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u-boot/lib/zstd/decompress.c
Marek Behún 8509f22aac lib: add Zstandard decompression support 
Add the zstd library from Linux kernel (only decompression support).
There are minimal changes to build with U-Boot, otherwise the files are
identical to Linux commit dc35da16 from March 2018, the files had not
been touched since in kernel. Also SPDX lincese tags were added.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
2019-05-05 08:48:50 -04:00

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// SPDX-License-Identifier: (GPL-2.0 or BSD-3-Clause-Clear)
/**
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*/
/* ***************************************************************
* 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/compat.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);
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