diff options
Diffstat (limited to 'vendor/github.com/DataDog/zstd/zstd_decompress_block.c')
| -rw-r--r-- | vendor/github.com/DataDog/zstd/zstd_decompress_block.c | 1311 |
1 files changed, 0 insertions, 1311 deletions
diff --git a/vendor/github.com/DataDog/zstd/zstd_decompress_block.c b/vendor/github.com/DataDog/zstd/zstd_decompress_block.c deleted file mode 100644 index a2a7eedcf..000000000 --- a/vendor/github.com/DataDog/zstd/zstd_decompress_block.c +++ /dev/null @@ -1,1311 +0,0 @@ -/* - * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under both the BSD-style license (found in the - * LICENSE file in the root directory of this source tree) and the GPLv2 (found - * in the COPYING file in the root directory of this source tree). - * You may select, at your option, one of the above-listed licenses. - */ - -/* zstd_decompress_block : - * this module takes care of decompressing _compressed_ block */ - -/*-******************************************************* -* Dependencies -*********************************************************/ -#include <string.h> /* memcpy, memmove, memset */ -#include "compiler.h" /* prefetch */ -#include "cpu.h" /* bmi2 */ -#include "mem.h" /* low level memory routines */ -#define FSE_STATIC_LINKING_ONLY -#include "fse.h" -#define HUF_STATIC_LINKING_ONLY -#include "huf.h" -#include "zstd_internal.h" -#include "zstd_decompress_internal.h" /* ZSTD_DCtx */ -#include "zstd_ddict.h" /* ZSTD_DDictDictContent */ -#include "zstd_decompress_block.h" - -/*_******************************************************* -* Macros -**********************************************************/ - -/* These two optional macros force the use one way or another of the two - * ZSTD_decompressSequences implementations. You can't force in both directions - * at the same time. - */ -#if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ - defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) -#error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!" -#endif - - -/*_******************************************************* -* Memory operations -**********************************************************/ -static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); } - - -/*-************************************************************* - * Block decoding - ***************************************************************/ - -/*! ZSTD_getcBlockSize() : - * Provides the size of compressed block from block header `src` */ -size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, - blockProperties_t* bpPtr) -{ - RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong); - - { U32 const cBlockHeader = MEM_readLE24(src); - U32 const cSize = cBlockHeader >> 3; - bpPtr->lastBlock = cBlockHeader & 1; - bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3); - bpPtr->origSize = cSize; /* only useful for RLE */ - if (bpPtr->blockType == bt_rle) return 1; - RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected); - return cSize; - } -} - - -/* Hidden declaration for fullbench */ -size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx, - const void* src, size_t srcSize); -/*! ZSTD_decodeLiteralsBlock() : - * @return : nb of bytes read from src (< srcSize ) - * note : symbol not declared but exposed for fullbench */ -size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx, - const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */ -{ - RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected); - - { const BYTE* const istart = (const BYTE*) src; - symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3); - - switch(litEncType) - { - case set_repeat: - RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted); - /* fall-through */ - - case set_compressed: - RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3"); - { size_t lhSize, litSize, litCSize; - U32 singleStream=0; - U32 const lhlCode = (istart[0] >> 2) & 3; - U32 const lhc = MEM_readLE32(istart); - size_t hufSuccess; - switch(lhlCode) - { - case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */ - /* 2 - 2 - 10 - 10 */ - singleStream = !lhlCode; - lhSize = 3; - litSize = (lhc >> 4) & 0x3FF; - litCSize = (lhc >> 14) & 0x3FF; - break; - case 2: - /* 2 - 2 - 14 - 14 */ - lhSize = 4; - litSize = (lhc >> 4) & 0x3FFF; - litCSize = lhc >> 18; - break; - case 3: - /* 2 - 2 - 18 - 18 */ - lhSize = 5; - litSize = (lhc >> 4) & 0x3FFFF; - litCSize = (lhc >> 22) + (istart[4] << 10); - break; - } - RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected); - RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected); - - /* prefetch huffman table if cold */ - if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) { - PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable)); - } - - if (litEncType==set_repeat) { - if (singleStream) { - hufSuccess = HUF_decompress1X_usingDTable_bmi2( - dctx->litBuffer, litSize, istart+lhSize, litCSize, - dctx->HUFptr, dctx->bmi2); - } else { - hufSuccess = HUF_decompress4X_usingDTable_bmi2( - dctx->litBuffer, litSize, istart+lhSize, litCSize, - dctx->HUFptr, dctx->bmi2); - } - } else { - if (singleStream) { -#if defined(HUF_FORCE_DECOMPRESS_X2) - hufSuccess = HUF_decompress1X_DCtx_wksp( - dctx->entropy.hufTable, dctx->litBuffer, litSize, - istart+lhSize, litCSize, dctx->workspace, - sizeof(dctx->workspace)); -#else - hufSuccess = HUF_decompress1X1_DCtx_wksp_bmi2( - dctx->entropy.hufTable, dctx->litBuffer, litSize, - istart+lhSize, litCSize, dctx->workspace, - sizeof(dctx->workspace), dctx->bmi2); -#endif - } else { - hufSuccess = HUF_decompress4X_hufOnly_wksp_bmi2( - dctx->entropy.hufTable, dctx->litBuffer, litSize, - istart+lhSize, litCSize, dctx->workspace, - sizeof(dctx->workspace), dctx->bmi2); - } - } - - RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected); - - dctx->litPtr = dctx->litBuffer; - dctx->litSize = litSize; - dctx->litEntropy = 1; - if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable; - memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); - return litCSize + lhSize; - } - - case set_basic: - { size_t litSize, lhSize; - U32 const lhlCode = ((istart[0]) >> 2) & 3; - switch(lhlCode) - { - case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ - lhSize = 1; - litSize = istart[0] >> 3; - break; - case 1: - lhSize = 2; - litSize = MEM_readLE16(istart) >> 4; - break; - case 3: - lhSize = 3; - litSize = MEM_readLE24(istart) >> 4; - break; - } - - if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */ - RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected); - memcpy(dctx->litBuffer, istart+lhSize, litSize); - dctx->litPtr = dctx->litBuffer; - dctx->litSize = litSize; - memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); - return lhSize+litSize; - } - /* direct reference into compressed stream */ - dctx->litPtr = istart+lhSize; - dctx->litSize = litSize; - return lhSize+litSize; - } - - case set_rle: - { U32 const lhlCode = ((istart[0]) >> 2) & 3; - size_t litSize, lhSize; - switch(lhlCode) - { - case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ - lhSize = 1; - litSize = istart[0] >> 3; - break; - case 1: - lhSize = 2; - litSize = MEM_readLE16(istart) >> 4; - break; - case 3: - lhSize = 3; - litSize = MEM_readLE24(istart) >> 4; - RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4"); - break; - } - RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected); - memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH); - dctx->litPtr = dctx->litBuffer; - dctx->litSize = litSize; - return lhSize+1; - } - default: - RETURN_ERROR(corruption_detected, "impossible"); - } - } -} - -/* Default FSE distribution tables. - * These are pre-calculated FSE decoding tables using default distributions as defined in specification : - * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#default-distributions - * They were generated programmatically with following method : - * - start from default distributions, present in /lib/common/zstd_internal.h - * - generate tables normally, using ZSTD_buildFSETable() - * - printout the content of tables - * - pretify output, report below, test with fuzzer to ensure it's correct */ - -/* Default FSE distribution table for Literal Lengths */ -static const ZSTD_seqSymbol LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = { - { 1, 1, 1, LL_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ - /* nextState, nbAddBits, nbBits, baseVal */ - { 0, 0, 4, 0}, { 16, 0, 4, 0}, - { 32, 0, 5, 1}, { 0, 0, 5, 3}, - { 0, 0, 5, 4}, { 0, 0, 5, 6}, - { 0, 0, 5, 7}, { 0, 0, 5, 9}, - { 0, 0, 5, 10}, { 0, 0, 5, 12}, - { 0, 0, 6, 14}, { 0, 1, 5, 16}, - { 0, 1, 5, 20}, { 0, 1, 5, 22}, - { 0, 2, 5, 28}, { 0, 3, 5, 32}, - { 0, 4, 5, 48}, { 32, 6, 5, 64}, - { 0, 7, 5, 128}, { 0, 8, 6, 256}, - { 0, 10, 6, 1024}, { 0, 12, 6, 4096}, - { 32, 0, 4, 0}, { 0, 0, 4, 1}, - { 0, 0, 5, 2}, { 32, 0, 5, 4}, - { 0, 0, 5, 5}, { 32, 0, 5, 7}, - { 0, 0, 5, 8}, { 32, 0, 5, 10}, - { 0, 0, 5, 11}, { 0, 0, 6, 13}, - { 32, 1, 5, 16}, { 0, 1, 5, 18}, - { 32, 1, 5, 22}, { 0, 2, 5, 24}, - { 32, 3, 5, 32}, { 0, 3, 5, 40}, - { 0, 6, 4, 64}, { 16, 6, 4, 64}, - { 32, 7, 5, 128}, { 0, 9, 6, 512}, - { 0, 11, 6, 2048}, { 48, 0, 4, 0}, - { 16, 0, 4, 1}, { 32, 0, 5, 2}, - { 32, 0, 5, 3}, { 32, 0, 5, 5}, - { 32, 0, 5, 6}, { 32, 0, 5, 8}, - { 32, 0, 5, 9}, { 32, 0, 5, 11}, - { 32, 0, 5, 12}, { 0, 0, 6, 15}, - { 32, 1, 5, 18}, { 32, 1, 5, 20}, - { 32, 2, 5, 24}, { 32, 2, 5, 28}, - { 32, 3, 5, 40}, { 32, 4, 5, 48}, - { 0, 16, 6,65536}, { 0, 15, 6,32768}, - { 0, 14, 6,16384}, { 0, 13, 6, 8192}, -}; /* LL_defaultDTable */ - -/* Default FSE distribution table for Offset Codes */ -static const ZSTD_seqSymbol OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = { - { 1, 1, 1, OF_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ - /* nextState, nbAddBits, nbBits, baseVal */ - { 0, 0, 5, 0}, { 0, 6, 4, 61}, - { 0, 9, 5, 509}, { 0, 15, 5,32765}, - { 0, 21, 5,2097149}, { 0, 3, 5, 5}, - { 0, 7, 4, 125}, { 0, 12, 5, 4093}, - { 0, 18, 5,262141}, { 0, 23, 5,8388605}, - { 0, 5, 5, 29}, { 0, 8, 4, 253}, - { 0, 14, 5,16381}, { 0, 20, 5,1048573}, - { 0, 2, 5, 1}, { 16, 7, 4, 125}, - { 0, 11, 5, 2045}, { 0, 17, 5,131069}, - { 0, 22, 5,4194301}, { 0, 4, 5, 13}, - { 16, 8, 4, 253}, { 0, 13, 5, 8189}, - { 0, 19, 5,524285}, { 0, 1, 5, 1}, - { 16, 6, 4, 61}, { 0, 10, 5, 1021}, - { 0, 16, 5,65533}, { 0, 28, 5,268435453}, - { 0, 27, 5,134217725}, { 0, 26, 5,67108861}, - { 0, 25, 5,33554429}, { 0, 24, 5,16777213}, -}; /* OF_defaultDTable */ - - -/* Default FSE distribution table for Match Lengths */ -static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = { - { 1, 1, 1, ML_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ - /* nextState, nbAddBits, nbBits, baseVal */ - { 0, 0, 6, 3}, { 0, 0, 4, 4}, - { 32, 0, 5, 5}, { 0, 0, 5, 6}, - { 0, 0, 5, 8}, { 0, 0, 5, 9}, - { 0, 0, 5, 11}, { 0, 0, 6, 13}, - { 0, 0, 6, 16}, { 0, 0, 6, 19}, - { 0, 0, 6, 22}, { 0, 0, 6, 25}, - { 0, 0, 6, 28}, { 0, 0, 6, 31}, - { 0, 0, 6, 34}, { 0, 1, 6, 37}, - { 0, 1, 6, 41}, { 0, 2, 6, 47}, - { 0, 3, 6, 59}, { 0, 4, 6, 83}, - { 0, 7, 6, 131}, { 0, 9, 6, 515}, - { 16, 0, 4, 4}, { 0, 0, 4, 5}, - { 32, 0, 5, 6}, { 0, 0, 5, 7}, - { 32, 0, 5, 9}, { 0, 0, 5, 10}, - { 0, 0, 6, 12}, { 0, 0, 6, 15}, - { 0, 0, 6, 18}, { 0, 0, 6, 21}, - { 0, 0, 6, 24}, { 0, 0, 6, 27}, - { 0, 0, 6, 30}, { 0, 0, 6, 33}, - { 0, 1, 6, 35}, { 0, 1, 6, 39}, - { 0, 2, 6, 43}, { 0, 3, 6, 51}, - { 0, 4, 6, 67}, { 0, 5, 6, 99}, - { 0, 8, 6, 259}, { 32, 0, 4, 4}, - { 48, 0, 4, 4}, { 16, 0, 4, 5}, - { 32, 0, 5, 7}, { 32, 0, 5, 8}, - { 32, 0, 5, 10}, { 32, 0, 5, 11}, - { 0, 0, 6, 14}, { 0, 0, 6, 17}, - { 0, 0, 6, 20}, { 0, 0, 6, 23}, - { 0, 0, 6, 26}, { 0, 0, 6, 29}, - { 0, 0, 6, 32}, { 0, 16, 6,65539}, - { 0, 15, 6,32771}, { 0, 14, 6,16387}, - { 0, 13, 6, 8195}, { 0, 12, 6, 4099}, - { 0, 11, 6, 2051}, { 0, 10, 6, 1027}, -}; /* ML_defaultDTable */ - - -static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddBits) -{ - void* ptr = dt; - ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr; - ZSTD_seqSymbol* const cell = dt + 1; - - DTableH->tableLog = 0; - DTableH->fastMode = 0; - - cell->nbBits = 0; - cell->nextState = 0; - assert(nbAddBits < 255); - cell->nbAdditionalBits = (BYTE)nbAddBits; - cell->baseValue = baseValue; -} - - -/* ZSTD_buildFSETable() : - * generate FSE decoding table for one symbol (ll, ml or off) - * cannot fail if input is valid => - * all inputs are presumed validated at this stage */ -void -ZSTD_buildFSETable(ZSTD_seqSymbol* dt, - const short* normalizedCounter, unsigned maxSymbolValue, - const U32* baseValue, const U32* nbAdditionalBits, - unsigned tableLog) -{ - ZSTD_seqSymbol* const tableDecode = dt+1; - U16 symbolNext[MaxSeq+1]; - - U32 const maxSV1 = maxSymbolValue + 1; - U32 const tableSize = 1 << tableLog; - U32 highThreshold = tableSize-1; - - /* Sanity Checks */ - assert(maxSymbolValue <= MaxSeq); - assert(tableLog <= MaxFSELog); - - /* Init, lay down lowprob symbols */ - { ZSTD_seqSymbol_header DTableH; - DTableH.tableLog = tableLog; - DTableH.fastMode = 1; - { S16 const largeLimit= (S16)(1 << (tableLog-1)); - U32 s; - for (s=0; s<maxSV1; s++) { - if (normalizedCounter[s]==-1) { - tableDecode[highThreshold--].baseValue = s; - symbolNext[s] = 1; - } else { - if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0; - symbolNext[s] = normalizedCounter[s]; - } } } - memcpy(dt, &DTableH, sizeof(DTableH)); - } - - /* Spread symbols */ - { U32 const tableMask = tableSize-1; - U32 const step = FSE_TABLESTEP(tableSize); - U32 s, position = 0; - for (s=0; s<maxSV1; s++) { - int i; - for (i=0; i<normalizedCounter[s]; i++) { - tableDecode[position].baseValue = s; - position = (position + step) & tableMask; - while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */ - } } - assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */ - } - - /* Build Decoding table */ - { U32 u; - for (u=0; u<tableSize; u++) { - U32 const symbol = tableDecode[u].baseValue; - U32 const nextState = symbolNext[symbol]++; - tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) ); - tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize); - assert(nbAdditionalBits[symbol] < 255); - tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol]; - tableDecode[u].baseValue = baseValue[symbol]; - } } -} - - -/*! ZSTD_buildSeqTable() : - * @return : nb bytes read from src, - * or an error code if it fails */ -static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr, - symbolEncodingType_e type, unsigned max, U32 maxLog, - const void* src, size_t srcSize, - const U32* baseValue, const U32* nbAdditionalBits, - const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable, - int ddictIsCold, int nbSeq) -{ - switch(type) - { - case set_rle : - RETURN_ERROR_IF(!srcSize, srcSize_wrong); - RETURN_ERROR_IF((*(const BYTE*)src) > max, corruption_detected); - { U32 const symbol = *(const BYTE*)src; - U32 const baseline = baseValue[symbol]; - U32 const nbBits = nbAdditionalBits[symbol]; - ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits); - } - *DTablePtr = DTableSpace; - return 1; - case set_basic : - *DTablePtr = defaultTable; - return 0; - case set_repeat: - RETURN_ERROR_IF(!flagRepeatTable, corruption_detected); - /* prefetch FSE table if used */ - if (ddictIsCold && (nbSeq > 24 /* heuristic */)) { - const void* const pStart = *DTablePtr; - size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog)); - PREFETCH_AREA(pStart, pSize); - } - return 0; - case set_compressed : - { unsigned tableLog; - S16 norm[MaxSeq+1]; - size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize); - RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected); - RETURN_ERROR_IF(tableLog > maxLog, corruption_detected); - ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog); - *DTablePtr = DTableSpace; - return headerSize; - } - default : - assert(0); - RETURN_ERROR(GENERIC, "impossible"); - } -} - -size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, - const void* src, size_t srcSize) -{ - const BYTE* const istart = (const BYTE* const)src; - const BYTE* const iend = istart + srcSize; - const BYTE* ip = istart; - int nbSeq; - DEBUGLOG(5, "ZSTD_decodeSeqHeaders"); - - /* check */ - RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong); - - /* SeqHead */ - nbSeq = *ip++; - if (!nbSeq) { - *nbSeqPtr=0; - RETURN_ERROR_IF(srcSize != 1, srcSize_wrong); - return 1; - } - if (nbSeq > 0x7F) { - if (nbSeq == 0xFF) { - RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong); - nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; - } else { - RETURN_ERROR_IF(ip >= iend, srcSize_wrong); - nbSeq = ((nbSeq-0x80)<<8) + *ip++; - } - } - *nbSeqPtr = nbSeq; - - /* FSE table descriptors */ - RETURN_ERROR_IF(ip+4 > iend, srcSize_wrong); /* minimum possible size */ - { symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6); - symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3); - symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3); - ip++; - - /* Build DTables */ - { size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr, - LLtype, MaxLL, LLFSELog, - ip, iend-ip, - LL_base, LL_bits, - LL_defaultDTable, dctx->fseEntropy, - dctx->ddictIsCold, nbSeq); - RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected); - ip += llhSize; - } - - { size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr, - OFtype, MaxOff, OffFSELog, - ip, iend-ip, - OF_base, OF_bits, - OF_defaultDTable, dctx->fseEntropy, - dctx->ddictIsCold, nbSeq); - RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected); - ip += ofhSize; - } - - { size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr, - MLtype, MaxML, MLFSELog, - ip, iend-ip, - ML_base, ML_bits, - ML_defaultDTable, dctx->fseEntropy, - dctx->ddictIsCold, nbSeq); - RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected); - ip += mlhSize; - } - } - - return ip-istart; -} - - -typedef struct { - size_t litLength; - size_t matchLength; - size_t offset; - const BYTE* match; -} seq_t; - -typedef struct { - size_t state; - const ZSTD_seqSymbol* table; -} ZSTD_fseState; - -typedef struct { - BIT_DStream_t DStream; - ZSTD_fseState stateLL; - ZSTD_fseState stateOffb; - ZSTD_fseState stateML; - size_t prevOffset[ZSTD_REP_NUM]; - const BYTE* prefixStart; - const BYTE* dictEnd; - size_t pos; -} seqState_t; - - -/* ZSTD_execSequenceLast7(): - * exceptional case : decompress a match starting within last 7 bytes of output buffer. - * requires more careful checks, to ensure there is no overflow. - * performance does not matter though. - * note : this case is supposed to be never generated "naturally" by reference encoder, - * since in most cases it needs at least 8 bytes to look for a match. - * but it's allowed by the specification. */ -FORCE_NOINLINE -size_t ZSTD_execSequenceLast7(BYTE* op, - BYTE* const oend, seq_t sequence, - const BYTE** litPtr, const BYTE* const litLimit, - const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd) -{ - BYTE* const oLitEnd = op + sequence.litLength; - size_t const sequenceLength = sequence.litLength + sequence.matchLength; - BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ - const BYTE* const iLitEnd = *litPtr + sequence.litLength; - const BYTE* match = oLitEnd - sequence.offset; - - /* check */ - RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must fit within dstBuffer"); - RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "try to read beyond literal buffer"); - - /* copy literals */ - while (op < oLitEnd) *op++ = *(*litPtr)++; - - /* copy Match */ - if (sequence.offset > (size_t)(oLitEnd - base)) { - /* offset beyond prefix */ - RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - vBase),corruption_detected); - match = dictEnd - (base-match); - if (match + sequence.matchLength <= dictEnd) { - memmove(oLitEnd, match, sequence.matchLength); - return sequenceLength; - } - /* span extDict & currentPrefixSegment */ - { size_t const length1 = dictEnd - match; - memmove(oLitEnd, match, length1); - op = oLitEnd + length1; - sequence.matchLength -= length1; - match = base; - } } - while (op < oMatchEnd) *op++ = *match++; - return sequenceLength; -} - - -HINT_INLINE -size_t ZSTD_execSequence(BYTE* op, - BYTE* const oend, seq_t sequence, - const BYTE** litPtr, const BYTE* const litLimit, - const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) -{ - BYTE* const oLitEnd = op + sequence.litLength; - size_t const sequenceLength = sequence.litLength + sequence.matchLength; - BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ - BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; - const BYTE* const iLitEnd = *litPtr + sequence.litLength; - const BYTE* match = oLitEnd - sequence.offset; - - /* check */ - RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend"); - RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer"); - if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd); - - /* copy Literals */ - ZSTD_copy8(op, *litPtr); - if (sequence.litLength > 8) - ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ - op = oLitEnd; - *litPtr = iLitEnd; /* update for next sequence */ - - /* copy Match */ - if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { - /* offset beyond prefix -> go into extDict */ - RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected); - match = dictEnd + (match - prefixStart); - if (match + sequence.matchLength <= dictEnd) { - memmove(oLitEnd, match, sequence.matchLength); - return sequenceLength; - } - /* span extDict & currentPrefixSegment */ - { size_t const length1 = dictEnd - match; - memmove(oLitEnd, match, length1); - op = oLitEnd + length1; - sequence.matchLength -= length1; - match = prefixStart; - if (op > oend_w || sequence.matchLength < MINMATCH) { - U32 i; - for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i]; - return sequenceLength; - } - } } - /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */ - - /* match within prefix */ - if (sequence.offset < 8) { - /* close range match, overlap */ - static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ - static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */ - int const sub2 = dec64table[sequence.offset]; - op[0] = match[0]; - op[1] = match[1]; - op[2] = match[2]; - op[3] = match[3]; - match += dec32table[sequence.offset]; - ZSTD_copy4(op+4, match); - match -= sub2; - } else { - ZSTD_copy8(op, match); - } - op += 8; match += 8; - - if (oMatchEnd > oend-(16-MINMATCH)) { - if (op < oend_w) { - ZSTD_wildcopy(op, match, oend_w - op); - match += oend_w - op; - op = oend_w; - } - while (op < oMatchEnd) *op++ = *match++; - } else { - ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */ - } - return sequenceLength; -} - - -HINT_INLINE -size_t ZSTD_execSequenceLong(BYTE* op, - BYTE* const oend, seq_t sequence, - const BYTE** litPtr, const BYTE* const litLimit, - const BYTE* const prefixStart, const BYTE* const dictStart, const BYTE* const dictEnd) -{ - BYTE* const oLitEnd = op + sequence.litLength; - size_t const sequenceLength = sequence.litLength + sequence.matchLength; - BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ - BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; - const BYTE* const iLitEnd = *litPtr + sequence.litLength; - const BYTE* match = sequence.match; - - /* check */ - RETURN_ERROR_IF(oMatchEnd > oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend"); - RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer"); - if (oLitEnd > oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, dictStart, dictEnd); - - /* copy Literals */ - ZSTD_copy8(op, *litPtr); /* note : op <= oLitEnd <= oend_w == oend - 8 */ - if (sequence.litLength > 8) - ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ - op = oLitEnd; - *litPtr = iLitEnd; /* update for next sequence */ - - /* copy Match */ - if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { - /* offset beyond prefix */ - RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - dictStart), corruption_detected); - if (match + sequence.matchLength <= dictEnd) { - memmove(oLitEnd, match, sequence.matchLength); - return sequenceLength; - } - /* span extDict & currentPrefixSegment */ - { size_t const length1 = dictEnd - match; - memmove(oLitEnd, match, length1); - op = oLitEnd + length1; - sequence.matchLength -= length1; - match = prefixStart; - if (op > oend_w || sequence.matchLength < MINMATCH) { - U32 i; - for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i]; - return sequenceLength; - } - } } - assert(op <= oend_w); - assert(sequence.matchLength >= MINMATCH); - - /* match within prefix */ - if (sequence.offset < 8) { - /* close range match, overlap */ - static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ - static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */ - int const sub2 = dec64table[sequence.offset]; - op[0] = match[0]; - op[1] = match[1]; - op[2] = match[2]; - op[3] = match[3]; - match += dec32table[sequence.offset]; - ZSTD_copy4(op+4, match); - match -= sub2; - } else { - ZSTD_copy8(op, match); - } - op += 8; match += 8; - - if (oMatchEnd > oend-(16-MINMATCH)) { - if (op < oend_w) { - ZSTD_wildcopy(op, match, oend_w - op); - match += oend_w - op; - op = oend_w; - } - while (op < oMatchEnd) *op++ = *match++; - } else { - ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */ - } - return sequenceLength; -} - -static void -ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt) -{ - const void* ptr = dt; - const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr; - DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog); - DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits", - (U32)DStatePtr->state, DTableH->tableLog); - BIT_reloadDStream(bitD); - DStatePtr->table = dt + 1; -} - -FORCE_INLINE_TEMPLATE void -ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD) -{ - ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state]; - U32 const nbBits = DInfo.nbBits; - size_t const lowBits = BIT_readBits(bitD, nbBits); - DStatePtr->state = DInfo.nextState + lowBits; -} - -/* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum - * offset bits. But we can only read at most (STREAM_ACCUMULATOR_MIN_32 - 1) - * bits before reloading. This value is the maximum number of bytes we read - * after reloading when we are decoding long offsets. - */ -#define LONG_OFFSETS_MAX_EXTRA_BITS_32 \ - (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32 \ - ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32 \ - : 0) - -typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e; - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG -FORCE_INLINE_TEMPLATE seq_t -ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets) -{ - seq_t seq; - U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits; - U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits; - U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits; - U32 const totalBits = llBits+mlBits+ofBits; - U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue; - U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue; - U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue; - - /* sequence */ - { size_t offset; - if (!ofBits) - offset = 0; - else { - ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1); - ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5); - assert(ofBits <= MaxOff); - if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) { - U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed); - offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); - BIT_reloadDStream(&seqState->DStream); - if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits); - assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32); /* to avoid another reload */ - } else { - offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ - if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); - } - } - - if (ofBits <= 1) { - offset += (llBase==0); - if (offset) { - size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; - temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ - if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset = temp; - } else { /* offset == 0 */ - offset = seqState->prevOffset[0]; - } - } else { - seqState->prevOffset[2] = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset; - } - seq.offset = offset; - } - - seq.matchLength = mlBase - + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0); /* <= 16 bits */ - if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) - BIT_reloadDStream(&seqState->DStream); - if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog))) - BIT_reloadDStream(&seqState->DStream); - /* Ensure there are enough bits to read the rest of data in 64-bit mode. */ - ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64); - - seq.litLength = llBase - + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0); /* <= 16 bits */ - if (MEM_32bits()) - BIT_reloadDStream(&seqState->DStream); - - DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u", - (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset); - - /* ANS state update */ - ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ - ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ - if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ - ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ - - return seq; -} - -FORCE_INLINE_TEMPLATE size_t -ZSTD_decompressSequences_body( ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - const BYTE* ip = (const BYTE*)seqStart; - const BYTE* const iend = ip + seqSize; - BYTE* const ostart = (BYTE* const)dst; - BYTE* const oend = ostart + maxDstSize; - BYTE* op = ostart; - const BYTE* litPtr = dctx->litPtr; - const BYTE* const litEnd = litPtr + dctx->litSize; - const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); - const BYTE* const vBase = (const BYTE*) (dctx->virtualStart); - const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); - DEBUGLOG(5, "ZSTD_decompressSequences_body"); - - /* Regen sequences */ - if (nbSeq) { - seqState_t seqState; - dctx->fseEntropy = 1; - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } - RETURN_ERROR_IF( - ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), - corruption_detected); - ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); - ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); - ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); - - for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) { - nbSeq--; - { seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset); - size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd); - DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); - if (ZSTD_isError(oneSeqSize)) return oneSeqSize; - op += oneSeqSize; - } } - - /* check if reached exact end */ - DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq); - RETURN_ERROR_IF(nbSeq, corruption_detected); - /* save reps for next block */ - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); } - } - - /* last literal segment */ - { size_t const lastLLSize = litEnd - litPtr; - RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall); - memcpy(op, litPtr, lastLLSize); - op += lastLLSize; - } - - return op-ostart; -} - -static size_t -ZSTD_decompressSequences_default(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ - - - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT -FORCE_INLINE_TEMPLATE seq_t -ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets) -{ - seq_t seq; - U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits; - U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits; - U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits; - U32 const totalBits = llBits+mlBits+ofBits; - U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue; - U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue; - U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue; - - /* sequence */ - { size_t offset; - if (!ofBits) - offset = 0; - else { - ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1); - ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5); - assert(ofBits <= MaxOff); - if (MEM_32bits() && longOffsets) { - U32 const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN_32-1); - offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); - if (MEM_32bits() || extraBits) BIT_reloadDStream(&seqState->DStream); - if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits); - } else { - offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ - if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); - } - } - - if (ofBits <= 1) { - offset += (llBase==0); - if (offset) { - size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; - temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ - if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset = temp; - } else { - offset = seqState->prevOffset[0]; - } - } else { - seqState->prevOffset[2] = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset; - } - seq.offset = offset; - } - - seq.matchLength = mlBase + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <= 16 bits */ - if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) - BIT_reloadDStream(&seqState->DStream); - if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog))) - BIT_reloadDStream(&seqState->DStream); - /* Verify that there is enough bits to read the rest of the data in 64-bit mode. */ - ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64); - - seq.litLength = llBase + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */ - if (MEM_32bits()) - BIT_reloadDStream(&seqState->DStream); - - { size_t const pos = seqState->pos + seq.litLength; - const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart; - seq.match = matchBase + pos - seq.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted. - * No consequence though : no memory access will occur, overly large offset will be detected in ZSTD_execSequenceLong() */ - seqState->pos = pos + seq.matchLength; - } - - /* ANS state update */ - ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ - ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ - if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ - ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ - - return seq; -} - -FORCE_INLINE_TEMPLATE size_t -ZSTD_decompressSequencesLong_body( - ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - const BYTE* ip = (const BYTE*)seqStart; - const BYTE* const iend = ip + seqSize; - BYTE* const ostart = (BYTE* const)dst; - BYTE* const oend = ostart + maxDstSize; - BYTE* op = ostart; - const BYTE* litPtr = dctx->litPtr; - const BYTE* const litEnd = litPtr + dctx->litSize; - const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); - const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart); - const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); - - /* Regen sequences */ - if (nbSeq) { -#define STORED_SEQS 4 -#define STORED_SEQS_MASK (STORED_SEQS-1) -#define ADVANCED_SEQS 4 - seq_t sequences[STORED_SEQS]; - int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS); - seqState_t seqState; - int seqNb; - dctx->fseEntropy = 1; - { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } - seqState.prefixStart = prefixStart; - seqState.pos = (size_t)(op-prefixStart); - seqState.dictEnd = dictEnd; - assert(iend >= ip); - RETURN_ERROR_IF( - ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), - corruption_detected); - ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); - ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); - ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); - - /* prepare in advance */ - for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNb<seqAdvance); seqNb++) { - sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, isLongOffset); - PREFETCH_L1(sequences[seqNb].match); PREFETCH_L1(sequences[seqNb].match + sequences[seqNb].matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ - } - RETURN_ERROR_IF(seqNb<seqAdvance, corruption_detected); - - /* decode and decompress */ - for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb<nbSeq) ; seqNb++) { - seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, isLongOffset); - size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); - if (ZSTD_isError(oneSeqSize)) return oneSeqSize; - PREFETCH_L1(sequence.match); PREFETCH_L1(sequence.match + sequence.matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ - sequences[seqNb & STORED_SEQS_MASK] = sequence; - op += oneSeqSize; - } - RETURN_ERROR_IF(seqNb<nbSeq, corruption_detected); - - /* finish queue */ - seqNb -= seqAdvance; - for ( ; seqNb<nbSeq ; seqNb++) { - size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb&STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); - if (ZSTD_isError(oneSeqSize)) return oneSeqSize; - op += oneSeqSize; - } - - /* save reps for next block */ - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); } - } - - /* last literal segment */ - { size_t const lastLLSize = litEnd - litPtr; - RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall); - memcpy(op, litPtr, lastLLSize); - op += lastLLSize; - } - - return op-ostart; -} - -static size_t -ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ - - - -#if DYNAMIC_BMI2 - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG -static TARGET_ATTRIBUTE("bmi2") size_t -ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT -static TARGET_ATTRIBUTE("bmi2") size_t -ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ - -#endif /* DYNAMIC_BMI2 */ - -typedef size_t (*ZSTD_decompressSequences_t)( - ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset); - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG -static size_t -ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - DEBUGLOG(5, "ZSTD_decompressSequences"); -#if DYNAMIC_BMI2 - if (dctx->bmi2) { - return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); - } -#endif - return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ - - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT -/* ZSTD_decompressSequencesLong() : - * decompression function triggered when a minimum share of offsets is considered "long", - * aka out of cache. - * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance". - * This function will try to mitigate main memory latency through the use of prefetching */ -static size_t -ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset) -{ - DEBUGLOG(5, "ZSTD_decompressSequencesLong"); -#if DYNAMIC_BMI2 - if (dctx->bmi2) { - return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); - } -#endif - return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ - - - -#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ - !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) -/* ZSTD_getLongOffsetsShare() : - * condition : offTable must be valid - * @return : "share" of long offsets (arbitrarily defined as > (1<<23)) - * compared to maximum possible of (1<<OffFSELog) */ -static unsigned -ZSTD_getLongOffsetsShare(const ZSTD_seqSymbol* offTable) -{ - const void* ptr = offTable; - U32 const tableLog = ((const ZSTD_seqSymbol_header*)ptr)[0].tableLog; - const ZSTD_seqSymbol* table = offTable + 1; - U32 const max = 1 << tableLog; - U32 u, total = 0; - DEBUGLOG(5, "ZSTD_getLongOffsetsShare: (tableLog=%u)", tableLog); - - assert(max <= (1 << OffFSELog)); /* max not too large */ - for (u=0; u<max; u++) { - if (table[u].nbAdditionalBits > 22) total += 1; - } - - assert(tableLog <= OffFSELog); - total <<= (OffFSELog - tableLog); /* scale to OffFSELog */ - - return total; -} -#endif - - -size_t -ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, - void* dst, size_t dstCapacity, - const void* src, size_t srcSize, const int frame) -{ /* blockType == blockCompressed */ - const BYTE* ip = (const BYTE*)src; - /* isLongOffset must be true if there are long offsets. - * Offsets are long if they are larger than 2^STREAM_ACCUMULATOR_MIN. - * We don't expect that to be the case in 64-bit mode. - * In block mode, window size is not known, so we have to be conservative. - * (note: but it could be evaluated from current-lowLimit) - */ - ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || (dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN)))); - DEBUGLOG(5, "ZSTD_decompressBlock_internal (size : %u)", (U32)srcSize); - - RETURN_ERROR_IF(srcSize >= ZSTD_BLOCKSIZE_MAX, srcSize_wrong); - - /* Decode literals section */ - { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize); - DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : %u", (U32)litCSize); - if (ZSTD_isError(litCSize)) return litCSize; - ip += litCSize; - srcSize -= litCSize; - } - - /* Build Decoding Tables */ - { - /* These macros control at build-time which decompressor implementation - * we use. If neither is defined, we do some inspection and dispatch at - * runtime. - */ -#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ - !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) - int usePrefetchDecoder = dctx->ddictIsCold; -#endif - int nbSeq; - size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize); - if (ZSTD_isError(seqHSize)) return seqHSize; - ip += seqHSize; - srcSize -= seqHSize; - -#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ - !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) - if ( !usePrefetchDecoder - && (!frame || (dctx->fParams.windowSize > (1<<24))) - && (nbSeq>ADVANCED_SEQS) ) { /* could probably use a larger nbSeq limit */ - U32 const shareLongOffsets = ZSTD_getLongOffsetsShare(dctx->OFTptr); - U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */ - usePrefetchDecoder = (shareLongOffsets >= minShare); - } -#endif - - dctx->ddictIsCold = 0; - -#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ - !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) - if (usePrefetchDecoder) -#endif -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT - return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); -#endif - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG - /* else */ - return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); -#endif - } -} - - -size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, - void* dst, size_t dstCapacity, - const void* src, size_t srcSize) -{ - size_t dSize; - ZSTD_checkContinuity(dctx, dst); - dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0); - dctx->previousDstEnd = (char*)dst + dSize; - return dSize; -} |