diff options
Diffstat (limited to 'lib/zstd/decompress/zstd_decompress_block.c')
| -rw-r--r-- | lib/zstd/decompress/zstd_decompress_block.c | 1540 |
1 files changed, 0 insertions, 1540 deletions
diff --git a/lib/zstd/decompress/zstd_decompress_block.c b/lib/zstd/decompress/zstd_decompress_block.c deleted file mode 100644 index 2d101d9a84..0000000000 --- a/lib/zstd/decompress/zstd_decompress_block.c +++ /dev/null @@ -1,1540 +0,0 @@ -/* - * Copyright (c) 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 "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ -#include "../common/compiler.h" /* prefetch */ -#include "../common/cpu.h" /* bmi2 */ -#include "../common/mem.h" /* low level memory routines */ -#define FSE_STATIC_LINKING_ONLY -#include "../common/fse.h" -#define HUF_STATIC_LINKING_ONLY -#include "../common/huf.h" -#include "../common/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) { ZSTD_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 */ -{ - DEBUGLOG(5, "ZSTD_decodeLiteralsBlock"); - 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: - DEBUGLOG(5, "set_repeat flag : re-using stats from previous compressed literals block"); - RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted, ""); - ZSTD_FALLTHROUGH; - - 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) + ((size_t)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; - ZSTD_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, ""); - ZSTD_memcpy(dctx->litBuffer, istart+lhSize, litSize); - dctx->litPtr = dctx->litBuffer; - dctx->litSize = litSize; - ZSTD_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, ""); - ZSTD_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/release/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 */ -FORCE_INLINE_TEMPLATE -void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt, - const short* normalizedCounter, unsigned maxSymbolValue, - const U32* baseValue, const U32* nbAdditionalBits, - unsigned tableLog, void* wksp, size_t wkspSize) -{ - ZSTD_seqSymbol* const tableDecode = dt+1; - U32 const maxSV1 = maxSymbolValue + 1; - U32 const tableSize = 1 << tableLog; - - U16* symbolNext = (U16*)wksp; - BYTE* spread = (BYTE*)(symbolNext + MaxSeq + 1); - U32 highThreshold = tableSize - 1; - - - /* Sanity Checks */ - assert(maxSymbolValue <= MaxSeq); - assert(tableLog <= MaxFSELog); - assert(wkspSize >= ZSTD_BUILD_FSE_TABLE_WKSP_SIZE); - (void)wkspSize; - /* 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; - assert(normalizedCounter[s]>=0); - symbolNext[s] = (U16)normalizedCounter[s]; - } } } - ZSTD_memcpy(dt, &DTableH, sizeof(DTableH)); - } - - /* Spread symbols */ - assert(tableSize <= 512); - /* Specialized symbol spreading for the case when there are - * no low probability (-1 count) symbols. When compressing - * small blocks we avoid low probability symbols to hit this - * case, since header decoding speed matters more. - */ - if (highThreshold == tableSize - 1) { - size_t const tableMask = tableSize-1; - size_t const step = FSE_TABLESTEP(tableSize); - /* First lay down the symbols in order. - * We use a uint64_t to lay down 8 bytes at a time. This reduces branch - * misses since small blocks generally have small table logs, so nearly - * all symbols have counts <= 8. We ensure we have 8 bytes at the end of - * our buffer to handle the over-write. - */ - { - U64 const add = 0x0101010101010101ull; - size_t pos = 0; - U64 sv = 0; - U32 s; - for (s=0; s<maxSV1; ++s, sv += add) { - int i; - int const n = normalizedCounter[s]; - MEM_write64(spread + pos, sv); - for (i = 8; i < n; i += 8) { - MEM_write64(spread + pos + i, sv); - } - pos += n; - } - } - /* Now we spread those positions across the table. - * The benefit of doing it in two stages is that we avoid the the - * variable size inner loop, which caused lots of branch misses. - * Now we can run through all the positions without any branch misses. - * We unroll the loop twice, since that is what emperically worked best. - */ - { - size_t position = 0; - size_t s; - size_t const unroll = 2; - assert(tableSize % unroll == 0); /* FSE_MIN_TABLELOG is 5 */ - for (s = 0; s < (size_t)tableSize; s += unroll) { - size_t u; - for (u = 0; u < unroll; ++u) { - size_t const uPosition = (position + (u * step)) & tableMask; - tableDecode[uPosition].baseValue = spread[s + u]; - } - position = (position + (unroll * step)) & tableMask; - } - assert(position == 0); - } - } else { - U32 const tableMask = tableSize-1; - U32 const step = FSE_TABLESTEP(tableSize); - U32 s, position = 0; - for (s=0; s<maxSV1; s++) { - int i; - int const n = normalizedCounter[s]; - for (i=0; i<n; 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]; - } - } -} - -/* Avoids the FORCE_INLINE of the _body() function. */ -static void ZSTD_buildFSETable_body_default(ZSTD_seqSymbol* dt, - const short* normalizedCounter, unsigned maxSymbolValue, - const U32* baseValue, const U32* nbAdditionalBits, - unsigned tableLog, void* wksp, size_t wkspSize) -{ - ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue, - baseValue, nbAdditionalBits, tableLog, wksp, wkspSize); -} - -#if DYNAMIC_BMI2 -TARGET_ATTRIBUTE("bmi2") static void ZSTD_buildFSETable_body_bmi2(ZSTD_seqSymbol* dt, - const short* normalizedCounter, unsigned maxSymbolValue, - const U32* baseValue, const U32* nbAdditionalBits, - unsigned tableLog, void* wksp, size_t wkspSize) -{ - ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue, - baseValue, nbAdditionalBits, tableLog, wksp, wkspSize); -} -#endif - -void ZSTD_buildFSETable(ZSTD_seqSymbol* dt, - const short* normalizedCounter, unsigned maxSymbolValue, - const U32* baseValue, const U32* nbAdditionalBits, - unsigned tableLog, void* wksp, size_t wkspSize, int bmi2) -{ -#if DYNAMIC_BMI2 - if (bmi2) { - ZSTD_buildFSETable_body_bmi2(dt, normalizedCounter, maxSymbolValue, - baseValue, nbAdditionalBits, tableLog, wksp, wkspSize); - return; - } -#endif - (void)bmi2; - ZSTD_buildFSETable_body_default(dt, normalizedCounter, maxSymbolValue, - baseValue, nbAdditionalBits, tableLog, wksp, wkspSize); -} - - -/*! 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, U32* wksp, size_t wkspSize, - int bmi2) -{ - 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, wksp, wkspSize, bmi2); - *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*)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+1 > iend, srcSize_wrong, ""); /* minimum possible size: 1 byte for symbol encoding types */ - { 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, - dctx->workspace, sizeof(dctx->workspace), - dctx->bmi2); - RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected, "ZSTD_buildSeqTable failed"); - 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, - dctx->workspace, sizeof(dctx->workspace), - dctx->bmi2); - RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected, "ZSTD_buildSeqTable failed"); - 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, - dctx->workspace, sizeof(dctx->workspace), - dctx->bmi2); - RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected, "ZSTD_buildSeqTable failed"); - 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_overlapCopy8() : - * Copies 8 bytes from ip to op and updates op and ip where ip <= op. - * If the offset is < 8 then the offset is spread to at least 8 bytes. - * - * Precondition: *ip <= *op - * Postcondition: *op - *op >= 8 - */ -HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) { - assert(*ip <= *op); - if (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[offset]; - (*op)[0] = (*ip)[0]; - (*op)[1] = (*ip)[1]; - (*op)[2] = (*ip)[2]; - (*op)[3] = (*ip)[3]; - *ip += dec32table[offset]; - ZSTD_copy4(*op+4, *ip); - *ip -= sub2; - } else { - ZSTD_copy8(*op, *ip); - } - *ip += 8; - *op += 8; - assert(*op - *ip >= 8); -} - -/*! ZSTD_safecopy() : - * Specialized version of memcpy() that is allowed to READ up to WILDCOPY_OVERLENGTH past the input buffer - * and write up to 16 bytes past oend_w (op >= oend_w is allowed). - * This function is only called in the uncommon case where the sequence is near the end of the block. It - * should be fast for a single long sequence, but can be slow for several short sequences. - * - * @param ovtype controls the overlap detection - * - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart. - * - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart. - * The src buffer must be before the dst buffer. - */ -static void ZSTD_safecopy(BYTE* op, BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) { - ptrdiff_t const diff = op - ip; - BYTE* const oend = op + length; - - assert((ovtype == ZSTD_no_overlap && (diff <= -8 || diff >= 8 || op >= oend_w)) || - (ovtype == ZSTD_overlap_src_before_dst && diff >= 0)); - - if (length < 8) { - /* Handle short lengths. */ - while (op < oend) *op++ = *ip++; - return; - } - if (ovtype == ZSTD_overlap_src_before_dst) { - /* Copy 8 bytes and ensure the offset >= 8 when there can be overlap. */ - assert(length >= 8); - ZSTD_overlapCopy8(&op, &ip, diff); - assert(op - ip >= 8); - assert(op <= oend); - } - - if (oend <= oend_w) { - /* No risk of overwrite. */ - ZSTD_wildcopy(op, ip, length, ovtype); - return; - } - if (op <= oend_w) { - /* Wildcopy until we get close to the end. */ - assert(oend > oend_w); - ZSTD_wildcopy(op, ip, oend_w - op, ovtype); - ip += oend_w - op; - op = oend_w; - } - /* Handle the leftovers. */ - while (op < oend) *op++ = *ip++; -} - -/* ZSTD_execSequenceEnd(): - * This version handles cases that are near the end of the output buffer. It requires - * more careful checks to make sure there is no overflow. By separating out these hard - * and unlikely cases, we can speed up the common cases. - * - * NOTE: This function needs to be fast for a single long sequence, but doesn't need - * to be optimized for many small sequences, since those fall into ZSTD_execSequence(). - */ -FORCE_NOINLINE -size_t ZSTD_execSequenceEnd(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; - const BYTE* const iLitEnd = *litPtr + sequence.litLength; - const BYTE* match = oLitEnd - sequence.offset; - BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; - - /* bounds checks : careful of address space overflow in 32-bit mode */ - RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer"); - RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer"); - assert(op < op + sequenceLength); - assert(oLitEnd < op + sequenceLength); - - /* copy literals */ - ZSTD_safecopy(op, oend_w, *litPtr, sequence.litLength, ZSTD_no_overlap); - op = oLitEnd; - *litPtr = iLitEnd; - - /* copy Match */ - if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { - /* offset beyond prefix */ - RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, ""); - match = dictEnd - (prefixStart-match); - if (match + sequence.matchLength <= dictEnd) { - ZSTD_memmove(oLitEnd, match, sequence.matchLength); - return sequenceLength; - } - /* span extDict & currentPrefixSegment */ - { size_t const length1 = dictEnd - match; - ZSTD_memmove(oLitEnd, match, length1); - op = oLitEnd + length1; - sequence.matchLength -= length1; - match = prefixStart; - } } - ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst); - 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; /* risk : address space underflow on oend=NULL */ - const BYTE* const iLitEnd = *litPtr + sequence.litLength; - const BYTE* match = oLitEnd - sequence.offset; - - assert(op != NULL /* Precondition */); - assert(oend_w < oend /* No underflow */); - /* Handle edge cases in a slow path: - * - Read beyond end of literals - * - Match end is within WILDCOPY_OVERLIMIT of oend - * - 32-bit mode and the match length overflows - */ - if (UNLIKELY( - iLitEnd > litLimit || - oMatchEnd > oend_w || - (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH))) - return ZSTD_execSequenceEnd(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd); - - /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */ - assert(op <= oLitEnd /* No overflow */); - assert(oLitEnd < oMatchEnd /* Non-zero match & no overflow */); - assert(oMatchEnd <= oend /* No underflow */); - assert(iLitEnd <= litLimit /* Literal length is in bounds */); - assert(oLitEnd <= oend_w /* Can wildcopy literals */); - assert(oMatchEnd <= oend_w /* Can wildcopy matches */); - - /* Copy Literals: - * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9. - * We likely don't need the full 32-byte wildcopy. - */ - assert(WILDCOPY_OVERLENGTH >= 16); - ZSTD_copy16(op, (*litPtr)); - if (UNLIKELY(sequence.litLength > 16)) { - ZSTD_wildcopy(op+16, (*litPtr)+16, sequence.litLength-16, ZSTD_no_overlap); - } - 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(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, ""); - match = dictEnd + (match - prefixStart); - if (match + sequence.matchLength <= dictEnd) { - ZSTD_memmove(oLitEnd, match, sequence.matchLength); - return sequenceLength; - } - /* span extDict & currentPrefixSegment */ - { size_t const length1 = dictEnd - match; - ZSTD_memmove(oLitEnd, match, length1); - op = oLitEnd + length1; - sequence.matchLength -= length1; - match = prefixStart; - } } - /* Match within prefix of 1 or more bytes */ - assert(op <= oMatchEnd); - assert(oMatchEnd <= oend_w); - assert(match >= prefixStart); - assert(sequence.matchLength >= 1); - - /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy - * without overlap checking. - */ - if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) { - /* We bet on a full wildcopy for matches, since we expect matches to be - * longer than literals (in general). In silesia, ~10% of matches are longer - * than 16 bytes. - */ - ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap); - return sequenceLength; - } - assert(sequence.offset < WILDCOPY_VECLEN); - - /* Copy 8 bytes and spread the offset to be >= 8. */ - ZSTD_overlapCopy8(&op, &match, sequence.offset); - - /* If the match length is > 8 bytes, then continue with the wildcopy. */ - if (sequence.matchLength > 8) { - assert(op < oMatchEnd); - ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst); - } - 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; -} - -FORCE_INLINE_TEMPLATE void -ZSTD_updateFseStateWithDInfo(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, ZSTD_seqSymbol const DInfo) -{ - 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; -typedef enum { ZSTD_p_noPrefetch=0, ZSTD_p_prefetch=1 } ZSTD_prefetch_e; - -FORCE_INLINE_TEMPLATE seq_t -ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const ZSTD_prefetch_e prefetch) -{ - seq_t seq; - ZSTD_seqSymbol const llDInfo = seqState->stateLL.table[seqState->stateLL.state]; - ZSTD_seqSymbol const mlDInfo = seqState->stateML.table[seqState->stateML.state]; - ZSTD_seqSymbol const ofDInfo = seqState->stateOffb.table[seqState->stateOffb.state]; - U32 const llBase = llDInfo.baseValue; - U32 const mlBase = mlDInfo.baseValue; - U32 const ofBase = ofDInfo.baseValue; - BYTE const llBits = llDInfo.nbAdditionalBits; - BYTE const mlBits = mlDInfo.nbAdditionalBits; - BYTE const ofBits = ofDInfo.nbAdditionalBits; - BYTE const totalBits = llBits+mlBits+ofBits; - - /* sequence */ - { size_t offset; - if (ofBits > 1) { - 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); - } - seqState->prevOffset[2] = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset; - } else { - U32 const ll0 = (llBase == 0); - if (LIKELY((ofBits == 0))) { - if (LIKELY(!ll0)) - offset = seqState->prevOffset[0]; - else { - offset = seqState->prevOffset[1]; - seqState->prevOffset[1] = seqState->prevOffset[0]; - seqState->prevOffset[0] = offset; - } - } else { - offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1); - { 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; - } } } - seq.offset = offset; - } - - seq.matchLength = mlBase; - if (mlBits > 0) - seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/); - - if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) - BIT_reloadDStream(&seqState->DStream); - if (MEM_64bits() && UNLIKELY(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; - if (llBits > 0) - seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits/*>0*/); - - 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); - - if (prefetch == ZSTD_p_prefetch) { - size_t const pos = seqState->pos + seq.litLength; - const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart; - seq.match = matchBase + pos - seq.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted. - * No consequence though : no memory access will occur, offset is only used for prefetching */ - seqState->pos = pos + seq.matchLength; - } - - /* ANS state update - * gcc-9.0.0 does 2.5% worse with ZSTD_updateFseStateWithDInfo(). - * clang-9.2.0 does 7% worse with ZSTD_updateFseState(). - * Naturally it seems like ZSTD_updateFseStateWithDInfo() should be the - * better option, so it is the default for other compilers. But, if you - * measure that it is worse, please put up a pull request. - */ - { -#if !defined(__clang__) - const int kUseUpdateFseState = 1; -#else - const int kUseUpdateFseState = 0; -#endif - if (kUseUpdateFseState) { - 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 */ - } else { - ZSTD_updateFseStateWithDInfo(&seqState->stateLL, &seqState->DStream, llDInfo); /* <= 9 bits */ - ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlDInfo); /* <= 9 bits */ - if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ - ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofDInfo); /* <= 8 bits */ - } - } - - return seq; -} - -#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -MEM_STATIC int ZSTD_dictionaryIsActive(ZSTD_DCtx const* dctx, BYTE const* prefixStart, BYTE const* oLitEnd) -{ - size_t const windowSize = dctx->fParams.windowSize; - /* No dictionary used. */ - if (dctx->dictContentEndForFuzzing == NULL) return 0; - /* Dictionary is our prefix. */ - if (prefixStart == dctx->dictContentBeginForFuzzing) return 1; - /* Dictionary is not our ext-dict. */ - if (dctx->dictEnd != dctx->dictContentEndForFuzzing) return 0; - /* Dictionary is not within our window size. */ - if ((size_t)(oLitEnd - prefixStart) >= windowSize) return 0; - /* Dictionary is active. */ - return 1; -} - -MEM_STATIC void ZSTD_assertValidSequence( - ZSTD_DCtx const* dctx, - BYTE const* op, BYTE const* oend, - seq_t const seq, - BYTE const* prefixStart, BYTE const* virtualStart) -{ -#if DEBUGLEVEL >= 1 - size_t const windowSize = dctx->fParams.windowSize; - size_t const sequenceSize = seq.litLength + seq.matchLength; - BYTE const* const oLitEnd = op + seq.litLength; - DEBUGLOG(6, "Checking sequence: litL=%u matchL=%u offset=%u", - (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset); - assert(op <= oend); - assert((size_t)(oend - op) >= sequenceSize); - assert(sequenceSize <= ZSTD_BLOCKSIZE_MAX); - if (ZSTD_dictionaryIsActive(dctx, prefixStart, oLitEnd)) { - size_t const dictSize = (size_t)((char const*)dctx->dictContentEndForFuzzing - (char const*)dctx->dictContentBeginForFuzzing); - /* Offset must be within the dictionary. */ - assert(seq.offset <= (size_t)(oLitEnd - virtualStart)); - assert(seq.offset <= windowSize + dictSize); - } else { - /* Offset must be within our window. */ - assert(seq.offset <= windowSize); - } -#else - (void)dctx, (void)op, (void)oend, (void)seq, (void)prefixStart, (void)virtualStart; -#endif -} -#endif - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG -FORCE_INLINE_TEMPLATE size_t -DONT_VECTORIZE -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 int frame) -{ - const BYTE* ip = (const BYTE*)seqStart; - const BYTE* const iend = ip + seqSize; - BYTE* const ostart = (BYTE*)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"); - (void)frame; - - /* Regen sequences */ - if (nbSeq) { - seqState_t seqState; - size_t error = 0; - dctx->fseEntropy = 1; - { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } - RETURN_ERROR_IF( - 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); - assert(dst != NULL); - - ZSTD_STATIC_ASSERT( - BIT_DStream_unfinished < BIT_DStream_completed && - BIT_DStream_endOfBuffer < BIT_DStream_completed && - BIT_DStream_completed < BIT_DStream_overflow); - -#if defined(__x86_64__) - /* Align the decompression loop to 32 + 16 bytes. - * - * zstd compiled with gcc-9 on an Intel i9-9900k shows 10% decompression - * speed swings based on the alignment of the decompression loop. This - * performance swing is caused by parts of the decompression loop falling - * out of the DSB. The entire decompression loop should fit in the DSB, - * when it can't we get much worse performance. You can measure if you've - * hit the good case or the bad case with this perf command for some - * compressed file test.zst: - * - * perf stat -e cycles -e instructions -e idq.all_dsb_cycles_any_uops \ - * -e idq.all_mite_cycles_any_uops -- ./zstd -tq test.zst - * - * If you see most cycles served out of the MITE you've hit the bad case. - * If you see most cycles served out of the DSB you've hit the good case. - * If it is pretty even then you may be in an okay case. - * - * I've been able to reproduce this issue on the following CPUs: - * - Kabylake: Macbook Pro (15-inch, 2019) 2.4 GHz Intel Core i9 - * Use Instruments->Counters to get DSB/MITE cycles. - * I never got performance swings, but I was able to - * go from the good case of mostly DSB to half of the - * cycles served from MITE. - * - Coffeelake: Intel i9-9900k - * - * I haven't been able to reproduce the instability or DSB misses on any - * of the following CPUS: - * - Haswell - * - Broadwell: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GH - * - Skylake - * - * If you are seeing performance stability this script can help test. - * It tests on 4 commits in zstd where I saw performance change. - * - * https://gist.github.com/terrelln/9889fc06a423fd5ca6e99351564473f4 - */ - __asm__(".p2align 5"); - __asm__("nop"); - __asm__(".p2align 4"); -#endif - for ( ; ; ) { - seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, ZSTD_p_noPrefetch); - size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd); -#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) - assert(!ZSTD_isError(oneSeqSize)); - if (frame) ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase); -#endif - DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); - BIT_reloadDStream(&(seqState.DStream)); - op += oneSeqSize; - /* gcc and clang both don't like early returns in this loop. - * Instead break and check for an error at the end of the loop. - */ - if (UNLIKELY(ZSTD_isError(oneSeqSize))) { - error = oneSeqSize; - break; - } - if (UNLIKELY(!--nbSeq)) break; - } - - /* check if reached exact end */ - DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq); - if (ZSTD_isError(error)) return error; - RETURN_ERROR_IF(nbSeq, corruption_detected, ""); - RETURN_ERROR_IF(BIT_reloadDStream(&seqState.DStream) < BIT_DStream_completed, corruption_detected, ""); - /* save reps for next block */ - { 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, ""); - if (op != NULL) { - ZSTD_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, - const int frame) -{ - return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT -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 int frame) -{ - const BYTE* ip = (const BYTE*)seqStart; - const BYTE* const iend = ip + seqSize; - BYTE* const ostart = (BYTE*)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); - (void)frame; - - /* 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(dst != NULL); - 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_decodeSequence(&seqState, isLongOffset, ZSTD_p_prefetch); - PREFETCH_L1(sequences[seqNb].match); PREFETCH_L1(sequences[seqNb].match + sequences[seqNb].matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ - } - RETURN_ERROR_IF(seqNb<seqAdvance, corruption_detected, ""); - - /* decode and decompress */ - for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb<nbSeq) ; seqNb++) { - seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, ZSTD_p_prefetch); - size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); -#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) - assert(!ZSTD_isError(oneSeqSize)); - if (frame) ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart); -#endif - if (ZSTD_isError(oneSeqSize)) return oneSeqSize; - PREFETCH_L1(sequence.match); PREFETCH_L1(sequence.match + sequence.matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ - 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_execSequence(op, oend, sequences[seqNb&STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); -#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE) - assert(!ZSTD_isError(oneSeqSize)); - if (frame) ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart); -#endif - 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, ""); - if (op != NULL) { - ZSTD_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, - const int frame) -{ - return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ - - - -#if DYNAMIC_BMI2 - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG -static TARGET_ATTRIBUTE("bmi2") size_t -DONT_VECTORIZE -ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx, - void* dst, size_t maxDstSize, - const void* seqStart, size_t seqSize, int nbSeq, - const ZSTD_longOffset_e isLongOffset, - const int frame) -{ - return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#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, - const int frame) -{ - return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#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, - const int frame); - -#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, - const int frame) -{ - DEBUGLOG(5, "ZSTD_decompressSequences"); -#if DYNAMIC_BMI2 - if (dctx->bmi2) { - return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); - } -#endif - return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#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, - const int frame) -{ - DEBUGLOG(5, "ZSTD_decompressSequencesLong"); -#if DYNAMIC_BMI2 - if (dctx->bmi2) { - return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); - } -#endif - return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset, frame); -} -#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; - - RETURN_ERROR_IF(dst == NULL && nbSeq > 0, dstSize_tooSmall, "NULL not handled"); - -#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, frame); -#endif - -#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG - /* else */ - return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset, frame); -#endif - } -} - - -void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize) -{ - if (dst != dctx->previousDstEnd && dstSize > 0) { /* not contiguous */ - dctx->dictEnd = dctx->previousDstEnd; - dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart)); - dctx->prefixStart = dst; - dctx->previousDstEnd = dst; - } -} - - -size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, - void* dst, size_t dstCapacity, - const void* src, size_t srcSize) -{ - size_t dSize; - ZSTD_checkContinuity(dctx, dst, dstCapacity); - dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0); - dctx->previousDstEnd = (char*)dst + dSize; - return dSize; -} |