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gerrit-public.fairphone.software / platform / external / zstd / 30c76989704975b3fe7f3561d751a5ba24d838e8 / . / lib / compress / zstd_compress.c
blob: e1c734927563a6a5b4553a90aee7ff11b6a446ca [file] [log] [blame]
/**
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
/*-*************************************
* Dependencies
***************************************/
#include <string.h> /* memset */
#include "mem.h"
#define FSE_STATIC_LINKING_ONLY /* FSE_encodeSymbol */
#include "fse.h"
#define HUF_STATIC_LINKING_ONLY
#include "huf.h"
#include "zstd_internal.h" /* includes zstd.h */
/*-*************************************
* Constants
***************************************/
static const U32 g_searchStrength = 8; /* control skip over incompressible data */
#define HASH_READ_SIZE 8
typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
/*-*************************************
* Helper functions
***************************************/
#define ZSTD_STATIC_ASSERT(c) { enum { ZSTD_static_assert = 1/(int)(!!(c)) }; }
size_t ZSTD_compressBound(size_t srcSize) {
size_t const lowLimit = 256 KB;
size_t const margin = (srcSize < lowLimit) ? (lowLimit-srcSize) >> 12 : 0; /* from 64 to 0 */
return srcSize + (srcSize >> 8) + margin;
}
/*-*************************************
* Sequence storage
***************************************/
static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
{
ssPtr->lit = ssPtr->litStart;
ssPtr->sequences = ssPtr->sequencesStart;
ssPtr->longLengthID = 0;
}
/*-*************************************
* Context memory management
***************************************/
struct ZSTD_CCtx_s {
const BYTE* nextSrc; /* next block here to continue on current prefix */
const BYTE* base; /* All regular indexes relative to this position */
const BYTE* dictBase; /* extDict indexes relative to this position */
U32 dictLimit; /* below that point, need extDict */
U32 lowLimit; /* below that point, no more data */
U32 nextToUpdate; /* index from which to continue dictionary update */
U32 nextToUpdate3; /* index from which to continue dictionary update */
U32 hashLog3; /* dispatch table : larger == faster, more memory */
U32 loadedDictEnd; /* index of end of dictionary */
U32 forceWindow; /* force back-references to respect limit of 1<<wLog, even for dictionary */
U32 forceRawDict; /* Force loading dictionary in "content-only" mode (no header analysis) */
ZSTD_compressionStage_e stage;
U32 rep[ZSTD_REP_NUM];
U32 repToConfirm[ZSTD_REP_NUM];
U32 dictID;
ZSTD_parameters params;
void* workSpace;
size_t workSpaceSize;
size_t blockSize;
U64 frameContentSize;
XXH64_state_t xxhState;
ZSTD_customMem customMem;
seqStore_t seqStore; /* sequences storage ptrs */
U32* hashTable;
U32* hashTable3;
U32* chainTable;
HUF_CElt* hufTable;
U32 flagStaticTables;
HUF_repeat flagStaticHufTable;
FSE_CTable offcodeCTable [FSE_CTABLE_SIZE_U32(OffFSELog, MaxOff)];
FSE_CTable matchlengthCTable[FSE_CTABLE_SIZE_U32(MLFSELog, MaxML)];
FSE_CTable litlengthCTable [FSE_CTABLE_SIZE_U32(LLFSELog, MaxLL)];
unsigned tmpCounters[HUF_WORKSPACE_SIZE_U32];
};
ZSTD_CCtx* ZSTD_createCCtx(void)
{
return ZSTD_createCCtx_advanced(defaultCustomMem);
}
ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem)
{
ZSTD_CCtx* cctx;
if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
if (!customMem.customAlloc || !customMem.customFree) return NULL;
cctx = (ZSTD_CCtx*) ZSTD_malloc(sizeof(ZSTD_CCtx), customMem);
if (!cctx) return NULL;
memset(cctx, 0, sizeof(ZSTD_CCtx));
cctx->customMem = customMem;
return cctx;
}
size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
{
if (cctx==NULL) return 0; /* support free on NULL */
ZSTD_free(cctx->workSpace, cctx->customMem);
ZSTD_free(cctx, cctx->customMem);
return 0; /* reserved as a potential error code in the future */
}
size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
{
if (cctx==NULL) return 0; /* support sizeof on NULL */
return sizeof(*cctx) + cctx->workSpaceSize;
}
size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned value)
{
switch(param)
{
case ZSTD_p_forceWindow : cctx->forceWindow = value>0; cctx->loadedDictEnd = 0; return 0;
case ZSTD_p_forceRawDict : cctx->forceRawDict = value>0; return 0;
default: return ERROR(parameter_unknown);
}
}
const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) /* hidden interface */
{
return &(ctx->seqStore);
}
static ZSTD_parameters ZSTD_getParamsFromCCtx(const ZSTD_CCtx* cctx)
{
return cctx->params;
}
/** ZSTD_checkParams() :
ensure param values remain within authorized range.
@return : 0, or an error code if one value is beyond authorized range */
size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
{
# define CLAMPCHECK(val,min,max) { if ((val<min) | (val>max)) return ERROR(compressionParameter_unsupported); }
CLAMPCHECK(cParams.windowLog, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
CLAMPCHECK(cParams.chainLog, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
CLAMPCHECK(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
CLAMPCHECK(cParams.searchLog, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
CLAMPCHECK(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
CLAMPCHECK(cParams.targetLength, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
if ((U32)(cParams.strategy) > (U32)ZSTD_btopt2) return ERROR(compressionParameter_unsupported);
return 0;
}
/** ZSTD_cycleLog() :
* condition for correct operation : hashLog > 1 */
static U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
{
U32 const btScale = ((U32)strat >= (U32)ZSTD_btlazy2);
return hashLog - btScale;
}
/** ZSTD_adjustCParams() :
optimize `cPar` for a given input (`srcSize` and `dictSize`).
mostly downsizing to reduce memory consumption and initialization.
Both `srcSize` and `dictSize` are optional (use 0 if unknown),
but if both are 0, no optimization can be done.
Note : cPar is considered validated at this stage. Use ZSTD_checkParams() to ensure that. */
ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize)
{
if (srcSize+dictSize == 0) return cPar; /* no size information available : no adjustment */
/* resize params, to use less memory when necessary */
{ U32 const minSrcSize = (srcSize==0) ? 500 : 0;
U64 const rSize = srcSize + dictSize + minSrcSize;
if (rSize < ((U64)1<<ZSTD_WINDOWLOG_MAX)) {
U32 const srcLog = MAX(ZSTD_HASHLOG_MIN, ZSTD_highbit32((U32)(rSize)-1) + 1);
if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
} }
if (cPar.hashLog > cPar.windowLog) cPar.hashLog = cPar.windowLog;
{ U32 const cycleLog = ZSTD_cycleLog(cPar.chainLog, cPar.strategy);
if (cycleLog > cPar.windowLog) cPar.chainLog -= (cycleLog - cPar.windowLog);
}
if (cPar.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN) cPar.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN; /* required for frame header */
return cPar;
}
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
{
size_t const blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (size_t)1 << cParams.windowLog);
U32 const divider = (cParams.searchLength==3) ? 3 : 4;
size_t const maxNbSeq = blockSize / divider;
size_t const tokenSpace = blockSize + 11*maxNbSeq;
size_t const chainSize = (cParams.strategy == ZSTD_fast) ? 0 : (1 << cParams.chainLog);
size_t const hSize = ((size_t)1) << cParams.hashLog;
U32 const hashLog3 = (cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, cParams.windowLog);
size_t const h3Size = ((size_t)1) << hashLog3;
size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<<Litbits))*sizeof(U32)
+ (ZSTD_OPT_NUM+1)*(sizeof(ZSTD_match_t) + sizeof(ZSTD_optimal_t));
size_t const neededSpace = tableSpace + (256*sizeof(U32)) /* huffTable */ + tokenSpace
+ (((cParams.strategy == ZSTD_btopt) || (cParams.strategy == ZSTD_btopt2)) ? optSpace : 0);
return sizeof(ZSTD_CCtx) + neededSpace;
}
static U32 ZSTD_equivalentParams(ZSTD_parameters param1, ZSTD_parameters param2)
{
return (param1.cParams.hashLog == param2.cParams.hashLog)
& (param1.cParams.chainLog == param2.cParams.chainLog)
& (param1.cParams.strategy == param2.cParams.strategy)
& ((param1.cParams.searchLength==3) == (param2.cParams.searchLength==3));
}
/*! ZSTD_continueCCtx() :
reuse CCtx without reset (note : requires no dictionary) */
static size_t ZSTD_continueCCtx(ZSTD_CCtx* cctx, ZSTD_parameters params, U64 frameContentSize)
{
U32 const end = (U32)(cctx->nextSrc - cctx->base);
cctx->params = params;
cctx->frameContentSize = frameContentSize;
cctx->lowLimit = end;
cctx->dictLimit = end;
cctx->nextToUpdate = end+1;
cctx->stage = ZSTDcs_init;
cctx->dictID = 0;
cctx->loadedDictEnd = 0;
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) cctx->rep[i] = repStartValue[i]; }
cctx->seqStore.litLengthSum = 0; /* force reset of btopt stats */
XXH64_reset(&cctx->xxhState, 0);
return 0;
}
typedef enum { ZSTDcrp_continue, ZSTDcrp_noMemset, ZSTDcrp_fullReset } ZSTD_compResetPolicy_e;
/*! ZSTD_resetCCtx_advanced() :
note : `params` must be validated */
static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
ZSTD_parameters params, U64 frameContentSize,
ZSTD_compResetPolicy_e const crp)
{
if (crp == ZSTDcrp_continue)
if (ZSTD_equivalentParams(params, zc->params)) {
zc->flagStaticTables = 0;
zc->flagStaticHufTable = HUF_repeat_none;
return ZSTD_continueCCtx(zc, params, frameContentSize);
}
{ size_t const blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (size_t)1 << params.cParams.windowLog);
U32 const divider = (params.cParams.searchLength==3) ? 3 : 4;
size_t const maxNbSeq = blockSize / divider;
size_t const tokenSpace = blockSize + 11*maxNbSeq;
size_t const chainSize = (params.cParams.strategy == ZSTD_fast) ? 0 : (1 << params.cParams.chainLog);
size_t const hSize = ((size_t)1) << params.cParams.hashLog;
U32 const hashLog3 = (params.cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, params.cParams.windowLog);
size_t const h3Size = ((size_t)1) << hashLog3;
size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
void* ptr;
/* Check if workSpace is large enough, alloc a new one if needed */
{ size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<<Litbits))*sizeof(U32)
+ (ZSTD_OPT_NUM+1)*(sizeof(ZSTD_match_t) + sizeof(ZSTD_optimal_t));
size_t const neededSpace = tableSpace + (256*sizeof(U32)) /* huffTable */ + tokenSpace
+ (((params.cParams.strategy == ZSTD_btopt) || (params.cParams.strategy == ZSTD_btopt2)) ? optSpace : 0);
if (zc->workSpaceSize < neededSpace) {
ZSTD_free(zc->workSpace, zc->customMem);
zc->workSpace = ZSTD_malloc(neededSpace, zc->customMem);
if (zc->workSpace == NULL) return ERROR(memory_allocation);
zc->workSpaceSize = neededSpace;
} }
if (crp!=ZSTDcrp_noMemset) memset(zc->workSpace, 0, tableSpace); /* reset tables only */
XXH64_reset(&zc->xxhState, 0);
zc->hashLog3 = hashLog3;
zc->hashTable = (U32*)(zc->workSpace);
zc->chainTable = zc->hashTable + hSize;
zc->hashTable3 = zc->chainTable + chainSize;
ptr = zc->hashTable3 + h3Size;
zc->hufTable = (HUF_CElt*)ptr;
zc->flagStaticTables = 0;
zc->flagStaticHufTable = HUF_repeat_none;
ptr = ((U32*)ptr) + 256; /* note : HUF_CElt* is incomplete type, size is simulated using U32 */
zc->nextToUpdate = 1;
zc->nextSrc = NULL;
zc->base = NULL;
zc->dictBase = NULL;
zc->dictLimit = 0;
zc->lowLimit = 0;
zc->params = params;
zc->blockSize = blockSize;
zc->frameContentSize = frameContentSize;
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) zc->rep[i] = repStartValue[i]; }
if ((params.cParams.strategy == ZSTD_btopt) || (params.cParams.strategy == ZSTD_btopt2)) {
zc->seqStore.litFreq = (U32*)ptr;
zc->seqStore.litLengthFreq = zc->seqStore.litFreq + (1<<Litbits);
zc->seqStore.matchLengthFreq = zc->seqStore.litLengthFreq + (MaxLL+1);
zc->seqStore.offCodeFreq = zc->seqStore.matchLengthFreq + (MaxML+1);
ptr = zc->seqStore.offCodeFreq + (MaxOff+1);
zc->seqStore.matchTable = (ZSTD_match_t*)ptr;
ptr = zc->seqStore.matchTable + ZSTD_OPT_NUM+1;
zc->seqStore.priceTable = (ZSTD_optimal_t*)ptr;
ptr = zc->seqStore.priceTable + ZSTD_OPT_NUM+1;
zc->seqStore.litLengthSum = 0;
}
zc->seqStore.sequencesStart = (seqDef*)ptr;
ptr = zc->seqStore.sequencesStart + maxNbSeq;
zc->seqStore.llCode = (BYTE*) ptr;
zc->seqStore.mlCode = zc->seqStore.llCode + maxNbSeq;
zc->seqStore.ofCode = zc->seqStore.mlCode + maxNbSeq;
zc->seqStore.litStart = zc->seqStore.ofCode + maxNbSeq;
zc->stage = ZSTDcs_init;
zc->dictID = 0;
zc->loadedDictEnd = 0;
return 0;
}
}
/* ZSTD_invalidateRepCodes() :
* ensures next compression will not use repcodes from previous block.
* Note : only works with regular variant;
* do not use with extDict variant ! */
void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
int i;
for (i=0; i<ZSTD_REP_NUM; i++) cctx->rep[i] = 0;
}
/*! ZSTD_copyCCtx() :
* Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
* Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
* @return : 0, or an error code */
size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
{
if (srcCCtx->stage!=ZSTDcs_init) return ERROR(stage_wrong);
memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
{ ZSTD_parameters params = srcCCtx->params;
params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
ZSTD_resetCCtx_advanced(dstCCtx, params, pledgedSrcSize, ZSTDcrp_noMemset);
}
/* copy tables */
{ size_t const chainSize = (srcCCtx->params.cParams.strategy == ZSTD_fast) ? 0 : (1 << srcCCtx->params.cParams.chainLog);
size_t const hSize = ((size_t)1) << srcCCtx->params.cParams.hashLog;
size_t const h3Size = (size_t)1 << srcCCtx->hashLog3;
size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
memcpy(dstCCtx->workSpace, srcCCtx->workSpace, tableSpace);
}
/* copy dictionary offsets */
dstCCtx->nextToUpdate = srcCCtx->nextToUpdate;
dstCCtx->nextToUpdate3= srcCCtx->nextToUpdate3;
dstCCtx->nextSrc = srcCCtx->nextSrc;
dstCCtx->base = srcCCtx->base;
dstCCtx->dictBase = srcCCtx->dictBase;
dstCCtx->dictLimit = srcCCtx->dictLimit;
dstCCtx->lowLimit = srcCCtx->lowLimit;
dstCCtx->loadedDictEnd= srcCCtx->loadedDictEnd;
dstCCtx->dictID = srcCCtx->dictID;
/* copy entropy tables */
dstCCtx->flagStaticTables = srcCCtx->flagStaticTables;
dstCCtx->flagStaticHufTable = srcCCtx->flagStaticHufTable;
if (srcCCtx->flagStaticTables) {
memcpy(dstCCtx->litlengthCTable, srcCCtx->litlengthCTable, sizeof(dstCCtx->litlengthCTable));
memcpy(dstCCtx->matchlengthCTable, srcCCtx->matchlengthCTable, sizeof(dstCCtx->matchlengthCTable));
memcpy(dstCCtx->offcodeCTable, srcCCtx->offcodeCTable, sizeof(dstCCtx->offcodeCTable));
}
if (srcCCtx->flagStaticHufTable) {
memcpy(dstCCtx->hufTable, srcCCtx->hufTable, 256*4);
}
return 0;
}
/*! ZSTD_reduceTable() :
* reduce table indexes by `reducerValue` */
static void ZSTD_reduceTable (U32* const table, U32 const size, U32 const reducerValue)
{
U32 u;
for (u=0 ; u < size ; u++) {
if (table[u] < reducerValue) table[u] = 0;
else table[u] -= reducerValue;
}
}
/*! ZSTD_reduceIndex() :
* rescale all indexes to avoid future overflow (indexes are U32) */
static void ZSTD_reduceIndex (ZSTD_CCtx* zc, const U32 reducerValue)
{
{ U32 const hSize = 1 << zc->params.cParams.hashLog;
ZSTD_reduceTable(zc->hashTable, hSize, reducerValue); }
{ U32 const chainSize = (zc->params.cParams.strategy == ZSTD_fast) ? 0 : (1 << zc->params.cParams.chainLog);
ZSTD_reduceTable(zc->chainTable, chainSize, reducerValue); }
{ U32 const h3Size = (zc->hashLog3) ? 1 << zc->hashLog3 : 0;
ZSTD_reduceTable(zc->hashTable3, h3Size, reducerValue); }
}
/*-*******************************************************
* Block entropic compression
*********************************************************/
/* See doc/zstd_compression_format.md for detailed format description */
size_t ZSTD_noCompressBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
if (srcSize + ZSTD_blockHeaderSize > dstCapacity) return ERROR(dstSize_tooSmall);
memcpy((BYTE*)dst + ZSTD_blockHeaderSize, src, srcSize);
MEM_writeLE24(dst, (U32)(srcSize << 2) + (U32)bt_raw);
return ZSTD_blockHeaderSize+srcSize;
}
static size_t ZSTD_noCompressLiterals (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
BYTE* const ostart = (BYTE* const)dst;
U32 const flSize = 1 + (srcSize>31) + (srcSize>4095);
if (srcSize + flSize > dstCapacity) return ERROR(dstSize_tooSmall);
switch(flSize)
{
case 1: /* 2 - 1 - 5 */
ostart[0] = (BYTE)((U32)set_basic + (srcSize<<3));
break;
case 2: /* 2 - 2 - 12 */
MEM_writeLE16(ostart, (U16)((U32)set_basic + (1<<2) + (srcSize<<4)));
break;
default: /*note : should not be necessary : flSize is within {1,2,3} */
case 3: /* 2 - 2 - 20 */
MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4)));
break;
}
memcpy(ostart + flSize, src, srcSize);
return srcSize + flSize;
}
static size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
BYTE* const ostart = (BYTE* const)dst;
U32 const flSize = 1 + (srcSize>31) + (srcSize>4095);
(void)dstCapacity; /* dstCapacity already guaranteed to be >=4, hence large enough */
switch(flSize)
{
case 1: /* 2 - 1 - 5 */
ostart[0] = (BYTE)((U32)set_rle + (srcSize<<3));
break;
case 2: /* 2 - 2 - 12 */
MEM_writeLE16(ostart, (U16)((U32)set_rle + (1<<2) + (srcSize<<4)));
break;
default: /*note : should not be necessary : flSize is necessarily within {1,2,3} */
case 3: /* 2 - 2 - 20 */
MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4)));
break;
}
ostart[flSize] = *(const BYTE*)src;
return flSize+1;
}
static size_t ZSTD_minGain(size_t srcSize) { return (srcSize >> 6) + 2; }
static size_t ZSTD_compressLiterals (ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
size_t const minGain = ZSTD_minGain(srcSize);
size_t const lhSize = 3 + (srcSize >= 1 KB) + (srcSize >= 16 KB);
BYTE* const ostart = (BYTE*)dst;
U32 singleStream = srcSize < 256;
symbolEncodingType_e hType = set_compressed;
size_t cLitSize;
/* small ? don't even attempt compression (speed opt) */
# define LITERAL_NOENTROPY 63
{ size_t const minLitSize = zc->flagStaticHufTable == HUF_repeat_valid ? 6 : LITERAL_NOENTROPY;
if (srcSize <= minLitSize) return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
}
if (dstCapacity < lhSize+1) return ERROR(dstSize_tooSmall); /* not enough space for compression */
{ HUF_repeat repeat = zc->flagStaticHufTable;
int const preferRepeat = zc->params.cParams.strategy < ZSTD_lazy ? srcSize <= 1024 : 0;
if (repeat == HUF_repeat_valid && lhSize == 3) singleStream = 1;
cLitSize = singleStream ? HUF_compress1X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11, zc->tmpCounters, sizeof(zc->tmpCounters), zc->hufTable, &repeat, preferRepeat)
: HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11, zc->tmpCounters, sizeof(zc->tmpCounters), zc->hufTable, &repeat, preferRepeat);
if (repeat != HUF_repeat_none) { hType = set_repeat; } /* reused the existing table */
else { zc->flagStaticHufTable = HUF_repeat_check; } /* now have a table to reuse */
}
if ((cLitSize==0) | (cLitSize >= srcSize - minGain)) {
zc->flagStaticHufTable = HUF_repeat_none;
return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
}
if (cLitSize==1) {
zc->flagStaticHufTable = HUF_repeat_none;
return ZSTD_compressRleLiteralsBlock(dst, dstCapacity, src, srcSize);
}
/* Build header */
switch(lhSize)
{
case 3: /* 2 - 2 - 10 - 10 */
{ U32 const lhc = hType + ((!singleStream) << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<14);
MEM_writeLE24(ostart, lhc);
break;
}
case 4: /* 2 - 2 - 14 - 14 */
{ U32 const lhc = hType + (2 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<18);
MEM_writeLE32(ostart, lhc);
break;
}
default: /* should not be necessary, lhSize is only {3,4,5} */
case 5: /* 2 - 2 - 18 - 18 */
{ U32 const lhc = hType + (3 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<22);
MEM_writeLE32(ostart, lhc);
ostart[4] = (BYTE)(cLitSize >> 10);
break;
}
}
return lhSize+cLitSize;
}
static const BYTE LL_Code[64] = { 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 16, 17, 17, 18, 18, 19, 19,
20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22,
23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24 };
static const BYTE ML_Code[128] = { 0, 1, 2, 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, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 37, 37, 37, 37,
38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39,
40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
{
BYTE const LL_deltaCode = 19;
BYTE const ML_deltaCode = 36;
const seqDef* const sequences = seqStorePtr->sequencesStart;
BYTE* const llCodeTable = seqStorePtr->llCode;
BYTE* const ofCodeTable = seqStorePtr->ofCode;
BYTE* const mlCodeTable = seqStorePtr->mlCode;
U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
U32 u;
for (u=0; u<nbSeq; u++) {
U32 const llv = sequences[u].litLength;
U32 const mlv = sequences[u].matchLength;
llCodeTable[u] = (llv> 63) ? (BYTE)ZSTD_highbit32(llv) + LL_deltaCode : LL_Code[llv];
ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offset);
mlCodeTable[u] = (mlv>127) ? (BYTE)ZSTD_highbit32(mlv) + ML_deltaCode : ML_Code[mlv];
}
if (seqStorePtr->longLengthID==1)
llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
if (seqStorePtr->longLengthID==2)
mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
}
MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
void* dst, size_t dstCapacity,
size_t srcSize)
{
const int longOffsets = zc->params.cParams.windowLog > STREAM_ACCUMULATOR_MIN;
const seqStore_t* seqStorePtr = &(zc->seqStore);
U32 count[MaxSeq+1];
S16 norm[MaxSeq+1];
FSE_CTable* CTable_LitLength = zc->litlengthCTable;
FSE_CTable* CTable_OffsetBits = zc->offcodeCTable;
FSE_CTable* CTable_MatchLength = zc->matchlengthCTable;
U32 LLtype, Offtype, MLtype; /* compressed, raw or rle */
const seqDef* const sequences = seqStorePtr->sequencesStart;
const BYTE* const ofCodeTable = seqStorePtr->ofCode;
const BYTE* const llCodeTable = seqStorePtr->llCode;
const BYTE* const mlCodeTable = seqStorePtr->mlCode;
BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = ostart + dstCapacity;
BYTE* op = ostart;
size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
BYTE* seqHead;
BYTE scratchBuffer[1<<MAX(MLFSELog,LLFSELog)];
/* Compress literals */
{ const BYTE* const literals = seqStorePtr->litStart;
size_t const litSize = seqStorePtr->lit - literals;
size_t const cSize = ZSTD_compressLiterals(zc, op, dstCapacity, literals, litSize);
if (ZSTD_isError(cSize)) return cSize;
op += cSize;
}
/* Sequences Header */
if ((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead */) return ERROR(dstSize_tooSmall);
if (nbSeq < 0x7F) *op++ = (BYTE)nbSeq;
else if (nbSeq < LONGNBSEQ) op[0] = (BYTE)((nbSeq>>8) + 0x80), op[1] = (BYTE)nbSeq, op+=2;
else op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
if (nbSeq==0) goto _check_compressibility;
/* seqHead : flags for FSE encoding type */
seqHead = op++;
#define MIN_SEQ_FOR_DYNAMIC_FSE 64
#define MAX_SEQ_FOR_STATIC_FSE 1000
/* convert length/distances into codes */
ZSTD_seqToCodes(seqStorePtr);
/* CTable for Literal Lengths */
{ U32 max = MaxLL;
size_t const mostFrequent = FSE_countFast_wksp(count, &max, llCodeTable, nbSeq, zc->tmpCounters);
if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
*op++ = llCodeTable[0];
FSE_buildCTable_rle(CTable_LitLength, (BYTE)max);
LLtype = set_rle;
} else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
LLtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LL_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_LitLength, LL_defaultNorm, MaxLL, LL_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
LLtype = set_basic;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(LLFSELog, nbSeq, max);
if (count[llCodeTable[nbSeq-1]]>1) { count[llCodeTable[nbSeq-1]]--; nbSeq_1--; }
FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max);
{ size_t const NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return NCountSize;
op += NCountSize; }
FSE_buildCTable_wksp(CTable_LitLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
LLtype = set_compressed;
} }
/* CTable for Offsets */
{ U32 max = MaxOff;
size_t const mostFrequent = FSE_countFast_wksp(count, &max, ofCodeTable, nbSeq, zc->tmpCounters);
if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
*op++ = ofCodeTable[0];
FSE_buildCTable_rle(CTable_OffsetBits, (BYTE)max);
Offtype = set_rle;
} else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
Offtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (OF_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_OffsetBits, OF_defaultNorm, MaxOff, OF_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
Offtype = set_basic;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(OffFSELog, nbSeq, max);
if (count[ofCodeTable[nbSeq-1]]>1) { count[ofCodeTable[nbSeq-1]]--; nbSeq_1--; }
FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max);
{ size_t const NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return NCountSize;
op += NCountSize; }
FSE_buildCTable_wksp(CTable_OffsetBits, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
Offtype = set_compressed;
} }
/* CTable for MatchLengths */
{ U32 max = MaxML;
size_t const mostFrequent = FSE_countFast_wksp(count, &max, mlCodeTable, nbSeq, zc->tmpCounters);
if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
*op++ = *mlCodeTable;
FSE_buildCTable_rle(CTable_MatchLength, (BYTE)max);
MLtype = set_rle;
} else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
MLtype = set_repeat;
} else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (ML_defaultNormLog-1)))) {
FSE_buildCTable_wksp(CTable_MatchLength, ML_defaultNorm, MaxML, ML_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
MLtype = set_basic;
} else {
size_t nbSeq_1 = nbSeq;
const U32 tableLog = FSE_optimalTableLog(MLFSELog, nbSeq, max);
if (count[mlCodeTable[nbSeq-1]]>1) { count[mlCodeTable[nbSeq-1]]--; nbSeq_1--; }
FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max);
{ size_t const NCountSize = FSE_writeNCount(op, oend-op, norm, max, tableLog); /* overflow protected */
if (FSE_isError(NCountSize)) return NCountSize;
op += NCountSize; }
FSE_buildCTable_wksp(CTable_MatchLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
MLtype = set_compressed;
} }
*seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
zc->flagStaticTables = 0;
/* Encoding Sequences */
{ BIT_CStream_t blockStream;
FSE_CState_t stateMatchLength;
FSE_CState_t stateOffsetBits;
FSE_CState_t stateLitLength;
CHECK_E(BIT_initCStream(&blockStream, op, oend-op), dstSize_tooSmall); /* not enough space remaining */
/* first symbols */
FSE_initCState2(&stateMatchLength, CTable_MatchLength, mlCodeTable[nbSeq-1]);
FSE_initCState2(&stateOffsetBits, CTable_OffsetBits, ofCodeTable[nbSeq-1]);
FSE_initCState2(&stateLitLength, CTable_LitLength, llCodeTable[nbSeq-1]);
BIT_addBits(&blockStream, sequences[nbSeq-1].litLength, LL_bits[llCodeTable[nbSeq-1]]);
if (MEM_32bits()) BIT_flushBits(&blockStream);
BIT_addBits(&blockStream, sequences[nbSeq-1].matchLength, ML_bits[mlCodeTable[nbSeq-1]]);
if (MEM_32bits()) BIT_flushBits(&blockStream);
if (longOffsets) {
U32 const ofBits = ofCodeTable[nbSeq-1];
int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
if (extraBits) {
BIT_addBits(&blockStream, sequences[nbSeq-1].offset, extraBits);
BIT_flushBits(&blockStream);
}
BIT_addBits(&blockStream, sequences[nbSeq-1].offset >> extraBits,
ofBits - extraBits);
} else {
BIT_addBits(&blockStream, sequences[nbSeq-1].offset, ofCodeTable[nbSeq-1]);
}
BIT_flushBits(&blockStream);
{ size_t n;
for (n=nbSeq-2 ; n<nbSeq ; n--) { /* intentional underflow */
BYTE const llCode = llCodeTable[n];
BYTE const ofCode = ofCodeTable[n];
BYTE const mlCode = mlCodeTable[n];
U32 const llBits = LL_bits[llCode];
U32 const ofBits = ofCode; /* 32b*/ /* 64b*/
U32 const mlBits = ML_bits[mlCode];
/* (7)*/ /* (7)*/
FSE_encodeSymbol(&blockStream, &stateOffsetBits, ofCode); /* 15 */ /* 15 */
FSE_encodeSymbol(&blockStream, &stateMatchLength, mlCode); /* 24 */ /* 24 */
if (MEM_32bits()) BIT_flushBits(&blockStream); /* (7)*/
FSE_encodeSymbol(&blockStream, &stateLitLength, llCode); /* 16 */ /* 33 */
if (MEM_32bits() || (ofBits+mlBits+llBits >= 64-7-(LLFSELog+MLFSELog+OffFSELog)))
BIT_flushBits(&blockStream); /* (7)*/
BIT_addBits(&blockStream, sequences[n].litLength, llBits);
if (MEM_32bits() && ((llBits+mlBits)>24)) BIT_flushBits(&blockStream);
BIT_addBits(&blockStream, sequences[n].matchLength, mlBits);
if (MEM_32bits()) BIT_flushBits(&blockStream); /* (7)*/
if (longOffsets) {
int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
if (extraBits) {
BIT_addBits(&blockStream, sequences[n].offset, extraBits);
BIT_flushBits(&blockStream); /* (7)*/
}
BIT_addBits(&blockStream, sequences[n].offset >> extraBits,
ofBits - extraBits); /* 31 */
} else {
BIT_addBits(&blockStream, sequences[n].offset, ofBits); /* 31 */
}
BIT_flushBits(&blockStream); /* (7)*/
} }
FSE_flushCState(&blockStream, &stateMatchLength);
FSE_flushCState(&blockStream, &stateOffsetBits);
FSE_flushCState(&blockStream, &stateLitLength);
{ size_t const streamSize = BIT_closeCStream(&blockStream);
if (streamSize==0) return ERROR(dstSize_tooSmall); /* not enough space */
op += streamSize;
} }
/* check compressibility */
_check_compressibility:
{ size_t const minGain = ZSTD_minGain(srcSize);
size_t const maxCSize = srcSize - minGain;
if ((size_t)(op-ostart) >= maxCSize) {
zc->flagStaticHufTable = HUF_repeat_none;
return 0;
} }
/* confirm repcodes */
{ int i; for (i=0; i<ZSTD_REP_NUM; i++) zc->rep[i] = zc->repToConfirm[i]; }
return op - ostart;
}
#if 0 /* for debug */
# define STORESEQ_DEBUG
#include <stdio.h> /* fprintf */
U32 g_startDebug = 0;
const BYTE* g_start = NULL;
#endif
/*! ZSTD_storeSeq() :
Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
`offsetCode` : distance to match, or 0 == repCode.
`matchCode` : matchLength - MINMATCH
*/
MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t matchCode)
{
#ifdef STORESEQ_DEBUG
if (g_startDebug) {
const U32 pos = (U32)((const BYTE*)literals - g_start);
if (g_start==NULL) g_start = (const BYTE*)literals;
if ((pos > 1895000) && (pos < 1895300))
fprintf(stderr, "Cpos %6u :%5u literals & match %3u bytes at distance %6u \n",
pos, (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
}
#endif
/* copy Literals */
ZSTD_wildcopy(seqStorePtr->lit, literals, litLength);
seqStorePtr->lit += litLength;
/* literal Length */
if (litLength>0xFFFF) { seqStorePtr->longLengthID = 1; seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); }
seqStorePtr->sequences[0].litLength = (U16)litLength;
/* match offset */
seqStorePtr->sequences[0].offset = offsetCode + 1;
/* match Length */
if (matchCode>0xFFFF) { seqStorePtr->longLengthID = 2; seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); }
seqStorePtr->sequences[0].matchLength = (U16)matchCode;
seqStorePtr->sequences++;
}
/*-*************************************
* Match length counter
***************************************/
static unsigned ZSTD_NbCommonBytes (register size_t val)
{
if (MEM_isLittleEndian()) {
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanForward64( &r, (U64)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctzll((U64)val) >> 3);
# else
static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
# endif
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r=0;
_BitScanForward( &r, (U32)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctz((U32)val) >> 3);
# else
static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
# endif
}
} else { /* Big Endian CPU */
if (MEM_64bits()) {
# if defined(_MSC_VER) && defined(_WIN64)
unsigned long r = 0;
_BitScanReverse64( &r, val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clzll(val) >> 3);
# else
unsigned r;
const unsigned n32 = sizeof(size_t)*4; /* calculate this way due to compiler complaining in 32-bits mode */
if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
r += (!val);
return r;
# endif
} else { /* 32 bits */
# if defined(_MSC_VER)
unsigned long r = 0;
_BitScanReverse( &r, (unsigned long)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clz((U32)val) >> 3);
# else
unsigned r;
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
r += (!val);
return r;
# endif
} }
}
static size_t ZSTD_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* const pInLimit)
{
const BYTE* const pStart = pIn;
const BYTE* const pInLoopLimit = pInLimit - (sizeof(size_t)-1);
while (pIn < pInLoopLimit) {
size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
if (!diff) { pIn+=sizeof(size_t); pMatch+=sizeof(size_t); continue; }
pIn += ZSTD_NbCommonBytes(diff);
return (size_t)(pIn - pStart);
}
if (MEM_64bits()) if ((pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
if ((pIn<(pInLimit-1)) && (MEM_read16(pMatch) == MEM_read16(pIn))) { pIn+=2; pMatch+=2; }
if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++;
return (size_t)(pIn - pStart);
}
/** ZSTD_count_2segments() :
* can count match length with `ip` & `match` in 2 different segments.
* convention : on reaching mEnd, match count continue starting from iStart
*/
static size_t ZSTD_count_2segments(const BYTE* ip, const BYTE* match, const BYTE* iEnd, const BYTE* mEnd, const BYTE* iStart)
{
const BYTE* const vEnd = MIN( ip + (mEnd - match), iEnd);
size_t const matchLength = ZSTD_count(ip, match, vEnd);
if (match + matchLength != mEnd) return matchLength;
return matchLength + ZSTD_count(ip+matchLength, iStart, iEnd);
}
/*-*************************************
* Hashes
***************************************/
static const U32 prime3bytes = 506832829U;
static U32 ZSTD_hash3(U32 u, U32 h) { return ((u << (32-24)) * prime3bytes) >> (32-h) ; }
MEM_STATIC size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_readLE32(ptr), h); } /* only in zstd_opt.h */
static const U32 prime4bytes = 2654435761U;
static U32 ZSTD_hash4(U32 u, U32 h) { return (u * prime4bytes) >> (32-h) ; }
static size_t ZSTD_hash4Ptr(const void* ptr, U32 h) { return ZSTD_hash4(MEM_read32(ptr), h); }
static const U64 prime5bytes = 889523592379ULL;
static size_t ZSTD_hash5(U64 u, U32 h) { return (size_t)(((u << (64-40)) * prime5bytes) >> (64-h)) ; }
static size_t ZSTD_hash5Ptr(const void* p, U32 h) { return ZSTD_hash5(MEM_readLE64(p), h); }
static const U64 prime6bytes = 227718039650203ULL;
static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * prime6bytes) >> (64-h)) ; }
static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
static const U64 prime7bytes = 58295818150454627ULL;
static size_t ZSTD_hash7(U64 u, U32 h) { return (size_t)(((u << (64-56)) * prime7bytes) >> (64-h)) ; }
static size_t ZSTD_hash7Ptr(const void* p, U32 h) { return ZSTD_hash7(MEM_readLE64(p), h); }
static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
static size_t ZSTD_hashPtr(const void* p, U32 hBits, U32 mls)
{
switch(mls)
{
//case 3: return ZSTD_hash3Ptr(p, hBits);
default:
case 4: return ZSTD_hash4Ptr(p, hBits);
case 5: return ZSTD_hash5Ptr(p, hBits);
case 6: return ZSTD_hash6Ptr(p, hBits);
case 7: return ZSTD_hash7Ptr(p, hBits);
case 8: return ZSTD_hash8Ptr(p, hBits);
}
}
/*-*************************************
* Fast Scan
***************************************/
static void ZSTD_fillHashTable (ZSTD_CCtx* zc, const void* end, const U32 mls)
{
U32* const hashTable = zc->hashTable;
U32 const hBits = zc->params.cParams.hashLog;
const BYTE* const base = zc->base;
const BYTE* ip = base + zc->nextToUpdate;
const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
const size_t fastHashFillStep = 3;
while(ip <= iend) {
hashTable[ZSTD_hashPtr(ip, hBits, mls)] = (U32)(ip - base);
ip += fastHashFillStep;
}
}
FORCE_INLINE
void ZSTD_compressBlock_fast_generic(ZSTD_CCtx* cctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashTable = cctx->hashTable;
U32 const hBits = cctx->params.cParams.hashLog;
seqStore_t* seqStorePtr = &(cctx->seqStore);
const BYTE* const base = cctx->base;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = cctx->dictLimit;
const BYTE* const lowest = base + lowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
U32 offset_1=cctx->rep[0], offset_2=cctx->rep[1];
U32 offsetSaved = 0;
/* init */
ip += (ip==lowest);
{ U32 const maxRep = (U32)(ip-lowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
size_t mLength;
size_t const h = ZSTD_hashPtr(ip, hBits, mls);
U32 const current = (U32)(ip-base);
U32 const matchIndex = hashTable[h];
const BYTE* match = base + matchIndex;
hashTable[h] = current; /* update hash table */
if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
U32 offset;
if ( (matchIndex <= lowestIndex) || (MEM_read32(match) != MEM_read32(ip)) ) {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
mLength = ZSTD_count(ip+4, match+4, iend) + 4;
offset = (U32)(ip-match);
while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
/* match found */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2; /* here because current+2 could be > iend-8 */
hashTable[ZSTD_hashPtr(ip-2, hBits, mls)] = (U32)(ip-2-base);
/* check immediate repcode */
while ( (ip <= ilimit)
&& ( (offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
{ U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
hashTable[ZSTD_hashPtr(ip, hBits, mls)] = (U32)(ip-base);
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
/* save reps for next block */
cctx->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
cctx->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
static void ZSTD_compressBlock_fast(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
const U32 mls = ctx->params.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 7); return;
}
}
static void ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* hashTable = ctx->hashTable;
const U32 hBits = ctx->params.cParams.hashLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const dictStart = dictBase + lowestIndex;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const lowPrefixPtr = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
U32 offset_1=ctx->rep[0], offset_2=ctx->rep[1];
/* Search Loop */
while (ip < ilimit) { /* < instead of <=, because (ip+1) */
const size_t h = ZSTD_hashPtr(ip, hBits, mls);
const U32 matchIndex = hashTable[h];
const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
const BYTE* match = matchBase + matchIndex;
const U32 current = (U32)(ip-base);
const U32 repIndex = current + 1 - offset_1; /* offset_1 expected <= current +1 */
const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* repMatch = repBase + repIndex;
size_t mLength;
hashTable[h] = current; /* update hash table */
if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repMatchEnd, lowPrefixPtr) + EQUAL_READ32;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
if ( (matchIndex < lowestIndex) ||
(MEM_read32(match) != MEM_read32(ip)) ) {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
{ const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
U32 offset;
mLength = ZSTD_count_2segments(ip+EQUAL_READ32, match+EQUAL_READ32, iend, matchEnd, lowPrefixPtr) + EQUAL_READ32;
while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
offset = current - matchIndex;
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} }
/* found a match : store it */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2;
hashTable[ZSTD_hashPtr(ip-2, hBits, mls)] = (U32)(ip-2-base);
/* check immediate repcode */
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex)) /* intentional overflow */
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
size_t repLength2 = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch2+EQUAL_READ32, iend, repEnd2, lowPrefixPtr) + EQUAL_READ32;
U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, repLength2-MINMATCH);
hashTable[ZSTD_hashPtr(ip, hBits, mls)] = current2;
ip += repLength2;
anchor = ip;
continue;
}
break;
} } }
/* save reps for next block */
ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
static void ZSTD_compressBlock_fast_extDict(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
U32 const mls = ctx->params.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 7); return;
}
}
/*-*************************************
* Double Fast
***************************************/
static void ZSTD_fillDoubleHashTable (ZSTD_CCtx* cctx, const void* end, const U32 mls)
{
U32* const hashLarge = cctx->hashTable;
U32 const hBitsL = cctx->params.cParams.hashLog;
U32* const hashSmall = cctx->chainTable;
U32 const hBitsS = cctx->params.cParams.chainLog;
const BYTE* const base = cctx->base;
const BYTE* ip = base + cctx->nextToUpdate;
const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
const size_t fastHashFillStep = 3;
while(ip <= iend) {
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip - base);
hashLarge[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip - base);
ip += fastHashFillStep;
}
}
FORCE_INLINE
void ZSTD_compressBlock_doubleFast_generic(ZSTD_CCtx* cctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashLong = cctx->hashTable;
const U32 hBitsL = cctx->params.cParams.hashLog;
U32* const hashSmall = cctx->chainTable;
const U32 hBitsS = cctx->params.cParams.chainLog;
seqStore_t* seqStorePtr = &(cctx->seqStore);
const BYTE* const base = cctx->base;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = cctx->dictLimit;
const BYTE* const lowest = base + lowestIndex;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - HASH_READ_SIZE;
U32 offset_1=cctx->rep[0], offset_2=cctx->rep[1];
U32 offsetSaved = 0;
/* init */
ip += (ip==lowest);
{ U32 const maxRep = (U32)(ip-lowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
size_t mLength;
size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
U32 const current = (U32)(ip-base);
U32 const matchIndexL = hashLong[h2];
U32 const matchIndexS = hashSmall[h];
const BYTE* matchLong = base + matchIndexL;
const BYTE* match = base + matchIndexS;
hashLong[h2] = hashSmall[h] = current; /* update hash tables */
if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) { /* note : by construction, offset_1 <= current */
mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
U32 offset;
if ( (matchIndexL > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip)) ) {
mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
offset = (U32)(ip-matchLong);
while (((ip>anchor) & (matchLong>lowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
} else if ( (matchIndexS > lowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) {
size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
U32 const matchIndex3 = hashLong[h3];
const BYTE* match3 = base + matchIndex3;
hashLong[h3] = current + 1;
if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
mLength = ZSTD_count(ip+9, match3+8, iend) + 8;
ip++;
offset = (U32)(ip-match3);
while (((ip>anchor) & (match3>lowest)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
} else {
mLength = ZSTD_count(ip+4, match+4, iend) + 4;
offset = (U32)(ip-match);
while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
}
} else {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
}
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
}
/* match found */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] =
hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2; /* here because current+2 could be > iend-8 */
hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] =
hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
/* check immediate repcode */
while ( (ip <= ilimit)
&& ( (offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
{ U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
ip += rLength;
anchor = ip;
continue; /* faster when present ... (?) */
} } }
/* save reps for next block */
cctx->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
cctx->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
static void ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
const U32 mls = ctx->params.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 7); return;
}
}
static void ZSTD_compressBlock_doubleFast_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 mls)
{
U32* const hashLong = ctx->hashTable;
U32 const hBitsL = ctx->params.cParams.hashLog;
U32* const hashSmall = ctx->chainTable;
U32 const hBitsS = ctx->params.cParams.chainLog;
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const base = ctx->base;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const dictStart = dictBase + lowestIndex;
const U32 dictLimit = ctx->dictLimit;
const BYTE* const lowPrefixPtr = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
U32 offset_1=ctx->rep[0], offset_2=ctx->rep[1];
/* Search Loop */
while (ip < ilimit) { /* < instead of <=, because (ip+1) */
const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
const U32 matchIndex = hashSmall[hSmall];
const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
const BYTE* match = matchBase + matchIndex;
const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
const U32 matchLongIndex = hashLong[hLong];
const BYTE* matchLongBase = matchLongIndex < dictLimit ? dictBase : base;
const BYTE* matchLong = matchLongBase + matchLongIndex;
const U32 current = (U32)(ip-base);
const U32 repIndex = current + 1 - offset_1; /* offset_1 expected <= current +1 */
const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* repMatch = repBase + repIndex;
size_t mLength;
hashSmall[hSmall] = hashLong[hLong] = current; /* update hash table */
if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
ip++;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
} else {
if ((matchLongIndex > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
const BYTE* matchEnd = matchLongIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchLongIndex < dictLimit ? dictStart : lowPrefixPtr;
U32 offset;
mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, lowPrefixPtr) + 8;
offset = current - matchLongIndex;
while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else if ((matchIndex > lowestIndex) && (MEM_read32(match) == MEM_read32(ip))) {
size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
U32 const matchIndex3 = hashLong[h3];
const BYTE* const match3Base = matchIndex3 < dictLimit ? dictBase : base;
const BYTE* match3 = match3Base + matchIndex3;
U32 offset;
hashLong[h3] = current + 1;
if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
const BYTE* matchEnd = matchIndex3 < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex3 < dictLimit ? dictStart : lowPrefixPtr;
mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, lowPrefixPtr) + 8;
ip++;
offset = current+1 - matchIndex3;
while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
} else {
const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4;
offset = current - matchIndex;
while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
}
offset_2 = offset_1;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
} else {
ip += ((ip-anchor) >> g_searchStrength) + 1;
continue;
} }
/* found a match : store it */
ip += mLength;
anchor = ip;
if (ip <= ilimit) {
/* Fill Table */
hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2;
hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = current+2;
hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
/* check immediate repcode */
while (ip <= ilimit) {
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex)) /* intentional overflow */
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
size_t const repLength2 = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch2+EQUAL_READ32, iend, repEnd2, lowPrefixPtr) + EQUAL_READ32;
U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, repLength2-MINMATCH);
hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
ip += repLength2;
anchor = ip;
continue;
}
break;
} } }
/* save reps for next block */
ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
static void ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx,
const void* src, size_t srcSize)
{
U32 const mls = ctx->params.cParams.searchLength;
switch(mls)
{
default: /* includes case 3 */
case 4 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 4); return;
case 5 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 5); return;
case 6 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 6); return;
case 7 :
ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 7); return;
}
}
/*-*************************************
* Binary Tree search
***************************************/
/** ZSTD_insertBt1() : add one or multiple positions to tree.
* ip : assumed <= iend-8 .
* @return : nb of positions added */
static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares,
U32 extDict)
{
U32* const hashTable = zc->hashTable;
U32 const hashLog = zc->params.cParams.hashLog;
size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const bt = zc->chainTable;
U32 const btLog = zc->params.cParams.chainLog - 1;
U32 const btMask = (1 << btLog) - 1;
U32 matchIndex = hashTable[h];
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* match;
const U32 current = (U32)(ip-base);
const U32 btLow = btMask >= current ? 0 : current - btMask;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = smallerPtr + 1;
U32 dummy32; /* to be nullified at the end */
U32 const windowLow = zc->lowLimit;
U32 matchEndIdx = current+8;
size_t bestLength = 8;
#ifdef ZSTD_C_PREDICT
U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0);
U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1);
predictedSmall += (predictedSmall>0);
predictedLarge += (predictedLarge>0);
#endif /* ZSTD_C_PREDICT */
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
#ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */
const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */
if (matchIndex == predictedSmall) {
/* no need to check length, result known */
*smallerPtr = matchIndex;
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
predictedSmall = predictPtr[1] + (predictPtr[1]>0);
continue;
}
if (matchIndex == predictedLarge) {
*largerPtr = matchIndex;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
predictedLarge = predictPtr[0] + (predictPtr[0]>0);
continue;
}
#endif
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength])
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
bestLength = matchLength;
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
}
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
if (match[matchLength] < ip[matchLength]) { /* necessarily within correct buffer */
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */
if (matchEndIdx > current + 8) return matchEndIdx - current - 8;
return 1;
}
static size_t ZSTD_insertBtAndFindBestMatch (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iend,
size_t* offsetPtr,
U32 nbCompares, const U32 mls,
U32 extDict)
{
U32* const hashTable = zc->hashTable;
U32 const hashLog = zc->params.cParams.hashLog;
size_t const h = ZSTD_hashPtr(ip, hashLog, mls);
U32* const bt = zc->chainTable;
U32 const btLog = zc->params.cParams.chainLog - 1;
U32 const btMask = (1 << btLog) - 1;
U32 matchIndex = hashTable[h];
size_t commonLengthSmaller=0, commonLengthLarger=0;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const U32 current = (U32)(ip-base);
const U32 btLow = btMask >= current ? 0 : current - btMask;
const U32 windowLow = zc->lowLimit;
U32* smallerPtr = bt + 2*(current&btMask);
U32* largerPtr = bt + 2*(current&btMask) + 1;
U32 matchEndIdx = current+8;
U32 dummy32; /* to be nullified at the end */
size_t bestLength = 0;
hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength])
matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
} else {
match = dictBase + matchIndex;
matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
if (matchIndex+matchLength >= dictLimit)
match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
}
if (matchLength > bestLength) {
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop, to guarantee consistency (miss a little bit of compression) */
}
if (match[matchLength] < ip[matchLength]) {
/* match is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else {
/* match is larger than current */
*largerPtr = matchIndex;
commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
largerPtr = nextPtr;
matchIndex = nextPtr[0];
} }
*smallerPtr = *largerPtr = 0;
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
return bestLength;
}
static void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while(idx < target)
idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 0);
}
/** ZSTD_BtFindBestMatch() : Tree updater, providing best match */
static size_t ZSTD_BtFindBestMatch (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 0);
}
static size_t ZSTD_BtFindBestMatch_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
case 5 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
case 7 :
case 6 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
}
}
static void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
{
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while (idx < target) idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 1);
}
/** Tree updater, providing best match */
static size_t ZSTD_BtFindBestMatch_extDict (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 1);
}
static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
case 5 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
case 7 :
case 6 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
}
}
/* *********************************
* Hash Chain
***********************************/
#define NEXT_IN_CHAIN(d, mask) chainTable[(d) & mask]
/* Update chains up to ip (excluded)
Assumption : always within prefix (i.e. not within extDict) */
FORCE_INLINE
U32 ZSTD_insertAndFindFirstIndex (ZSTD_CCtx* zc, const BYTE* ip, U32 mls)
{
U32* const hashTable = zc->hashTable;
const U32 hashLog = zc->params.cParams.hashLog;
U32* const chainTable = zc->chainTable;
const U32 chainMask = (1 << zc->params.cParams.chainLog) - 1;
const BYTE* const base = zc->base;
const U32 target = (U32)(ip - base);
U32 idx = zc->nextToUpdate;
while(idx < target) { /* catch up */
size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls);
NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
hashTable[h] = idx;
idx++;
}
zc->nextToUpdate = target;
return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
}
FORCE_INLINE /* inlining is important to hardwire a hot branch (template emulation) */
size_t ZSTD_HcFindBestMatch_generic (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 mls, const U32 extDict)
{
U32* const chainTable = zc->chainTable;
const U32 chainSize = (1 << zc->params.cParams.chainLog);
const U32 chainMask = chainSize-1;
const BYTE* const base = zc->base;
const BYTE* const dictBase = zc->dictBase;
const U32 dictLimit = zc->dictLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictEnd = dictBase + dictLimit;
const U32 lowLimit = zc->lowLimit;
const U32 current = (U32)(ip-base);
const U32 minChain = current > chainSize ? current - chainSize : 0;
int nbAttempts=maxNbAttempts;
size_t ml=EQUAL_READ32-1;
/* HC4 match finder */
U32 matchIndex = ZSTD_insertAndFindFirstIndex (zc, ip, mls);
for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
const BYTE* match;
size_t currentMl=0;
if ((!extDict) || matchIndex >= dictLimit) {
match = base + matchIndex;
if (match[ml] == ip[ml]) /* potentially better */
currentMl = ZSTD_count(ip, match, iLimit);
} else {
match = dictBase + matchIndex;
if (MEM_read32(match) == MEM_read32(ip)) /* assumption : matchIndex <= dictLimit-4 (by table construction) */
currentMl = ZSTD_count_2segments(ip+EQUAL_READ32, match+EQUAL_READ32, iLimit, dictEnd, prefixStart) + EQUAL_READ32;
}
/* save best solution */
if (currentMl > ml) { ml = currentMl; *offsetPtr = current - matchIndex + ZSTD_REP_MOVE; if (ip+currentMl == iLimit) break; /* best possible, and avoid read overflow*/ }
if (matchIndex <= minChain) break;
matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
}
return ml;
}
FORCE_INLINE size_t ZSTD_HcFindBestMatch_selectMLS (
ZSTD_CCtx* zc,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 0);
case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 0);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 0);
}
}
FORCE_INLINE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
ZSTD_CCtx* zc,
const BYTE* ip, const BYTE* const iLimit,
size_t* offsetPtr,
const U32 maxNbAttempts, const U32 matchLengthSearch)
{
switch(matchLengthSearch)
{
default : /* includes case 3 */
case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 1);
case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 1);
case 7 :
case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 1);
}
}
/* *******************************
* Common parser - lazy strategy
*********************************/
FORCE_INLINE
void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 searchMethod, const U32 depth)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base + ctx->dictLimit;
U32 const maxSearches = 1 << ctx->params.cParams.searchLog;
U32 const mls = ctx->params.cParams.searchLength;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
U32 maxNbAttempts, U32 matchLengthSearch);
searchMax_f const searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
U32 offset_1 = ctx->rep[0], offset_2 = ctx->rep[1], savedOffset=0;
/* init */
ip += (ip==base);
ctx->nextToUpdate3 = ctx->nextToUpdate;
{ U32 const maxRep = (U32)(ip-base);
if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
}
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
/* check repCode */
if ((offset_1>0) & (MEM_read32(ip+1) == MEM_read32(ip+1 - offset_1))) {
/* repcode : we take it */
matchLength = ZSTD_count(ip+1+EQUAL_READ32, ip+1+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
if (depth==0) goto _storeSequence;
}
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound;
}
if (matchLength < EQUAL_READ32) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* let's try to find a better solution */
if (depth>=1)
while (ip<ilimit) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+EQUAL_READ32, ip+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
int const gain2 = (int)(mlRep * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((mlRep >= EQUAL_READ32) && (gain2 > gain1))
matchLength = mlRep, offset = 0, start = ip;
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
if ((ml2 >= EQUAL_READ32) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */
} }
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
if ((offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const ml2 = ZSTD_count(ip+EQUAL_READ32, ip+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
int const gain2 = (int)(ml2 * 4);
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((ml2 >= EQUAL_READ32) && (gain2 > gain1))
matchLength = ml2, offset = 0, start = ip;
}
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
if ((ml2 >= EQUAL_READ32) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* catch up */
if (offset) {
while ((start>anchor) && (start>base+offset-ZSTD_REP_MOVE) && (start[-1] == start[-1-offset+ZSTD_REP_MOVE])) /* only search for offset within prefix */
{ start--; matchLength++; }
offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
}
/* store sequence */
_storeSequence:
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, (U32)offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while ( (ip <= ilimit)
&& ((offset_2>0)
& (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
/* store sequence */
matchLength = ZSTD_count(ip+EQUAL_READ32, ip+EQUAL_READ32-offset_2, iend) + EQUAL_READ32;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
} }
/* Save reps for next block */
ctx->repToConfirm[0] = offset_1 ? offset_1 : savedOffset;
ctx->repToConfirm[1] = offset_2 ? offset_2 : savedOffset;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
static void ZSTD_compressBlock_btlazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 1, 2);
}
static void ZSTD_compressBlock_lazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 2);
}
static void ZSTD_compressBlock_lazy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 1);
}
static void ZSTD_compressBlock_greedy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 0);
}
FORCE_INLINE
void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize,
const U32 searchMethod, const U32 depth)
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
const BYTE* const base = ctx->base;
const U32 dictLimit = ctx->dictLimit;
const U32 lowestIndex = ctx->lowLimit;
const BYTE* const prefixStart = base + dictLimit;
const BYTE* const dictBase = ctx->dictBase;
const BYTE* const dictEnd = dictBase + dictLimit;
const BYTE* const dictStart = dictBase + ctx->lowLimit;
const U32 maxSearches = 1 << ctx->params.cParams.searchLog;
const U32 mls = ctx->params.cParams.searchLength;
typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
size_t* offsetPtr,
U32 maxNbAttempts, U32 matchLengthSearch);
searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS_extDict : ZSTD_HcFindBestMatch_extDict_selectMLS;
U32 offset_1 = ctx->rep[0], offset_2 = ctx->rep[1];
/* init */
ctx->nextToUpdate3 = ctx->nextToUpdate;
ip += (ip == prefixStart);
/* Match Loop */
while (ip < ilimit) {
size_t matchLength=0;
size_t offset=0;
const BYTE* start=ip+1;
U32 current = (U32)(ip-base);
/* check repCode */
{ const U32 repIndex = (U32)(current+1 - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+1+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
if (depth==0) goto _storeSequence;
} }
/* first search (depth 0) */
{ size_t offsetFound = 99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offsetFound, maxSearches, mls);
if (ml2 > matchLength)
matchLength = ml2, start = ip, offset=offsetFound;
}
if (matchLength < EQUAL_READ32) {
ip += ((ip-anchor) >> g_searchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
/* let's try to find a better solution */
if (depth>=1)
while (ip<ilimit) {
ip ++;
current++;
/* check repCode */
if (offset) {
const U32 repIndex = (U32)(current - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t const repLength = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
int const gain2 = (int)(repLength * 3);
int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
if ((repLength >= EQUAL_READ32) && (gain2 > gain1))
matchLength = repLength, offset = 0, start = ip;
} }
/* search match, depth 1 */
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
if ((ml2 >= EQUAL_READ32) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */
} }
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
ip ++;
current++;
/* check repCode */
if (offset) {
const U32 repIndex = (U32)(current - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t repLength = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
int gain2 = (int)(repLength * 4);
int gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
if ((repLength >= EQUAL_READ32) && (gain2 > gain1))
matchLength = repLength, offset = 0, start = ip;
} }
/* search match, depth 2 */
{ size_t offset2=99999999;
size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
if ((ml2 >= EQUAL_READ32) && (gain2 > gain1)) {
matchLength = ml2, offset = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* catch up */
if (offset) {
U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
}
/* store sequence */
_storeSequence:
{ size_t const litLength = start - anchor;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, (U32)offset, matchLength-MINMATCH);
anchor = ip = start + matchLength;
}
/* check immediate repcode */
while (ip <= ilimit) {
const U32 repIndex = (U32)((ip-base) - offset_2);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset history */
ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
}
break;
} }
/* Save reps for next block */
ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
/* Last Literals */
{ size_t const lastLLSize = iend - anchor;
memcpy(seqStorePtr->lit, anchor, lastLLSize);
seqStorePtr->lit += lastLLSize;
}
}
void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 0);
}
static void ZSTD_compressBlock_lazy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 1);
}
static void ZSTD_compressBlock_lazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 2);
}
static void ZSTD_compressBlock_btlazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 1, 2);
}
/* The optimal parser */
#include "zstd_opt.h"
static void ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
#ifdef ZSTD_OPT_H_91842398743
ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0);
#else
(void)ctx; (void)src; (void)srcSize;
return;
#endif
}
static void ZSTD_compressBlock_btopt2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
#ifdef ZSTD_OPT_H_91842398743
ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 1);
#else
(void)ctx; (void)src; (void)srcSize;
return;
#endif
}
static void ZSTD_compressBlock_btopt_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
#ifdef ZSTD_OPT_H_91842398743
ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 0);
#else
(void)ctx; (void)src; (void)srcSize;
return;
#endif
}
static void ZSTD_compressBlock_btopt2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
{
#ifdef ZSTD_OPT_H_91842398743
ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 1);
#else
(void)ctx; (void)src; (void)srcSize;
return;
#endif
}
typedef void (*ZSTD_blockCompressor) (ZSTD_CCtx* ctx, const void* src, size_t srcSize);
static ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict)
{
static const ZSTD_blockCompressor blockCompressor[2][8] = {
{ ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy, ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2, ZSTD_compressBlock_btopt, ZSTD_compressBlock_btopt2 },
{ ZSTD_compressBlock_fast_extDict, ZSTD_compressBlock_doubleFast_extDict, ZSTD_compressBlock_greedy_extDict, ZSTD_compressBlock_lazy_extDict,ZSTD_compressBlock_lazy2_extDict, ZSTD_compressBlock_btlazy2_extDict, ZSTD_compressBlock_btopt_extDict, ZSTD_compressBlock_btopt2_extDict }
};
return blockCompressor[extDict][(U32)strat];
}
static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->params.cParams.strategy, zc->lowLimit < zc->dictLimit);
const BYTE* const base = zc->base;
const BYTE* const istart = (const BYTE*)src;
const U32 current = (U32)(istart-base);
if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) return 0; /* don't even attempt compression below a certain srcSize */
ZSTD_resetSeqStore(&(zc->seqStore));
if (current > zc->nextToUpdate + 384)
zc->nextToUpdate = current - MIN(192, (U32)(current - zc->nextToUpdate - 384)); /* update tree not updated after finding very long rep matches */
blockCompressor(zc, src, srcSize);
return ZSTD_compressSequences(zc, dst, dstCapacity, srcSize);
}
/*! ZSTD_compress_generic() :
* Compress a chunk of data into one or multiple blocks.
* All blocks will be terminated, all input will be consumed.
* Function will issue an error if there is not enough `dstCapacity` to hold the compressed content.
* Frame is supposed already started (header already produced)
* @return : compressed size, or an error code
*/
static size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 lastFrameChunk)
{
size_t blockSize = cctx->blockSize;
size_t remaining = srcSize;
const BYTE* ip = (const BYTE*)src;
BYTE* const ostart = (BYTE*)dst;
BYTE* op = ostart;
U32 const maxDist = 1 << cctx->params.cParams.windowLog;
if (cctx->params.fParams.checksumFlag && srcSize)
XXH64_update(&cctx->xxhState, src, srcSize);
while (remaining) {
U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
size_t cSize;
if (dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE) return ERROR(dstSize_tooSmall); /* not enough space to store compressed block */
if (remaining < blockSize) blockSize = remaining;
/* preemptive overflow correction */
if (cctx->lowLimit > (3U<<29)) {
U32 const cycleMask = (1 << ZSTD_cycleLog(cctx->params.cParams.hashLog, cctx->params.cParams.strategy)) - 1;
U32 const current = (U32)(ip - cctx->base);
U32 const newCurrent = (current & cycleMask) + (1 << cctx->params.cParams.windowLog);
U32 const correction = current - newCurrent;
ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_64 <= 30);
ZSTD_reduceIndex(cctx, correction);
cctx->base += correction;
cctx->dictBase += correction;
cctx->lowLimit -= correction;
cctx->dictLimit -= correction;
if (cctx->nextToUpdate < correction) cctx->nextToUpdate = 0;
else cctx->nextToUpdate -= correction;
}
if ((U32)(ip+blockSize - cctx->base) > cctx->loadedDictEnd + maxDist) {
/* enforce maxDist */
U32 const newLowLimit = (U32)(ip+blockSize - cctx->base) - maxDist;
if (cctx->lowLimit < newLowLimit) cctx->lowLimit = newLowLimit;
if (cctx->dictLimit < cctx->lowLimit) cctx->dictLimit = cctx->lowLimit;
}
cSize = ZSTD_compressBlock_internal(cctx, op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize, ip, blockSize);
if (ZSTD_isError(cSize)) return cSize;
if (cSize == 0) { /* block is not compressible */
U32 const cBlockHeader24 = lastBlock + (((U32)bt_raw)<<1) + (U32)(blockSize << 3);
if (blockSize + ZSTD_blockHeaderSize > dstCapacity) return ERROR(dstSize_tooSmall);
MEM_writeLE32(op, cBlockHeader24); /* no pb, 4th byte will be overwritten */
memcpy(op + ZSTD_blockHeaderSize, ip, blockSize);
cSize = ZSTD_blockHeaderSize+blockSize;
} else {
U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
MEM_writeLE24(op, cBlockHeader24);
cSize += ZSTD_blockHeaderSize;
}
remaining -= blockSize;
dstCapacity -= cSize;
ip += blockSize;
op += cSize;
}
if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
return op-ostart;
}
static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
ZSTD_parameters params, U64 pledgedSrcSize, U32 dictID)
{ BYTE* const op = (BYTE*)dst;
U32 const dictIDSizeCode = (dictID>0) + (dictID>=256) + (dictID>=65536); /* 0-3 */
U32 const checksumFlag = params.fParams.checksumFlag>0;
U32 const windowSize = 1U << params.cParams.windowLog;
U32 const singleSegment = params.fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
BYTE const windowLogByte = (BYTE)((params.cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
U32 const fcsCode = params.fParams.contentSizeFlag ?
(pledgedSrcSize>=256) + (pledgedSrcSize>=65536+256) + (pledgedSrcSize>=0xFFFFFFFFU) : /* 0-3 */
0;
BYTE const frameHeaderDecriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
size_t pos;
if (dstCapacity < ZSTD_frameHeaderSize_max) return ERROR(dstSize_tooSmall);
MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
op[4] = frameHeaderDecriptionByte; pos=5;
if (!singleSegment) op[pos++] = windowLogByte;
switch(dictIDSizeCode)
{
default: /* impossible */
case 0 : break;
case 1 : op[pos] = (BYTE)(dictID); pos++; break;
case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
case 3 : MEM_writeLE32(op+pos, dictID); pos+=4; break;
}
switch(fcsCode)
{
default: /* impossible */
case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
case 3 : MEM_writeLE64(op+pos, (U64)(pledgedSrcSize)); pos+=8; break;
}
return pos;
}
static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
U32 frame, U32 lastFrameChunk)
{
const BYTE* const ip = (const BYTE*) src;
size_t fhSize = 0;
if (cctx->stage==ZSTDcs_created) return ERROR(stage_wrong); /* missing init (ZSTD_compressBegin) */
if (frame && (cctx->stage==ZSTDcs_init)) {
fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->params, cctx->frameContentSize, cctx->dictID);
if (ZSTD_isError(fhSize)) return fhSize;
dstCapacity -= fhSize;
dst = (char*)dst + fhSize;
cctx->stage = ZSTDcs_ongoing;
}
/* Check if blocks follow each other */
if (src != cctx->nextSrc) {
/* not contiguous */
ptrdiff_t const delta = cctx->nextSrc - ip;
cctx->lowLimit = cctx->dictLimit;
cctx->dictLimit = (U32)(cctx->nextSrc - cctx->base);
cctx->dictBase = cctx->base;
cctx->base -= delta;
cctx->nextToUpdate = cctx->dictLimit;
if (cctx->dictLimit - cctx->lowLimit < HASH_READ_SIZE) cctx->lowLimit = cctx->dictLimit; /* too small extDict */
}
/* if input and dictionary overlap : reduce dictionary (area presumed modified by input) */
if ((ip+srcSize > cctx->dictBase + cctx->lowLimit) & (ip < cctx->dictBase + cctx->dictLimit)) {
ptrdiff_t const highInputIdx = (ip + srcSize) - cctx->dictBase;
U32 const lowLimitMax = (highInputIdx > (ptrdiff_t)cctx->dictLimit) ? cctx->dictLimit : (U32)highInputIdx;
cctx->lowLimit = lowLimitMax;
}
cctx->nextSrc = ip + srcSize;
if (srcSize) {
size_t const cSize = frame ?
ZSTD_compress_generic (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize);
if (ZSTD_isError(cSize)) return cSize;
return cSize + fhSize;
} else
return fhSize;
}
size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1, 0);
}
size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx)
{
return MIN (ZSTD_BLOCKSIZE_ABSOLUTEMAX, 1 << cctx->params.cParams.windowLog);
}
size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
size_t const blockSizeMax = ZSTD_getBlockSizeMax(cctx);
if (srcSize > blockSizeMax) return ERROR(srcSize_wrong);
return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0, 0);
}
/*! ZSTD_loadDictionaryContent() :
* @return : 0, or an error code
*/
static size_t ZSTD_loadDictionaryContent(ZSTD_CCtx* zc, const void* src, size_t srcSize)
{
const BYTE* const ip = (const BYTE*) src;
const BYTE* const iend = ip + srcSize;
/* input becomes current prefix */
zc->lowLimit = zc->dictLimit;
zc->dictLimit = (U32)(zc->nextSrc - zc->base);
zc->dictBase = zc->base;
zc->base += ip - zc->nextSrc;
zc->nextToUpdate = zc->dictLimit;
zc->loadedDictEnd = zc->forceWindow ? 0 : (U32)(iend - zc->base);
zc->nextSrc = iend;
if (srcSize <= HASH_READ_SIZE) return 0;
switch(zc->params.cParams.strategy)
{
case ZSTD_fast:
ZSTD_fillHashTable (zc, iend, zc->params.cParams.searchLength);
break;
case ZSTD_dfast:
ZSTD_fillDoubleHashTable (zc, iend, zc->params.cParams.searchLength);
break;
case ZSTD_greedy:
case ZSTD_lazy:
case ZSTD_lazy2:
if (srcSize >= HASH_READ_SIZE)
ZSTD_insertAndFindFirstIndex(zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength);
break;
case ZSTD_btlazy2:
case ZSTD_btopt:
case ZSTD_btopt2:
if (srcSize >= HASH_READ_SIZE)
ZSTD_updateTree(zc, iend-HASH_READ_SIZE, iend, 1 << zc->params.cParams.searchLog, zc->params.cParams.searchLength);
break;
default:
return ERROR(GENERIC); /* strategy doesn't exist; impossible */
}
zc->nextToUpdate = (U32)(iend - zc->base);
return 0;
}
/* Dictionaries that assign zero probability to symbols that show up causes problems
when FSE encoding. Refuse dictionaries that assign zero probability to symbols
that we may encounter during compression.
NOTE: This behavior is not standard and could be improved in the future. */
static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSymbolValue, unsigned maxSymbolValue) {
U32 s;
if (dictMaxSymbolValue < maxSymbolValue) return ERROR(dictionary_corrupted);
for (s = 0; s <= maxSymbolValue; ++s) {
if (normalizedCounter[s] == 0) return ERROR(dictionary_corrupted);
}
return 0;
}
/* Dictionary format :
* See :
* https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
*/
/*! ZSTD_loadZstdDictionary() :
* @return : 0, or an error code
* assumptions : magic number supposed already checked
* dictSize supposed > 8
*/
static size_t ZSTD_loadZstdDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
{
const BYTE* dictPtr = (const BYTE*)dict;
const BYTE* const dictEnd = dictPtr + dictSize;
short offcodeNCount[MaxOff+1];
unsigned offcodeMaxValue = MaxOff;
BYTE scratchBuffer[1<<MAX(MLFSELog,LLFSELog)];
dictPtr += 4; /* skip magic number */
cctx->dictID = cctx->params.fParams.noDictIDFlag ? 0 : MEM_readLE32(dictPtr);
dictPtr += 4;
{ size_t const hufHeaderSize = HUF_readCTable(cctx->hufTable, 255, dictPtr, dictEnd-dictPtr);
if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
dictPtr += hufHeaderSize;
}
{ unsigned 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);
/* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
CHECK_E (FSE_buildCTable_wksp(cctx->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog, scratchBuffer, sizeof(scratchBuffer)), 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);
/* Every match length code must have non-zero probability */
CHECK_F (ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
CHECK_E (FSE_buildCTable_wksp(cctx->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, scratchBuffer, sizeof(scratchBuffer)), 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);
/* Every literal length code must have non-zero probability */
CHECK_F (ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
CHECK_E(FSE_buildCTable_wksp(cctx->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, scratchBuffer, sizeof(scratchBuffer)), dictionary_corrupted);
dictPtr += litlengthHeaderSize;
}
if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
cctx->rep[0] = MEM_readLE32(dictPtr+0);
cctx->rep[1] = MEM_readLE32(dictPtr+4);
cctx->rep[2] = MEM_readLE32(dictPtr+8);
dictPtr += 12;
{ size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
U32 offcodeMax = MaxOff;
if (dictContentSize <= ((U32)-1) - 128 KB) {
U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
}
/* All offset values <= dictContentSize + 128 KB must be representable */
CHECK_F (ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff)));
/* All repCodes must be <= dictContentSize and != 0*/
{ U32 u;
for (u=0; u<3; u++) {
if (cctx->rep[u] == 0) return ERROR(dictionary_corrupted);
if (cctx->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
} }
cctx->flagStaticTables = 1;
cctx->flagStaticHufTable = HUF_repeat_valid;
return ZSTD_loadDictionaryContent(cctx, dictPtr, dictContentSize);
}
}
/** ZSTD_compress_insertDictionary() :
* @return : 0, or an error code */
static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
{
if ((dict==NULL) || (dictSize<=8)) return 0;
/* dict as pure content */
if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (cctx->forceRawDict))
return ZSTD_loadDictionaryContent(cctx, dict, dictSize);
/* dict as zstd dictionary */
return ZSTD_loadZstdDictionary(cctx, dict, dictSize);
}
/*! ZSTD_compressBegin_internal() :
* @return : 0, or an error code */
static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
const void* dict, size_t dictSize,
ZSTD_parameters params, U64 pledgedSrcSize)
{
ZSTD_compResetPolicy_e const crp = dictSize ? ZSTDcrp_fullReset : ZSTDcrp_continue;
CHECK_F(ZSTD_resetCCtx_advanced(cctx, params, pledgedSrcSize, crp));
return ZSTD_compress_insertDictionary(cctx, dict, dictSize);
}
/*! ZSTD_compressBegin_advanced() :
* @return : 0, or an error code */
size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx,
const void* dict, size_t dictSize,
ZSTD_parameters params, unsigned long long pledgedSrcSize)
{
/* compression parameters verification and optimization */
CHECK_F(ZSTD_checkCParams(params.cParams));
return ZSTD_compressBegin_internal(cctx, dict, dictSize, params, pledgedSrcSize);
}
size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
{
ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, dictSize);
return ZSTD_compressBegin_internal(cctx, dict, dictSize, params, 0);
}
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel)
{
return ZSTD_compressBegin_usingDict(cctx, NULL, 0, compressionLevel);
}
/*! ZSTD_writeEpilogue() :
* Ends a frame.
* @return : nb of bytes written into dst (or an error code) */
static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
{
BYTE* const ostart = (BYTE*)dst;
BYTE* op = ostart;
size_t fhSize = 0;
if (cctx->stage == ZSTDcs_created) return ERROR(stage_wrong); /* init missing */
/* special case : empty frame */
if (cctx->stage == ZSTDcs_init) {
fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->params, 0, 0);
if (ZSTD_isError(fhSize)) return fhSize;
dstCapacity -= fhSize;
op += fhSize;
cctx->stage = ZSTDcs_ongoing;
}
if (cctx->stage != ZSTDcs_ending) {
/* write one last empty block, make it the "last" block */
U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1) + 0;
if (dstCapacity<4) return ERROR(dstSize_tooSmall);
MEM_writeLE32(op, cBlockHeader24);
op += ZSTD_blockHeaderSize;
dstCapacity -= ZSTD_blockHeaderSize;
}
if (cctx->params.fParams.checksumFlag) {
U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
if (dstCapacity<4) return ERROR(dstSize_tooSmall);
MEM_writeLE32(op, checksum);
op += 4;
}
cctx->stage = ZSTDcs_created; /* return to "created but no init" status */
return op-ostart;
}
size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
size_t endResult;
size_t const cSize = ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1, 1);
if (ZSTD_isError(cSize)) return cSize;
endResult = ZSTD_writeEpilogue(cctx, (char*)dst + cSize, dstCapacity-cSize);
if (ZSTD_isError(endResult)) return endResult;
return cSize + endResult;
}
static size_t ZSTD_compress_internal (ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const void* dict,size_t dictSize,
ZSTD_parameters params)
{
CHECK_F(ZSTD_compressBegin_internal(cctx, dict, dictSize, params, srcSize));
return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
}
size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const void* dict,size_t dictSize,
ZSTD_parameters params)
{
CHECK_F(ZSTD_checkCParams(params.cParams));
return ZSTD_compress_internal(ctx, dst, dstCapacity, src, srcSize, dict, dictSize, params);
}
size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, const void* dict, size_t dictSize, int compressionLevel)
{
ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, dict ? dictSize : 0);
params.fParams.contentSizeFlag = 1;
return ZSTD_compress_internal(ctx, dst, dstCapacity, src, srcSize, dict, dictSize, params);
}
size_t ZSTD_compressCCtx (ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel)
{
return ZSTD_compress_usingDict(ctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
}
size_t ZSTD_compress(void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel)
{
size_t result;
ZSTD_CCtx ctxBody;
memset(&ctxBody, 0, sizeof(ctxBody));
memcpy(&ctxBody.customMem, &defaultCustomMem, sizeof(ZSTD_customMem));
result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
ZSTD_free(ctxBody.workSpace, defaultCustomMem); /* can't free ctxBody itself, as it's on stack; free only heap content */
return result;
}
/* ===== Dictionary API ===== */
struct ZSTD_CDict_s {
void* dictBuffer;
const void* dictContent;
size_t dictContentSize;
ZSTD_CCtx* refContext;
}; /* typedef'd tp ZSTD_CDict within "zstd.h" */
size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
{
if (cdict==NULL) return 0; /* support sizeof on NULL */
return ZSTD_sizeof_CCtx(cdict->refContext) + (cdict->dictBuffer ? cdict->dictContentSize : 0) + sizeof(*cdict);
}
ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize, unsigned byReference,
ZSTD_parameters params, ZSTD_customMem customMem)
{
if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
if (!customMem.customAlloc || !customMem.customFree) return NULL;
{ ZSTD_CDict* const cdict = (ZSTD_CDict*) ZSTD_malloc(sizeof(ZSTD_CDict), customMem);
ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(customMem);
if (!cdict || !cctx) {
ZSTD_free(cdict, customMem);
ZSTD_freeCCtx(cctx);
return NULL;
}
if ((byReference) || (!dictBuffer) || (!dictSize)) {
cdict->dictBuffer = NULL;
cdict->dictContent = dictBuffer;
} else {
void* const internalBuffer = ZSTD_malloc(dictSize, customMem);
if (!internalBuffer) { ZSTD_free(cctx, customMem); ZSTD_free(cdict, customMem); return NULL; }
memcpy(internalBuffer, dictBuffer, dictSize);
cdict->dictBuffer = internalBuffer;
cdict->dictContent = internalBuffer;
}
{ size_t const errorCode = ZSTD_compressBegin_advanced(cctx, cdict->dictContent, dictSize, params, 0);
if (ZSTD_isError(errorCode)) {
ZSTD_free(cdict->dictBuffer, customMem);
ZSTD_free(cdict, customMem);
ZSTD_freeCCtx(cctx);
return NULL;
} }
cdict->refContext = cctx;
cdict->dictContentSize = dictSize;
return cdict;
}
}
ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
{
ZSTD_customMem const allocator = { NULL, NULL, NULL };
ZSTD_parameters params = ZSTD_getParams(compressionLevel, 0, dictSize);
params.fParams.contentSizeFlag = 1;
return ZSTD_createCDict_advanced(dict, dictSize, 0, params, allocator);
}
ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
{
ZSTD_customMem const allocator = { NULL, NULL, NULL };
ZSTD_parameters params = ZSTD_getParams(compressionLevel, 0, dictSize);
params.fParams.contentSizeFlag = 1;
return ZSTD_createCDict_advanced(dict, dictSize, 1, params, allocator);
}
size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
{
if (cdict==NULL) return 0; /* support free on NULL */
{ ZSTD_customMem const cMem = cdict->refContext->customMem;
ZSTD_freeCCtx(cdict->refContext);
ZSTD_free(cdict->dictBuffer, cMem);
ZSTD_free(cdict, cMem);
return 0;
}
}
static ZSTD_parameters ZSTD_getParamsFromCDict(const ZSTD_CDict* cdict) {
return ZSTD_getParamsFromCCtx(cdict->refContext);
}
size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize)
{
if (cdict->dictContentSize) CHECK_F(ZSTD_copyCCtx(cctx, cdict->refContext, pledgedSrcSize))
else {
ZSTD_parameters params = cdict->refContext->params;
params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
CHECK_F(ZSTD_compressBegin_advanced(cctx, NULL, 0, params, pledgedSrcSize));
}
return 0;
}
/*! ZSTD_compress_usingCDict() :
* Compression using a digested Dictionary.
* Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
* Note that compression level is decided during dictionary creation */
size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const ZSTD_CDict* cdict)
{
CHECK_F(ZSTD_compressBegin_usingCDict(cctx, cdict, srcSize));
if (cdict->refContext->params.fParams.contentSizeFlag==1) {
cctx->params.fParams.contentSizeFlag = 1;
cctx->frameContentSize = srcSize;
}
return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
}
/* ******************************************************************
* Streaming
********************************************************************/
typedef enum { zcss_init, zcss_load, zcss_flush, zcss_final } ZSTD_cStreamStage;
struct ZSTD_CStream_s {
ZSTD_CCtx* cctx;
ZSTD_CDict* cdictLocal;
const ZSTD_CDict* cdict;
char* inBuff;
size_t inBuffSize;
size_t inToCompress;
size_t inBuffPos;
size_t inBuffTarget;
size_t blockSize;
char* outBuff;
size_t outBuffSize;
size_t outBuffContentSize;
size_t outBuffFlushedSize;
ZSTD_cStreamStage stage;
U32 checksum;
U32 frameEnded;
U64 pledgedSrcSize;
U64 inputProcessed;
ZSTD_parameters params;
ZSTD_customMem customMem;
}; /* typedef'd to ZSTD_CStream within "zstd.h" */
ZSTD_CStream* ZSTD_createCStream(void)
{
return ZSTD_createCStream_advanced(defaultCustomMem);
}
ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
{
ZSTD_CStream* zcs;
if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
if (!customMem.customAlloc || !customMem.customFree) return NULL;
zcs = (ZSTD_CStream*)ZSTD_malloc(sizeof(ZSTD_CStream), customMem);
if (zcs==NULL) return NULL;
memset(zcs, 0, sizeof(ZSTD_CStream));
memcpy(&zcs->customMem, &customMem, sizeof(ZSTD_customMem));
zcs->cctx = ZSTD_createCCtx_advanced(customMem);
if (zcs->cctx == NULL) { ZSTD_freeCStream(zcs); return NULL; }
return zcs;
}
size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
{
if (zcs==NULL) return 0; /* support free on NULL */
{ ZSTD_customMem const cMem = zcs->customMem;
ZSTD_freeCCtx(zcs->cctx);
zcs->cctx = NULL;
ZSTD_freeCDict(zcs->cdictLocal);
zcs->cdictLocal = NULL;
ZSTD_free(zcs->inBuff, cMem);
zcs->inBuff = NULL;
ZSTD_free(zcs->outBuff, cMem);
zcs->outBuff = NULL;
ZSTD_free(zcs, cMem);
return 0;
}
}
/*====== Initialization ======*/
size_t ZSTD_CStreamInSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; }
size_t ZSTD_CStreamOutSize(void) { return ZSTD_compressBound(ZSTD_BLOCKSIZE_ABSOLUTEMAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ; }
static size_t ZSTD_resetCStream_internal(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
{
if (zcs->inBuffSize==0) return ERROR(stage_wrong); /* zcs has not been init at least once => can't reset */
if (zcs->cdict) CHECK_F(ZSTD_compressBegin_usingCDict(zcs->cctx, zcs->cdict, pledgedSrcSize))
else CHECK_F(ZSTD_compressBegin_advanced(zcs->cctx, NULL, 0, zcs->params, pledgedSrcSize));
zcs->inToCompress = 0;
zcs->inBuffPos = 0;
zcs->inBuffTarget = zcs->blockSize;
zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
zcs->stage = zcss_load;
zcs->frameEnded = 0;
zcs->pledgedSrcSize = pledgedSrcSize;
zcs->inputProcessed = 0;
return 0; /* ready to go */
}
size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
{
zcs->params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
return ZSTD_resetCStream_internal(zcs, pledgedSrcSize);
}
size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
const void* dict, size_t dictSize,
ZSTD_parameters params, unsigned long long pledgedSrcSize)
{
/* allocate buffers */
{ size_t const neededInBuffSize = (size_t)1 << params.cParams.windowLog;
if (zcs->inBuffSize < neededInBuffSize) {
zcs->inBuffSize = neededInBuffSize;
ZSTD_free(zcs->inBuff, zcs->customMem);
zcs->inBuff = (char*) ZSTD_malloc(neededInBuffSize, zcs->customMem);
if (zcs->inBuff == NULL) return ERROR(memory_allocation);
}
zcs->blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, neededInBuffSize);
}
if (zcs->outBuffSize < ZSTD_compressBound(zcs->blockSize)+1) {
zcs->outBuffSize = ZSTD_compressBound(zcs->blockSize)+1;
ZSTD_free(zcs->outBuff, zcs->customMem);
zcs->outBuff = (char*) ZSTD_malloc(zcs->outBuffSize, zcs->customMem);
if (zcs->outBuff == NULL) return ERROR(memory_allocation);
}
if (dict && dictSize >= 8) {
ZSTD_freeCDict(zcs->cdictLocal);
zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize, 0, params, zcs->customMem);
if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
zcs->cdict = zcs->cdictLocal;
} else zcs->cdict = NULL;
zcs->checksum = params.fParams.checksumFlag > 0;
zcs->params = params;
return ZSTD_resetCStream_internal(zcs, pledgedSrcSize);
}
/* note : cdict must outlive compression session */
size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
{
ZSTD_parameters const params = ZSTD_getParamsFromCDict(cdict);
size_t const initError = ZSTD_initCStream_advanced(zcs, NULL, 0, params, 0);
zcs->cdict = cdict;
zcs->cctx->dictID = params.fParams.noDictIDFlag ? 0 : cdict->refContext->dictID;
return initError;
}
size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel)
{
ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, dictSize);
return ZSTD_initCStream_advanced(zcs, dict, dictSize, params, 0);
}
size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize)
{
ZSTD_parameters params = ZSTD_getParams(compressionLevel, pledgedSrcSize, 0);
if (pledgedSrcSize) params.fParams.contentSizeFlag = 1;
return ZSTD_initCStream_advanced(zcs, NULL, 0, params, pledgedSrcSize);
}
size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
{
return ZSTD_initCStream_usingDict(zcs, NULL, 0, compressionLevel);
}
size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
{
if (zcs==NULL) return 0; /* support sizeof on NULL */
return sizeof(*zcs) + ZSTD_sizeof_CCtx(zcs->cctx) + ZSTD_sizeof_CDict(zcs->cdictLocal) + zcs->outBuffSize + zcs->inBuffSize;
}
/*====== Compression ======*/
typedef enum { zsf_gather, zsf_flush, zsf_end } ZSTD_flush_e;
MEM_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;
}
static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
void* dst, size_t* dstCapacityPtr,
const void* src, size_t* srcSizePtr,
ZSTD_flush_e const flush)
{
U32 someMoreWork = 1;
const char* const istart = (const char*)src;
const char* const iend = istart + *srcSizePtr;
const char* ip = istart;
char* const ostart = (char*)dst;
char* const oend = ostart + *dstCapacityPtr;
char* op = ostart;
while (someMoreWork) {
switch(zcs->stage)
{
case zcss_init: return ERROR(init_missing); /* call ZBUFF_compressInit() first ! */
case zcss_load:
/* complete inBuffer */
{ size_t const toLoad = zcs->inBuffTarget - zcs->inBuffPos;
size_t const loaded = ZSTD_limitCopy(zcs->inBuff + zcs->inBuffPos, toLoad, ip, iend-ip);
zcs->inBuffPos += loaded;
ip += loaded;
if ( (zcs->inBuffPos==zcs->inToCompress) || (!flush && (toLoad != loaded)) ) {
someMoreWork = 0; break; /* not enough input to get a full block : stop there, wait for more */
} }
/* compress current block (note : this stage cannot be stopped in the middle) */
{ void* cDst;
size_t cSize;
size_t const iSize = zcs->inBuffPos - zcs->inToCompress;
size_t oSize = oend-op;
if (oSize >= ZSTD_compressBound(iSize))
cDst = op; /* compress directly into output buffer (avoid flush stage) */
else
cDst = zcs->outBuff, oSize = zcs->outBuffSize;
cSize = (flush == zsf_end) ?
ZSTD_compressEnd(zcs->cctx, cDst, oSize, zcs->inBuff + zcs->inToCompress, iSize) :
ZSTD_compressContinue(zcs->cctx, cDst, oSize, zcs->inBuff + zcs->inToCompress, iSize);
if (ZSTD_isError(cSize)) return cSize;
if (flush == zsf_end) zcs->frameEnded = 1;
/* prepare next block */
zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
if (zcs->inBuffTarget > zcs->inBuffSize)
zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize; /* note : inBuffSize >= blockSize */
zcs->inToCompress = zcs->inBuffPos;
if (cDst == op) { op += cSize; break; } /* no need to flush */
zcs->outBuffContentSize = cSize;
zcs->outBuffFlushedSize = 0;
zcs->stage = zcss_flush; /* pass-through to flush stage */
}
case zcss_flush:
{ size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
size_t const flushed = ZSTD_limitCopy(op, oend-op, zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
op += flushed;
zcs->outBuffFlushedSize += flushed;
if (toFlush!=flushed) { someMoreWork = 0; break; } /* dst too small to store flushed data : stop there */
zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
zcs->stage = zcss_load;
break;
}
case zcss_final:
someMoreWork = 0; /* do nothing */
break;
default:
return ERROR(GENERIC); /* impossible */
}
}
*srcSizePtr = ip - istart;
*dstCapacityPtr = op - ostart;
zcs->inputProcessed += *srcSizePtr;
if (zcs->frameEnded) return 0;
{ size_t hintInSize = zcs->inBuffTarget - zcs->inBuffPos;
if (hintInSize==0) hintInSize = zcs->blockSize;
return hintInSize;
}
}
size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
{
size_t sizeRead = input->size - input->pos;
size_t sizeWritten = output->size - output->pos;
size_t const result = ZSTD_compressStream_generic(zcs,
(char*)(output->dst) + output->pos, &sizeWritten,
(const char*)(input->src) + input->pos, &sizeRead, zsf_gather);
input->pos += sizeRead;
output->pos += sizeWritten;
return result;
}
/*====== Finalize ======*/
/*! ZSTD_flushStream() :
* @return : amount of data remaining to flush */
size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
{
size_t srcSize = 0;
size_t sizeWritten = output->size - output->pos;
size_t const result = ZSTD_compressStream_generic(zcs,
(char*)(output->dst) + output->pos, &sizeWritten,
&srcSize, &srcSize, /* use a valid src address instead of NULL */
zsf_flush);
output->pos += sizeWritten;
if (ZSTD_isError(result)) return result;
return zcs->outBuffContentSize - zcs->outBuffFlushedSize; /* remaining to flush */
}
size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
{
BYTE* const ostart = (BYTE*)(output->dst) + output->pos;
BYTE* const oend = (BYTE*)(output->dst) + output->size;
BYTE* op = ostart;
if ((zcs->pledgedSrcSize) && (zcs->inputProcessed != zcs->pledgedSrcSize))
return ERROR(srcSize_wrong); /* pledgedSrcSize not respected */
if (zcs->stage != zcss_final) {
/* flush whatever remains */
size_t srcSize = 0;
size_t sizeWritten = output->size - output->pos;
size_t const notEnded = ZSTD_compressStream_generic(zcs, ostart, &sizeWritten, &srcSize, &srcSize, zsf_end); /* use a valid src address instead of NULL */
size_t const remainingToFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
op += sizeWritten;
if (remainingToFlush) {
output->pos += sizeWritten;
return remainingToFlush + ZSTD_BLOCKHEADERSIZE /* final empty block */ + (zcs->checksum * 4);
}
/* create epilogue */
zcs->stage = zcss_final;
zcs->outBuffContentSize = !notEnded ? 0 :
ZSTD_compressEnd(zcs->cctx, zcs->outBuff, zcs->outBuffSize, NULL, 0); /* write epilogue, including final empty block, into outBuff */
}
/* flush epilogue */
{ size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
size_t const flushed = ZSTD_limitCopy(op, oend-op, zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
op += flushed;
zcs->outBuffFlushedSize += flushed;
output->pos += op-ostart;
if (toFlush==flushed) zcs->stage = zcss_init; /* end reached */
return toFlush - flushed;
}
}
/*-===== Pre-defined compression levels =====-*/
#define ZSTD_DEFAULT_CLEVEL 1
#define ZSTD_MAX_CLEVEL 22
int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
{ /* "default" */
/* W, C, H, S, L, TL, strat */
{ 18, 12, 12, 1, 7, 16, ZSTD_fast }, /* level 0 - never used */
{ 19, 13, 14, 1, 7, 16, ZSTD_fast }, /* level 1 */
{ 19, 15, 16, 1, 6, 16, ZSTD_fast }, /* level 2 */
{ 20, 16, 17, 1, 5, 16, ZSTD_dfast }, /* level 3.*/
{ 20, 18, 18, 1, 5, 16, ZSTD_dfast }, /* level 4.*/
{ 20, 15, 18, 3, 5, 16, ZSTD_greedy }, /* level 5 */
{ 21, 16, 19, 2, 5, 16, ZSTD_lazy }, /* level 6 */
{ 21, 17, 20, 3, 5, 16, ZSTD_lazy }, /* level 7 */
{ 21, 18, 20, 3, 5, 16, ZSTD_lazy2 }, /* level 8 */
{ 21, 20, 20, 3, 5, 16, ZSTD_lazy2 }, /* level 9 */
{ 21, 19, 21, 4, 5, 16, ZSTD_lazy2 }, /* level 10 */
{ 22, 20, 22, 4, 5, 16, ZSTD_lazy2 }, /* level 11 */
{ 22, 20, 22, 5, 5, 16, ZSTD_lazy2 }, /* level 12 */
{ 22, 21, 22, 5, 5, 16, ZSTD_lazy2 }, /* level 13 */
{ 22, 21, 22, 6, 5, 16, ZSTD_lazy2 }, /* level 14 */
{ 22, 21, 21, 5, 5, 16, ZSTD_btlazy2 }, /* level 15 */
{ 23, 22, 22, 5, 5, 16, ZSTD_btlazy2 }, /* level 16 */
{ 23, 21, 22, 4, 5, 24, ZSTD_btopt }, /* level 17 */
{ 23, 23, 22, 6, 5, 32, ZSTD_btopt }, /* level 18 */
{ 23, 23, 22, 6, 3, 48, ZSTD_btopt }, /* level 19 */
{ 25, 25, 23, 7, 3, 64, ZSTD_btopt2 }, /* level 20 */
{ 26, 26, 23, 7, 3,256, ZSTD_btopt2 }, /* level 21 */
{ 27, 27, 25, 9, 3,512, ZSTD_btopt2 }, /* level 22 */
},
{ /* for srcSize <= 256 KB */
/* W, C, H, S, L, T, strat */
{ 0, 0, 0, 0, 0, 0, ZSTD_fast }, /* level 0 - not used */
{ 18, 13, 14, 1, 6, 8, ZSTD_fast }, /* level 1 */
{ 18, 14, 13, 1, 5, 8, ZSTD_dfast }, /* level 2 */
{ 18, 16, 15, 1, 5, 8, ZSTD_dfast }, /* level 3 */
{ 18, 15, 17, 1, 5, 8, ZSTD_greedy }, /* level 4.*/
{ 18, 16, 17, 4, 5, 8, ZSTD_greedy }, /* level 5.*/
{ 18, 16, 17, 3, 5, 8, ZSTD_lazy }, /* level 6.*/
{ 18, 17, 17, 4, 4, 8, ZSTD_lazy }, /* level 7 */
{ 18, 17, 17, 4, 4, 8, ZSTD_lazy2 }, /* level 8 */
{ 18, 17, 17, 5, 4, 8, ZSTD_lazy2 }, /* level 9 */
{ 18, 17, 17, 6, 4, 8, ZSTD_lazy2 }, /* level 10 */
{ 18, 18, 17, 6, 4, 8, ZSTD_lazy2 }, /* level 11.*/
{ 18, 18, 17, 7, 4, 8, ZSTD_lazy2 }, /* level 12.*/
{ 18, 19, 17, 6, 4, 8, ZSTD_btlazy2 }, /* level 13 */
{ 18, 18, 18, 4, 4, 16, ZSTD_btopt }, /* level 14.*/
{ 18, 18, 18, 4, 3, 16, ZSTD_btopt }, /* level 15.*/
{ 18, 19, 18, 6, 3, 32, ZSTD_btopt }, /* level 16.*/
{ 18, 19, 18, 8, 3, 64, ZSTD_btopt }, /* level 17.*/
{ 18, 19, 18, 9, 3,128, ZSTD_btopt }, /* level 18.*/
{ 18, 19, 18, 10, 3,256, ZSTD_btopt }, /* level 19.*/
{ 18, 19, 18, 11, 3,512, ZSTD_btopt2 }, /* level 20.*/
{ 18, 19, 18, 12, 3,512, ZSTD_btopt2 }, /* level 21.*/
{ 18, 19, 18, 13, 3,512, ZSTD_btopt2 }, /* level 22.*/
},
{ /* for srcSize <= 128 KB */
/* W, C, H, S, L, T, strat */
{ 17, 12, 12, 1, 7, 8, ZSTD_fast }, /* level 0 - not used */
{ 17, 12, 13, 1, 6, 8, ZSTD_fast }, /* level 1 */
{ 17, 13, 16, 1, 5, 8, ZSTD_fast }, /* level 2 */
{ 17, 16, 16, 2, 5, 8, ZSTD_dfast }, /* level 3 */
{ 17, 13, 15, 3, 4, 8, ZSTD_greedy }, /* level 4 */
{ 17, 15, 17, 4, 4, 8, ZSTD_greedy }, /* level 5 */
{ 17, 16, 17, 3, 4, 8, ZSTD_lazy }, /* level 6 */
{ 17, 15, 17, 4, 4, 8, ZSTD_lazy2 }, /* level 7 */
{ 17, 17, 17, 4, 4, 8, ZSTD_lazy2 }, /* level 8 */
{ 17, 17, 17, 5, 4, 8, ZSTD_lazy2 }, /* level 9 */
{ 17, 17, 17, 6, 4, 8, ZSTD_lazy2 }, /* level 10 */
{ 17, 17, 17, 7, 4, 8, ZSTD_lazy2 }, /* level 11 */
{ 17, 17, 17, 8, 4, 8, ZSTD_lazy2 }, /* level 12 */
{ 17, 18, 17, 6, 4, 8, ZSTD_btlazy2 }, /* level 13.*/
{ 17, 17, 17, 7, 3, 8, ZSTD_btopt }, /* level 14.*/
{ 17, 17, 17, 7, 3, 16, ZSTD_btopt }, /* level 15.*/
{ 17, 18, 17, 7, 3, 32, ZSTD_btopt }, /* level 16.*/
{ 17, 18, 17, 7, 3, 64, ZSTD_btopt }, /* level 17.*/
{ 17, 18, 17, 7, 3,256, ZSTD_btopt }, /* level 18.*/
{ 17, 18, 17, 8, 3,256, ZSTD_btopt }, /* level 19.*/
{ 17, 18, 17, 9, 3,256, ZSTD_btopt2 }, /* level 20.*/
{ 17, 18, 17, 10, 3,256, ZSTD_btopt2 }, /* level 21.*/
{ 17, 18, 17, 11, 3,512, ZSTD_btopt2 }, /* level 22.*/
},
{ /* for srcSize <= 16 KB */
/* W, C, H, S, L, T, strat */
{ 14, 12, 12, 1, 7, 6, ZSTD_fast }, /* level 0 - not used */
{ 14, 14, 14, 1, 6, 6, ZSTD_fast }, /* level 1 */
{ 14, 14, 14, 1, 4, 6, ZSTD_fast }, /* level 2 */
{ 14, 14, 14, 1, 4, 6, ZSTD_dfast }, /* level 3.*/
{ 14, 14, 14, 4, 4, 6, ZSTD_greedy }, /* level 4.*/
{ 14, 14, 14, 3, 4, 6, ZSTD_lazy }, /* level 5.*/
{ 14, 14, 14, 4, 4, 6, ZSTD_lazy2 }, /* level 6 */
{ 14, 14, 14, 5, 4, 6, ZSTD_lazy2 }, /* level 7 */
{ 14, 14, 14, 6, 4, 6, ZSTD_lazy2 }, /* level 8.*/
{ 14, 15, 14, 6, 4, 6, ZSTD_btlazy2 }, /* level 9.*/
{ 14, 15, 14, 3, 3, 6, ZSTD_btopt }, /* level 10.*/
{ 14, 15, 14, 6, 3, 8, ZSTD_btopt }, /* level 11.*/
{ 14, 15, 14, 6, 3, 16, ZSTD_btopt }, /* level 12.*/
{ 14, 15, 14, 6, 3, 24, ZSTD_btopt }, /* level 13.*/
{ 14, 15, 15, 6, 3, 48, ZSTD_btopt }, /* level 14.*/
{ 14, 15, 15, 6, 3, 64, ZSTD_btopt }, /* level 15.*/
{ 14, 15, 15, 6, 3, 96, ZSTD_btopt }, /* level 16.*/
{ 14, 15, 15, 6, 3,128, ZSTD_btopt }, /* level 17.*/
{ 14, 15, 15, 6, 3,256, ZSTD_btopt }, /* level 18.*/
{ 14, 15, 15, 7, 3,256, ZSTD_btopt }, /* level 19.*/
{ 14, 15, 15, 8, 3,256, ZSTD_btopt2 }, /* level 20.*/
{ 14, 15, 15, 9, 3,256, ZSTD_btopt2 }, /* level 21.*/
{ 14, 15, 15, 10, 3,256, ZSTD_btopt2 }, /* level 22.*/
},
};
/*! ZSTD_getCParams() :
* @return ZSTD_compressionParameters structure for a selected compression level, `srcSize` and `dictSize`.
* Size values are optional, provide 0 if not known or unused */
ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSize, size_t dictSize)
{
ZSTD_compressionParameters cp;
size_t const addedSize = srcSize ? 0 : 500;
U64 const rSize = srcSize+dictSize ? srcSize+dictSize+addedSize : (U64)-1;
U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB); /* intentional underflow for srcSizeHint == 0 */
if (compressionLevel <= 0) compressionLevel = ZSTD_DEFAULT_CLEVEL; /* 0 == default; no negative compressionLevel yet */
if (compressionLevel > ZSTD_MAX_CLEVEL) compressionLevel = ZSTD_MAX_CLEVEL;
cp = ZSTD_defaultCParameters[tableID][compressionLevel];
if (MEM_32bits()) { /* auto-correction, for 32-bits mode */
if (cp.windowLog > ZSTD_WINDOWLOG_MAX) cp.windowLog = ZSTD_WINDOWLOG_MAX;
if (cp.chainLog > ZSTD_CHAINLOG_MAX) cp.chainLog = ZSTD_CHAINLOG_MAX;
if (cp.hashLog > ZSTD_HASHLOG_MAX) cp.hashLog = ZSTD_HASHLOG_MAX;
}
cp = ZSTD_adjustCParams(cp, srcSize, dictSize);
return cp;
}
/*! ZSTD_getParams() :
* same as ZSTD_getCParams(), but @return a `ZSTD_parameters` object (instead of `ZSTD_compressionParameters`).
* All fields of `ZSTD_frameParameters` are set to default (0) */
ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSize, size_t dictSize) {
ZSTD_parameters params;
ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, srcSize, dictSize);
memset(&params, 0, sizeof(params));
params.cParams = cParams;
return params;
}