zstd: Update to upstream version 1.5.0

Release notes: https://github.com/facebook/zstd/releases/tag/v1.5.0
This commit is contained in:
Rémi Verschelde 2021-11-19 12:54:45 +01:00
parent 42f8bfaff0
commit 5bea1370f0
No known key found for this signature in database
GPG key ID: C3336907360768E1
57 changed files with 4124 additions and 1358 deletions

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@ -1,7 +1,7 @@
/* ******************************************************************
* huff0 huffman decoder,
* part of Finite State Entropy library
* Copyright (c) 2013-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
*
* You can contact the author at :
* - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
@ -528,13 +528,15 @@ typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];
static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 consumed,
const U32* rankValOrigin, const int minWeight,
const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
U32 nbBitsBaseline, U16 baseSeq)
U32 nbBitsBaseline, U16 baseSeq, U32* wksp, size_t wkspSize)
{
HUF_DEltX2 DElt;
U32 rankVal[HUF_TABLELOG_MAX + 1];
U32* rankVal = wksp;
assert(wkspSize >= HUF_TABLELOG_MAX + 1);
(void)wkspSize;
/* get pre-calculated rankVal */
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(rankVal));
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1));
/* fill skipped values */
if (minWeight>1) {
@ -569,14 +571,18 @@ static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 co
static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
const sortedSymbol_t* sortedList, const U32 sortedListSize,
const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
const U32 nbBitsBaseline)
const U32 nbBitsBaseline, U32* wksp, size_t wkspSize)
{
U32 rankVal[HUF_TABLELOG_MAX + 1];
U32* rankVal = wksp;
const int scaleLog = nbBitsBaseline - targetLog; /* note : targetLog >= srcLog, hence scaleLog <= 1 */
const U32 minBits = nbBitsBaseline - maxWeight;
U32 s;
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(rankVal));
assert(wkspSize >= HUF_TABLELOG_MAX + 1);
wksp += HUF_TABLELOG_MAX + 1;
wkspSize -= HUF_TABLELOG_MAX + 1;
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1));
/* fill DTable */
for (s=0; s<sortedListSize; s++) {
@ -594,7 +600,7 @@ static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
HUF_fillDTableX2Level2(DTable+start, targetLog-nbBits, nbBits,
rankValOrigin[nbBits], minWeight,
sortedList+sortedRank, sortedListSize-sortedRank,
nbBitsBaseline, symbol);
nbBitsBaseline, symbol, wksp, wkspSize);
} else {
HUF_DEltX2 DElt;
MEM_writeLE16(&(DElt.sequence), symbol);
@ -608,6 +614,15 @@ static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
}
}
typedef struct {
rankValCol_t rankVal[HUF_TABLELOG_MAX];
U32 rankStats[HUF_TABLELOG_MAX + 1];
U32 rankStart0[HUF_TABLELOG_MAX + 2];
sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1];
BYTE weightList[HUF_SYMBOLVALUE_MAX + 1];
U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
} HUF_ReadDTableX2_Workspace;
size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
const void* src, size_t srcSize,
void* workSpace, size_t wkspSize)
@ -620,47 +635,32 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
U32 *rankStart;
rankValCol_t* rankVal;
U32* rankStats;
U32* rankStart0;
sortedSymbol_t* sortedSymbol;
BYTE* weightList;
size_t spaceUsed32 = 0;
HUF_ReadDTableX2_Workspace* const wksp = (HUF_ReadDTableX2_Workspace*)workSpace;
rankVal = (rankValCol_t *)((U32 *)workSpace + spaceUsed32);
spaceUsed32 += (sizeof(rankValCol_t) * HUF_TABLELOG_MAX) >> 2;
rankStats = (U32 *)workSpace + spaceUsed32;
spaceUsed32 += HUF_TABLELOG_MAX + 1;
rankStart0 = (U32 *)workSpace + spaceUsed32;
spaceUsed32 += HUF_TABLELOG_MAX + 2;
sortedSymbol = (sortedSymbol_t *)workSpace + (spaceUsed32 * sizeof(U32)) / sizeof(sortedSymbol_t);
spaceUsed32 += HUF_ALIGN(sizeof(sortedSymbol_t) * (HUF_SYMBOLVALUE_MAX + 1), sizeof(U32)) >> 2;
weightList = (BYTE *)((U32 *)workSpace + spaceUsed32);
spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
if (sizeof(*wksp) > wkspSize) return ERROR(GENERIC);
if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge);
rankStart = rankStart0 + 1;
ZSTD_memset(rankStats, 0, sizeof(U32) * (2 * HUF_TABLELOG_MAX + 2 + 1));
rankStart = wksp->rankStart0 + 1;
ZSTD_memset(wksp->rankStats, 0, sizeof(wksp->rankStats));
ZSTD_memset(wksp->rankStart0, 0, sizeof(wksp->rankStart0));
DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable)); /* if compiler fails here, assertion is wrong */
if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
/* ZSTD_memset(weightList, 0, sizeof(weightList)); */ /* is not necessary, even though some analyzer complain ... */
iSize = HUF_readStats(weightList, HUF_SYMBOLVALUE_MAX + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), /* bmi2 */ 0);
if (HUF_isError(iSize)) return iSize;
/* check result */
if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge); /* DTable can't fit code depth */
/* find maxWeight */
for (maxW = tableLog; rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */
for (maxW = tableLog; wksp->rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */
/* Get start index of each weight */
{ U32 w, nextRankStart = 0;
for (w=1; w<maxW+1; w++) {
U32 curr = nextRankStart;
nextRankStart += rankStats[w];
nextRankStart += wksp->rankStats[w];
rankStart[w] = curr;
}
rankStart[0] = nextRankStart; /* put all 0w symbols at the end of sorted list*/
@ -670,37 +670,38 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
/* sort symbols by weight */
{ U32 s;
for (s=0; s<nbSymbols; s++) {
U32 const w = weightList[s];
U32 const w = wksp->weightList[s];
U32 const r = rankStart[w]++;
sortedSymbol[r].symbol = (BYTE)s;
sortedSymbol[r].weight = (BYTE)w;
wksp->sortedSymbol[r].symbol = (BYTE)s;
wksp->sortedSymbol[r].weight = (BYTE)w;
}
rankStart[0] = 0; /* forget 0w symbols; this is beginning of weight(1) */
}
/* Build rankVal */
{ U32* const rankVal0 = rankVal[0];
{ U32* const rankVal0 = wksp->rankVal[0];
{ int const rescale = (maxTableLog-tableLog) - 1; /* tableLog <= maxTableLog */
U32 nextRankVal = 0;
U32 w;
for (w=1; w<maxW+1; w++) {
U32 curr = nextRankVal;
nextRankVal += rankStats[w] << (w+rescale);
nextRankVal += wksp->rankStats[w] << (w+rescale);
rankVal0[w] = curr;
} }
{ U32 const minBits = tableLog+1 - maxW;
U32 consumed;
for (consumed = minBits; consumed < maxTableLog - minBits + 1; consumed++) {
U32* const rankValPtr = rankVal[consumed];
U32* const rankValPtr = wksp->rankVal[consumed];
U32 w;
for (w = 1; w < maxW+1; w++) {
rankValPtr[w] = rankVal0[w] >> consumed;
} } } }
HUF_fillDTableX2(dt, maxTableLog,
sortedSymbol, sizeOfSort,
rankStart0, rankVal, maxW,
tableLog+1);
wksp->sortedSymbol, sizeOfSort,
wksp->rankStart0, wksp->rankVal, maxW,
tableLog+1,
wksp->calleeWksp, sizeof(wksp->calleeWksp) / sizeof(U32));
dtd.tableLog = (BYTE)maxTableLog;
dtd.tableType = 1;
@ -1225,7 +1226,7 @@ size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cS
HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX);
return HUF_decompress1X1_DCtx (DTable, dst, dstSize, cSrc, cSrcSize);
}
#endif
#endif
#ifndef HUF_FORCE_DECOMPRESS_X1
size_t HUF_readDTableX2(HUF_DTable* DTable, const void* src, size_t srcSize)

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@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the

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@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the

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@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
@ -62,6 +62,7 @@
#include "../common/fse.h"
#define HUF_STATIC_LINKING_ONLY
#include "../common/huf.h"
#include "../common/xxhash.h" /* XXH64_reset, XXH64_update, XXH64_digest, XXH64 */
#include "../common/zstd_internal.h" /* blockProperties_t */
#include "zstd_decompress_internal.h" /* ZSTD_DCtx */
#include "zstd_ddict.h" /* ZSTD_DDictDictContent */
@ -72,6 +73,144 @@
#endif
/*************************************
* Multiple DDicts Hashset internals *
*************************************/
#define DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT 4
#define DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT 3 /* These two constants represent SIZE_MULT/COUNT_MULT load factor without using a float.
* Currently, that means a 0.75 load factor.
* So, if count * COUNT_MULT / size * SIZE_MULT != 0, then we've exceeded
* the load factor of the ddict hash set.
*/
#define DDICT_HASHSET_TABLE_BASE_SIZE 64
#define DDICT_HASHSET_RESIZE_FACTOR 2
/* Hash function to determine starting position of dict insertion within the table
* Returns an index between [0, hashSet->ddictPtrTableSize]
*/
static size_t ZSTD_DDictHashSet_getIndex(const ZSTD_DDictHashSet* hashSet, U32 dictID) {
const U64 hash = XXH64(&dictID, sizeof(U32), 0);
/* DDict ptr table size is a multiple of 2, use size - 1 as mask to get index within [0, hashSet->ddictPtrTableSize) */
return hash & (hashSet->ddictPtrTableSize - 1);
}
/* Adds DDict to a hashset without resizing it.
* If inserting a DDict with a dictID that already exists in the set, replaces the one in the set.
* Returns 0 if successful, or a zstd error code if something went wrong.
*/
static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict) {
const U32 dictID = ZSTD_getDictID_fromDDict(ddict);
size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
RETURN_ERROR_IF(hashSet->ddictPtrCount == hashSet->ddictPtrTableSize, GENERIC, "Hash set is full!");
DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
while (hashSet->ddictPtrTable[idx] != NULL) {
/* Replace existing ddict if inserting ddict with same dictID */
if (ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]) == dictID) {
DEBUGLOG(4, "DictID already exists, replacing rather than adding");
hashSet->ddictPtrTable[idx] = ddict;
return 0;
}
idx &= idxRangeMask;
idx++;
}
DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
hashSet->ddictPtrTable[idx] = ddict;
hashSet->ddictPtrCount++;
return 0;
}
/* Expands hash table by factor of DDICT_HASHSET_RESIZE_FACTOR and
* rehashes all values, allocates new table, frees old table.
* Returns 0 on success, otherwise a zstd error code.
*/
static size_t ZSTD_DDictHashSet_expand(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) {
size_t newTableSize = hashSet->ddictPtrTableSize * DDICT_HASHSET_RESIZE_FACTOR;
const ZSTD_DDict** newTable = (const ZSTD_DDict**)ZSTD_customCalloc(sizeof(ZSTD_DDict*) * newTableSize, customMem);
const ZSTD_DDict** oldTable = hashSet->ddictPtrTable;
size_t oldTableSize = hashSet->ddictPtrTableSize;
size_t i;
DEBUGLOG(4, "Expanding DDict hash table! Old size: %zu new size: %zu", oldTableSize, newTableSize);
RETURN_ERROR_IF(!newTable, memory_allocation, "Expanded hashset allocation failed!");
hashSet->ddictPtrTable = newTable;
hashSet->ddictPtrTableSize = newTableSize;
hashSet->ddictPtrCount = 0;
for (i = 0; i < oldTableSize; ++i) {
if (oldTable[i] != NULL) {
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i]), "");
}
}
ZSTD_customFree((void*)oldTable, customMem);
DEBUGLOG(4, "Finished re-hash");
return 0;
}
/* Fetches a DDict with the given dictID
* Returns the ZSTD_DDict* with the requested dictID. If it doesn't exist, then returns NULL.
*/
static const ZSTD_DDict* ZSTD_DDictHashSet_getDDict(ZSTD_DDictHashSet* hashSet, U32 dictID) {
size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
for (;;) {
size_t currDictID = ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]);
if (currDictID == dictID || currDictID == 0) {
/* currDictID == 0 implies a NULL ddict entry */
break;
} else {
idx &= idxRangeMask; /* Goes to start of table when we reach the end */
idx++;
}
}
DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
return hashSet->ddictPtrTable[idx];
}
/* Allocates space for and returns a ddict hash set
* The hash set's ZSTD_DDict* table has all values automatically set to NULL to begin with.
* Returns NULL if allocation failed.
*/
static ZSTD_DDictHashSet* ZSTD_createDDictHashSet(ZSTD_customMem customMem) {
ZSTD_DDictHashSet* ret = (ZSTD_DDictHashSet*)ZSTD_customMalloc(sizeof(ZSTD_DDictHashSet), customMem);
DEBUGLOG(4, "Allocating new hash set");
ret->ddictPtrTable = (const ZSTD_DDict**)ZSTD_customCalloc(DDICT_HASHSET_TABLE_BASE_SIZE * sizeof(ZSTD_DDict*), customMem);
ret->ddictPtrTableSize = DDICT_HASHSET_TABLE_BASE_SIZE;
ret->ddictPtrCount = 0;
if (!ret || !ret->ddictPtrTable) {
return NULL;
}
return ret;
}
/* Frees the table of ZSTD_DDict* within a hashset, then frees the hashset itself.
* Note: The ZSTD_DDict* within the table are NOT freed.
*/
static void ZSTD_freeDDictHashSet(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) {
DEBUGLOG(4, "Freeing ddict hash set");
if (hashSet && hashSet->ddictPtrTable) {
ZSTD_customFree((void*)hashSet->ddictPtrTable, customMem);
}
if (hashSet) {
ZSTD_customFree(hashSet, customMem);
}
}
/* Public function: Adds a DDict into the ZSTD_DDictHashSet, possibly triggering a resize of the hash set.
* Returns 0 on success, or a ZSTD error.
*/
static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, ZSTD_customMem customMem) {
DEBUGLOG(4, "Adding dict ID: %u to hashset with - Count: %zu Tablesize: %zu", ZSTD_getDictID_fromDDict(ddict), hashSet->ddictPtrCount, hashSet->ddictPtrTableSize);
if (hashSet->ddictPtrCount * DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT / hashSet->ddictPtrTableSize * DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT != 0) {
FORWARD_IF_ERROR(ZSTD_DDictHashSet_expand(hashSet, customMem), "");
}
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict), "");
return 0;
}
/*-*************************************************************
* Context management
***************************************************************/
@ -101,6 +240,7 @@ static void ZSTD_DCtx_resetParameters(ZSTD_DCtx* dctx)
dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
dctx->outBufferMode = ZSTD_bm_buffered;
dctx->forceIgnoreChecksum = ZSTD_d_validateChecksum;
dctx->refMultipleDDicts = ZSTD_rmd_refSingleDDict;
}
static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
@ -120,8 +260,8 @@ static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
dctx->noForwardProgress = 0;
dctx->oversizedDuration = 0;
dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
dctx->ddictSet = NULL;
ZSTD_DCtx_resetParameters(dctx);
dctx->validateChecksum = 1;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
dctx->dictContentEndForFuzzing = NULL;
#endif
@ -178,6 +318,10 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
if (dctx->legacyContext)
ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
#endif
if (dctx->ddictSet) {
ZSTD_freeDDictHashSet(dctx->ddictSet, cMem);
dctx->ddictSet = NULL;
}
ZSTD_customFree(dctx, cMem);
return 0;
}
@ -190,6 +334,29 @@ void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
ZSTD_memcpy(dstDCtx, srcDCtx, toCopy); /* no need to copy workspace */
}
/* Given a dctx with a digested frame params, re-selects the correct ZSTD_DDict based on
* the requested dict ID from the frame. If there exists a reference to the correct ZSTD_DDict, then
* accordingly sets the ddict to be used to decompress the frame.
*
* If no DDict is found, then no action is taken, and the ZSTD_DCtx::ddict remains as-is.
*
* ZSTD_d_refMultipleDDicts must be enabled for this function to be called.
*/
static void ZSTD_DCtx_selectFrameDDict(ZSTD_DCtx* dctx) {
assert(dctx->refMultipleDDicts && dctx->ddictSet);
DEBUGLOG(4, "Adjusting DDict based on requested dict ID from frame");
if (dctx->ddict) {
const ZSTD_DDict* frameDDict = ZSTD_DDictHashSet_getDDict(dctx->ddictSet, dctx->fParams.dictID);
if (frameDDict) {
DEBUGLOG(4, "DDict found!");
ZSTD_clearDict(dctx);
dctx->dictID = dctx->fParams.dictID;
dctx->ddict = frameDDict;
dctx->dictUses = ZSTD_use_indefinitely;
}
}
}
/*-*************************************************************
* Frame header decoding
@ -441,12 +608,19 @@ unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
/** ZSTD_decodeFrameHeader() :
* `headerSize` must be the size provided by ZSTD_frameHeaderSize().
* If multiple DDict references are enabled, also will choose the correct DDict to use.
* @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_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
if (ZSTD_isError(result)) return result; /* invalid header */
RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small");
/* Reference DDict requested by frame if dctx references multiple ddicts */
if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts && dctx->ddictSet) {
ZSTD_DCtx_selectFrameDDict(dctx);
}
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
/* Skip the dictID check in fuzzing mode, because it makes the search
* harder.
@ -456,6 +630,7 @@ static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t he
#endif
dctx->validateChecksum = (dctx->fParams.checksumFlag && !dctx->forceIgnoreChecksum) ? 1 : 0;
if (dctx->validateChecksum) XXH64_reset(&dctx->xxhState, 0);
dctx->processedCSize += headerSize;
return 0;
}
@ -578,7 +753,7 @@ unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
{
DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize);
ZSTD_checkContinuity(dctx, blockStart);
ZSTD_checkContinuity(dctx, blockStart, blockSize);
dctx->previousDstEnd = (const char*)blockStart + blockSize;
return blockSize;
}
@ -610,6 +785,32 @@ static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
return regenSize;
}
static void ZSTD_DCtx_trace_end(ZSTD_DCtx const* dctx, U64 uncompressedSize, U64 compressedSize, unsigned streaming)
{
#if ZSTD_TRACE
if (dctx->traceCtx && ZSTD_trace_decompress_end != NULL) {
ZSTD_Trace trace;
ZSTD_memset(&trace, 0, sizeof(trace));
trace.version = ZSTD_VERSION_NUMBER;
trace.streaming = streaming;
if (dctx->ddict) {
trace.dictionaryID = ZSTD_getDictID_fromDDict(dctx->ddict);
trace.dictionarySize = ZSTD_DDict_dictSize(dctx->ddict);
trace.dictionaryIsCold = dctx->ddictIsCold;
}
trace.uncompressedSize = (size_t)uncompressedSize;
trace.compressedSize = (size_t)compressedSize;
trace.dctx = dctx;
ZSTD_trace_decompress_end(dctx->traceCtx, &trace);
}
#else
(void)dctx;
(void)uncompressedSize;
(void)compressedSize;
(void)streaming;
#endif
}
/*! ZSTD_decompressFrame() :
* @dctx must be properly initialized
@ -619,8 +820,9 @@ 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;
const BYTE* const istart = (const BYTE*)(*srcPtr);
const BYTE* ip = istart;
BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart;
BYTE* op = ostart;
size_t remainingSrcSize = *srcSizePtr;
@ -695,7 +897,7 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
ip += 4;
remainingSrcSize -= 4;
}
ZSTD_DCtx_trace_end(dctx, (U64)(op-ostart), (U64)(ip-istart), /* streaming */ 0);
/* Allow caller to get size read */
*srcPtr = ip;
*srcSizePtr = remainingSrcSize;
@ -764,7 +966,7 @@ static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
* use this in all cases but ddict */
FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize), "");
}
ZSTD_checkContinuity(dctx, dst);
ZSTD_checkContinuity(dctx, dst, dstCapacity);
{ const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
&src, &srcSize);
@ -899,7 +1101,9 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c
DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize);
/* Sanity check */
RETURN_ERROR_IF(srcSize != ZSTD_nextSrcSizeToDecompressWithInputSize(dctx, srcSize), srcSize_wrong, "not allowed");
if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
ZSTD_checkContinuity(dctx, dst, dstCapacity);
dctx->processedCSize += srcSize;
switch (dctx->stage)
{
@ -1004,6 +1208,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c
dctx->expected = 4;
dctx->stage = ZSTDds_checkChecksum;
} else {
ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
dctx->expected = 0; /* ends here */
dctx->stage = ZSTDds_getFrameHeaderSize;
}
@ -1023,6 +1228,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c
DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32);
RETURN_ERROR_IF(check32 != h32, checksum_wrong, "");
}
ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
dctx->expected = 0;
dctx->stage = ZSTDds_getFrameHeaderSize;
return 0;
@ -1176,8 +1382,12 @@ static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict
size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
{
assert(dctx != NULL);
#if ZSTD_TRACE
dctx->traceCtx = (ZSTD_trace_decompress_begin != NULL) ? ZSTD_trace_decompress_begin(dctx) : 0;
#endif
dctx->expected = ZSTD_startingInputLength(dctx->format); /* dctx->format must be properly set */
dctx->stage = ZSTDds_getFrameHeaderSize;
dctx->processedCSize = 0;
dctx->decodedSize = 0;
dctx->previousDstEnd = NULL;
dctx->prefixStart = NULL;
@ -1391,6 +1601,16 @@ size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
if (ddict) {
dctx->ddict = ddict;
dctx->dictUses = ZSTD_use_indefinitely;
if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts) {
if (dctx->ddictSet == NULL) {
dctx->ddictSet = ZSTD_createDDictHashSet(dctx->customMem);
if (!dctx->ddictSet) {
RETURN_ERROR(memory_allocation, "Failed to allocate memory for hash set!");
}
}
assert(!dctx->staticSize); /* Impossible: ddictSet cannot have been allocated if static dctx */
FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict, dctx->customMem), "");
}
}
return 0;
}
@ -1436,6 +1656,10 @@ ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam)
bounds.lowerBound = (int)ZSTD_d_validateChecksum;
bounds.upperBound = (int)ZSTD_d_ignoreChecksum;
return bounds;
case ZSTD_d_refMultipleDDicts:
bounds.lowerBound = (int)ZSTD_rmd_refSingleDDict;
bounds.upperBound = (int)ZSTD_rmd_refMultipleDDicts;
return bounds;
default:;
}
bounds.error = ERROR(parameter_unsupported);
@ -1473,6 +1697,9 @@ size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value
case ZSTD_d_forceIgnoreChecksum:
*value = (int)dctx->forceIgnoreChecksum;
return 0;
case ZSTD_d_refMultipleDDicts:
*value = (int)dctx->refMultipleDDicts;
return 0;
default:;
}
RETURN_ERROR(parameter_unsupported, "");
@ -1499,6 +1726,13 @@ size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value
CHECK_DBOUNDS(ZSTD_d_forceIgnoreChecksum, value);
dctx->forceIgnoreChecksum = (ZSTD_forceIgnoreChecksum_e)value;
return 0;
case ZSTD_d_refMultipleDDicts:
CHECK_DBOUNDS(ZSTD_d_refMultipleDDicts, value);
if (dctx->staticSize != 0) {
RETURN_ERROR(parameter_unsupported, "Static dctx does not support multiple DDicts!");
}
dctx->refMultipleDDicts = (ZSTD_refMultipleDDicts_e)value;
return 0;
default:;
}
RETURN_ERROR(parameter_unsupported, "");
@ -1680,6 +1914,9 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
} }
#endif
{ size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
if (zds->refMultipleDDicts && zds->ddictSet) {
ZSTD_DCtx_selectFrameDDict(zds);
}
DEBUGLOG(5, "header size : %u", (U32)hSize);
if (ZSTD_isError(hSize)) {
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
@ -577,7 +577,7 @@ static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymb
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 istart = (const BYTE*)src;
const BYTE* const iend = istart + srcSize;
const BYTE* ip = istart;
int nbSeq;
@ -658,7 +658,6 @@ typedef struct {
size_t litLength;
size_t matchLength;
size_t offset;
const BYTE* match;
} seq_t;
typedef struct {
@ -672,9 +671,6 @@ typedef struct {
ZSTD_fseState stateOffb;
ZSTD_fseState stateML;
size_t prevOffset[ZSTD_REP_NUM];
const BYTE* prefixStart;
const BYTE* dictEnd;
size_t pos;
} seqState_t;
/*! ZSTD_overlapCopy8() :
@ -936,10 +932,9 @@ ZSTD_updateFseStateWithDInfo(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, ZSTD
: 0)
typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
typedef enum { ZSTD_p_noPrefetch=0, ZSTD_p_prefetch=1 } ZSTD_prefetch_e;
FORCE_INLINE_TEMPLATE seq_t
ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const ZSTD_prefetch_e prefetch)
ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
{
seq_t seq;
ZSTD_seqSymbol const llDInfo = seqState->stateLL.table[seqState->stateLL.state];
@ -1014,14 +1009,6 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, c
DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
(U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
if (prefetch == ZSTD_p_prefetch) {
size_t const pos = seqState->pos + seq.litLength;
const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart;
seq.match = matchBase + pos - seq.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
* No consequence though : no memory access will occur, offset is only used for prefetching */
seqState->pos = pos + seq.matchLength;
}
/* ANS state update
* gcc-9.0.0 does 2.5% worse with ZSTD_updateFseStateWithDInfo().
* clang-9.2.0 does 7% worse with ZSTD_updateFseState().
@ -1108,7 +1095,7 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
{
const BYTE* ip = (const BYTE*)seqStart;
const BYTE* const iend = ip + seqSize;
BYTE* const ostart = (BYTE* const)dst;
BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = ostart + maxDstSize;
BYTE* op = ostart;
const BYTE* litPtr = dctx->litPtr;
@ -1122,7 +1109,6 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
/* Regen sequences */
if (nbSeq) {
seqState_t seqState;
size_t error = 0;
dctx->fseEntropy = 1;
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
RETURN_ERROR_IF(
@ -1156,13 +1142,14 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
* If you see most cycles served out of the DSB you've hit the good case.
* If it is pretty even then you may be in an okay case.
*
* I've been able to reproduce this issue on the following CPUs:
* This issue has been reproduced on the following CPUs:
* - Kabylake: Macbook Pro (15-inch, 2019) 2.4 GHz Intel Core i9
* Use Instruments->Counters to get DSB/MITE cycles.
* I never got performance swings, but I was able to
* go from the good case of mostly DSB to half of the
* cycles served from MITE.
* - Coffeelake: Intel i9-9900k
* - Coffeelake: Intel i7-9700k
*
* I haven't been able to reproduce the instability or DSB misses on any
* of the following CPUS:
@ -1175,33 +1162,35 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
*
* https://gist.github.com/terrelln/9889fc06a423fd5ca6e99351564473f4
*/
__asm__(".p2align 6");
__asm__("nop");
__asm__(".p2align 5");
__asm__("nop");
# if __GNUC__ >= 9
/* better for gcc-9 and gcc-10, worse for clang and gcc-8 */
__asm__(".p2align 3");
# else
__asm__(".p2align 4");
# endif
#endif
for ( ; ; ) {
seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, ZSTD_p_noPrefetch);
seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
assert(!ZSTD_isError(oneSeqSize));
if (frame) ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
#endif
if (UNLIKELY(ZSTD_isError(oneSeqSize)))
return oneSeqSize;
DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
BIT_reloadDStream(&(seqState.DStream));
op += oneSeqSize;
/* gcc and clang both don't like early returns in this loop.
* Instead break and check for an error at the end of the loop.
*/
if (UNLIKELY(ZSTD_isError(oneSeqSize))) {
error = oneSeqSize;
if (UNLIKELY(!--nbSeq))
break;
}
if (UNLIKELY(!--nbSeq)) break;
BIT_reloadDStream(&(seqState.DStream));
}
/* check if reached exact end */
DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq);
if (ZSTD_isError(error)) return error;
RETURN_ERROR_IF(nbSeq, corruption_detected, "");
RETURN_ERROR_IF(BIT_reloadDStream(&seqState.DStream) < BIT_DStream_completed, corruption_detected, "");
/* save reps for next block */
@ -1232,6 +1221,24 @@ ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */
#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
FORCE_INLINE_TEMPLATE size_t
ZSTD_prefetchMatch(size_t prefetchPos, seq_t const sequence,
const BYTE* const prefixStart, const BYTE* const dictEnd)
{
prefetchPos += sequence.litLength;
{ const BYTE* const matchBase = (sequence.offset > prefetchPos) ? dictEnd : prefixStart;
const BYTE* const match = matchBase + prefetchPos - sequence.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
* No consequence though : memory address is only used for prefetching, not for dereferencing */
PREFETCH_L1(match); PREFETCH_L1(match+CACHELINE_SIZE); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
}
return prefetchPos + sequence.matchLength;
}
/* This decoding function employs prefetching
* to reduce latency impact of cache misses.
* It's generally employed when block contains a significant portion of long-distance matches
* or when coupled with a "cold" dictionary */
FORCE_INLINE_TEMPLATE size_t
ZSTD_decompressSequencesLong_body(
ZSTD_DCtx* dctx,
@ -1242,7 +1249,7 @@ ZSTD_decompressSequencesLong_body(
{
const BYTE* ip = (const BYTE*)seqStart;
const BYTE* const iend = ip + seqSize;
BYTE* const ostart = (BYTE* const)dst;
BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = ostart + maxDstSize;
BYTE* op = ostart;
const BYTE* litPtr = dctx->litPtr;
@ -1254,18 +1261,17 @@ ZSTD_decompressSequencesLong_body(
/* Regen sequences */
if (nbSeq) {
#define STORED_SEQS 4
#define STORED_SEQS 8
#define STORED_SEQS_MASK (STORED_SEQS-1)
#define ADVANCED_SEQS 4
#define ADVANCED_SEQS STORED_SEQS
seq_t sequences[STORED_SEQS];
int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
seqState_t seqState;
int seqNb;
size_t prefetchPos = (size_t)(op-prefixStart); /* track position relative to prefixStart */
dctx->fseEntropy = 1;
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
seqState.prefixStart = prefixStart;
seqState.pos = (size_t)(op-prefixStart);
seqState.dictEnd = dictEnd;
assert(dst != NULL);
assert(iend >= ip);
RETURN_ERROR_IF(
@ -1277,21 +1283,23 @@ ZSTD_decompressSequencesLong_body(
/* prepare in advance */
for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNb<seqAdvance); seqNb++) {
sequences[seqNb] = ZSTD_decodeSequence(&seqState, isLongOffset, ZSTD_p_prefetch);
PREFETCH_L1(sequences[seqNb].match); PREFETCH_L1(sequences[seqNb].match + sequences[seqNb].matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
sequences[seqNb] = sequence;
}
RETURN_ERROR_IF(seqNb<seqAdvance, corruption_detected, "");
/* decode and decompress */
for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb<nbSeq) ; seqNb++) {
seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, ZSTD_p_prefetch);
seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
assert(!ZSTD_isError(oneSeqSize));
if (frame) ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart);
#endif
if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
PREFETCH_L1(sequence.match); PREFETCH_L1(sequence.match + sequence.matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
sequences[seqNb & STORED_SEQS_MASK] = sequence;
op += oneSeqSize;
}
@ -1517,9 +1525,9 @@ ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
}
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst)
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize)
{
if (dst != dctx->previousDstEnd) { /* not contiguous */
if (dst != dctx->previousDstEnd && dstSize > 0) { /* not contiguous */
dctx->dictEnd = dctx->previousDstEnd;
dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
dctx->prefixStart = dst;
@ -1533,7 +1541,7 @@ size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
const void* src, size_t srcSize)
{
size_t dSize;
ZSTD_checkContinuity(dctx, dst);
ZSTD_checkContinuity(dctx, dst, dstCapacity);
dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0);
dctx->previousDstEnd = (char*)dst + dSize;
return dSize;

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
@ -99,6 +99,13 @@ typedef enum {
ZSTD_use_once = 1 /* Use the dictionary once and set to ZSTD_dont_use */
} ZSTD_dictUses_e;
/* Hashset for storing references to multiple ZSTD_DDict within ZSTD_DCtx */
typedef struct {
const ZSTD_DDict** ddictPtrTable;
size_t ddictPtrTableSize;
size_t ddictPtrCount;
} ZSTD_DDictHashSet;
struct ZSTD_DCtx_s
{
const ZSTD_seqSymbol* LLTptr;
@ -113,6 +120,7 @@ struct ZSTD_DCtx_s
const void* dictEnd; /* end of previous segment */
size_t expected;
ZSTD_frameHeader fParams;
U64 processedCSize;
U64 decodedSize;
blockType_e bType; /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
ZSTD_dStage stage;
@ -136,6 +144,8 @@ struct ZSTD_DCtx_s
U32 dictID;
int ddictIsCold; /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
ZSTD_dictUses_e dictUses;
ZSTD_DDictHashSet* ddictSet; /* Hash set for multiple ddicts */
ZSTD_refMultipleDDicts_e refMultipleDDicts; /* User specified: if == 1, will allow references to multiple DDicts. Default == 0 (disabled) */
/* streaming */
ZSTD_dStreamStage streamStage;
@ -166,6 +176,11 @@ struct ZSTD_DCtx_s
void const* dictContentBeginForFuzzing;
void const* dictContentEndForFuzzing;
#endif
/* Tracing */
#if ZSTD_TRACE
ZSTD_TraceCtx traceCtx;
#endif
}; /* typedef'd to ZSTD_DCtx within "zstd.h" */
@ -184,7 +199,7 @@ size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
* If yes, do nothing (continue on current segment).
* If not, classify previous segment as "external dictionary", and start a new segment.
* This function cannot fail. */
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst);
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize);
#endif /* ZSTD_DECOMPRESS_INTERNAL_H */