corruption_detected); /* impossible */
+               }
+       }
+}
+
+typedef union {
+       FSE_decode_t realData;
+       U32 alignedBy4;
+} FSE_decode_t4;
+
+static const FSE_decode_t4 LL_defaultDTable[(1 << LL_DEFAULTNORMLOG) + 1] = {
+    {{LL_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */
+    {{0, 0, 4}},                /* 0 : base, symbol, bits */
+    {{16, 0, 4}},
+    {{32, 1, 5}},
+    {{0, 3, 5}},
+    {{0, 4, 5}},
+    {{0, 6, 5}},
+    {{0, 7, 5}},
+    {{0, 9, 5}},
+    {{0, 10, 5}},
+    {{0, 12, 5}},
+    {{0, 14, 6}},
+    {{0, 16, 5}},
+    {{0, 18, 5}},
+    {{0, 19, 5}},
+    {{0, 21, 5}},
+    {{0, 22, 5}},
+    {{0, 24, 5}},
+    {{32, 25, 5}},
+    {{0, 26, 5}},
+    {{0, 27, 6}},
+    {{0, 29, 6}},
+    {{0, 31, 6}},
+    {{32, 0, 4}},
+    {{0, 1, 4}},
+    {{0, 2, 5}},
+    {{32, 4, 5}},
+    {{0, 5, 5}},
+    {{32, 7, 5}},
+    {{0, 8, 5}},
+    {{32, 10, 5}},
+    {{0, 11, 5}},
+    {{0, 13, 6}},
+    {{32, 16, 5}},
+    {{0, 17, 5}},
+    {{32, 19, 5}},
+    {{0, 20, 5}},
+    {{32, 22, 5}},
+    {{0, 23, 5}},
+    {{0, 25, 4}},
+    {{16, 25, 4}},
+    {{32, 26, 5}},
+    {{0, 28, 6}},
+    {{0, 30, 6}},
+    {{48, 0, 4}},
+    {{16, 1, 4}},
+    {{32, 2, 5}},
+    {{32, 3, 5}},
+    {{32, 5, 5}},
+    {{32, 6, 5}},
+    {{32, 8, 5}},
+    {{32, 9, 5}},
+    {{32, 11, 5}},
+    {{32, 12, 5}},
+    {{0, 15, 6}},
+    {{32, 17, 5}},
+    {{32, 18, 5}},
+    {{32, 20, 5}},
+    {{32, 21, 5}},
+    {{32, 23, 5}},
+    {{32, 24, 5}},
+    {{0, 35, 6}},
+    {{0, 34, 6}},
+    {{0, 33, 6}},
+    {{0, 32, 6}},
+}; /* LL_defaultDTable */
+
+static const FSE_decode_t4 ML_defaultDTable[(1 << ML_DEFAULTNORMLOG) + 1] = {
+    {{ML_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */
+    {{0, 0, 6}},                /* 0 : base, symbol, bits */
+    {{0, 1, 4}},
+    {{32, 2, 5}},
+    {{0, 3, 5}},
+    {{0, 5, 5}},
+    {{0, 6, 5}},
+    {{0, 8, 5}},
+    {{0, 10, 6}},
+    {{0, 13, 6}},
+    {{0, 16, 6}},
+    {{0, 19, 6}},
+    {{0, 22, 6}},
+    {{0, 25, 6}},
+    {{0, 28, 6}},
+    {{0, 31, 6}},
+    {{0, 33, 6}},
+    {{0, 35, 6}},
+    {{0, 37, 6}},
+    {{0, 39, 6}},
+    {{0, 41, 6}},
+    {{0, 43, 6}},
+    {{0, 45, 6}},
+    {{16, 1, 4}},
+    {{0, 2, 4}},
+    {{32, 3, 5}},
+    {{0, 4, 5}},
+    {{32, 6, 5}},
+    {{0, 7, 5}},
+    {{0, 9, 6}},
+    {{0, 12, 6}},
+    {{0, 15, 6}},
+    {{0, 18, 6}},
+    {{0, 21, 6}},
+    {{0, 24, 6}},
+    {{0, 27, 6}},
+    {{0, 30, 6}},
+    {{0, 32, 6}},
+    {{0, 34, 6}},
+    {{0, 36, 6}},
+    {{0, 38, 6}},
+    {{0, 40, 6}},
+    {{0, 42, 6}},
+    {{0, 44, 6}},
+    {{32, 1, 4}},
+    {{48, 1, 4}},
+    {{16, 2, 4}},
+    {{32, 4, 5}},
+    {{32, 5, 5}},
+    {{32, 7, 5}},
+    {{32, 8, 5}},
+    {{0, 11, 6}},
+    {{0, 14, 6}},
+    {{0, 17, 6}},
+    {{0, 20, 6}},
+    {{0, 23, 6}},
+    {{0, 26, 6}},
+    {{0, 29, 6}},
+    {{0, 52, 6}},
+    {{0, 51, 6}},
+    {{0, 50, 6}},
+    {{0, 49, 6}},
+    {{0, 48, 6}},
+    {{0, 47, 6}},
+    {{0, 46, 6}},
+}; /* ML_defaultDTable */
+
+static const FSE_decode_t4 OF_defaultDTable[(1 << OF_DEFAULTNORMLOG) + 1] = {
+    {{OF_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */
+    {{0, 0, 5}},                /* 0 : base, symbol, bits */
+    {{0, 6, 4}},
+    {{0, 9, 5}},
+    {{0, 15, 5}},
+    {{0, 21, 5}},
+    {{0, 3, 5}},
+    {{0, 7, 4}},
+    {{0, 12, 5}},
+    {{0, 18, 5}},
+    {{0, 23, 5}},
+    {{0, 5, 5}},
+    {{0, 8, 4}},
+    {{0, 14, 5}},
+    {{0, 20, 5}},
+    {{0, 2, 5}},
+    {{16, 7, 4}},
+    {{0, 11, 5}},
+    {{0, 17, 5}},
+    {{0, 22, 5}},
+    {{0, 4, 5}},
+    {{16, 8, 4}},
+    {{0, 13, 5}},
+    {{0, 19, 5}},
+    {{0, 1, 5}},
+    {{16, 6, 4}},
+    {{0, 10, 5}},
+    {{0, 16, 5}},
+    {{0, 28, 5}},
+    {{0, 27, 5}},
+    {{0, 26, 5}},
+    {{0, 25, 5}},
+    {{0, 24, 5}},
+}; /* OF_defaultDTable */
+
+/*! ZSTD_buildSeqTable() :
+       @return : nb bytes read from src,
+                         or an error code if it fails, testable with ZSTD_isError()
+*/
+static size_t ZSTD_buildSeqTable(FSE_DTable *DTableSpace, const FSE_DTable **DTablePtr, symbolEncodingType_e type, U32 max, U32 maxLog, const void *src,
+                                size_t srcSize, const FSE_decode_t4 *defaultTable, U32 flagRepeatTable, void *workspace, size_t workspaceSize)
+{
+       const void *const tmpPtr = defaultTable; /* bypass strict aliasing */
+       switch (type) {
+       case set_rle:
+               if (!srcSize)
+                       return ERROR(srcSize_wrong);
+               if ((*(const BYTE *)src) > max)
+                       return ERROR(corruption_detected);
+               FSE_buildDTable_rle(DTableSpace, *(const BYTE *)src);
+               *DTablePtr = DTableSpace;
+               return 1;
+       case set_basic: *DTablePtr = (const FSE_DTable *)tmpPtr; return 0;
+       case set_repeat:
+               if (!flagRepeatTable)
+                       return ERROR(corruption_detected);
+               return 0;
+       default: /* impossible */
+       case set_compressed: {
+               U32 tableLog;
+               S16 *norm = (S16 *)workspace;
+               size_t const spaceUsed32 = ALIGN(sizeof(S16) * (MaxSeq + 1), sizeof(U32)) >> 2;
+
+               if ((spaceUsed32 << 2) > workspaceSize)
+                       return ERROR(GENERIC);
+               workspace = (U32 *)workspace + spaceUsed32;
+               workspaceSize -= (spaceUsed32 << 2);
+               {
+                       size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
+                       if (FSE_isError(headerSize))
+                               return ERROR(corruption_detected);
+                       if (tableLog > maxLog)
+                               return ERROR(corruption_detected);
+                       FSE_buildDTable_wksp(DTableSpace, norm, max, tableLog, workspace, workspaceSize);
+                       *DTablePtr = DTableSpace;
+                       return headerSize;
+               }
+       }
+       }
+}
+
+size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx *dctx, int *nbSeqPtr, const void *src, size_t srcSize)
+{
+       const BYTE *const istart = (const BYTE *const)src;
+       const BYTE *const iend = istart + srcSize;
+       const BYTE *ip = istart;
+
+       /* check */
+       if (srcSize < MIN_SEQUENCES_SIZE)
+               return ERROR(srcSize_wrong);
+
+       /* SeqHead */
+       {
+               int nbSeq = *ip++;
+               if (!nbSeq) {
+                       *nbSeqPtr = 0;
+                       return 1;
+               }
+               if (nbSeq > 0x7F) {
+                       if (nbSeq == 0xFF) {
+                               if (ip + 2 > iend)
+                                       return ERROR(srcSize_wrong);
+                               nbSeq = ZSTD_readLE16(ip) + LONGNBSEQ, ip += 2;
+                       } else {
+                               if (ip >= iend)
+                                       return ERROR(srcSize_wrong);
+                               nbSeq = ((nbSeq - 0x80) << 8) + *ip++;
+                       }
+               }
+               *nbSeqPtr = nbSeq;
+       }
+
+       /* FSE table descriptors */
+       if (ip + 4 > iend)
+               return ERROR(srcSize_wrong); /* minimum possible size */
+       {
+               symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
+               symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
+               symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
+               ip++;
+
+               /* Build DTables */
+               {
+                       size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr, LLtype, MaxLL, LLFSELog, ip, iend - ip,
+                                                                 LL_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace));
+                       if (ZSTD_isError(llhSize))
+                               return ERROR(corruption_detected);
+                       ip += llhSize;
+               }
+               {
+                       size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr, OFtype, MaxOff, OffFSELog, ip, iend - ip,
+                                                                 OF_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace));
+                       if (ZSTD_isError(ofhSize))
+                               return ERROR(corruption_detected);
+                       ip += ofhSize;
+               }
+               {
+                       size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr, MLtype, MaxML, MLFSELog, ip, iend - ip,
+                                                                 ML_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace));
+                       if (ZSTD_isError(mlhSize))
+                               return ERROR(corruption_detected);
+                       ip += mlhSize;
+               }
+       }
+
+       return ip - istart;
+}
+
+typedef struct {
+       size_t litLength;
+       size_t matchLength;
+       size_t offset;
+       const BYTE *match;
+} seq_t;
+
+typedef struct {
+       BIT_DStream_t DStream;
+       FSE_DState_t stateLL;
+       FSE_DState_t stateOffb;
+       FSE_DState_t stateML;
+       size_t prevOffset[ZSTD_REP_NUM];
+       const BYTE *base;
+       size_t pos;
+       uPtrDiff gotoDict;
+} seqState_t;
+
+FORCE_NOINLINE
+size_t ZSTD_execSequenceLast7(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base,
+                             const BYTE *const vBase, const BYTE *const dictEnd)
+{
+       BYTE *const oLitEnd = op + sequence.litLength;
+       size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+       BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+       BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH;
+       const BYTE *const iLitEnd = *litPtr + sequence.litLength;
+       const BYTE *match = oLitEnd - sequence.offset;
+
+       /* check */
+       if (oMatchEnd > oend)
+               return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+       if (iLitEnd > litLimit)
+               return ERROR(corruption_detected); /* over-read beyond lit buffer */
+       if (oLitEnd <= oend_w)
+               return ERROR(GENERIC); /* Precondition */
+
+       /* copy literals */
+       if (op < oend_w) {
+               ZSTD_wildcopy(op, *litPtr, oend_w - op);
+               *litPtr += oend_w - op;
+               op = oend_w;
+       }
+       while (op < oLitEnd)
+               *op++ = *(*litPtr)++;
+
+       /* copy Match */
+       if (sequence.offset > (size_t)(oLitEnd - base)) {
+               /* offset beyond prefix */
+               if (sequence.offset > (size_t)(oLitEnd - vBase))
+                       return ERROR(corruption_detected);
+               match = dictEnd - (base - match);
+               if (match + sequence.matchLength <= dictEnd) {
+                       memmove(oLitEnd, match, sequence.matchLength);
+                       return sequenceLength;
+               }
+               /* span extDict & currPrefixSegment */
+               {
+                       size_t const length1 = dictEnd - match;
+                       memmove(oLitEnd, match, length1);
+                       op = oLitEnd + length1;
+                       sequence.matchLength -= length1;
+                       match = base;
+               }
+       }
+       while (op < oMatchEnd)
+               *op++ = *match++;
+       return sequenceLength;
+}
+
+static seq_t ZSTD_decodeSequence(seqState_t *seqState)
+{
+       seq_t seq;
+
+       U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
+       U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
+       U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= maxOff, by table construction */
+
+       U32 const llBits = LL_bits[llCode];
+       U32 const mlBits = ML_bits[mlCode];
+       U32 const ofBits = ofCode;
+       U32 const totalBits = llBits + mlBits + ofBits;
+
+       static const U32 LL_base[MaxLL + 1] = {0,  1,  2,  3,  4,  5,  6,  7,  8,    9,     10,    11,    12,    13,     14,     15,     16,     18,
+                                              20, 22, 24, 28, 32, 40, 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000, 0x10000};
+
+       static const U32 ML_base[MaxML + 1] = {3,  4,  5,  6,  7,  8,  9,  10,   11,    12,    13,    14,    15,     16,     17,     18,     19,     20,
+                                              21, 22, 23, 24, 25, 26, 27, 28,   29,    30,    31,    32,    33,     34,     35,     37,     39,     41,
+                                              43, 47, 51, 59, 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, 0x1003, 0x2003, 0x4003, 0x8003, 0x10003};
+
+       static const U32 OF_base[MaxOff + 1] = {0,       1,     1,      5,      0xD,      0x1D,      0x3D,      0x7D,      0xFD,     0x1FD,
+                                               0x3FD,   0x7FD,    0xFFD,    0x1FFD,   0x3FFD,   0x7FFD,    0xFFFD,    0x1FFFD,   0x3FFFD,  0x7FFFD,
+                                               0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD};
+
+       /* sequence */
+       {
+               size_t offset;
+               if (!ofCode)
+                       offset = 0;
+               else {
+                       offset = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits); /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
+                       if (ZSTD_32bits())
+                               BIT_reloadDStream(&seqState->DStream);
+               }
+
+               if (ofCode <= 1) {
+                       offset += (llCode == 0);
+                       if (offset) {
+                               size_t temp = (offset == 3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
+                               temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
+                               if (offset != 1)
+                                       seqState->prevOffset[2] = seqState->prevOffset[1];
+                               seqState->prevOffset[1] = seqState->prevOffset[0];
+                               seqState->prevOffset[0] = offset = temp;
+                       } else {
+                               offset = seqState->prevOffset[0];
+                       }
+               } else {
+                       seqState->prevOffset[2] = seqState->prevOffset[1];
+                       seqState->prevOffset[1] = seqState->prevOffset[0];
+                       seqState->prevOffset[0] = offset;
+               }
+               seq.offset = offset;
+       }
+
+       seq.matchLength = ML_base[mlCode] + ((mlCode > 31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <=  16 bits */
+       if (ZSTD_32bits() && (mlBits + llBits > 24))
+               BIT_reloadDStream(&seqState->DStream);
+
+       seq.litLength = LL_base[llCode] + ((llCode > 15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <=  16 bits */
+       if (ZSTD_32bits() || (totalBits > 64 - 7 - (LLFSELog + MLFSELog + OffFSELog)))
+               BIT_reloadDStream(&seqState->DStream);
+
+       /* ANS state update */
+       FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <=  9 bits */
+       FSE_updateState(&seqState->stateML, &seqState->DStream); /* <=  9 bits */
+       if (ZSTD_32bits())
+               BIT_reloadDStream(&seqState->DStream);             /* <= 18 bits */
+       FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <=  8 bits */
+
+       seq.match = NULL;
+
+       return seq;
+}
+
+FORCE_INLINE
+size_t ZSTD_execSequence(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base,
+                        const BYTE *const vBase, const BYTE *const dictEnd)
+{
+       BYTE *const oLitEnd = op + sequence.litLength;
+       size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+       BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+       BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH;
+       const BYTE *const iLitEnd = *litPtr + sequence.litLength;
+       const BYTE *match = oLitEnd - sequence.offset;
+
+       /* check */
+       if (oMatchEnd > oend)
+               return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+       if (iLitEnd > litLimit)
+               return ERROR(corruption_detected); /* over-read beyond lit buffer */
+       if (oLitEnd > oend_w)
+               return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd);
+
+       /* copy Literals */
+       ZSTD_copy8(op, *litPtr);
+       if (sequence.litLength > 8)
+               ZSTD_wildcopy(op + 8, (*litPtr) + 8,
+                             sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
+       op = oLitEnd;
+       *litPtr = iLitEnd; /* update for next sequence */
+
+       /* copy Match */
+       if (sequence.offset > (size_t)(oLitEnd - base)) {
+               /* offset beyond prefix */
+               if (sequence.offset > (size_t)(oLitEnd - vBase))
+                       return ERROR(corruption_detected);
+               match = dictEnd + (match - base);
+               if (match + sequence.matchLength <= dictEnd) {
+                       memmove(oLitEnd, match, sequence.matchLength);
+                       return sequenceLength;
+               }
+               /* span extDict & currPrefixSegment */
+               {
+                       size_t const length1 = dictEnd - match;
+                       memmove(oLitEnd, match, length1);
+                       op = oLitEnd + length1;
+                       sequence.matchLength -= length1;
+                       match = base;
+                       if (op > oend_w || sequence.matchLength < MINMATCH) {
+                               U32 i;
+                               for (i = 0; i < sequence.matchLength; ++i)
+                                       op[i] = match[i];
+                               return sequenceLength;
+                       }
+               }
+       }
+       /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
+
+       /* match within prefix */
+       if (sequence.offset < 8) {
+               /* close range match, overlap */
+               static const U32 dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
+               static const int dec64table[] = {8, 8, 8, 7, 8, 9, 10, 11}; /* subtracted */
+               int const sub2 = dec64table[sequence.offset];
+               op[0] = match[0];
+               op[1] = match[1];
+               op[2] = match[2];
+               op[3] = match[3];
+               match += dec32table[sequence.offset];
+               ZSTD_copy4(op + 4, match);
+               match -= sub2;
+       } else {
+               ZSTD_copy8(op, match);
+       }
+       op += 8;
+       match += 8;
+
+       if (oMatchEnd > oend - (16 - MINMATCH)) {
+               if (op < oend_w) {
+                       ZSTD_wildcopy(op, match, oend_w - op);
+                       match += oend_w - op;
+                       op = oend_w;
+               }
+               while (op < oMatchEnd)
+                       *op++ = *match++;
+       } else {
+               ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8); /* works even if matchLength < 8 */
+       }
+       return sequenceLength;
+}
+
+static size_t ZSTD_decompressSequences(ZSTD_DCtx *dctx, void *dst, size_t maxDstSize, const void *seqStart, size_t seqSize)
+{
+       const BYTE *ip = (const BYTE *)seqStart;
+       const BYTE *const iend = ip + seqSize;
+       BYTE *const ostart = (BYTE * const)dst;
+       BYTE *const oend = ostart + maxDstSize;
+       BYTE *op = ostart;
+       const BYTE *litPtr = dctx->litPtr;
+       const BYTE *const litEnd = litPtr + dctx->litSize;
+       const BYTE *const base = (const BYTE *)(dctx->base);
+       const BYTE *const vBase = (const BYTE *)(dctx->vBase);
+       const BYTE *const dictEnd = (const BYTE *)(dctx->dictEnd);
+       int nbSeq;
+
+       /* Build Decoding Tables */
+       {
+               size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize);
+               if (ZSTD_isError(seqHSize))
+                       return seqHSize;
+               ip += seqHSize;
+       }
+
+       /* Regen sequences */
+       if (nbSeq) {
+               seqState_t seqState;
+               dctx->fseEntropy = 1;
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               seqState.prevOffset[i] = dctx->entropy.rep[i];
+               }
+               CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend - ip), corruption_detected);
+               FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
+               FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
+               FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
+
+               for (; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq;) {
+                       nbSeq--;
+                       {
+                               seq_t const sequence = ZSTD_decodeSequence(&seqState);
+                               size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
+                               if (ZSTD_isError(oneSeqSize))
+                                       return oneSeqSize;
+                               op += oneSeqSize;
+                       }
+               }
+
+               /* check if reached exact end */
+               if (nbSeq)
+                       return ERROR(corruption_detected);
+               /* save reps for next block */
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]);
+               }
+       }
+
+       /* last literal segment */
+       {
+               size_t const lastLLSize = litEnd - litPtr;
+               if (lastLLSize > (size_t)(oend - op))
+                       return ERROR(dstSize_tooSmall);
+               memcpy(op, litPtr, lastLLSize);
+               op += lastLLSize;
+       }
+
+       return op - ostart;
+}
+
+FORCE_INLINE seq_t ZSTD_decodeSequenceLong_generic(seqState_t *seqState, int const longOffsets)
+{
+       seq_t seq;
+
+       U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
+       U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
+       U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= maxOff, by table construction */
+
+       U32 const llBits = LL_bits[llCode];
+       U32 const mlBits = ML_bits[mlCode];
+       U32 const ofBits = ofCode;
+       U32 const totalBits = llBits + mlBits + ofBits;
+
+       static const U32 LL_base[MaxLL + 1] = {0,  1,  2,  3,  4,  5,  6,  7,  8,    9,     10,    11,    12,    13,     14,     15,     16,     18,
+                                              20, 22, 24, 28, 32, 40, 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000, 0x10000};
+
+       static const U32 ML_base[MaxML + 1] = {3,  4,  5,  6,  7,  8,  9,  10,   11,    12,    13,    14,    15,     16,     17,     18,     19,     20,
+                                              21, 22, 23, 24, 25, 26, 27, 28,   29,    30,    31,    32,    33,     34,     35,     37,     39,     41,
+                                              43, 47, 51, 59, 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, 0x1003, 0x2003, 0x4003, 0x8003, 0x10003};
+
+       static const U32 OF_base[MaxOff + 1] = {0,       1,     1,      5,      0xD,      0x1D,      0x3D,      0x7D,      0xFD,     0x1FD,
+                                               0x3FD,   0x7FD,    0xFFD,    0x1FFD,   0x3FFD,   0x7FFD,    0xFFFD,    0x1FFFD,   0x3FFFD,  0x7FFFD,
+                                               0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD};
+
+       /* sequence */
+       {
+               size_t offset;
+               if (!ofCode)
+                       offset = 0;
+               else {
+                       if (longOffsets) {
+                               int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN);
+                               offset = OF_base[ofCode] + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
+                               if (ZSTD_32bits() || extraBits)
+                                       BIT_reloadDStream(&seqState->DStream);
+                               if (extraBits)
+                                       offset += BIT_readBitsFast(&seqState->DStream, extraBits);
+                       } else {
+                               offset = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits); /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
+                               if (ZSTD_32bits())
+                                       BIT_reloadDStream(&seqState->DStream);
+                       }
+               }
+
+               if (ofCode <= 1) {
+                       offset += (llCode == 0);
+                       if (offset) {
+                               size_t temp = (offset == 3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
+                               temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
+                               if (offset != 1)
+                                       seqState->prevOffset[2] = seqState->prevOffset[1];
+                               seqState->prevOffset[1] = seqState->prevOffset[0];
+                               seqState->prevOffset[0] = offset = temp;
+                       } else {
+                               offset = seqState->prevOffset[0];
+                       }
+               } else {
+                       seqState->prevOffset[2] = seqState->prevOffset[1];
+                       seqState->prevOffset[1] = seqState->prevOffset[0];
+                       seqState->prevOffset[0] = offset;
+               }
+               seq.offset = offset;
+       }
+
+       seq.matchLength = ML_base[mlCode] + ((mlCode > 31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <=  16 bits */
+       if (ZSTD_32bits() && (mlBits + llBits > 24))
+               BIT_reloadDStream(&seqState->DStream);
+
+       seq.litLength = LL_base[llCode] + ((llCode > 15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <=  16 bits */
+       if (ZSTD_32bits() || (totalBits > 64 - 7 - (LLFSELog + MLFSELog + OffFSELog)))
+               BIT_reloadDStream(&seqState->DStream);
+
+       {
+               size_t const pos = seqState->pos + seq.litLength;
+               seq.match = seqState->base + pos - seq.offset; /* single memory segment */
+               if (seq.offset > pos)
+                       seq.match += seqState->gotoDict; /* separate memory segment */
+               seqState->pos = pos + seq.matchLength;
+       }
+
+       /* ANS state update */
+       FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <=  9 bits */
+       FSE_updateState(&seqState->stateML, &seqState->DStream); /* <=  9 bits */
+       if (ZSTD_32bits())
+               BIT_reloadDStream(&seqState->DStream);             /* <= 18 bits */
+       FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <=  8 bits */
+
+       return seq;
+}
+
+static seq_t ZSTD_decodeSequenceLong(seqState_t *seqState, unsigned const windowSize)
+{
+       if (ZSTD_highbit32(windowSize) > STREAM_ACCUMULATOR_MIN) {
+               return ZSTD_decodeSequenceLong_generic(seqState, 1);
+       } else {
+               return ZSTD_decodeSequenceLong_generic(seqState, 0);
+       }
+}
+
+FORCE_INLINE
+size_t ZSTD_execSequenceLong(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base,
+                            const BYTE *const vBase, const BYTE *const dictEnd)
+{
+       BYTE *const oLitEnd = op + sequence.litLength;
+       size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+       BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+       BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH;
+       const BYTE *const iLitEnd = *litPtr + sequence.litLength;
+       const BYTE *match = sequence.match;
+
+       /* check */
+       if (oMatchEnd > oend)
+               return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+       if (iLitEnd > litLimit)
+               return ERROR(corruption_detected); /* over-read beyond lit buffer */
+       if (oLitEnd > oend_w)
+               return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd);
+
+       /* copy Literals */
+       ZSTD_copy8(op, *litPtr);
+       if (sequence.litLength > 8)
+               ZSTD_wildcopy(op + 8, (*litPtr) + 8,
+                             sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
+       op = oLitEnd;
+       *litPtr = iLitEnd; /* update for next sequence */
+
+       /* copy Match */
+       if (sequence.offset > (size_t)(oLitEnd - base)) {
+               /* offset beyond prefix */
+               if (sequence.offset > (size_t)(oLitEnd - vBase))
+                       return ERROR(corruption_detected);
+               if (match + sequence.matchLength <= dictEnd) {
+                       memmove(oLitEnd, match, sequence.matchLength);
+                       return sequenceLength;
+               }
+               /* span extDict & currPrefixSegment */
+               {
+                       size_t const length1 = dictEnd - match;
+                       memmove(oLitEnd, match, length1);
+                       op = oLitEnd + length1;
+                       sequence.matchLength -= length1;
+                       match = base;
+                       if (op > oend_w || sequence.matchLength < MINMATCH) {
+                               U32 i;
+                               for (i = 0; i < sequence.matchLength; ++i)
+                                       op[i] = match[i];
+                               return sequenceLength;
+                       }
+               }
+       }
+       /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
+
+       /* match within prefix */
+       if (sequence.offset < 8) {
+               /* close range match, overlap */
+               static const U32 dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
+               static const int dec64table[] = {8, 8, 8, 7, 8, 9, 10, 11}; /* subtracted */
+               int const sub2 = dec64table[sequence.offset];
+               op[0] = match[0];
+               op[1] = match[1];
+               op[2] = match[2];
+               op[3] = match[3];
+               match += dec32table[sequence.offset];
+               ZSTD_copy4(op + 4, match);
+               match -= sub2;
+       } else {
+               ZSTD_copy8(op, match);
+       }
+       op += 8;
+       match += 8;
+
+       if (oMatchEnd > oend - (16 - MINMATCH)) {
+               if (op < oend_w) {
+                       ZSTD_wildcopy(op, match, oend_w - op);
+                       match += oend_w - op;
+                       op = oend_w;
+               }
+               while (op < oMatchEnd)
+                       *op++ = *match++;
+       } else {
+               ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8); /* works even if matchLength < 8 */
+       }
+       return sequenceLength;
+}
+
+static size_t ZSTD_decompressSequencesLong(ZSTD_DCtx *dctx, void *dst, size_t maxDstSize, const void *seqStart, size_t seqSize)
+{
+       const BYTE *ip = (const BYTE *)seqStart;
+       const BYTE *const iend = ip + seqSize;
+       BYTE *const ostart = (BYTE * const)dst;
+       BYTE *const oend = ostart + maxDstSize;
+       BYTE *op = ostart;
+       const BYTE *litPtr = dctx->litPtr;
+       const BYTE *const litEnd = litPtr + dctx->litSize;
+       const BYTE *const base = (const BYTE *)(dctx->base);
+       const BYTE *const vBase = (const BYTE *)(dctx->vBase);
+       const BYTE *const dictEnd = (const BYTE *)(dctx->dictEnd);
+       unsigned const windowSize = dctx->fParams.windowSize;
+       int nbSeq;
+
+       /* Build Decoding Tables */
+       {
+               size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize);
+               if (ZSTD_isError(seqHSize))
+                       return seqHSize;
+               ip += seqHSize;
+       }
+
+       /* Regen sequences */
+       if (nbSeq) {
+#define STORED_SEQS 4
+#define STOSEQ_MASK (STORED_SEQS - 1)
+#define ADVANCED_SEQS 4
+               seq_t *sequences = (seq_t *)dctx->entropy.workspace;
+               int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
+               seqState_t seqState;
+               int seqNb;
+               ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.workspace) >= sizeof(seq_t) * STORED_SEQS);
+               dctx->fseEntropy = 1;
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               seqState.prevOffset[i] = dctx->entropy.rep[i];
+               }
+               seqState.base = base;
+               seqState.pos = (size_t)(op - base);
+               seqState.gotoDict = (uPtrDiff)dictEnd - (uPtrDiff)base; /* cast to avoid undefined behaviour */
+               CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend - ip), corruption_detected);
+               FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
+               FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
+               FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
+
+               /* prepare in advance */
+               for (seqNb = 0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && seqNb < seqAdvance; seqNb++) {
+                       sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, windowSize);
+               }
+               if (seqNb < seqAdvance)
+                       return ERROR(corruption_detected);
+
+               /* decode and decompress */
+               for (; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && seqNb < nbSeq; seqNb++) {
+                       seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, windowSize);
+                       size_t const oneSeqSize =
+                           ZSTD_execSequenceLong(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd);
+                       if (ZSTD_isError(oneSeqSize))
+                               return oneSeqSize;
+                       ZSTD_PREFETCH(sequence.match);
+                       sequences[seqNb & STOSEQ_MASK] = sequence;
+                       op += oneSeqSize;
+               }
+               if (seqNb < nbSeq)
+                       return ERROR(corruption_detected);
+
+               /* finish queue */
+               seqNb -= seqAdvance;
+               for (; seqNb < nbSeq; seqNb++) {
+                       size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb & STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd);
+                       if (ZSTD_isError(oneSeqSize))
+                               return oneSeqSize;
+                       op += oneSeqSize;
+               }
+
+               /* save reps for next block */
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]);
+               }
+       }
+
+       /* last literal segment */
+       {
+               size_t const lastLLSize = litEnd - litPtr;
+               if (lastLLSize > (size_t)(oend - op))
+                       return ERROR(dstSize_tooSmall);
+               memcpy(op, litPtr, lastLLSize);
+               op += lastLLSize;
+       }
+
+       return op - ostart;
+}
+
+static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{ /* blockType == blockCompressed */
+       const BYTE *ip = (const BYTE *)src;
+
+       if (srcSize >= ZSTD_BLOCKSIZE_ABSOLUTEMAX)
+               return ERROR(srcSize_wrong);
+
+       /* Decode literals section */
+       {
+               size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
+               if (ZSTD_isError(litCSize))
+                       return litCSize;
+               ip += litCSize;
+               srcSize -= litCSize;
+       }
+       if (sizeof(size_t) > 4) /* do not enable prefetching on 32-bits x86, as it's performance detrimental */
+                               /* likely because of register pressure */
+                               /* if that's the correct cause, then 32-bits ARM should be affected differently */
+                               /* it would be good to test this on ARM real hardware, to see if prefetch version improves speed */
+               if (dctx->fParams.windowSize > (1 << 23))
+                       return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize);
+       return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize);
+}
+
+static void ZSTD_checkContinuity(ZSTD_DCtx *dctx, const void *dst)
+{
+       if (dst != dctx->previousDstEnd) { /* not contiguous */
+               dctx->dictEnd = dctx->previousDstEnd;
+               dctx->vBase = (const char *)dst - ((const char *)(dctx->previousDstEnd) - (const char *)(dctx->base));
+               dctx->base = dst;
+               dctx->previousDstEnd = dst;
+       }
+}
+
+size_t ZSTD_decompressBlock(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{
+       size_t dSize;
+       ZSTD_checkContinuity(dctx, dst);
+       dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize);
+       dctx->previousDstEnd = (char *)dst + dSize;
+       return dSize;
+}
+
+/** ZSTD_insertBlock() :
+       insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
+size_t ZSTD_insertBlock(ZSTD_DCtx *dctx, const void *blockStart, size_t blockSize)
+{
+       ZSTD_checkContinuity(dctx, blockStart);
+       dctx->previousDstEnd = (const char *)blockStart + blockSize;
+       return blockSize;
+}
+
+size_t ZSTD_generateNxBytes(void *dst, size_t dstCapacity, BYTE byte, size_t length)
+{
+       if (length > dstCapacity)
+               return ERROR(dstSize_tooSmall);
+       memset(dst, byte, length);
+       return length;
+}
+
+/** ZSTD_findFrameCompressedSize() :
+ *  compatible with legacy mode
+ *  `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame
+ *  `srcSize` must be at least as large as the frame contained
+ *  @return : the compressed size of the frame starting at `src` */
+size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
+{
+       if (srcSize >= ZSTD_skippableHeaderSize && (ZSTD_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+               return ZSTD_skippableHeaderSize + ZSTD_readLE32((const BYTE *)src + 4);
+       } else {
+               const BYTE *ip = (const BYTE *)src;
+               const BYTE *const ipstart = ip;
+               size_t remainingSize = srcSize;
+               ZSTD_frameParams fParams;
+
+               size_t const headerSize = ZSTD_frameHeaderSize(ip, remainingSize);
+               if (ZSTD_isError(headerSize))
+                       return headerSize;
+
+               /* Frame Header */
+               {
+                       size_t const ret = ZSTD_getFrameParams(&fParams, ip, remainingSize);
+                       if (ZSTD_isError(ret))
+                               return ret;
+                       if (ret > 0)
+                               return ERROR(srcSize_wrong);
+               }
+
+               ip += headerSize;
+               remainingSize -= headerSize;
+
+               /* Loop on each block */
+               while (1) {
+                       blockProperties_t blockProperties;
+                       size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
+                       if (ZSTD_isError(cBlockSize))
+                               return cBlockSize;
+
+                       if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
+                               return ERROR(srcSize_wrong);
+
+                       ip += ZSTD_blockHeaderSize + cBlockSize;
+                       remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
+
+                       if (blockProperties.lastBlock)
+                               break;
+               }
+
+               if (fParams.checksumFlag) { /* Frame content checksum */
+                       if (remainingSize < 4)
+                               return ERROR(srcSize_wrong);
+                       ip += 4;
+                       remainingSize -= 4;
+               }
+
+               return ip - ipstart;
+       }
+}
+
+/*! ZSTD_decompressFrame() :
+*   @dctx must be properly initialized */
+static size_t ZSTD_decompressFrame(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void **srcPtr, size_t *srcSizePtr)
+{
+       const BYTE *ip = (const BYTE *)(*srcPtr);
+       BYTE *const ostart = (BYTE * const)dst;
+       BYTE *const oend = ostart + dstCapacity;
+       BYTE *op = ostart;
+       size_t remainingSize = *srcSizePtr;
+
+       /* check */
+       if (remainingSize < ZSTD_frameHeaderSize_min + ZSTD_blockHeaderSize)
+               return ERROR(srcSize_wrong);
+
+       /* Frame Header */
+       {
+               size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_frameHeaderSize_prefix);
+               if (ZSTD_isError(frameHeaderSize))
+                       return frameHeaderSize;
+               if (remainingSize < frameHeaderSize + ZSTD_blockHeaderSize)
+                       return ERROR(srcSize_wrong);
+               CHECK_F(ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize));
+               ip += frameHeaderSize;
+               remainingSize -= frameHeaderSize;
+       }
+
+       /* Loop on each block */
+       while (1) {
+               size_t decodedSize;
+               blockProperties_t blockProperties;
+               size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
+               if (ZSTD_isError(cBlockSize))
+                       return cBlockSize;
+
+               ip += ZSTD_blockHeaderSize;
+               remainingSize -= ZSTD_blockHeaderSize;
+               if (cBlockSize > remainingSize)
+                       return ERROR(srcSize_wrong);
+
+               switch (blockProperties.blockType) {
+               case bt_compressed: decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend - op, ip, cBlockSize); break;
+               case bt_raw: decodedSize = ZSTD_copyRawBlock(op, oend - op, ip, cBlockSize); break;
+               case bt_rle: decodedSize = ZSTD_generateNxBytes(op, oend - op, *ip, blockProperties.origSize); break;
+               case bt_reserved:
+               default: return ERROR(corruption_detected);
+               }
+
+               if (ZSTD_isError(decodedSize))
+                       return decodedSize;
+               if (dctx->fParams.checksumFlag)
+                       xxh64_update(&dctx->xxhState, op, decodedSize);
+               op += decodedSize;
+               ip += cBlockSize;
+               remainingSize -= cBlockSize;
+               if (blockProperties.lastBlock)
+                       break;
+       }
+
+       if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
+               U32 const checkCalc = (U32)xxh64_digest(&dctx->xxhState);
+               U32 checkRead;
+               if (remainingSize < 4)
+                       return ERROR(checksum_wrong);
+               checkRead = ZSTD_readLE32(ip);
+               if (checkRead != checkCalc)
+                       return ERROR(checksum_wrong);
+               ip += 4;
+               remainingSize -= 4;
+       }
+
+       /* Allow caller to get size read */
+       *srcPtr = ip;
+       *srcSizePtr = remainingSize;
+       return op - ostart;
+}
+
+static const void *ZSTD_DDictDictContent(const ZSTD_DDict *ddict);
+static size_t ZSTD_DDictDictSize(const ZSTD_DDict *ddict);
+
+static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const void *dict, size_t dictSize,
+                                       const ZSTD_DDict *ddict)
+{
+       void *const dststart = dst;
+
+       if (ddict) {
+               if (dict) {
+                       /* programmer error, these two cases should be mutually exclusive */
+                       return ERROR(GENERIC);
+               }
+
+               dict = ZSTD_DDictDictContent(ddict);
+               dictSize = ZSTD_DDictDictSize(ddict);
+       }
+
+       while (srcSize >= ZSTD_frameHeaderSize_prefix) {
+               U32 magicNumber;
+
+               magicNumber = ZSTD_readLE32(src);
+               if (magicNumber != ZSTD_MAGICNUMBER) {
+                       if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+                               size_t skippableSize;
+                               if (srcSize < ZSTD_skippableHeaderSize)
+                                       return ERROR(srcSize_wrong);
+                               skippableSize = ZSTD_readLE32((const BYTE *)src + 4) + ZSTD_skippableHeaderSize;
+                               if (srcSize < skippableSize) {
+                                       return ERROR(srcSize_wrong);
+                               }
+
+                               src = (const BYTE *)src + skippableSize;
+                               srcSize -= skippableSize;
+                               continue;
+                       } else {
+                               return ERROR(prefix_unknown);
+                       }
+               }
+
+               if (ddict) {
+                       /* we were called from ZSTD_decompress_usingDDict */
+                       ZSTD_refDDict(dctx, ddict);
+               } else {
+                       /* this will initialize correctly with no dict if dict == NULL, so
+                        * use this in all cases but ddict */
+                       CHECK_F(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize));
+               }
+               ZSTD_checkContinuity(dctx, dst);
+
+               {
+                       const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity, &src, &srcSize);
+                       if (ZSTD_isError(res))
+                               return res;
+                       /* don't need to bounds check this, ZSTD_decompressFrame will have
+                        * already */
+                       dst = (BYTE *)dst + res;
+                       dstCapacity -= res;
+               }
+       }
+
+       if (srcSize)
+               return ERROR(srcSize_wrong); /* input not entirely consumed */
+
+       return (BYTE *)dst - (BYTE *)dststart;
+}
+
+size_t ZSTD_decompress_usingDict(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const void *dict, size_t dictSize)
+{
+       return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL);
+}
+
+size_t ZSTD_decompressDCtx(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{
+       return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0);
+}
+
+/*-**************************************
+*   Advanced Streaming Decompression API
+*   Bufferless and synchronous
+****************************************/
+size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx *dctx) { return dctx->expected; }
+
+ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx *dctx)
+{
+       switch (dctx->stage) {
+       default: /* should not happen */
+       case ZSTDds_getFrameHeaderSize:
+       case ZSTDds_decodeFrameHeader: return ZSTDnit_frameHeader;
+       case ZSTDds_decodeBlockHeader: return ZSTDnit_blockHeader;
+       case ZSTDds_decompressBlock: return ZSTDnit_block;
+       case ZSTDds_decompressLastBlock: return ZSTDnit_lastBlock;
+       case ZSTDds_checkChecksum: return ZSTDnit_checksum;
+       case ZSTDds_decodeSkippableHeader:
+       case ZSTDds_skipFrame: return ZSTDnit_skippableFrame;
+       }
+}
+
+int ZSTD_isSkipFrame(ZSTD_DCtx *dctx) { return dctx->stage == ZSTDds_skipFrame; } /* for zbuff */
+
+/** ZSTD_decompressContinue() :
+*   @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
+*             or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_decompressContinue(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{
+       /* Sanity check */
+       if (srcSize != dctx->expected)
+               return ERROR(srcSize_wrong);
+       if (dstCapacity)
+               ZSTD_checkContinuity(dctx, dst);
+
+       switch (dctx->stage) {
+       case ZSTDds_getFrameHeaderSize:
+               if (srcSize != ZSTD_frameHeaderSize_prefix)
+                       return ERROR(srcSize_wrong);                                    /* impossible */
+               if ((ZSTD_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */
+                       memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix);
+                       dctx->expected = ZSTD_skippableHeaderSize - ZSTD_frameHeaderSize_prefix; /* magic number + skippable frame length */
+                       dctx->stage = ZSTDds_decodeSkippableHeader;
+                       return 0;
+               }
+               dctx->headerSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_prefix);
+               if (ZSTD_isError(dctx->headerSize))
+                       return dctx->headerSize;
+               memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix);
+               if (dctx->headerSize > ZSTD_frameHeaderSize_prefix) {
+                       dctx->expected = dctx->headerSize - ZSTD_frameHeaderSize_prefix;
+                       dctx->stage = ZSTDds_decodeFrameHeader;
+                       return 0;
+               }
+               dctx->expected = 0; /* not necessary to copy more */
+
+       case ZSTDds_decodeFrameHeader:
+               memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected);
+               CHECK_F(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize));
+               dctx->expected = ZSTD_blockHeaderSize;
+               dctx->stage = ZSTDds_decodeBlockHeader;
+               return 0;
+
+       case ZSTDds_decodeBlockHeader: {
+               blockProperties_t bp;
+               size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
+               if (ZSTD_isError(cBlockSize))
+                       return cBlockSize;
+               dctx->expected = cBlockSize;
+               dctx->bType = bp.blockType;
+               dctx->rleSize = bp.origSize;
+               if (cBlockSize) {
+                       dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
+                       return 0;
+               }
+               /* empty block */
+               if (bp.lastBlock) {
+                       if (dctx->fParams.checksumFlag) {
+                               dctx->expected = 4;
+                               dctx->stage = ZSTDds_checkChecksum;
+                       } else {
+                               dctx->expected = 0; /* end of frame */
+                               dctx->stage = ZSTDds_getFrameHeaderSize;
+                       }
+               } else {
+                       dctx->expected = 3; /* go directly to next header */
+                       dctx->stage = ZSTDds_decodeBlockHeader;
+               }
+               return 0;
+       }
+       case ZSTDds_decompressLastBlock:
+       case ZSTDds_decompressBlock: {
+               size_t rSize;
+               switch (dctx->bType) {
+               case bt_compressed: rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize); break;
+               case bt_raw: rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize); break;
+               case bt_rle: rSize = ZSTD_setRleBlock(dst, dstCapacity, src, srcSize, dctx->rleSize); break;
+               case bt_reserved: /* should never happen */
+               default: return ERROR(corruption_detected);
+               }
+               if (ZSTD_isError(rSize))
+                       return rSize;
+               if (dctx->fParams.checksumFlag)
+                       xxh64_update(&dctx->xxhState, dst, rSize);
+
+               if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */
+                       if (dctx->fParams.checksumFlag) {       /* another round for frame checksum */
+                               dctx->expected = 4;
+                               dctx->stage = ZSTDds_checkChecksum;
+                       } else {
+                               dctx->expected = 0; /* ends here */
+                               dctx->stage = ZSTDds_getFrameHeaderSize;
+                       }
+               } else {
+                       dctx->stage = ZSTDds_decodeBlockHeader;
+                       dctx->expected = ZSTD_blockHeaderSize;
+                       dctx->previousDstEnd = (char *)dst + rSize;
+               }
+               return rSize;
+       }
+       case ZSTDds_checkChecksum: {
+               U32 const h32 = (U32)xxh64_digest(&dctx->xxhState);
+               U32 const check32 = ZSTD_readLE32(src); /* srcSize == 4, guaranteed by dctx->expected */
+               if (check32 != h32)
+                       return ERROR(checksum_wrong);
+               dctx->expected = 0;
+               dctx->stage = ZSTDds_getFrameHeaderSize;
+               return 0;
+       }
+       case ZSTDds_decodeSkippableHeader: {
+               memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected);
+               dctx->expected = ZSTD_readLE32(dctx->headerBuffer + 4);
+               dctx->stage = ZSTDds_skipFrame;
+               return 0;
+       }
+       case ZSTDds_skipFrame: {
+               dctx->expected = 0;
+               dctx->stage = ZSTDds_getFrameHeaderSize;
+               return 0;
+       }
+       default:
+               return ERROR(GENERIC); /* impossible */
+       }
+}
+
+static size_t ZSTD_refDictContent(ZSTD_DCtx *dctx, const void *dict, size_t dictSize)
+{
+       dctx->dictEnd = dctx->previousDstEnd;
+       dctx->vBase = (const char *)dict - ((const char *)(dctx->previousDstEnd) - (const char *)(dctx->base));
+       dctx->base = dict;
+       dctx->previousDstEnd = (const char *)dict + dictSize;
+       return 0;
+}
+
+/* ZSTD_loadEntropy() :
+ * dict : must point at beginning of a valid zstd dictionary
+ * @return : size of entropy tables read */
+static size_t ZSTD_loadEntropy(ZSTD_entropyTables_t *entropy, const void *const dict, size_t const dictSize)
+{
+       const BYTE *dictPtr = (const BYTE *)dict;
+       const BYTE *const dictEnd = dictPtr + dictSize;
+
+       if (dictSize <= 8)
+               return ERROR(dictionary_corrupted);
+       dictPtr += 8; /* skip header = magic + dictID */
+
+       {
+               size_t const hSize = HUF_readDTableX4_wksp(entropy->hufTable, dictPtr, dictEnd - dictPtr, entropy->workspace, sizeof(entropy->workspace));
+               if (HUF_isError(hSize))
+                       return ERROR(dictionary_corrupted);
+               dictPtr += hSize;
+       }
+
+       {
+               short offcodeNCount[MaxOff + 1];
+               U32 offcodeMaxValue = MaxOff, offcodeLog;
+               size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd - dictPtr);
+               if (FSE_isError(offcodeHeaderSize))
+                       return ERROR(dictionary_corrupted);
+               if (offcodeLog > OffFSELog)
+                       return ERROR(dictionary_corrupted);
+               CHECK_E(FSE_buildDTable_wksp(entropy->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted);
+               dictPtr += offcodeHeaderSize;
+       }
+
+       {
+               short matchlengthNCount[MaxML + 1];
+               unsigned matchlengthMaxValue = MaxML, matchlengthLog;
+               size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd - dictPtr);
+               if (FSE_isError(matchlengthHeaderSize))
+                       return ERROR(dictionary_corrupted);
+               if (matchlengthLog > MLFSELog)
+                       return ERROR(dictionary_corrupted);
+               CHECK_E(FSE_buildDTable_wksp(entropy->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted);
+               dictPtr += matchlengthHeaderSize;
+       }
+
+       {
+               short litlengthNCount[MaxLL + 1];
+               unsigned litlengthMaxValue = MaxLL, litlengthLog;
+               size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd - dictPtr);
+               if (FSE_isError(litlengthHeaderSize))
+                       return ERROR(dictionary_corrupted);
+               if (litlengthLog > LLFSELog)
+                       return ERROR(dictionary_corrupted);
+               CHECK_E(FSE_buildDTable_wksp(entropy->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted);
+               dictPtr += litlengthHeaderSize;
+       }
+
+       if (dictPtr + 12 > dictEnd)
+               return ERROR(dictionary_corrupted);
+       {
+               int i;
+               size_t const dictContentSize = (size_t)(dictEnd - (dictPtr + 12));
+               for (i = 0; i < 3; i++) {
+                       U32 const rep = ZSTD_readLE32(dictPtr);
+                       dictPtr += 4;
+                       if (rep == 0 || rep >= dictContentSize)
+                               return ERROR(dictionary_corrupted);
+                       entropy->rep[i] = rep;
+               }
+       }
+
+       return dictPtr - (const BYTE *)dict;
+}
+
+static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx *dctx, const void *dict, size_t dictSize)
+{
+       if (dictSize < 8)
+               return ZSTD_refDictContent(dctx, dict, dictSize);
+       {
+               U32 const magic = ZSTD_readLE32(dict);
+               if (magic != ZSTD_DICT_MAGIC) {
+                       return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */
+               }
+       }
+       dctx->dictID = ZSTD_readLE32((const char *)dict + 4);
+
+       /* load entropy tables */
+       {
+               size_t const eSize = ZSTD_loadEntropy(&dctx->entropy, dict, dictSize);
+               if (ZSTD_isError(eSize))
+                       return ERROR(dictionary_corrupted);
+               dict = (const char *)dict + eSize;
+               dictSize -= eSize;
+       }
+       dctx->litEntropy = dctx->fseEntropy = 1;
+
+       /* reference dictionary content */
+       return ZSTD_refDictContent(dctx, dict, dictSize);
+}
+
+size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx *dctx, const void *dict, size_t dictSize)
+{
+       CHECK_F(ZSTD_decompressBegin(dctx));
+       if (dict && dictSize)
+               CHECK_E(ZSTD_decompress_insertDictionary(dctx, dict, dictSize), dictionary_corrupted);
+       return 0;
+}
+
+/* ======   ZSTD_DDict   ====== */
+
+struct ZSTD_DDict_s {
+       void *dictBuffer;
+       const void *dictContent;
+       size_t dictSize;
+       ZSTD_entropyTables_t entropy;
+       U32 dictID;
+       U32 entropyPresent;
+       ZSTD_customMem cMem;
+}; /* typedef'd to ZSTD_DDict within "zstd.h" */
+
+size_t ZSTD_DDictWorkspaceBound(void) { return ZSTD_ALIGN(sizeof(ZSTD_stack)) + ZSTD_ALIGN(sizeof(ZSTD_DDict)); }
+
+static const void *ZSTD_DDictDictContent(const ZSTD_DDict *ddict) { return ddict->dictContent; }
+
+static size_t ZSTD_DDictDictSize(const ZSTD_DDict *ddict) { return ddict->dictSize; }
+
+static void ZSTD_refDDict(ZSTD_DCtx *dstDCtx, const ZSTD_DDict *ddict)
+{
+       ZSTD_decompressBegin(dstDCtx); /* init */
+       if (ddict) {                   /* support refDDict on NULL */
+               dstDCtx->dictID = ddict->dictID;
+               dstDCtx->base = ddict->dictContent;
+               dstDCtx->vBase = ddict->dictContent;
+               dstDCtx->dictEnd = (const BYTE *)ddict->dictContent + ddict->dictSize;
+               dstDCtx->previousDstEnd = dstDCtx->dictEnd;
+               if (ddict->entropyPresent) {
+                       dstDCtx->litEntropy = 1;
+                       dstDCtx->fseEntropy = 1;
+                       dstDCtx->LLTptr = ddict->entropy.LLTable;
+                       dstDCtx->MLTptr = ddict->entropy.MLTable;
+                       dstDCtx->OFTptr = ddict->entropy.OFTable;
+                       dstDCtx->HUFptr = ddict->entropy.hufTable;
+                       dstDCtx->entropy.rep[0] = ddict->entropy.rep[0];
+                       dstDCtx->entropy.rep[1] = ddict->entropy.rep[1];
+                       dstDCtx->entropy.rep[2] = ddict->entropy.rep[2];
+               } else {
+                       dstDCtx->litEntropy = 0;
+                       dstDCtx->fseEntropy = 0;
+               }
+       }
+}
+
+static size_t ZSTD_loadEntropy_inDDict(ZSTD_DDict *ddict)
+{
+       ddict->dictID = 0;
+       ddict->entropyPresent = 0;
+       if (ddict->dictSize < 8)
+               return 0;
+       {
+               U32 const magic = ZSTD_readLE32(ddict->dictContent);
+               if (magic != ZSTD_DICT_MAGIC)
+                       return 0; /* pure content mode */
+       }
+       ddict->dictID = ZSTD_readLE32((const char *)ddict->dictContent + 4);
+
+       /* load entropy tables */
+       CHECK_E(ZSTD_loadEntropy(&ddict->entropy, ddict->dictContent, ddict->dictSize), dictionary_corrupted);
+       ddict->entropyPresent = 1;
+       return 0;
+}
+
+static ZSTD_DDict *ZSTD_createDDict_advanced(const void *dict, size_t dictSize, unsigned byReference, ZSTD_customMem customMem)
+{
+       if (!customMem.customAlloc || !customMem.customFree)
+               return NULL;
+
+       {
+               ZSTD_DDict *const ddict = (ZSTD_DDict *)ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
+               if (!ddict)
+                       return NULL;
+               ddict->cMem = customMem;
+
+               if ((byReference) || (!dict) || (!dictSize)) {
+                       ddict->dictBuffer = NULL;
+                       ddict->dictContent = dict;
+               } else {
+                       void *const internalBuffer = ZSTD_malloc(dictSize, customMem);
+                       if (!internalBuffer) {
+                               ZSTD_freeDDict(ddict);
+                               return NULL;
+                       }
+                       memcpy(internalBuffer, dict, dictSize);
+                       ddict->dictBuffer = internalBuffer;
+                       ddict->dictContent = internalBuffer;
+               }
+               ddict->dictSize = dictSize;
+               ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */
+               /* parse dictionary content */
+               {
+                       size_t const errorCode = ZSTD_loadEntropy_inDDict(ddict);
+                       if (ZSTD_isError(errorCode)) {
+                               ZSTD_freeDDict(ddict);
+                               return NULL;
+                       }
+               }
+
+               return ddict;
+       }
+}
+
+/*! ZSTD_initDDict() :
+*   Create a digested dictionary, to start decompression without startup delay.
+*   `dict` content is copied inside DDict.
+*   Consequently, `dict` can be released after `ZSTD_DDict` creation */
+ZSTD_DDict *ZSTD_initDDict(const void *dict, size_t dictSize, void *workspace, size_t workspaceSize)
+{
+       ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize);
+       return ZSTD_createDDict_advanced(dict, dictSize, 1, stackMem);
+}
+
+size_t ZSTD_freeDDict(ZSTD_DDict *ddict)
+{
+       if (ddict == NULL)
+               return 0; /* support free on NULL */
+       {
+               ZSTD_customMem const cMem = ddict->cMem;
+               ZSTD_free(ddict->dictBuffer, cMem);
+               ZSTD_free(ddict, cMem);
+               return 0;
+       }
+}
+
+/*! ZSTD_getDictID_fromDict() :
+ *  Provides the dictID stored within dictionary.
+ *  if @return == 0, the dictionary is not conformant with Zstandard specification.
+ *  It can still be loaded, but as a content-only dictionary. */
+unsigned ZSTD_getDictID_fromDict(const void *dict, size_t dictSize)
+{
+       if (dictSize < 8)
+               return 0;
+       if (ZSTD_readLE32(dict) != ZSTD_DICT_MAGIC)
+               return 0;
+       return ZSTD_readLE32((const char *)dict + 4);
+}
+
+/*! ZSTD_getDictID_fromDDict() :
+ *  Provides the dictID of the dictionary loaded into `ddict`.
+ *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+ *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
+unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict *ddict)
+{
+       if (ddict == NULL)
+               return 0;
+       return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize);
+}
+
+/*! ZSTD_getDictID_fromFrame() :
+ *  Provides the dictID required to decompressed the frame stored within `src`.
+ *  If @return == 0, the dictID could not be decoded.
+ *  This could for one of the following reasons :
+ *  - The frame does not require a dictionary to be decoded (most common case).
+ *  - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
+ *    Note : this use case also happens when using a non-conformant dictionary.
+ *  - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
+ *  - This is not a Zstandard frame.
+ *  When identifying the exact failure cause, it's possible to used ZSTD_getFrameParams(), which will provide a more precise error code. */
+unsigned ZSTD_getDictID_fromFrame(const void *src, size_t srcSize)
+{
+       ZSTD_frameParams zfp = {0, 0, 0, 0};
+       size_t const hError = ZSTD_getFrameParams(&zfp, src, srcSize);
+       if (ZSTD_isError(hError))
+               return 0;
+       return zfp.dictID;
+}
+
+/*! ZSTD_decompress_usingDDict() :
+*   Decompression using a pre-digested Dictionary
+*   Use dictionary without significant overhead. */
+size_t ZSTD_decompress_usingDDict(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const ZSTD_DDict *ddict)
+{
+       /* pass content and size in case legacy frames are encountered */
+       return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, NULL, 0, ddict);
+}
+
+/*=====================================
+*   Streaming decompression
+*====================================*/
+
+typedef enum { zdss_init, zdss_loadHeader, zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
+
+/* *** Resource management *** */
+struct ZSTD_DStream_s {
+       ZSTD_DCtx *dctx;
+       ZSTD_DDict *ddictLocal;
+       const ZSTD_DDict *ddict;
+       ZSTD_frameParams fParams;
+       ZSTD_dStreamStage stage;
+       char *inBuff;
+       size_t inBuffSize;
+       size_t inPos;
+       size_t maxWindowSize;
+       char *outBuff;
+       size_t outBuffSize;
+       size_t outStart;
+       size_t outEnd;
+       size_t blockSize;
+       BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; /* tmp buffer to store frame header */
+       size_t lhSize;
+       ZSTD_customMem customMem;
+       void *legacyContext;
+       U32 previousLegacyVersion;
+       U32 legacyVersion;
+       U32 hostageByte;
+}; /* typedef'd to ZSTD_DStream within "zstd.h" */
+
+size_t ZSTD_DStreamWorkspaceBound(size_t maxWindowSize)
+{
+       size_t const blockSize = MIN(maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
+       size_t const inBuffSize = blockSize;
+       size_t const outBuffSize = maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
+       return ZSTD_DCtxWorkspaceBound() + ZSTD_ALIGN(sizeof(ZSTD_DStream)) + ZSTD_ALIGN(inBuffSize) + ZSTD_ALIGN(outBuffSize);
+}
+
+static ZSTD_DStream *ZSTD_createDStream_advanced(ZSTD_customMem customMem)
+{
+       ZSTD_DStream *zds;
+
+       if (!customMem.customAlloc || !customMem.customFree)
+               return NULL;
+
+       zds = (ZSTD_DStream *)ZSTD_malloc(sizeof(ZSTD_DStream), customMem);
+       if (zds == NULL)
+               return NULL;
+       memset(zds, 0, sizeof(ZSTD_DStream));
+       memcpy(&zds->customMem, &customMem, sizeof(ZSTD_customMem));
+       zds->dctx = ZSTD_createDCtx_advanced(customMem);
+       if (zds->dctx == NULL) {
+               ZSTD_freeDStream(zds);
+               return NULL;
+       }
+       zds->stage = zdss_init;
+       zds->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
+       return zds;
+}
+
+ZSTD_DStream *ZSTD_initDStream(size_t maxWindowSize, void *workspace, size_t workspaceSize)
+{
+       ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize);
+       ZSTD_DStream *zds = ZSTD_createDStream_advanced(stackMem);
+       if (!zds) {
+               return NULL;
+       }
+
+       zds->maxWindowSize = maxWindowSize;
+       zds->stage = zdss_loadHeader;
+       zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
+       ZSTD_freeDDict(zds->ddictLocal);
+       zds->ddictLocal = NULL;
+       zds->ddict = zds->ddictLocal;
+       zds->legacyVersion = 0;
+       zds->hostageByte = 0;
+
+       {
+               size_t const blockSize = MIN(zds->maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
+               size_t const neededOutSize = zds->maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
+
+               zds->inBuff = (char *)ZSTD_malloc(blockSize, zds->customMem);
+               zds->inBuffSize = blockSize;
+               zds->outBuff = (char *)ZSTD_malloc(neededOutSize, zds->customMem);
+               zds->outBuffSize = neededOutSize;
+               if (zds->inBuff == NULL || zds->outBuff == NULL) {
+                       ZSTD_freeDStream(zds);
+                       return NULL;
+               }
+       }
+       return zds;
+}
+
+ZSTD_DStream *ZSTD_initDStream_usingDDict(size_t maxWindowSize, const ZSTD_DDict *ddict, void *workspace, size_t workspaceSize)
+{
+       ZSTD_DStream *zds = ZSTD_initDStream(maxWindowSize, workspace, workspaceSize);
+       if (zds) {
+               zds->ddict = ddict;
+       }
+       return zds;
+}
+
+size_t ZSTD_freeDStream(ZSTD_DStream *zds)
+{
+       if (zds == NULL)
+               return 0; /* support free on null */
+       {
+               ZSTD_customMem const cMem = zds->customMem;
+               ZSTD_freeDCtx(zds->dctx);
+               zds->dctx = NULL;
+               ZSTD_freeDDict(zds->ddictLocal);
+               zds->ddictLocal = NULL;
+               ZSTD_free(zds->inBuff, cMem);
+               zds->inBuff = NULL;
+               ZSTD_free(zds->outBuff, cMem);
+               zds->outBuff = NULL;
+               ZSTD_free(zds, cMem);
+               return 0;
+       }
+}
+
+/* *** Initialization *** */
+
+size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX + ZSTD_blockHeaderSize; }
+size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; }
+
+size_t ZSTD_resetDStream(ZSTD_DStream *zds)
+{
+       zds->stage = zdss_loadHeader;
+       zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
+       zds->legacyVersion = 0;
+       zds->hostageByte = 0;
+       return ZSTD_frameHeaderSize_prefix;
+}
+
+/* *****   Decompression   ***** */
+
+ZSTD_STATIC size_t ZSTD_limitCopy(void *dst, size_t dstCapacity, const void *src, size_t srcSize)
+{
+       size_t const length = MIN(dstCapacity, srcSize);
+       memcpy(dst, src, length);
+       return length;
+}
+
+size_t ZSTD_decompressStream(ZSTD_DStream *zds, ZSTD_outBuffer *output, ZSTD_inBuffer *input)
+{
+       const char *const istart = (const char *)(input->src) + input->pos;
+       const char *const iend = (const char *)(input->src) + input->size;
+       const char *ip = istart;
+       char *const ostart = (char *)(output->dst) + output->pos;
+       char *const oend = (char *)(output->dst) + output->size;
+       char *op = ostart;
+       U32 someMoreWork = 1;
+
+       while (someMoreWork) {
+               switch (zds->stage) {
+               case zdss_init:
+                       ZSTD_resetDStream(zds); /* transparent reset on starting decoding a new frame */
+                                               /* fall-through */
+
+               case zdss_loadHeader: {
+                       size_t const hSize = ZSTD_getFrameParams(&zds->fParams, zds->headerBuffer, zds->lhSize);
+                       if (ZSTD_isError(hSize))
+                               return hSize;
+                       if (hSize != 0) {                                  /* need more input */
+                               size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */
+                               if (toLoad > (size_t)(iend - ip)) {     /* not enough input to load full header */
+                                       memcpy(zds->headerBuffer + zds->lhSize, ip, iend - ip);
+                                       zds->lhSize += iend - ip;
+                                       input->pos = input->size;
+                                       return (MAX(ZSTD_frameHeaderSize_min, hSize) - zds->lhSize) +
+                                              ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
+                               }
+                               memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad);
+                               zds->lhSize = hSize;
+                               ip += toLoad;
+                               break;
+                       }
+
+                       /* check for single-pass mode opportunity */
+                       if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */
+                           && (U64)(size_t)(oend - op) >= zds->fParams.frameContentSize) {
+                               size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend - istart);
+                               if (cSize <= (size_t)(iend - istart)) {
+                                       size_t const decompressedSize = ZSTD_decompress_usingDDict(zds->dctx, op, oend - op, istart, cSize, zds->ddict);
+                                       if (ZSTD_isError(decompressedSize))
+                                               return decompressedSize;
+                                       ip = istart + cSize;
+                                       op += decompressedSize;
+                                       zds->dctx->expected = 0;
+                                       zds->stage = zdss_init;
+                                       someMoreWork = 0;
+                                       break;
+                               }
+                       }
+
+                       /* Consume header */
+                       ZSTD_refDDict(zds->dctx, zds->ddict);
+                       {
+                               size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zds->dctx); /* == ZSTD_frameHeaderSize_prefix */
+                               CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer, h1Size));
+                               {
+                                       size_t const h2Size = ZSTD_nextSrcSizeToDecompress(zds->dctx);
+                                       CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer + h1Size, h2Size));
+                               }
+                       }
+
+                       zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
+                       if (zds->fParams.windowSize > zds->maxWindowSize)
+                               return ERROR(frameParameter_windowTooLarge);
+
+                       /* Buffers are preallocated, but double check */
+                       {
+                               size_t const blockSize = MIN(zds->maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
+                               size_t const neededOutSize = zds->maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
+                               if (zds->inBuffSize < blockSize) {
+                                       return ERROR(GENERIC);
+                               }
+                               if (zds->outBuffSize < neededOutSize) {
+                                       return ERROR(GENERIC);
+                               }
+                               zds->blockSize = blockSize;
+                       }
+                       zds->stage = zdss_read;
+               }
+               /* pass-through */
+
+               case zdss_read: {
+                       size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx);
+                       if (neededInSize == 0) { /* end of frame */
+                               zds->stage = zdss_init;
+                               someMoreWork = 0;
+                               break;
+                       }
+                       if ((size_t)(iend - ip) >= neededInSize) { /* decode directly from src */
+                               const int isSkipFrame = ZSTD_isSkipFrame(zds->dctx);
+                               size_t const decodedSize = ZSTD_decompressContinue(zds->dctx, zds->outBuff + zds->outStart,
+                                                                                  (isSkipFrame ? 0 : zds->outBuffSize - zds->outStart), ip, neededInSize);
+                               if (ZSTD_isError(decodedSize))
+                                       return decodedSize;
+                               ip += neededInSize;
+                               if (!decodedSize && !isSkipFrame)
+                                       break; /* this was just a header */
+                               zds->outEnd = zds->outStart + decodedSize;
+                               zds->stage = zdss_flush;
+                               break;
+                       }
+                       if (ip == iend) {
+                               someMoreWork = 0;
+                               break;
+                       } /* no more input */
+                       zds->stage = zdss_load;
+                       /* pass-through */
+               }
+
+               case zdss_load: {
+                       size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx);
+                       size_t const toLoad = neededInSize - zds->inPos; /* should always be <= remaining space within inBuff */
+                       size_t loadedSize;
+                       if (toLoad > zds->inBuffSize - zds->inPos)
+                               return ERROR(corruption_detected); /* should never happen */
+                       loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, iend - ip);
+                       ip += loadedSize;
+                       zds->inPos += loadedSize;
+                       if (loadedSize < toLoad) {
+                               someMoreWork = 0;
+                               break;
+                       } /* not enough input, wait for more */
+
+                       /* decode loaded input */
+                       {
+                               const int isSkipFrame = ZSTD_isSkipFrame(zds->dctx);
+                               size_t const decodedSize = ZSTD_decompressContinue(zds->dctx, zds->outBuff + zds->outStart, zds->outBuffSize - zds->outStart,
+                                                                                  zds->inBuff, neededInSize);
+                               if (ZSTD_isError(decodedSize))
+                                       return decodedSize;
+                               zds->inPos = 0; /* input is consumed */
+                               if (!decodedSize && !isSkipFrame) {
+                                       zds->stage = zdss_read;
+                                       break;
+                               } /* this was just a header */
+                               zds->outEnd = zds->outStart + decodedSize;
+                               zds->stage = zdss_flush;
+                               /* pass-through */
+                       }
+               }
+
+               case zdss_flush: {
+                       size_t const toFlushSize = zds->outEnd - zds->outStart;
+                       size_t const flushedSize = ZSTD_limitCopy(op, oend - op, zds->outBuff + zds->outStart, toFlushSize);
+                       op += flushedSize;
+                       zds->outStart += flushedSize;
+                       if (flushedSize == toFlushSize) { /* flush completed */
+                               zds->stage = zdss_read;
+                               if (zds->outStart + zds->blockSize > zds->outBuffSize)
+                                       zds->outStart = zds->outEnd = 0;
+                               break;
+                       }
+                       /* cannot complete flush */
+                       someMoreWork = 0;
+                       break;
+               }
+               default:
+                       return ERROR(GENERIC); /* impossible */
+               }
+       }
+
+       /* result */
+       input->pos += (size_t)(ip - istart);
+       output->pos += (size_t)(op - ostart);
+       {
+               size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds->dctx);
+               if (!nextSrcSizeHint) {                     /* frame fully decoded */
+                       if (zds->outEnd == zds->outStart) { /* output fully flushed */
+                               if (zds->hostageByte) {
+                                       if (input->pos >= input->size) {
+                                               zds->stage = zdss_read;
+                                               return 1;
+                                       }            /* can't release hostage (not present) */
+                                       input->pos++; /* release hostage */
+                               }
+                               return 0;
+                       }
+                       if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
+                               input->pos--;    /* note : pos > 0, otherwise, impossible to finish reading last block */
+                               zds->hostageByte = 1;
+                       }
+                       return 1;
+               }
+               nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->dctx) == ZSTDnit_block); /* preload header of next block */
+               if (zds->inPos > nextSrcSizeHint)
+                       return ERROR(GENERIC); /* should never happen */
+               nextSrcSizeHint -= zds->inPos; /* already loaded*/
+               return nextSrcSizeHint;
+       }
+}
+
+EXPORT_SYMBOL(ZSTD_DCtxWorkspaceBound);
+EXPORT_SYMBOL(ZSTD_initDCtx);
+EXPORT_SYMBOL(ZSTD_decompressDCtx);
+EXPORT_SYMBOL(ZSTD_decompress_usingDict);
+
+EXPORT_SYMBOL(ZSTD_DDictWorkspaceBound);
+EXPORT_SYMBOL(ZSTD_initDDict);
+EXPORT_SYMBOL(ZSTD_decompress_usingDDict);
+
+EXPORT_SYMBOL(ZSTD_DStreamWorkspaceBound);
+EXPORT_SYMBOL(ZSTD_initDStream);
+EXPORT_SYMBOL(ZSTD_initDStream_usingDDict);
+EXPORT_SYMBOL(ZSTD_resetDStream);
+EXPORT_SYMBOL(ZSTD_decompressStream);
+EXPORT_SYMBOL(ZSTD_DStreamInSize);
+EXPORT_SYMBOL(ZSTD_DStreamOutSize);
+
+EXPORT_SYMBOL(ZSTD_findFrameCompressedSize);
+EXPORT_SYMBOL(ZSTD_getFrameContentSize);
+EXPORT_SYMBOL(ZSTD_findDecompressedSize);
+
+EXPORT_SYMBOL(ZSTD_isFrame);
+EXPORT_SYMBOL(ZSTD_getDictID_fromDict);
+EXPORT_SYMBOL(ZSTD_getDictID_fromDDict);
+EXPORT_SYMBOL(ZSTD_getDictID_fromFrame);
+
+EXPORT_SYMBOL(ZSTD_getFrameParams);
+EXPORT_SYMBOL(ZSTD_decompressBegin);
+EXPORT_SYMBOL(ZSTD_decompressBegin_usingDict);
+EXPORT_SYMBOL(ZSTD_copyDCtx);
+EXPORT_SYMBOL(ZSTD_nextSrcSizeToDecompress);
+EXPORT_SYMBOL(ZSTD_decompressContinue);
+EXPORT_SYMBOL(ZSTD_nextInputType);
+
+EXPORT_SYMBOL(ZSTD_decompressBlock);
+EXPORT_SYMBOL(ZSTD_insertBlock);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Zstd Decompressor");

grub-core/lib/zstd/entropy_common.c new file +243 -0

new file mode 100644
index 000000000..2b0a643c3
@@ -0,0 +1,243 @@
+/*
+ * Common functions of New Generation Entropy library
+ * Copyright (C) 2016, Yann Collet.
+ *
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ *
+ * You can contact the author at :
+ * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ */
+
+/* *************************************
+*  Dependencies
+***************************************/
+#include "error_private.h" /* ERR_*, ERROR */
+#include "fse.h"
+#include "huf.h"
+#include "mem.h"
+
+/*===   Version   ===*/
+unsigned FSE_versionNumber(void) { return FSE_VERSION_NUMBER; }
+
+/*===   Error Management   ===*/
+unsigned FSE_isError(size_t code) { return ERR_isError(code); }
+
+unsigned HUF_isError(size_t code) { return ERR_isError(code); }
+
+/*-**************************************************************
+*  FSE NCount encoding-decoding
+****************************************************************/
+size_t FSE_readNCount(short *normalizedCounter, unsigned *maxSVPtr, unsigned *tableLogPtr, const void *headerBuffer, size_t hbSize)
+{
+       const BYTE *const istart = (const BYTE *)headerBuffer;
+       const BYTE *const iend = istart + hbSize;
+       const BYTE *ip = istart;
+       int nbBits;
+       int remaining;
+       int threshold;
+       U32 bitStream;
+       int bitCount;
+       unsigned charnum = 0;
+       int previous0 = 0;
+
+       if (hbSize < 4)
+               return ERROR(srcSize_wrong);
+       bitStream = ZSTD_readLE32(ip);
+       nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG; /* extract tableLog */
+       if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX)
+               return ERROR(tableLog_tooLarge);
+       bitStream >>= 4;
+       bitCount = 4;
+       *tableLogPtr = nbBits;
+       remaining = (1 << nbBits) + 1;
+       threshold = 1 << nbBits;
+       nbBits++;
+
+       while ((remaining > 1) & (charnum <= *maxSVPtr)) {
+               if (previous0) {
+                       unsigned n0 = charnum;
+                       while ((bitStream & 0xFFFF) == 0xFFFF) {
+                               n0 += 24;
+                               if (ip < iend - 5) {
+                                       ip += 2;
+                                       bitStream = ZSTD_readLE32(ip) >> bitCount;
+                               } else {
+                                       bitStream >>= 16;
+                                       bitCount += 16;
+                               }
+                       }
+                       while ((bitStream & 3) == 3) {
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grub-core/lib/zstd/error_private.h new file +53 -0

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grub-core/lib/zstd/fse.h new file +575 -0

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grub-core/lib/zstd/fse_decompress.c new file +332 -0

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grub-core/lib/zstd/huf.h new file +212 -0

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grub-core/lib/zstd/huf_decompress.c new file +960 -0

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grub-core/lib/zstd/mem.h new file +151 -0

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grub-core/lib/zstd/xxhash.c new file +500 -0

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grub-core/lib/zstd/xxhash.h new file +236 -0

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grub-core/lib/zstd/zstd.h new file +1157 -0

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grub-core/lib/zstd/zstd_common.c new file +75 -0

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grub-core/lib/zstd/zstd_internal.h new file +263 -1

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2.16.2

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