diff --git a/build/VS2008/fullbench/fullbench.vcproj b/build/VS2008/fullbench/fullbench.vcproj index 6a6494d1e..55f784977 100644 --- a/build/VS2008/fullbench/fullbench.vcproj +++ b/build/VS2008/fullbench/fullbench.vcproj @@ -380,6 +380,10 @@ RelativePath="..\..\..\lib\decompress\zstd_decompress.c" > + + diff --git a/build/VS2008/fuzzer/fuzzer.vcproj b/build/VS2008/fuzzer/fuzzer.vcproj index dcc750529..25924c8b7 100644 --- a/build/VS2008/fuzzer/fuzzer.vcproj +++ b/build/VS2008/fuzzer/fuzzer.vcproj @@ -412,6 +412,10 @@ RelativePath="..\..\..\lib\decompress\zstd_decompress.c" > + + diff --git a/build/VS2008/zstd/zstd.vcproj b/build/VS2008/zstd/zstd.vcproj index 352682e83..7584636f3 100644 --- a/build/VS2008/zstd/zstd.vcproj +++ b/build/VS2008/zstd/zstd.vcproj @@ -420,6 +420,10 @@ RelativePath="..\..\..\lib\decompress\zstd_decompress.c" > + + diff --git a/build/VS2008/zstdlib/zstdlib.vcproj b/build/VS2008/zstdlib/zstdlib.vcproj index 9737d5157..4dc91516e 100644 --- a/build/VS2008/zstdlib/zstdlib.vcproj +++ b/build/VS2008/zstdlib/zstdlib.vcproj @@ -420,6 +420,10 @@ RelativePath="..\..\..\lib\decompress\zstd_decompress.c" > + + diff --git a/build/VS2010/fuzzer/fuzzer.vcxproj b/build/VS2010/fuzzer/fuzzer.vcxproj index a0aba109b..106dcf99c 100644 --- a/build/VS2010/fuzzer/fuzzer.vcxproj +++ b/build/VS2010/fuzzer/fuzzer.vcxproj @@ -175,6 +175,7 @@ + diff --git a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj index 6bb42c37d..2c4f126e9 100644 --- a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj +++ b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj @@ -39,6 +39,7 @@ + diff --git a/build/VS2010/libzstd/libzstd.vcxproj b/build/VS2010/libzstd/libzstd.vcxproj index a394a4593..27a4889f6 100644 --- a/build/VS2010/libzstd/libzstd.vcxproj +++ b/build/VS2010/libzstd/libzstd.vcxproj @@ -39,6 +39,7 @@ + diff --git a/build/VS2010/zstd/zstd.vcxproj b/build/VS2010/zstd/zstd.vcxproj index 6de9aaa2a..554ae7958 100644 --- a/build/VS2010/zstd/zstd.vcxproj +++ b/build/VS2010/zstd/zstd.vcxproj @@ -39,6 +39,7 @@ + diff --git a/build/cmake/lib/CMakeLists.txt b/build/cmake/lib/CMakeLists.txt index bc5ac432e..ef3389e24 100644 --- a/build/cmake/lib/CMakeLists.txt +++ b/build/cmake/lib/CMakeLists.txt @@ -46,6 +46,7 @@ SET(Sources ${LIBRARY_DIR}/compress/zstd_ldm.c ${LIBRARY_DIR}/decompress/huf_decompress.c ${LIBRARY_DIR}/decompress/zstd_decompress.c + ${LIBRARY_DIR}/decompress/zstd_decompress_block.c ${LIBRARY_DIR}/decompress/zstd_ddict.c ${LIBRARY_DIR}/dictBuilder/cover.c ${LIBRARY_DIR}/dictBuilder/fastcover.c @@ -75,8 +76,9 @@ SET(Headers ${LIBRARY_DIR}/compress/zstd_opt.h ${LIBRARY_DIR}/compress/zstd_ldm.h ${LIBRARY_DIR}/compress/zstdmt_compress.h - ${LIBRARY_DIR}/decompress/zstd_ddict.h ${LIBRARY_DIR}/decompress/zstd_decompress_internal.h + ${LIBRARY_DIR}/decompress/zstd_decompress_block.h + ${LIBRARY_DIR}/decompress/zstd_ddict.h ${LIBRARY_DIR}/dictBuilder/zdict.h ${LIBRARY_DIR}/dictBuilder/cover.h ${LIBRARY_DIR}/deprecated/zbuff.h) diff --git a/build/cmake/programs/CMakeLists.txt b/build/cmake/programs/CMakeLists.txt index ef60a2dda..e0a32047f 100644 --- a/build/cmake/programs/CMakeLists.txt +++ b/build/cmake/programs/CMakeLists.txt @@ -36,7 +36,6 @@ INSTALL(TARGETS zstd RUNTIME DESTINATION "bin") IF (UNIX) ADD_CUSTOM_TARGET(zstdcat ALL ${CMAKE_COMMAND} -E create_symlink zstd zstdcat DEPENDS zstd COMMENT "Creating zstdcat symlink") ADD_CUSTOM_TARGET(unzstd ALL ${CMAKE_COMMAND} -E create_symlink zstd unzstd DEPENDS zstd COMMENT "Creating unzstd symlink") - INSTALL(TARGETS zstd RUNTIME DESTINATION "bin") INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/zstdcat DESTINATION "bin") INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/unzstd DESTINATION "bin") diff --git a/lib/common/zstd_internal.h b/lib/common/zstd_internal.h index 202caacfb..e6286548d 100644 --- a/lib/common/zstd_internal.h +++ b/lib/common/zstd_internal.h @@ -245,7 +245,7 @@ typedef struct { blockType_e blockType; U32 lastBlock; U32 origSize; -} blockProperties_t; +} blockProperties_t; /* declared here for decompress and fullbench */ /*! ZSTD_getcBlockSize() : * Provides the size of compressed block from block header `src` */ @@ -253,6 +253,13 @@ typedef struct { size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr); +/*! ZSTD_decodeSeqHeaders() : + * decode sequence header from src */ +/* Used by: decompress, fullbench (does not get its definition from here) */ +size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, + const void* src, size_t srcSize); + + #if defined (__cplusplus) } #endif diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c index 54b9bf70d..d981e863a 100644 --- a/lib/decompress/zstd_decompress.c +++ b/lib/decompress/zstd_decompress.c @@ -63,29 +63,19 @@ #include "fse.h" #define HUF_STATIC_LINKING_ONLY #include "huf.h" -#include "zstd_internal.h" +#include "zstd_internal.h" /* blockProperties_t */ #include "zstd_decompress_internal.h" /* ZSTD_DCtx */ #include "zstd_ddict.h" /* ZSTD_DDictDictContent */ +#include "zstd_decompress_block.h" /* ZSTD_decompressBlock_internal */ #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) # include "zstd_legacy.h" #endif -/*_******************************************************* -* Memory operations -**********************************************************/ -static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); } - - /*-************************************************************* * Context management ***************************************************************/ -typedef struct { - U32 fastMode; - U32 tableLog; -} ZSTD_seqSymbol_header; - size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) { if (dctx==NULL) return 0; /* support sizeof NULL */ @@ -434,1279 +424,6 @@ static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t he } -/*-************************************************************* - * 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) -{ - if (srcSize < ZSTD_blockHeaderSize) return ERROR(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; - if (bpPtr->blockType == bt_reserved) return ERROR(corruption_detected); - return cSize; - } -} - - -static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, - const void* src, size_t srcSize) -{ - if (dst==NULL) return ERROR(dstSize_tooSmall); - if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall); - memcpy(dst, src, srcSize); - return srcSize; -} - - -static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity, - const void* src, size_t srcSize, - size_t regenSize) -{ - if (srcSize != 1) return ERROR(srcSize_wrong); - if (regenSize > dstCapacity) return ERROR(dstSize_tooSmall); - memset(dst, *(const BYTE*)src, regenSize); - return regenSize; -} - -/* 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 */ -{ - if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected); - - { const BYTE* const istart = (const BYTE*) src; - symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3); - - switch(litEncType) - { - case set_repeat: - if (dctx->litEntropy==0) return ERROR(dictionary_corrupted); - /* fall-through */ - - case set_compressed: - if (srcSize < 5) return ERROR(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); - 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; - } - if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected); - if (litCSize + lhSize > srcSize) return ERROR(corruption_detected); - - /* prefetch huffman table if cold */ - if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) { - PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable)); - } - - if (HUF_isError((litEncType==set_repeat) ? - ( singleStream ? - HUF_decompress1X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) : - HUF_decompress4X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) ) : - ( singleStream ? - HUF_decompress1X1_DCtx_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, - dctx->workspace, sizeof(dctx->workspace), dctx->bmi2) : - HUF_decompress4X_hufOnly_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, - dctx->workspace, sizeof(dctx->workspace), dctx->bmi2)))) - return ERROR(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 */ - if (litSize+lhSize > srcSize) return ERROR(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; - if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */ - break; - } - if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(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<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) */ -static 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= 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 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 max) return ERROR(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: - if (!flagRepeatTable) return ERROR(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 : - { U32 tableLog; - S16 norm[MaxSeq+1]; - size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize); - if (FSE_isError(headerSize)) return ERROR(corruption_detected); - if (tableLog > maxLog) return ERROR(corruption_detected); - ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog); - *DTablePtr = DTableSpace; - return headerSize; - } - default : /* impossible */ - assert(0); - return ERROR(GENERIC); - } -} - -static const U32 LL_base[MaxLL+1] = { - 0, 1, 2, 3, 4, 5, 6, 7, - 8, 9, 10, 11, 12, 13, 14, 15, - 16, 18, 20, 22, 24, 28, 32, 40, - 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, - 0x2000, 0x4000, 0x8000, 0x10000 }; - -static const U32 OF_base[MaxOff+1] = { - 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D, - 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD, - 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, - 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD }; - -static const U32 OF_bits[MaxOff+1] = { - 0, 1, 2, 3, 4, 5, 6, 7, - 8, 9, 10, 11, 12, 13, 14, 15, - 16, 17, 18, 19, 20, 21, 22, 23, - 24, 25, 26, 27, 28, 29, 30, 31 }; - -static const U32 ML_base[MaxML+1] = { - 3, 4, 5, 6, 7, 8, 9, 10, - 11, 12, 13, 14, 15, 16, 17, 18, - 19, 20, 21, 22, 23, 24, 25, 26, - 27, 28, 29, 30, 31, 32, 33, 34, - 35, 37, 39, 41, 43, 47, 51, 59, - 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, - 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 }; - -/* Function required by fullbench; Hidden declaration to respect -Wmissing-prototypes */ -size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, - const void* src, size_t srcSize); - -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 */ - if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong); - - /* SeqHead */ - nbSeq = *ip++; - if (!nbSeq) { - *nbSeqPtr=0; - if (srcSize != 1) return ERROR(srcSize_wrong); - return 1; - } - if (nbSeq > 0x7F) { - if (nbSeq == 0xFF) { - if (ip+2 > iend) return ERROR(srcSize_wrong); - nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; - } else { - if (ip >= iend) return ERROR(srcSize_wrong); - nbSeq = ((nbSeq-0x80)<<8) + *ip++; - } - } - *nbSeqPtr = nbSeq; - - /* FSE table descriptors */ - if (ip+4 > iend) return ERROR(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); - if (ZSTD_isError(llhSize)) return ERROR(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); - if (ZSTD_isError(ofhSize)) return ERROR(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); - if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected); - ip += mlhSize; - } - } - - /* prefetch dictionary content */ - if (dctx->ddictIsCold) { - size_t const dictSize = (const char*)dctx->prefixStart - (const char*)dctx->virtualStart; - size_t const psmin = MIN(dictSize, (size_t)(64*nbSeq) /* heuristic */ ); - size_t const pSize = MIN(psmin, 128 KB /* protection */ ); - const void* const pStart = (const char*)dctx->dictEnd - pSize; - PREFETCH_AREA(pStart, pSize); - dctx->ddictIsCold = 0; - } - - 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 */ - if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must fit within dstBuffer */ - if (iLitEnd > litLimit) return ERROR(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 */ - if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(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 */ - if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ - if (iLitEnd > litLimit) return ERROR(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 */ - if (sequence.offset > (size_t)(oLitEnd - virtualStart)) - return ERROR(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 */ - if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ - if (iLitEnd > litLimit) return ERROR(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 */ - if (sequence.offset > (size_t)(oLitEnd - dictStart)) return ERROR(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 offets. - */ -#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; - -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; ientropy.rep[i]; } - CHECK_E(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); - if (nbSeq) return ERROR(corruption_detected); - /* save reps for next block */ - { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); } - } - - /* last literal segment */ - { size_t const lastLLSize = litEnd - litPtr; - if (lastLLSize > (size_t)(oend-op)) return ERROR(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); -} - - - -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 STOSEQ_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; - { U32 i; for (i=0; ientropy.rep[i]; } - seqState.prefixStart = prefixStart; - seqState.pos = (size_t)(op-prefixStart); - seqState.dictEnd = dictEnd; - CHECK_E(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) && (seqNbentropy.rep[i] = (U32)(seqState.prevOffset[i]); } -#undef STORED_SEQS -#undef STOSEQ_MASK -#undef ADVANCED_SEQS - } - - /* last literal segment */ - { size_t const lastLLSize = litEnd - litPtr; - if (lastLLSize > (size_t)(oend-op)) return ERROR(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); -} - - - -#if DYNAMIC_BMI2 - -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); -} - -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 - -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); - -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); -} - -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); -} - -/* ZSTD_getLongOffsetsShare() : - * condition : offTable must be valid - * @return : "share" of long offsets (arbitrarily defined as > (1<<23)) - * compared to maximum possible of (1< 22) total += 1; - } - - assert(tableLog <= OffFSELog); - total <<= (OffFSELog - tableLog); /* scale to OffFSELog */ - - return total; -} - - -static 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); - - if (srcSize >= ZSTD_BLOCKSIZE_MAX) return ERROR(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 */ - { int nbSeq; - size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize); - if (ZSTD_isError(seqHSize)) return seqHSize; - ip += seqHSize; - srcSize -= seqHSize; - - if ( (!frame || dctx->fParams.windowSize > (1<<24)) - && (nbSeq>0) ) { /* 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% */ - if (shareLongOffsets >= minShare) - return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); - } - - return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); - } -} - - -static void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst) -{ - if (dst != dctx->previousDstEnd) { /* 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); - dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0); - dctx->previousDstEnd = (char*)dst + dSize; - return dSize; -} - - -/** ZSTD_insertBlock() : - insert `src` block into `dctx` history. Useful to track uncompressed blocks. */ -ZSTDLIB_API size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize) -{ - ZSTD_checkContinuity(dctx, blockStart); - dctx->previousDstEnd = (const char*)blockStart + blockSize; - return blockSize; -} - - -static size_t ZSTD_generateNxBytes(void* dst, size_t dstCapacity, BYTE value, size_t length) -{ - if (length > dstCapacity) return ERROR(dstSize_tooSmall); - memset(dst, value, length); - return length; -} - /** ZSTD_findFrameCompressedSize() : * compatible with legacy mode * `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame @@ -1760,6 +477,52 @@ size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize) } } + + +/*-************************************************************* + * Frame decoding + ***************************************************************/ + + +void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst) +{ + if (dst != dctx->previousDstEnd) { /* 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; + } +} + +/** ZSTD_insertBlock() : + insert `src` block into `dctx` history. Useful to track uncompressed blocks. */ +size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize) +{ + ZSTD_checkContinuity(dctx, blockStart); + dctx->previousDstEnd = (const char*)blockStart + blockSize; + return blockSize; +} + + +static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, + const void* src, size_t srcSize) +{ + if (dst==NULL) return ERROR(dstSize_tooSmall); + if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall); + memcpy(dst, src, srcSize); + return srcSize; +} + +static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity, + BYTE b, + size_t regenSize) +{ + if (regenSize > dstCapacity) return ERROR(dstSize_tooSmall); + memset(dst, b, regenSize); + return regenSize; +} + + /*! ZSTD_decompressFrame() : * @dctx must be properly initialized */ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, @@ -1805,7 +568,7 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize); break; case bt_rle : - decodedSize = ZSTD_generateNxBytes(op, oend-op, *ip, blockProperties.origSize); + decodedSize = ZSTD_setRleBlock(op, oend-op, *ip, blockProperties.origSize); break; case bt_reserved : default: @@ -2075,7 +838,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize); break; case bt_rle : - rSize = ZSTD_setRleBlock(dst, dstCapacity, src, srcSize, dctx->rleSize); + rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize); break; case bt_reserved : /* should never happen */ default: diff --git a/lib/decompress/zstd_decompress_block.c b/lib/decompress/zstd_decompress_block.c new file mode 100644 index 000000000..14249b0e3 --- /dev/null +++ b/lib/decompress/zstd_decompress_block.c @@ -0,0 +1,1231 @@ +/* + * 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 /* 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" + + + +/*_******************************************************* +* 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) +{ + if (srcSize < ZSTD_blockHeaderSize) return ERROR(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; + if (bpPtr->blockType == bt_reserved) return ERROR(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 */ +{ + if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected); + + { const BYTE* const istart = (const BYTE*) src; + symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3); + + switch(litEncType) + { + case set_repeat: + if (dctx->litEntropy==0) return ERROR(dictionary_corrupted); + /* fall-through */ + + case set_compressed: + if (srcSize < 5) return ERROR(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); + 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; + } + if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected); + if (litCSize + lhSize > srcSize) return ERROR(corruption_detected); + + /* prefetch huffman table if cold */ + if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) { + PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable)); + } + + if (HUF_isError((litEncType==set_repeat) ? + ( singleStream ? + HUF_decompress1X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) : + HUF_decompress4X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) ) : + ( singleStream ? + HUF_decompress1X1_DCtx_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->workspace, sizeof(dctx->workspace), dctx->bmi2) : + HUF_decompress4X_hufOnly_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->workspace, sizeof(dctx->workspace), dctx->bmi2)))) + return ERROR(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 */ + if (litSize+lhSize > srcSize) return ERROR(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; + if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */ + break; + } + if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(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<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) */ +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= 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 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 max) return ERROR(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: + if (!flagRepeatTable) return ERROR(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 : + { U32 tableLog; + S16 norm[MaxSeq+1]; + size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize); + if (FSE_isError(headerSize)) return ERROR(corruption_detected); + if (tableLog > maxLog) return ERROR(corruption_detected); + ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog); + *DTablePtr = DTableSpace; + return headerSize; + } + default : /* impossible */ + assert(0); + return ERROR(GENERIC); + } +} + +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 */ + if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong); + + /* SeqHead */ + nbSeq = *ip++; + if (!nbSeq) { + *nbSeqPtr=0; + if (srcSize != 1) return ERROR(srcSize_wrong); + return 1; + } + if (nbSeq > 0x7F) { + if (nbSeq == 0xFF) { + if (ip+2 > iend) return ERROR(srcSize_wrong); + nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; + } else { + if (ip >= iend) return ERROR(srcSize_wrong); + nbSeq = ((nbSeq-0x80)<<8) + *ip++; + } + } + *nbSeqPtr = nbSeq; + + /* FSE table descriptors */ + if (ip+4 > iend) return ERROR(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); + if (ZSTD_isError(llhSize)) return ERROR(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); + if (ZSTD_isError(ofhSize)) return ERROR(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); + if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected); + ip += mlhSize; + } + } + + /* prefetch dictionary content */ + if (dctx->ddictIsCold) { + size_t const dictSize = (const char*)dctx->prefixStart - (const char*)dctx->virtualStart; + size_t const psmin = MIN(dictSize, (size_t)(64*nbSeq) /* heuristic */ ); + size_t const pSize = MIN(psmin, 128 KB /* protection */ ); + const void* const pStart = (const char*)dctx->dictEnd - pSize; + PREFETCH_AREA(pStart, pSize); + dctx->ddictIsCold = 0; + } + + 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 */ + if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must fit within dstBuffer */ + if (iLitEnd > litLimit) return ERROR(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 */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(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 */ + if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ + if (iLitEnd > litLimit) return ERROR(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 */ + if (sequence.offset > (size_t)(oLitEnd - virtualStart)) + return ERROR(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 */ + if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ + if (iLitEnd > litLimit) return ERROR(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 */ + if (sequence.offset > (size_t)(oLitEnd - dictStart)) return ERROR(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 offets. + */ +#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; + +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; ientropy.rep[i]; } + CHECK_E(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); + if (nbSeq) return ERROR(corruption_detected); + /* save reps for next block */ + { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); } + } + + /* last literal segment */ + { size_t const lastLLSize = litEnd - litPtr; + if (lastLLSize > (size_t)(oend-op)) return ERROR(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); +} + + + +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 STOSEQ_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; + { U32 i; for (i=0; ientropy.rep[i]; } + seqState.prefixStart = prefixStart; + seqState.pos = (size_t)(op-prefixStart); + seqState.dictEnd = dictEnd; + CHECK_E(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) && (seqNbentropy.rep[i] = (U32)(seqState.prevOffset[i]); } +#undef STORED_SEQS +#undef STOSEQ_MASK +#undef ADVANCED_SEQS + } + + /* last literal segment */ + { size_t const lastLLSize = litEnd - litPtr; + if (lastLLSize > (size_t)(oend-op)) return ERROR(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); +} + + + +#if DYNAMIC_BMI2 + +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); +} + +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 + +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); + +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); +} + +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); +} + +/* ZSTD_getLongOffsetsShare() : + * condition : offTable must be valid + * @return : "share" of long offsets (arbitrarily defined as > (1<<23)) + * compared to maximum possible of (1< 22) total += 1; + } + + assert(tableLog <= OffFSELog); + total <<= (OffFSELog - tableLog); /* scale to OffFSELog */ + + return total; +} + + +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); + + if (srcSize >= ZSTD_BLOCKSIZE_MAX) return ERROR(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 */ + { int nbSeq; + size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize); + if (ZSTD_isError(seqHSize)) return seqHSize; + ip += seqHSize; + srcSize -= seqHSize; + + if ( (!frame || dctx->fParams.windowSize > (1<<24)) + && (nbSeq>0) ) { /* 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% */ + if (shareLongOffsets >= minShare) + return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); + } + + return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); + } +} + + +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; +} diff --git a/lib/decompress/zstd_decompress_block.h b/lib/decompress/zstd_decompress_block.h new file mode 100644 index 000000000..4b1cf2371 --- /dev/null +++ b/lib/decompress/zstd_decompress_block.h @@ -0,0 +1,55 @@ +/* + * 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. + */ + + +#ifndef ZSTD_DEC_BLOCK_H +#define ZSTD_DEC_BLOCK_H + +/*-******************************************************* + * Dependencies + *********************************************************/ +#include /* size_t */ +#include "zstd.h" /* DCtx, and some public functions */ +#include "zstd_internal.h" /* blockProperties_t, and some public functions */ + + +/* === Prototypes === */ + +/* note: prototypes already published within `zstd.h` : + * ZSTD_decompressBlock() + */ + +/* note: prototypes already published within `zstd_internal.h` : + * ZSTD_getcBlockSize() + * ZSTD_decodeSeqHeaders() + */ + + +/* ZSTD_decompressBlock_internal() : + * decompress block, starting at `src`, + * into destination buffer `dst`. + * @return : decompressed block size, + * or an error code (which can be tested using ZSTD_isError()) + */ +size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, const int frame); + +/* ZSTD_buildFSETable() : + * generate FSE decoding table for one symbol (ll, ml or off) + * this function cannot fail + */ +void ZSTD_buildFSETable(ZSTD_seqSymbol* dt, + const short* normalizedCounter, unsigned maxSymbolValue, + const U32* baseValue, const U32* nbAdditionalBits, + unsigned tableLog); + + +#endif /* ZSTD_DEC_BLOCK_H */ diff --git a/lib/decompress/zstd_decompress_internal.h b/lib/decompress/zstd_decompress_internal.h index 3de8e4e7d..abd003051 100644 --- a/lib/decompress/zstd_decompress_internal.h +++ b/lib/decompress/zstd_decompress_internal.h @@ -23,9 +23,47 @@ #include "zstd_internal.h" /* ZSTD_seqSymbol */ + +/*-******************************************************* + * Constants + *********************************************************/ +static const U32 LL_base[MaxLL+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 18, 20, 22, 24, 28, 32, 40, + 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, + 0x2000, 0x4000, 0x8000, 0x10000 }; + +static const U32 OF_base[MaxOff+1] = { + 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D, + 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD, + 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, + 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD }; + +static const U32 OF_bits[MaxOff+1] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, 26, 27, 28, 29, 30, 31 }; + +static const U32 ML_base[MaxML+1] = { + 3, 4, 5, 6, 7, 8, 9, 10, + 11, 12, 13, 14, 15, 16, 17, 18, + 19, 20, 21, 22, 23, 24, 25, 26, + 27, 28, 29, 30, 31, 32, 33, 34, + 35, 37, 39, 41, 43, 47, 51, 59, + 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, + 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 }; + + /*-******************************************************* * Decompression types *********************************************************/ + typedef struct { + U32 fastMode; + U32 tableLog; + } ZSTD_seqSymbol_header; + typedef struct { U16 nextState; BYTE nbAdditionalBits; @@ -113,11 +151,18 @@ struct ZSTD_DCtx_s * Shared internal functions *********************************************************/ - /*! ZSTD_loadDEntropy() : - * dict : must point at beginning of a valid zstd dictionary. - * @return : size of entropy tables read */ - size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy, - const void* const dict, size_t const dictSize); +/*! ZSTD_loadDEntropy() : + * dict : must point at beginning of a valid zstd dictionary. + * @return : size of entropy tables read */ +size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy, + const void* const dict, size_t const dictSize); + +/*! ZSTD_checkContinuity() : + * check if next `dst` follows previous position, where decompression ended. + * If yes, do nothing (continue on current segment). + * If not, classify previous segment as "external dictionary", and start a new segment. + * This function cannot fail. */ +void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst); #endif /* ZSTD_DECOMPRESS_INTERNAL_H */