/** * 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 /* memset */ #include "mem.h" #define XXH_STATIC_LINKING_ONLY /* XXH64_state_t */ #include "xxhash.h" /* XXH_reset, update, digest */ #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 ***************************************/ size_t ZSTD_compressBound(size_t srcSize) { return FSE_compressBound(srcSize) + 12; } /*-************************************* * 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; ZSTD_compressionStage_e stage; U32 rep[ZSTD_REP_NUM]; U32 savedRep[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; 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)]; }; 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)); memcpy(&(cctx->customMem), &customMem, sizeof(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; } 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 ((valmax)) 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); { U32 const searchLengthMin = ((cParams.strategy == ZSTD_fast) | (cParams.strategy == ZSTD_greedy)) ? ZSTD_SEARCHLENGTH_MIN+1 : ZSTD_SEARCHLENGTH_MIN; U32 const searchLengthMax = (cParams.strategy == ZSTD_fast) ? ZSTD_SEARCHLENGTH_MAX : ZSTD_SEARCHLENGTH_MAX-1; CLAMPCHECK(cParams.searchLength, searchLengthMin, searchLengthMax); } CLAMPCHECK(cParams.targetLength, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX); if ((U32)(cParams.strategy) > (U32)ZSTD_btopt2) return ERROR(compressionParameter_unsupported); return 0; } /** 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< srcLog) cPar.windowLog = srcLog; } } if (cPar.hashLog > cPar.windowLog) cPar.hashLog = cPar.windowLog; { U32 const btPlus = (cPar.strategy == ZSTD_btlazy2) | (cPar.strategy == ZSTD_btopt) | (cPar.strategy == ZSTD_btopt2); U32 const maxChainLog = cPar.windowLog+btPlus; if (cPar.chainLog > maxChainLog) cPar.chainLog = maxChainLog; } /* <= ZSTD_CHAINLOG_MAX */ 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<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; irep[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)) 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<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; 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; irep[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<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_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_resetCCtx_advanced(dstCCtx, srcCCtx->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; if (srcCCtx->flagStaticTables) { memcpy(dstCCtx->hufTable, srcCCtx->hufTable, 256*4); memcpy(dstCCtx->litlengthCTable, srcCCtx->litlengthCTable, sizeof(dstCCtx->litlengthCTable)); memcpy(dstCCtx->matchlengthCTable, srcCCtx->matchlengthCTable, sizeof(dstCCtx->matchlengthCTable)); memcpy(dstCCtx->offcodeCTable, srcCCtx->offcodeCTable, sizeof(dstCCtx->offcodeCTable)); } 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->flagStaticTables ? 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 */ if (zc->flagStaticTables && (lhSize==3)) { hType = set_repeat; singleStream = 1; cLitSize = HUF_compress1X_usingCTable(ostart+lhSize, dstCapacity-lhSize, src, srcSize, zc->hufTable); } else { cLitSize = singleStream ? HUF_compress1X(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11) : HUF_compress2 (ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11); } if ((cLitSize==0) | (cLitSize >= srcSize - minGain)) return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize); if (cLitSize==1) 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 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; } size_t ZSTD_compressSequences(ZSTD_CCtx* zc, void* dst, size_t dstCapacity, size_t srcSize) { 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; /* 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(count, &max, llCodeTable, nbSeq); 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(CTable_LitLength, LL_defaultNorm, MaxLL, LL_defaultNormLog); 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 ERROR(GENERIC); op += NCountSize; } FSE_buildCTable(CTable_LitLength, norm, max, tableLog); LLtype = set_compressed; } } /* CTable for Offsets */ { U32 max = MaxOff; size_t const mostFrequent = FSE_countFast(count, &max, ofCodeTable, nbSeq); 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(CTable_OffsetBits, OF_defaultNorm, MaxOff, OF_defaultNormLog); 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 ERROR(GENERIC); op += NCountSize; } FSE_buildCTable(CTable_OffsetBits, norm, max, tableLog); Offtype = set_compressed; } } /* CTable for MatchLengths */ { U32 max = MaxML; size_t const mostFrequent = FSE_countFast(count, &max, mlCodeTable, nbSeq); 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(CTable_MatchLength, ML_defaultNorm, MaxML, ML_defaultNormLog); 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 ERROR(GENERIC); op += NCountSize; } FSE_buildCTable(CTable_MatchLength, norm, max, tableLog); 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); BIT_addBits(&blockStream, sequences[nbSeq-1].offset, ofCodeTable[nbSeq-1]); BIT_flushBits(&blockStream); { size_t n; for (n=nbSeq-2 ; n= 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)*/ 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) return 0; } /* confirm repcodes */ { int i; for (i=0; irep[i] = zc->savedRep[i]; } return op - ostart; } /*! 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) { #if 0 /* for debug */ static const BYTE* g_start = NULL; const U32 pos = (U32)(literals - g_start); if (g_start==NULL) g_start = literals; //if ((pos > 1) && (pos < 50000)) printf("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> (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) { 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->savedRep[0] = offset_1 ? offset_1 : offsetSaved; cctx->savedRep[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: 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->savedRep[0] = offset_1; ctx->savedRep[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: 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->savedRep[0] = offset_1 ? offset_1 : offsetSaved; cctx->savedRep[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: 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->savedRep[0] = offset_1; ctx->savedRep[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: 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* 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* 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 : case 4 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4); case 5 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5); 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 : 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 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 (ie. 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 : 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 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 : 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 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 (ip0) & (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) && (ip0) & (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->savedRep[0] = offset_1 ? offset_1 : savedOffset; ctx->savedRep[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= 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= 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->savedRep[0] = offset_1; ctx->savedRep[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 > (1<<30)) { U32 const btplus = (cctx->params.cParams.strategy == ZSTD_btlazy2) | (cctx->params.cParams.strategy == ZSTD_btopt) | (cctx->params.cParams.strategy == ZSTD_btopt2); U32 const chainMask = (1 << (cctx->params.cParams.chainLog - btplus)) - 1; U32 const supLog = MAX(cctx->params.cParams.chainLog, 17 /* blockSize */); U32 const newLowLimit = (cctx->lowLimit & chainMask) + (1 << supLog); /* preserve position % chainSize, ensure current-repcode doesn't underflow */ U32 const correction = cctx->lowLimit - newLowLimit; ZSTD_reduceIndex(cctx, correction); cctx->base += correction; cctx->dictBase += correction; cctx->lowLimit = newLowLimit; 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-1)); 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; { 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; } } 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); } 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 = (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: ZSTD_insertAndFindFirstIndex (zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength); break; case ZSTD_btlazy2: case ZSTD_btopt: case ZSTD_btopt2: 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 = zc->loadedDictEnd; 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 : Magic == ZSTD_DICT_MAGIC (4 bytes) HUF_writeCTable(256) FSE_writeNCount(off) FSE_writeNCount(ml) FSE_writeNCount(ll) RepOffsets Dictionary content */ /*! ZSTD_loadDictEntropyStats() : @return : size read from dictionary note : magic number supposed already checked */ static size_t ZSTD_loadDictEntropyStats(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; { size_t const hufHeaderSize = HUF_readCTable(cctx->hufTable, 255, dict, dictSize); 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(cctx->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog), 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(cctx->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog), 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(cctx->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog), dictionary_corrupted); dictPtr += litlengthHeaderSize; } if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted); cctx->rep[0] = MEM_readLE32(dictPtr+0); if (cctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted); cctx->rep[1] = MEM_readLE32(dictPtr+4); if (cctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted); cctx->rep[2] = MEM_readLE32(dictPtr+8); if (cctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted); dictPtr += 12; { U32 offcodeMax = MaxOff; if ((size_t)(dictEnd - dictPtr) <= ((U32)-1) - 128 KB) { U32 const maxOffset = (U32)(dictEnd - dictPtr) + 128 KB; /* The maximum offset that must be supported */ /* Calculate minimum offset code required to represent maxOffset */ offcodeMax = ZSTD_highbit32(maxOffset); } /* Every possible supported offset <= dictContentSize + 128 KB must be representable */ CHECK_F (ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff))); } cctx->flagStaticTables = 1; return dictPtr - (const BYTE*)dict; } /** ZSTD_compress_insertDictionary() : * @return : 0, or an error code */ static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* zc, const void* dict, size_t dictSize) { if ((dict==NULL) || (dictSize<=8)) return 0; /* default : dict is pure content */ if (MEM_readLE32(dict) != ZSTD_DICT_MAGIC) return ZSTD_loadDictionaryContent(zc, dict, dictSize); zc->dictID = zc->params.fParams.noDictIDFlag ? 0 : MEM_readLE32((const char*)dict+4); /* known magic number : dict is parsed for entropy stats and content */ { size_t const loadError = ZSTD_loadDictEntropyStats(zc, (const char*)dict+8 /* skip dictHeader */, dictSize-8); size_t const eSize = loadError + 8; if (ZSTD_isError(loadError)) return loadError; return ZSTD_loadDictionaryContent(zc, (const char*)dict+eSize, dictSize-eSize); } } /*! 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* zc, int compressionLevel) { return ZSTD_compressBegin_usingDict(zc, 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, dictSize); 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* 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->dictContentSize; } ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize, 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); void* const dictContent = ZSTD_malloc(dictSize, customMem); ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(customMem); if (!dictContent || !cdict || !cctx) { ZSTD_free(dictContent, customMem); ZSTD_free(cdict, customMem); ZSTD_free(cctx, customMem); return NULL; } if (dictSize) { memcpy(dictContent, dict, dictSize); } { size_t const errorCode = ZSTD_compressBegin_advanced(cctx, dictContent, dictSize, params, 0); if (ZSTD_isError(errorCode)) { ZSTD_free(dictContent, customMem); ZSTD_free(cdict, customMem); ZSTD_free(cctx, customMem); return NULL; } } cdict->dictContent = dictContent; cdict->dictContentSize = dictSize; cdict->refContext = cctx; 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, 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->dictContent, 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, U64 pledgedSrcSize) { if (cdict->dictContentSize) CHECK_F(ZSTD_copyCCtx(cctx, cdict->refContext, pledgedSrcSize)) else CHECK_F(ZSTD_compressBegin_advanced(cctx, NULL, 0, cdict->refContext->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; 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); ZSTD_freeCDict(zcs->cdictLocal); ZSTD_free(zcs->inBuff, cMem); ZSTD_free(zcs->outBuff, cMem); 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 */ ; } size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize) { if (zcs->inBuffSize==0) return ERROR(stage_wrong); /* zcs has not been init at least once */ 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; return 0; /* ready to go */ } 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) { ZSTD_freeCDict(zcs->cdictLocal); zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize, 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(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; 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(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; 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->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(¶ms, 0, sizeof(params)); params.cParams = cParams; return params; }