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Diffstat (limited to '')
| -rw-r--r-- | src/zstd/lib/decompress/zstd_decompress.c | 2655 |
1 files changed, 2655 insertions, 0 deletions
diff --git a/src/zstd/lib/decompress/zstd_decompress.c b/src/zstd/lib/decompress/zstd_decompress.c new file mode 100644 index 00000000..96fc6090 --- /dev/null +++ b/src/zstd/lib/decompress/zstd_decompress.c @@ -0,0 +1,2655 @@ +/* + * 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. + */ + + +/* *************************************************************** +* Tuning parameters +*****************************************************************/ +/*! + * HEAPMODE : + * Select how default decompression function ZSTD_decompress() will allocate memory, + * in memory stack (0), or in memory heap (1, requires malloc()) + */ +#ifndef ZSTD_HEAPMODE +# define ZSTD_HEAPMODE 1 +#endif + +/*! +* LEGACY_SUPPORT : +* if set to 1, ZSTD_decompress() can decode older formats (v0.1+) +*/ +#ifndef ZSTD_LEGACY_SUPPORT +# define ZSTD_LEGACY_SUPPORT 0 +#endif + +/*! +* MAXWINDOWSIZE_DEFAULT : +* maximum window size accepted by DStream, by default. +* Frames requiring more memory will be rejected. +*/ +#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT +# define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_DEFAULTMAX) + 1) +#endif + + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include <string.h> /* memcpy, memmove, memset */ +#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" + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) +# include "zstd_legacy.h" +#endif + + +/*-************************************* +* Errors +***************************************/ +#define ZSTD_isError ERR_isError /* for inlining */ +#define FSE_isError ERR_isError +#define HUF_isError ERR_isError + + +/*_******************************************************* +* Memory operations +**********************************************************/ +static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); } + + +/*-************************************************************* +* Context management +***************************************************************/ +typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader, + ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock, + ZSTDds_decompressLastBlock, ZSTDds_checkChecksum, + ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage; + +typedef enum { zdss_init=0, zdss_loadHeader, + zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage; + +typedef struct { + FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)]; + FSE_DTable OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)]; + FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)]; + HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */ + U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32]; + U32 rep[ZSTD_REP_NUM]; +} ZSTD_entropyDTables_t; + +struct ZSTD_DCtx_s +{ + const FSE_DTable* LLTptr; + const FSE_DTable* MLTptr; + const FSE_DTable* OFTptr; + const HUF_DTable* HUFptr; + ZSTD_entropyDTables_t entropy; + const void* previousDstEnd; /* detect continuity */ + const void* base; /* start of current segment */ + const void* vBase; /* virtual start of previous segment if it was just before current one */ + const void* dictEnd; /* end of previous segment */ + size_t expected; + ZSTD_frameHeader fParams; + U64 decodedSize; + blockType_e bType; /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */ + ZSTD_dStage stage; + U32 litEntropy; + U32 fseEntropy; + XXH64_state_t xxhState; + size_t headerSize; + U32 dictID; + ZSTD_format_e format; + const BYTE* litPtr; + ZSTD_customMem customMem; + size_t litSize; + size_t rleSize; + size_t staticSize; + + /* streaming */ + ZSTD_DDict* ddictLocal; + const ZSTD_DDict* ddict; + ZSTD_dStreamStage streamStage; + char* inBuff; + size_t inBuffSize; + size_t inPos; + size_t maxWindowSize; + char* outBuff; + size_t outBuffSize; + size_t outStart; + size_t outEnd; + size_t lhSize; + void* legacyContext; + U32 previousLegacyVersion; + U32 legacyVersion; + U32 hostageByte; + + /* workspace */ + BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH]; + BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; +}; /* typedef'd to ZSTD_DCtx within "zstd.h" */ + +size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) +{ + if (dctx==NULL) return 0; /* support sizeof NULL */ + return sizeof(*dctx) + + ZSTD_sizeof_DDict(dctx->ddictLocal) + + dctx->inBuffSize + dctx->outBuffSize; +} + +size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); } + + +static size_t ZSTD_startingInputLength(ZSTD_format_e format) +{ + size_t const startingInputLength = (format==ZSTD_f_zstd1_magicless) ? + ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize : + ZSTD_frameHeaderSize_prefix; + ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE); + /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */ + assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) ); + return startingInputLength; +} + +static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx) +{ + dctx->format = ZSTD_f_zstd1; /* ZSTD_decompressBegin() invokes ZSTD_startingInputLength() with argument dctx->format */ + dctx->staticSize = 0; + dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT; + dctx->ddict = NULL; + dctx->ddictLocal = NULL; + dctx->inBuff = NULL; + dctx->inBuffSize = 0; + dctx->outBuffSize = 0; + dctx->streamStage = zdss_init; +} + +ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize) +{ + ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace; + + if ((size_t)workspace & 7) return NULL; /* 8-aligned */ + if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL; /* minimum size */ + + ZSTD_initDCtx_internal(dctx); + dctx->staticSize = workspaceSize; + dctx->inBuff = (char*)(dctx+1); + return dctx; +} + +ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) +{ + if (!customMem.customAlloc ^ !customMem.customFree) return NULL; + + { ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(*dctx), customMem); + if (!dctx) return NULL; + dctx->customMem = customMem; + dctx->legacyContext = NULL; + dctx->previousLegacyVersion = 0; + ZSTD_initDCtx_internal(dctx); + return dctx; + } +} + +ZSTD_DCtx* ZSTD_createDCtx(void) +{ + return ZSTD_createDCtx_advanced(ZSTD_defaultCMem); +} + +size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx) +{ + if (dctx==NULL) return 0; /* support free on NULL */ + if (dctx->staticSize) return ERROR(memory_allocation); /* not compatible with static DCtx */ + { ZSTD_customMem const cMem = dctx->customMem; + ZSTD_freeDDict(dctx->ddictLocal); + dctx->ddictLocal = NULL; + ZSTD_free(dctx->inBuff, cMem); + dctx->inBuff = NULL; +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (dctx->legacyContext) + ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion); +#endif + ZSTD_free(dctx, cMem); + return 0; + } +} + +/* no longer useful */ +void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx) +{ + size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx); + memcpy(dstDCtx, srcDCtx, toCopy); /* no need to copy workspace */ +} + + +/*-************************************************************* +* Decompression section +***************************************************************/ + +/*! ZSTD_isFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled. + * Note 3 : Skippable Frame Identifiers are considered valid. */ +unsigned ZSTD_isFrame(const void* buffer, size_t size) +{ + if (size < ZSTD_frameIdSize) return 0; + { U32 const magic = MEM_readLE32(buffer); + if (magic == ZSTD_MAGICNUMBER) return 1; + if ((magic & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) return 1; + } +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(buffer, size)) return 1; +#endif + return 0; +} + +/** ZSTD_frameHeaderSize_internal() : + * srcSize must be large enough to reach header size fields. + * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless + * @return : size of the Frame Header + * or an error code, which can be tested with ZSTD_isError() */ +static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format) +{ + size_t const minInputSize = ZSTD_startingInputLength(format); + if (srcSize < minInputSize) return ERROR(srcSize_wrong); + + { BYTE const fhd = ((const BYTE*)src)[minInputSize-1]; + U32 const dictID= fhd & 3; + U32 const singleSegment = (fhd >> 5) & 1; + U32 const fcsId = fhd >> 6; + return minInputSize + !singleSegment + + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId] + + (singleSegment && !fcsId); + } +} + +/** ZSTD_frameHeaderSize() : + * srcSize must be >= ZSTD_frameHeaderSize_prefix. + * @return : size of the Frame Header */ +size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize) +{ + return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1); +} + + +/** ZSTD_getFrameHeader_internal() : + * decode Frame Header, or require larger `srcSize`. + * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless + * @return : 0, `zfhPtr` is correctly filled, + * >0, `srcSize` is too small, value is wanted `srcSize` amount, + * or an error code, which can be tested using ZSTD_isError() */ +static size_t ZSTD_getFrameHeader_internal(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format) +{ + const BYTE* ip = (const BYTE*)src; + size_t const minInputSize = ZSTD_startingInputLength(format); + + if (srcSize < minInputSize) return minInputSize; + + if ( (format != ZSTD_f_zstd1_magicless) + && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) { + if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + /* skippable frame */ + if (srcSize < ZSTD_skippableHeaderSize) + return ZSTD_skippableHeaderSize; /* magic number + frame length */ + memset(zfhPtr, 0, sizeof(*zfhPtr)); + zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_frameIdSize); + zfhPtr->frameType = ZSTD_skippableFrame; + return 0; + } + return ERROR(prefix_unknown); + } + + /* ensure there is enough `srcSize` to fully read/decode frame header */ + { size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format); + if (srcSize < fhsize) return fhsize; + zfhPtr->headerSize = (U32)fhsize; + } + + { BYTE const fhdByte = ip[minInputSize-1]; + size_t pos = minInputSize; + U32 const dictIDSizeCode = fhdByte&3; + U32 const checksumFlag = (fhdByte>>2)&1; + U32 const singleSegment = (fhdByte>>5)&1; + U32 const fcsID = fhdByte>>6; + U64 windowSize = 0; + U32 dictID = 0; + U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN; + if ((fhdByte & 0x08) != 0) + return ERROR(frameParameter_unsupported); /* reserved bits, must be zero */ + + if (!singleSegment) { + BYTE const wlByte = ip[pos++]; + U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN; + if (windowLog > ZSTD_WINDOWLOG_MAX) + return ERROR(frameParameter_windowTooLarge); + windowSize = (1ULL << windowLog); + windowSize += (windowSize >> 3) * (wlByte&7); + } + switch(dictIDSizeCode) + { + default: assert(0); /* impossible */ + case 0 : break; + case 1 : dictID = ip[pos]; pos++; break; + case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break; + case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break; + } + switch(fcsID) + { + default: assert(0); /* impossible */ + case 0 : if (singleSegment) frameContentSize = ip[pos]; break; + case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break; + case 2 : frameContentSize = MEM_readLE32(ip+pos); break; + case 3 : frameContentSize = MEM_readLE64(ip+pos); break; + } + if (singleSegment) windowSize = frameContentSize; + + zfhPtr->frameType = ZSTD_frame; + zfhPtr->frameContentSize = frameContentSize; + zfhPtr->windowSize = windowSize; + zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX); + zfhPtr->dictID = dictID; + zfhPtr->checksumFlag = checksumFlag; + } + return 0; +} + +/** ZSTD_getFrameHeader() : + * decode Frame Header, or require larger `srcSize`. + * note : this function does not consume input, it only reads it. + * @return : 0, `zfhPtr` is correctly filled, + * >0, `srcSize` is too small, value is wanted `srcSize` amount, + * or an error code, which can be tested using ZSTD_isError() */ +size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize) +{ + return ZSTD_getFrameHeader_internal(zfhPtr, src, srcSize, ZSTD_f_zstd1); +} + + +/** ZSTD_getFrameContentSize() : + * compatible with legacy mode + * @return : decompressed size of the single frame pointed to be `src` if known, otherwise + * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined + * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */ +unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize) +{ +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(src, srcSize)) { + unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize); + return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret; + } +#endif + { ZSTD_frameHeader zfh; + if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0) + return ZSTD_CONTENTSIZE_ERROR; + if (zfh.frameType == ZSTD_skippableFrame) { + return 0; + } else { + return zfh.frameContentSize; + } } +} + +/** ZSTD_findDecompressedSize() : + * compatible with legacy mode + * `srcSize` must be the exact length of some number of ZSTD compressed and/or + * skippable frames + * @return : decompressed size of the frames contained */ +unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize) +{ + unsigned long long totalDstSize = 0; + + while (srcSize >= ZSTD_frameHeaderSize_prefix) { + U32 const magicNumber = MEM_readLE32(src); + + if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + size_t skippableSize; + if (srcSize < ZSTD_skippableHeaderSize) + return ERROR(srcSize_wrong); + skippableSize = MEM_readLE32((const BYTE *)src + ZSTD_frameIdSize) + + ZSTD_skippableHeaderSize; + if (srcSize < skippableSize) { + return ZSTD_CONTENTSIZE_ERROR; + } + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; + } + + { unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize); + if (ret >= ZSTD_CONTENTSIZE_ERROR) return ret; + + /* check for overflow */ + if (totalDstSize + ret < totalDstSize) return ZSTD_CONTENTSIZE_ERROR; + totalDstSize += ret; + } + { size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize); + if (ZSTD_isError(frameSrcSize)) { + return ZSTD_CONTENTSIZE_ERROR; + } + + src = (const BYTE *)src + frameSrcSize; + srcSize -= frameSrcSize; + } + } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */ + + if (srcSize) return ZSTD_CONTENTSIZE_ERROR; + + return totalDstSize; +} + +/** ZSTD_getDecompressedSize() : +* compatible with legacy mode +* @return : decompressed size if known, 0 otherwise + note : 0 can mean any of the following : + - frame content is empty + - decompressed size field is not present in frame header + - frame header unknown / not supported + - frame header not complete (`srcSize` too small) */ +unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize) +{ + unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize); + ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN); + return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret; +} + + +/** ZSTD_decodeFrameHeader() : +* `headerSize` must be the size provided by ZSTD_frameHeaderSize(). +* @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */ +static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize) +{ + size_t const result = ZSTD_getFrameHeader_internal(&(dctx->fParams), src, headerSize, dctx->format); + if (ZSTD_isError(result)) return result; /* invalid header */ + if (result>0) return ERROR(srcSize_wrong); /* headerSize too small */ + if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID)) + return ERROR(dictionary_wrong); + if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0); + return 0; +} + + +/*! 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 (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; +} + +/*! 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); + + if (HUF_isError((litEncType==set_repeat) ? + ( singleStream ? + HUF_decompress1X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) : + HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) ) : + ( singleStream ? + HUF_decompress1X2_DCtx_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->entropy.workspace, sizeof(dctx->entropy.workspace)) : + HUF_decompress4X_hufOnly_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize, + dctx->entropy.workspace, sizeof(dctx->entropy.workspace))))) + 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 */ + } + } +} + + +typedef union { + FSE_decode_t realData; + U32 alignedBy4; +} FSE_decode_t4; + +/* Default FSE distribution table for Literal Lengths */ +static const FSE_decode_t4 LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = { + { { LL_DEFAULTNORMLOG, 1, 1 } }, /* header : tableLog, fastMode, fastMode */ + /* base, symbol, bits */ + { { 0, 0, 4 } }, { { 16, 0, 4 } }, { { 32, 1, 5 } }, { { 0, 3, 5 } }, + { { 0, 4, 5 } }, { { 0, 6, 5 } }, { { 0, 7, 5 } }, { { 0, 9, 5 } }, + { { 0, 10, 5 } }, { { 0, 12, 5 } }, { { 0, 14, 6 } }, { { 0, 16, 5 } }, + { { 0, 18, 5 } }, { { 0, 19, 5 } }, { { 0, 21, 5 } }, { { 0, 22, 5 } }, + { { 0, 24, 5 } }, { { 32, 25, 5 } }, { { 0, 26, 5 } }, { { 0, 27, 6 } }, + { { 0, 29, 6 } }, { { 0, 31, 6 } }, { { 32, 0, 4 } }, { { 0, 1, 4 } }, + { { 0, 2, 5 } }, { { 32, 4, 5 } }, { { 0, 5, 5 } }, { { 32, 7, 5 } }, + { { 0, 8, 5 } }, { { 32, 10, 5 } }, { { 0, 11, 5 } }, { { 0, 13, 6 } }, + { { 32, 16, 5 } }, { { 0, 17, 5 } }, { { 32, 19, 5 } }, { { 0, 20, 5 } }, + { { 32, 22, 5 } }, { { 0, 23, 5 } }, { { 0, 25, 4 } }, { { 16, 25, 4 } }, + { { 32, 26, 5 } }, { { 0, 28, 6 } }, { { 0, 30, 6 } }, { { 48, 0, 4 } }, + { { 16, 1, 4 } }, { { 32, 2, 5 } }, { { 32, 3, 5 } }, { { 32, 5, 5 } }, + { { 32, 6, 5 } }, { { 32, 8, 5 } }, { { 32, 9, 5 } }, { { 32, 11, 5 } }, + { { 32, 12, 5 } }, { { 0, 15, 6 } }, { { 32, 17, 5 } }, { { 32, 18, 5 } }, + { { 32, 20, 5 } }, { { 32, 21, 5 } }, { { 32, 23, 5 } }, { { 32, 24, 5 } }, + { { 0, 35, 6 } }, { { 0, 34, 6 } }, { { 0, 33, 6 } }, { { 0, 32, 6 } }, +}; /* LL_defaultDTable */ + +/* Default FSE distribution table for Match Lengths */ +static const FSE_decode_t4 ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = { + { { ML_DEFAULTNORMLOG, 1, 1 } }, /* header : tableLog, fastMode, fastMode */ + /* base, symbol, bits */ + { { 0, 0, 6 } }, { { 0, 1, 4 } }, { { 32, 2, 5 } }, { { 0, 3, 5 } }, + { { 0, 5, 5 } }, { { 0, 6, 5 } }, { { 0, 8, 5 } }, { { 0, 10, 6 } }, + { { 0, 13, 6 } }, { { 0, 16, 6 } }, { { 0, 19, 6 } }, { { 0, 22, 6 } }, + { { 0, 25, 6 } }, { { 0, 28, 6 } }, { { 0, 31, 6 } }, { { 0, 33, 6 } }, + { { 0, 35, 6 } }, { { 0, 37, 6 } }, { { 0, 39, 6 } }, { { 0, 41, 6 } }, + { { 0, 43, 6 } }, { { 0, 45, 6 } }, { { 16, 1, 4 } }, { { 0, 2, 4 } }, + { { 32, 3, 5 } }, { { 0, 4, 5 } }, { { 32, 6, 5 } }, { { 0, 7, 5 } }, + { { 0, 9, 6 } }, { { 0, 12, 6 } }, { { 0, 15, 6 } }, { { 0, 18, 6 } }, + { { 0, 21, 6 } }, { { 0, 24, 6 } }, { { 0, 27, 6 } }, { { 0, 30, 6 } }, + { { 0, 32, 6 } }, { { 0, 34, 6 } }, { { 0, 36, 6 } }, { { 0, 38, 6 } }, + { { 0, 40, 6 } }, { { 0, 42, 6 } }, { { 0, 44, 6 } }, { { 32, 1, 4 } }, + { { 48, 1, 4 } }, { { 16, 2, 4 } }, { { 32, 4, 5 } }, { { 32, 5, 5 } }, + { { 32, 7, 5 } }, { { 32, 8, 5 } }, { { 0, 11, 6 } }, { { 0, 14, 6 } }, + { { 0, 17, 6 } }, { { 0, 20, 6 } }, { { 0, 23, 6 } }, { { 0, 26, 6 } }, + { { 0, 29, 6 } }, { { 0, 52, 6 } }, { { 0, 51, 6 } }, { { 0, 50, 6 } }, + { { 0, 49, 6 } }, { { 0, 48, 6 } }, { { 0, 47, 6 } }, { { 0, 46, 6 } }, +}; /* ML_defaultDTable */ + +/* Default FSE distribution table for Offset Codes */ +static const FSE_decode_t4 OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = { + { { OF_DEFAULTNORMLOG, 1, 1 } }, /* header : tableLog, fastMode, fastMode */ + /* base, symbol, bits */ + { { 0, 0, 5 } }, { { 0, 6, 4 } }, + { { 0, 9, 5 } }, { { 0, 15, 5 } }, + { { 0, 21, 5 } }, { { 0, 3, 5 } }, + { { 0, 7, 4 } }, { { 0, 12, 5 } }, + { { 0, 18, 5 } }, { { 0, 23, 5 } }, + { { 0, 5, 5 } }, { { 0, 8, 4 } }, + { { 0, 14, 5 } }, { { 0, 20, 5 } }, + { { 0, 2, 5 } }, { { 16, 7, 4 } }, + { { 0, 11, 5 } }, { { 0, 17, 5 } }, + { { 0, 22, 5 } }, { { 0, 4, 5 } }, + { { 16, 8, 4 } }, { { 0, 13, 5 } }, + { { 0, 19, 5 } }, { { 0, 1, 5 } }, + { { 16, 6, 4 } }, { { 0, 10, 5 } }, + { { 0, 16, 5 } }, { { 0, 28, 5 } }, + { { 0, 27, 5 } }, { { 0, 26, 5 } }, + { { 0, 25, 5 } }, { { 0, 24, 5 } }, +}; /* OF_defaultDTable */ + +/*! ZSTD_buildSeqTable() : + * @return : nb bytes read from src, + * or an error code if it fails, testable with ZSTD_isError() + */ +static size_t ZSTD_buildSeqTable(FSE_DTable* DTableSpace, const FSE_DTable** DTablePtr, + symbolEncodingType_e type, U32 max, U32 maxLog, + const void* src, size_t srcSize, + const FSE_decode_t4* defaultTable, U32 flagRepeatTable) +{ + const void* const tmpPtr = defaultTable; /* bypass strict aliasing */ + switch(type) + { + case set_rle : + if (!srcSize) return ERROR(srcSize_wrong); + if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected); + FSE_buildDTable_rle(DTableSpace, *(const BYTE*)src); + *DTablePtr = DTableSpace; + return 1; + case set_basic : + *DTablePtr = (const FSE_DTable*)tmpPtr; + return 0; + case set_repeat: + if (!flagRepeatTable) return ERROR(corruption_detected); + return 0; + default : /* impossible */ + 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); + FSE_buildDTable(DTableSpace, norm, max, tableLog); + *DTablePtr = DTableSpace; + return headerSize; + } } +} + +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; + DEBUGLOG(5, "ZSTD_decodeSeqHeaders"); + + /* check */ + if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong); + + /* SeqHead */ + { int nbSeq = *ip++; + if (!nbSeq) { *nbSeqPtr=0; 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_defaultDTable, dctx->fseEntropy); + 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_defaultDTable, dctx->fseEntropy); + 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_defaultDTable, dctx->fseEntropy); + if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected); + ip += mlhSize; + } + } + + return ip-istart; +} + + +typedef struct { + size_t litLength; + size_t matchLength; + size_t offset; + const BYTE* match; +} seq_t; + +typedef struct { + BIT_DStream_t DStream; + FSE_DState_t stateLL; + FSE_DState_t stateOffb; + FSE_DState_t stateML; + size_t prevOffset[ZSTD_REP_NUM]; + const BYTE* base; + size_t pos; + uPtrDiff gotoDict; +} seqState_t; + + +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) */ + 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 ERROR(GENERIC); /* Precondition */ + + /* copy literals */ + if (op < oend_w) { + ZSTD_wildcopy(op, *litPtr, oend_w - op); + *litPtr += oend_w - op; + op = oend_w; + } + 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; +} + + +typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e; + +/* 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) + +static seq_t ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets) +{ + seq_t seq; + + U32 const llCode = FSE_peekSymbol(&seqState->stateLL); + U32 const mlCode = FSE_peekSymbol(&seqState->stateML); + U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= MaxOff, by table construction */ + + U32 const llBits = LL_bits[llCode]; + U32 const mlBits = ML_bits[mlCode]; + U32 const ofBits = ofCode; + U32 const totalBits = llBits+mlBits+ofBits; + + 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 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 }; + + 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 }; + + /* sequence */ + { size_t offset; + if (!ofCode) + 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 = OF_base[ofCode] + (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 = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); + } + } + + if (ofCode <= 1) { + offset += (llCode==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 = ML_base[mlCode] + + ((mlCode>31) ? 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 = LL_base[llCode] + + ((llCode>15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 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 */ + FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ + FSE_updateState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ + FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ + + return seq; +} + + +HINT_INLINE +size_t ZSTD_execSequence(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) */ + 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, base, vBase, 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 - base)) { + /* offset beyond prefix -> go into extDict */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) + return ERROR(corruption_detected); + match = dictEnd + (match - base); + 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; + 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; +} + + +static size_t ZSTD_decompressSequences( + ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, + 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 base = (const BYTE*) (dctx->base); + const BYTE* const vBase = (const BYTE*) (dctx->vBase); + const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); + int nbSeq; + DEBUGLOG(5, "ZSTD_decompressSequences"); + + /* Build Decoding Tables */ + { size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize); + DEBUGLOG(5, "ZSTD_decodeSeqHeaders: size=%u, nbSeq=%i", + (U32)seqHSize, nbSeq); + if (ZSTD_isError(seqHSize)) return seqHSize; + ip += seqHSize; + } + + /* Regen sequences */ + if (nbSeq) { + seqState_t seqState; + dctx->fseEntropy = 1; + { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } + CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected); + FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + FSE_initDState(&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, base, 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, "after decode loop, remaining nbSeq : %i", nbSeq); + if (nbSeq) return ERROR(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; + if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall); + memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } + + return op-ostart; +} + + +HINT_INLINE +seq_t ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets) +{ + seq_t seq; + + U32 const llCode = FSE_peekSymbol(&seqState->stateLL); + U32 const mlCode = FSE_peekSymbol(&seqState->stateML); + U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= MaxOff, by table construction */ + + U32 const llBits = LL_bits[llCode]; + U32 const mlBits = ML_bits[mlCode]; + U32 const ofBits = ofCode; + U32 const totalBits = llBits+mlBits+ofBits; + + 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 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 }; + + 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 }; + + /* sequence */ + { size_t offset; + if (!ofCode) + 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 = OF_base[ofCode] + (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 = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); + } + } + + if (ofCode <= 1) { + offset += (llCode==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 = ML_base[mlCode] + ((mlCode>31) ? 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 = LL_base[llCode] + ((llCode>15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */ + if (MEM_32bits()) + BIT_reloadDStream(&seqState->DStream); + + { size_t const pos = seqState->pos + seq.litLength; + seq.match = seqState->base + pos - seq.offset; /* single memory segment */ + if (seq.offset > pos) seq.match += seqState->gotoDict; /* separate memory segment */ + seqState->pos = pos + seq.matchLength; + } + + /* ANS state update */ + FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ + FSE_updateState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ + if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ + FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ + + return seq; +} + + +HINT_INLINE +size_t ZSTD_execSequenceLong(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) */ + 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, base, vBase, 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 - base)) { + /* offset beyond prefix */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) 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 = base; + 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 size_t ZSTD_decompressSequencesLong( + ZSTD_DCtx* dctx, + void* dst, size_t maxDstSize, + const void* seqStart, size_t seqSize, + 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 base = (const BYTE*) (dctx->base); + const BYTE* const vBase = (const BYTE*) (dctx->vBase); + const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); + int nbSeq; + + /* Build Decoding Tables */ + { size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize); + if (ZSTD_isError(seqHSize)) return seqHSize; + ip += seqHSize; + } + + /* 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; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } + seqState.base = base; + seqState.pos = (size_t)(op-base); + seqState.gotoDict = (uPtrDiff)dictEnd - (uPtrDiff)base; /* cast to avoid undefined behaviour */ + CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected); + FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + + /* prepare in advance */ + for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && seqNb<seqAdvance; seqNb++) { + sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, isLongOffset); + } + if (seqNb<seqAdvance) return ERROR(corruption_detected); + + /* decode and decompress */ + for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && seqNb<nbSeq ; seqNb++) { + seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, isLongOffset); + size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd); + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + PREFETCH(sequence.match); + sequences[seqNb&STOSEQ_MASK] = sequence; + op += oneSeqSize; + } + if (seqNb<nbSeq) return ERROR(corruption_detected); + + /* finish queue */ + seqNb -= seqAdvance; + for ( ; seqNb<nbSeq ; seqNb++) { + size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb&STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd); + if (ZSTD_isError(oneSeqSize)) return oneSeqSize; + op += oneSeqSize; + } + + /* save reps for next block */ + { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); } + } + + /* last literal segment */ + { size_t const lastLLSize = litEnd - litPtr; + if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall); + memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } + + return op-ostart; +} + + +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. + * If we are in block mode we don't know the window size, so we have to be + * conservative. + */ + ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN))); + /* windowSize could be any value at this point, since it is only validated + * in the streaming API. + */ + 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; + } + if (frame && dctx->fParams.windowSize > (1<<23)) + return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, isLongOffset); + return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, isLongOffset); +} + + +static void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst) +{ + if (dst != dctx->previousDstEnd) { /* not contiguous */ + dctx->dictEnd = dctx->previousDstEnd; + dctx->vBase = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base)); + dctx->base = 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 byte, size_t length) +{ + if (length > dstCapacity) return ERROR(dstSize_tooSmall); + memset(dst, byte, 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 + * `srcSize` must be at least as large as the frame contained + * @return : the compressed size of the frame starting at `src` */ +size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize) +{ +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(src, srcSize)) + return ZSTD_findFrameCompressedSizeLegacy(src, srcSize); +#endif + if ( (srcSize >= ZSTD_skippableHeaderSize) + && (MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START ) { + return ZSTD_skippableHeaderSize + MEM_readLE32((const BYTE*)src + ZSTD_frameIdSize); + } else { + const BYTE* ip = (const BYTE*)src; + const BYTE* const ipstart = ip; + size_t remainingSize = srcSize; + ZSTD_frameHeader zfh; + + /* Extract Frame Header */ + { size_t const ret = ZSTD_getFrameHeader(&zfh, src, srcSize); + if (ZSTD_isError(ret)) return ret; + if (ret > 0) return ERROR(srcSize_wrong); + } + + ip += zfh.headerSize; + remainingSize -= zfh.headerSize; + + /* Loop on each block */ + while (1) { + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) return cBlockSize; + + if (ZSTD_blockHeaderSize + cBlockSize > remainingSize) + return ERROR(srcSize_wrong); + + ip += ZSTD_blockHeaderSize + cBlockSize; + remainingSize -= ZSTD_blockHeaderSize + cBlockSize; + + if (blockProperties.lastBlock) break; + } + + if (zfh.checksumFlag) { /* Final frame content checksum */ + if (remainingSize < 4) return ERROR(srcSize_wrong); + ip += 4; + remainingSize -= 4; + } + + return ip - ipstart; + } +} + +/*! ZSTD_decompressFrame() : +* @dctx must be properly initialized */ +static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void** srcPtr, size_t *srcSizePtr) +{ + const BYTE* ip = (const BYTE*)(*srcPtr); + BYTE* const ostart = (BYTE* const)dst; + BYTE* const oend = ostart + dstCapacity; + BYTE* op = ostart; + size_t remainingSize = *srcSizePtr; + + /* check */ + if (remainingSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) + return ERROR(srcSize_wrong); + + /* Frame Header */ + { size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_frameHeaderSize_prefix); + if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize; + if (remainingSize < frameHeaderSize+ZSTD_blockHeaderSize) + return ERROR(srcSize_wrong); + CHECK_F( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) ); + ip += frameHeaderSize; remainingSize -= frameHeaderSize; + } + + /* Loop on each block */ + while (1) { + size_t decodedSize; + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) return cBlockSize; + + ip += ZSTD_blockHeaderSize; + remainingSize -= ZSTD_blockHeaderSize; + if (cBlockSize > remainingSize) return ERROR(srcSize_wrong); + + switch(blockProperties.blockType) + { + case bt_compressed: + decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend-op, ip, cBlockSize, /* frame */ 1); + break; + case bt_raw : + decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize); + break; + case bt_rle : + decodedSize = ZSTD_generateNxBytes(op, oend-op, *ip, blockProperties.origSize); + break; + case bt_reserved : + default: + return ERROR(corruption_detected); + } + + if (ZSTD_isError(decodedSize)) return decodedSize; + if (dctx->fParams.checksumFlag) + XXH64_update(&dctx->xxhState, op, decodedSize); + op += decodedSize; + ip += cBlockSize; + remainingSize -= cBlockSize; + if (blockProperties.lastBlock) break; + } + + if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) { + if ((U64)(op-ostart) != dctx->fParams.frameContentSize) { + return ERROR(corruption_detected); + } } + if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */ + U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState); + U32 checkRead; + if (remainingSize<4) return ERROR(checksum_wrong); + checkRead = MEM_readLE32(ip); + if (checkRead != checkCalc) return ERROR(checksum_wrong); + ip += 4; + remainingSize -= 4; + } + + /* Allow caller to get size read */ + *srcPtr = ip; + *srcSizePtr = remainingSize; + return op-ostart; +} + +static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict); +static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict); + +static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const void* dict, size_t dictSize, + const ZSTD_DDict* ddict) +{ + void* const dststart = dst; + assert(dict==NULL || ddict==NULL); /* either dict or ddict set, not both */ + + if (ddict) { + dict = ZSTD_DDictDictContent(ddict); + dictSize = ZSTD_DDictDictSize(ddict); + } + + while (srcSize >= ZSTD_frameHeaderSize_prefix) { + U32 magicNumber; + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1) + if (ZSTD_isLegacy(src, srcSize)) { + size_t decodedSize; + size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize); + if (ZSTD_isError(frameSize)) return frameSize; + /* legacy support is not compatible with static dctx */ + if (dctx->staticSize) return ERROR(memory_allocation); + + decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize); + + dst = (BYTE*)dst + decodedSize; + dstCapacity -= decodedSize; + + src = (const BYTE*)src + frameSize; + srcSize -= frameSize; + + continue; + } +#endif + + magicNumber = MEM_readLE32(src); + DEBUGLOG(4, "reading magic number %08X (expecting %08X)", + (U32)magicNumber, (U32)ZSTD_MAGICNUMBER); + if (magicNumber != ZSTD_MAGICNUMBER) { + if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + size_t skippableSize; + if (srcSize < ZSTD_skippableHeaderSize) + return ERROR(srcSize_wrong); + skippableSize = MEM_readLE32((const BYTE*)src + ZSTD_frameIdSize) + + ZSTD_skippableHeaderSize; + if (srcSize < skippableSize) return ERROR(srcSize_wrong); + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; + } + return ERROR(prefix_unknown); + } + + if (ddict) { + /* we were called from ZSTD_decompress_usingDDict */ + CHECK_F(ZSTD_decompressBegin_usingDDict(dctx, ddict)); + } else { + /* this will initialize correctly with no dict if dict == NULL, so + * use this in all cases but ddict */ + CHECK_F(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize)); + } + ZSTD_checkContinuity(dctx, dst); + + { const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity, + &src, &srcSize); + if (ZSTD_isError(res)) return res; + /* no need to bound check, ZSTD_decompressFrame already has */ + dst = (BYTE*)dst + res; + dstCapacity -= res; + } + } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */ + + if (srcSize) return ERROR(srcSize_wrong); /* input not entirely consumed */ + + return (BYTE*)dst - (BYTE*)dststart; +} + +size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const void* dict, size_t dictSize) +{ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL); +} + + +size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ + return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0); +} + + +size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ +#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1) + size_t regenSize; + ZSTD_DCtx* const dctx = ZSTD_createDCtx(); + if (dctx==NULL) return ERROR(memory_allocation); + regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize); + ZSTD_freeDCtx(dctx); + return regenSize; +#else /* stack mode */ + ZSTD_DCtx dctx; + return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize); +#endif +} + + +/*-************************************** +* Advanced Streaming Decompression API +* Bufferless and synchronous +****************************************/ +size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; } + +ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) { + switch(dctx->stage) + { + default: /* should not happen */ + assert(0); + case ZSTDds_getFrameHeaderSize: + case ZSTDds_decodeFrameHeader: + return ZSTDnit_frameHeader; + case ZSTDds_decodeBlockHeader: + return ZSTDnit_blockHeader; + case ZSTDds_decompressBlock: + return ZSTDnit_block; + case ZSTDds_decompressLastBlock: + return ZSTDnit_lastBlock; + case ZSTDds_checkChecksum: + return ZSTDnit_checksum; + case ZSTDds_decodeSkippableHeader: + case ZSTDds_skipFrame: + return ZSTDnit_skippableFrame; + } +} + +static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; } + +/** ZSTD_decompressContinue() : + * srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress()) + * @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity) + * or an error code, which can be tested using ZSTD_isError() */ +size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ + DEBUGLOG(5, "ZSTD_decompressContinue"); + /* Sanity check */ + if (srcSize != dctx->expected) return ERROR(srcSize_wrong); /* not allowed */ + if (dstCapacity) ZSTD_checkContinuity(dctx, dst); + + switch (dctx->stage) + { + case ZSTDds_getFrameHeaderSize : + assert(src != NULL); + if (dctx->format == ZSTD_f_zstd1) { /* allows header */ + assert(srcSize >= ZSTD_frameIdSize); /* to read skippable magic number */ + if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */ + memcpy(dctx->headerBuffer, src, srcSize); + dctx->expected = ZSTD_skippableHeaderSize - srcSize; /* remaining to load to get full skippable frame header */ + dctx->stage = ZSTDds_decodeSkippableHeader; + return 0; + } } + dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format); + if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize; + memcpy(dctx->headerBuffer, src, srcSize); + dctx->expected = dctx->headerSize - srcSize; + dctx->stage = ZSTDds_decodeFrameHeader; + return 0; + + case ZSTDds_decodeFrameHeader: + assert(src != NULL); + memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize); + CHECK_F(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize)); + dctx->expected = ZSTD_blockHeaderSize; + dctx->stage = ZSTDds_decodeBlockHeader; + return 0; + + case ZSTDds_decodeBlockHeader: + { blockProperties_t bp; + size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp); + if (ZSTD_isError(cBlockSize)) return cBlockSize; + dctx->expected = cBlockSize; + dctx->bType = bp.blockType; + dctx->rleSize = bp.origSize; + if (cBlockSize) { + dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock; + return 0; + } + /* empty block */ + if (bp.lastBlock) { + if (dctx->fParams.checksumFlag) { + dctx->expected = 4; + dctx->stage = ZSTDds_checkChecksum; + } else { + dctx->expected = 0; /* end of frame */ + dctx->stage = ZSTDds_getFrameHeaderSize; + } + } else { + dctx->expected = ZSTD_blockHeaderSize; /* jump to next header */ + dctx->stage = ZSTDds_decodeBlockHeader; + } + return 0; + } + + case ZSTDds_decompressLastBlock: + case ZSTDds_decompressBlock: + DEBUGLOG(5, "case ZSTDds_decompressBlock"); + { size_t rSize; + switch(dctx->bType) + { + case bt_compressed: + DEBUGLOG(5, "case bt_compressed"); + rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1); + break; + case bt_raw : + rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize); + break; + case bt_rle : + rSize = ZSTD_setRleBlock(dst, dstCapacity, src, srcSize, dctx->rleSize); + break; + case bt_reserved : /* should never happen */ + default: + return ERROR(corruption_detected); + } + if (ZSTD_isError(rSize)) return rSize; + DEBUGLOG(5, "decoded size from block : %u", (U32)rSize); + dctx->decodedSize += rSize; + if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize); + + if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */ + DEBUGLOG(4, "decoded size from frame : %u", (U32)dctx->decodedSize); + if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) { + if (dctx->decodedSize != dctx->fParams.frameContentSize) { + return ERROR(corruption_detected); + } } + if (dctx->fParams.checksumFlag) { /* another round for frame checksum */ + dctx->expected = 4; + dctx->stage = ZSTDds_checkChecksum; + } else { + dctx->expected = 0; /* ends here */ + dctx->stage = ZSTDds_getFrameHeaderSize; + } + } else { + dctx->stage = ZSTDds_decodeBlockHeader; + dctx->expected = ZSTD_blockHeaderSize; + dctx->previousDstEnd = (char*)dst + rSize; + } + return rSize; + } + + case ZSTDds_checkChecksum: + assert(srcSize == 4); /* guaranteed by dctx->expected */ + { U32 const h32 = (U32)XXH64_digest(&dctx->xxhState); + U32 const check32 = MEM_readLE32(src); + DEBUGLOG(4, "checksum : calculated %08X :: %08X read", h32, check32); + if (check32 != h32) return ERROR(checksum_wrong); + dctx->expected = 0; + dctx->stage = ZSTDds_getFrameHeaderSize; + return 0; + } + + case ZSTDds_decodeSkippableHeader: + assert(src != NULL); + assert(srcSize <= ZSTD_skippableHeaderSize); + memcpy(dctx->headerBuffer + (ZSTD_skippableHeaderSize - srcSize), src, srcSize); /* complete skippable header */ + dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_frameIdSize); /* note : dctx->expected can grow seriously large, beyond local buffer size */ + dctx->stage = ZSTDds_skipFrame; + return 0; + + case ZSTDds_skipFrame: + dctx->expected = 0; + dctx->stage = ZSTDds_getFrameHeaderSize; + return 0; + + default: + return ERROR(GENERIC); /* impossible */ + } +} + + +static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + dctx->dictEnd = dctx->previousDstEnd; + dctx->vBase = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base)); + dctx->base = dict; + dctx->previousDstEnd = (const char*)dict + dictSize; + return 0; +} + +/* ZSTD_loadEntropy() : + * dict : must point at beginning of a valid zstd dictionary + * @return : size of entropy tables read */ +static size_t ZSTD_loadEntropy(ZSTD_entropyDTables_t* entropy, const void* const dict, size_t const dictSize) +{ + const BYTE* dictPtr = (const BYTE*)dict; + const BYTE* const dictEnd = dictPtr + dictSize; + + if (dictSize <= 8) return ERROR(dictionary_corrupted); + dictPtr += 8; /* skip header = magic + dictID */ + + + { size_t const hSize = HUF_readDTableX4_wksp( + entropy->hufTable, dictPtr, dictEnd - dictPtr, + entropy->workspace, sizeof(entropy->workspace)); + if (HUF_isError(hSize)) return ERROR(dictionary_corrupted); + dictPtr += hSize; + } + + { short offcodeNCount[MaxOff+1]; + U32 offcodeMaxValue = MaxOff, offcodeLog; + size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr); + if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted); + if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable(entropy->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog), dictionary_corrupted); + dictPtr += offcodeHeaderSize; + } + + { short matchlengthNCount[MaxML+1]; + unsigned matchlengthMaxValue = MaxML, matchlengthLog; + size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr); + if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted); + if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable(entropy->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog), dictionary_corrupted); + dictPtr += matchlengthHeaderSize; + } + + { short litlengthNCount[MaxLL+1]; + unsigned litlengthMaxValue = MaxLL, litlengthLog; + size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr); + if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted); + if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable(entropy->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog), dictionary_corrupted); + dictPtr += litlengthHeaderSize; + } + + if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted); + { int i; + size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12)); + for (i=0; i<3; i++) { + U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4; + if (rep==0 || rep >= dictContentSize) return ERROR(dictionary_corrupted); + entropy->rep[i] = rep; + } } + + return dictPtr - (const BYTE*)dict; +} + +static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize); + { U32 const magic = MEM_readLE32(dict); + if (magic != ZSTD_MAGIC_DICTIONARY) { + return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */ + } } + dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_frameIdSize); + + /* load entropy tables */ + { size_t const eSize = ZSTD_loadEntropy(&dctx->entropy, dict, dictSize); + if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted); + dict = (const char*)dict + eSize; + dictSize -= eSize; + } + dctx->litEntropy = dctx->fseEntropy = 1; + + /* reference dictionary content */ + return ZSTD_refDictContent(dctx, dict, dictSize); +} + +/* Note : this function cannot fail */ +size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx) +{ + assert(dctx != NULL); + dctx->expected = ZSTD_startingInputLength(dctx->format); /* dctx->format must be properly set */ + dctx->stage = ZSTDds_getFrameHeaderSize; + dctx->decodedSize = 0; + dctx->previousDstEnd = NULL; + dctx->base = NULL; + dctx->vBase = NULL; + dctx->dictEnd = NULL; + dctx->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ + dctx->litEntropy = dctx->fseEntropy = 0; + dctx->dictID = 0; + ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue)); + memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */ + dctx->LLTptr = dctx->entropy.LLTable; + dctx->MLTptr = dctx->entropy.MLTable; + dctx->OFTptr = dctx->entropy.OFTable; + dctx->HUFptr = dctx->entropy.hufTable; + return 0; +} + +size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) +{ + CHECK_F( ZSTD_decompressBegin(dctx) ); + if (dict && dictSize) + CHECK_E(ZSTD_decompress_insertDictionary(dctx, dict, dictSize), dictionary_corrupted); + return 0; +} + + +/* ====== ZSTD_DDict ====== */ + +struct ZSTD_DDict_s { + void* dictBuffer; + const void* dictContent; + size_t dictSize; + ZSTD_entropyDTables_t entropy; + U32 dictID; + U32 entropyPresent; + ZSTD_customMem cMem; +}; /* typedef'd to ZSTD_DDict within "zstd.h" */ + +static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict) +{ + return ddict->dictContent; +} + +static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict) +{ + return ddict->dictSize; +} + +size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dstDCtx, const ZSTD_DDict* ddict) +{ + CHECK_F( ZSTD_decompressBegin(dstDCtx) ); + if (ddict) { /* support begin on NULL */ + dstDCtx->dictID = ddict->dictID; + dstDCtx->base = ddict->dictContent; + dstDCtx->vBase = ddict->dictContent; + dstDCtx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize; + dstDCtx->previousDstEnd = dstDCtx->dictEnd; + if (ddict->entropyPresent) { + dstDCtx->litEntropy = 1; + dstDCtx->fseEntropy = 1; + dstDCtx->LLTptr = ddict->entropy.LLTable; + dstDCtx->MLTptr = ddict->entropy.MLTable; + dstDCtx->OFTptr = ddict->entropy.OFTable; + dstDCtx->HUFptr = ddict->entropy.hufTable; + dstDCtx->entropy.rep[0] = ddict->entropy.rep[0]; + dstDCtx->entropy.rep[1] = ddict->entropy.rep[1]; + dstDCtx->entropy.rep[2] = ddict->entropy.rep[2]; + } else { + dstDCtx->litEntropy = 0; + dstDCtx->fseEntropy = 0; + } + } + return 0; +} + +static size_t ZSTD_loadEntropy_inDDict(ZSTD_DDict* ddict) +{ + ddict->dictID = 0; + ddict->entropyPresent = 0; + if (ddict->dictSize < 8) return 0; + { U32 const magic = MEM_readLE32(ddict->dictContent); + if (magic != ZSTD_MAGIC_DICTIONARY) return 0; /* pure content mode */ + } + ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_frameIdSize); + + /* load entropy tables */ + CHECK_E( ZSTD_loadEntropy(&ddict->entropy, ddict->dictContent, ddict->dictSize), dictionary_corrupted ); + ddict->entropyPresent = 1; + return 0; +} + + +static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod) +{ + if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) { + ddict->dictBuffer = NULL; + ddict->dictContent = dict; + } else { + void* const internalBuffer = ZSTD_malloc(dictSize, ddict->cMem); + ddict->dictBuffer = internalBuffer; + ddict->dictContent = internalBuffer; + if (!internalBuffer) return ERROR(memory_allocation); + memcpy(internalBuffer, dict, dictSize); + } + ddict->dictSize = dictSize; + ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ + + /* parse dictionary content */ + CHECK_F( ZSTD_loadEntropy_inDDict(ddict) ); + + return 0; +} + +ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_customMem customMem) +{ + if (!customMem.customAlloc ^ !customMem.customFree) return NULL; + + { ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem); + if (!ddict) return NULL; + ddict->cMem = customMem; + + if (ZSTD_isError( ZSTD_initDDict_internal(ddict, dict, dictSize, dictLoadMethod) )) { + ZSTD_freeDDict(ddict); + return NULL; + } + + return ddict; + } +} + +/*! ZSTD_createDDict() : +* Create a digested dictionary, to start decompression without startup delay. +* `dict` content is copied inside DDict. +* Consequently, `dict` can be released after `ZSTD_DDict` creation */ +ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, allocator); +} + +/*! ZSTD_createDDict_byReference() : + * Create a digested dictionary, to start decompression without startup delay. + * Dictionary content is simply referenced, it will be accessed during decompression. + * Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */ +ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize) +{ + ZSTD_customMem const allocator = { NULL, NULL, NULL }; + return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, allocator); +} + + +ZSTD_DDict* ZSTD_initStaticDDict(void* workspace, size_t workspaceSize, + const void* dict, size_t dictSize, + ZSTD_dictLoadMethod_e dictLoadMethod) +{ + size_t const neededSpace = + sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); + ZSTD_DDict* const ddict = (ZSTD_DDict*)workspace; + assert(workspace != NULL); + assert(dict != NULL); + if ((size_t)workspace & 7) return NULL; /* 8-aligned */ + if (workspaceSize < neededSpace) return NULL; + if (dictLoadMethod == ZSTD_dlm_byCopy) { + memcpy(ddict+1, dict, dictSize); /* local copy */ + dict = ddict+1; + } + if (ZSTD_isError( ZSTD_initDDict_internal(ddict, dict, dictSize, ZSTD_dlm_byRef) )) + return NULL; + return ddict; +} + + +size_t ZSTD_freeDDict(ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support free on NULL */ + { ZSTD_customMem const cMem = ddict->cMem; + ZSTD_free(ddict->dictBuffer, cMem); + ZSTD_free(ddict, cMem); + return 0; + } +} + +/*! ZSTD_estimateDDictSize() : + * Estimate amount of memory that will be needed to create a dictionary for decompression. + * Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */ +size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod) +{ + return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize); +} + +size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; /* support sizeof on NULL */ + return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ; +} + +/*! ZSTD_getDictID_fromDict() : + * Provides the dictID stored within dictionary. + * if @return == 0, the dictionary is not conformant with Zstandard specification. + * It can still be loaded, but as a content-only dictionary. */ +unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize) +{ + if (dictSize < 8) return 0; + if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0; + return MEM_readLE32((const char*)dict + ZSTD_frameIdSize); +} + +/*! ZSTD_getDictID_fromDDict() : + * Provides the dictID of the dictionary loaded into `ddict`. + * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty. + * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */ +unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict) +{ + if (ddict==NULL) return 0; + return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize); +} + +/*! ZSTD_getDictID_fromFrame() : + * Provides the dictID required to decompresse frame stored within `src`. + * If @return == 0, the dictID could not be decoded. + * This could for one of the following reasons : + * - The frame does not require a dictionary (most common case). + * - The frame was built with dictID intentionally removed. + * Needed dictionary is a hidden information. + * Note : this use case also happens when using a non-conformant dictionary. + * - `srcSize` is too small, and as a result, frame header could not be decoded. + * Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`. + * - This is not a Zstandard frame. + * When identifying the exact failure cause, it's possible to use + * ZSTD_getFrameHeader(), which will provide a more precise error code. */ +unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize) +{ + ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0 }; + size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize); + if (ZSTD_isError(hError)) return 0; + return zfp.dictID; +} + + +/*! ZSTD_decompress_usingDDict() : +* Decompression using a pre-digested Dictionary +* Use dictionary without significant overhead. */ +size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, + const void* src, size_t srcSize, + const ZSTD_DDict* ddict) +{ + /* pass content and size in case legacy frames are encountered */ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, + NULL, 0, + ddict); +} + + +/*===================================== +* Streaming decompression +*====================================*/ + +ZSTD_DStream* ZSTD_createDStream(void) +{ + return ZSTD_createDStream_advanced(ZSTD_defaultCMem); +} + +ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize) +{ + return ZSTD_initStaticDCtx(workspace, workspaceSize); +} + +ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem) +{ + return ZSTD_createDCtx_advanced(customMem); +} + +size_t ZSTD_freeDStream(ZSTD_DStream* zds) +{ + return ZSTD_freeDCtx(zds); +} + + +/* *** Initialization *** */ + +size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; } +size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; } + +size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize) +{ + zds->streamStage = zdss_loadHeader; + zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; + ZSTD_freeDDict(zds->ddictLocal); + if (dict && dictSize >= 8) { + zds->ddictLocal = ZSTD_createDDict(dict, dictSize); + if (zds->ddictLocal == NULL) return ERROR(memory_allocation); + } else zds->ddictLocal = NULL; + zds->ddict = zds->ddictLocal; + zds->legacyVersion = 0; + zds->hostageByte = 0; + return ZSTD_frameHeaderSize_prefix; +} + +/* note : this variant can't fail */ +size_t ZSTD_initDStream(ZSTD_DStream* zds) +{ + return ZSTD_initDStream_usingDict(zds, NULL, 0); +} + +/* ZSTD_initDStream_usingDDict() : + * ddict will just be referenced, and must outlive decompression session + * this function cannot fail */ +size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict) +{ + size_t const initResult = ZSTD_initDStream(zds); + zds->ddict = ddict; + return initResult; +} + +size_t ZSTD_resetDStream(ZSTD_DStream* zds) +{ + zds->streamStage = zdss_loadHeader; + zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; + zds->legacyVersion = 0; + zds->hostageByte = 0; + return ZSTD_frameHeaderSize_prefix; +} + +size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, + ZSTD_DStreamParameter_e paramType, unsigned paramValue) +{ + ZSTD_STATIC_ASSERT((unsigned)zdss_loadHeader >= (unsigned)zdss_init); + if ((unsigned)zds->streamStage > (unsigned)zdss_loadHeader) + return ERROR(stage_wrong); + switch(paramType) + { + default : return ERROR(parameter_unsupported); + case DStream_p_maxWindowSize : + DEBUGLOG(4, "setting maxWindowSize = %u KB", paramValue >> 10); + zds->maxWindowSize = paramValue ? paramValue : (U32)(-1); + break; + } + return 0; +} + +size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize) +{ + ZSTD_STATIC_ASSERT((unsigned)zdss_loadHeader >= (unsigned)zdss_init); + if ((unsigned)dctx->streamStage > (unsigned)zdss_loadHeader) + return ERROR(stage_wrong); + dctx->maxWindowSize = maxWindowSize; + return 0; +} + +size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format) +{ + DEBUGLOG(4, "ZSTD_DCtx_setFormat : %u", (unsigned)format); + ZSTD_STATIC_ASSERT((unsigned)zdss_loadHeader >= (unsigned)zdss_init); + if ((unsigned)dctx->streamStage > (unsigned)zdss_loadHeader) + return ERROR(stage_wrong); + dctx->format = format; + return 0; +} + + +size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds) +{ + return ZSTD_sizeof_DCtx(zds); +} + +size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize) +{ + size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX); + unsigned long long const neededRBSize = windowSize + blockSize + (WILDCOPY_OVERLENGTH * 2); + unsigned long long const neededSize = MIN(frameContentSize, neededRBSize); + size_t const minRBSize = (size_t) neededSize; + if ((unsigned long long)minRBSize != neededSize) return ERROR(frameParameter_windowTooLarge); + return minRBSize; +} + +size_t ZSTD_estimateDStreamSize(size_t windowSize) +{ + size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX); + size_t const inBuffSize = blockSize; /* no block can be larger */ + size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN); + return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize; +} + +size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize) +{ + U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX; /* note : should be user-selectable */ + ZSTD_frameHeader zfh; + size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize); + if (ZSTD_isError(err)) return err; + if (err>0) return ERROR(srcSize_wrong); + if (zfh.windowSize > windowSizeMax) + return ERROR(frameParameter_windowTooLarge); + return ZSTD_estimateDStreamSize((size_t)zfh.windowSize); +} + + +/* ***** Decompression ***** */ + +MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize) +{ + size_t const length = MIN(dstCapacity, srcSize); + memcpy(dst, src, length); + return length; +} + + +size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input) +{ + const char* const istart = (const char*)(input->src) + input->pos; + const char* const iend = (const char*)(input->src) + input->size; + const char* ip = istart; + char* const ostart = (char*)(output->dst) + output->pos; + char* const oend = (char*)(output->dst) + output->size; + char* op = ostart; + U32 someMoreWork = 1; + + DEBUGLOG(5, "ZSTD_decompressStream"); + if (input->pos > input->size) { /* forbidden */ + DEBUGLOG(5, "in: pos: %u vs size: %u", + (U32)input->pos, (U32)input->size); + return ERROR(srcSize_wrong); + } + if (output->pos > output->size) { /* forbidden */ + DEBUGLOG(5, "out: pos: %u vs size: %u", + (U32)output->pos, (U32)output->size); + return ERROR(dstSize_tooSmall); + } + DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos)); + +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + if (zds->legacyVersion) { + /* legacy support is incompatible with static dctx */ + if (zds->staticSize) return ERROR(memory_allocation); + return ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input); + } +#endif + + while (someMoreWork) { + switch(zds->streamStage) + { + case zdss_init : + ZSTD_resetDStream(zds); /* transparent reset on starting decoding a new frame */ + /* fall-through */ + + case zdss_loadHeader : + DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip)); + { size_t const hSize = ZSTD_getFrameHeader_internal(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format); + DEBUGLOG(5, "header size : %u", (U32)hSize); + if (ZSTD_isError(hSize)) { +#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1) + U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart); + if (legacyVersion) { + const void* const dict = zds->ddict ? zds->ddict->dictContent : NULL; + size_t const dictSize = zds->ddict ? zds->ddict->dictSize : 0; + /* legacy support is incompatible with static dctx */ + if (zds->staticSize) return ERROR(memory_allocation); + CHECK_F(ZSTD_initLegacyStream(&zds->legacyContext, + zds->previousLegacyVersion, legacyVersion, + dict, dictSize)); + zds->legacyVersion = zds->previousLegacyVersion = legacyVersion; + return ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input); + } +#endif + return hSize; /* error */ + } + if (hSize != 0) { /* need more input */ + size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */ + if (toLoad > (size_t)(iend-ip)) { /* not enough input to load full header */ + if (iend-ip > 0) { + memcpy(zds->headerBuffer + zds->lhSize, ip, iend-ip); + zds->lhSize += iend-ip; + } + input->pos = input->size; + return (MAX(ZSTD_frameHeaderSize_min, hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */ + } + assert(ip != NULL); + memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad; + break; + } } + + /* check for single-pass mode opportunity */ + if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */ + && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) { + size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend-istart); + if (cSize <= (size_t)(iend-istart)) { + size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, oend-op, istart, cSize, zds->ddict); + if (ZSTD_isError(decompressedSize)) return decompressedSize; + ip = istart + cSize; + op += decompressedSize; + zds->expected = 0; + zds->streamStage = zdss_init; + someMoreWork = 0; + break; + } } + + /* Consume header (see ZSTDds_decodeFrameHeader) */ + DEBUGLOG(4, "Consume header"); + CHECK_F(ZSTD_decompressBegin_usingDDict(zds, zds->ddict)); + + if ((MEM_readLE32(zds->headerBuffer) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */ + zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_frameIdSize); + zds->stage = ZSTDds_skipFrame; + } else { + CHECK_F(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize)); + zds->expected = ZSTD_blockHeaderSize; + zds->stage = ZSTDds_decodeBlockHeader; + } + + /* control buffer memory usage */ + DEBUGLOG(4, "Control max buffer memory usage (max %u KB)", + (U32)(zds->maxWindowSize >> 10)); + zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN); + if (zds->fParams.windowSize > zds->maxWindowSize) return ERROR(frameParameter_windowTooLarge); + + /* Adapt buffer sizes to frame header instructions */ + { size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */); + size_t const neededOutBuffSize = ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize); + if ((zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize)) { + size_t const bufferSize = neededInBuffSize + neededOutBuffSize; + DEBUGLOG(4, "inBuff : from %u to %u", + (U32)zds->inBuffSize, (U32)neededInBuffSize); + DEBUGLOG(4, "outBuff : from %u to %u", + (U32)zds->outBuffSize, (U32)neededOutBuffSize); + if (zds->staticSize) { /* static DCtx */ + DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize); + assert(zds->staticSize >= sizeof(ZSTD_DCtx)); /* controlled at init */ + if (bufferSize > zds->staticSize - sizeof(ZSTD_DCtx)) + return ERROR(memory_allocation); + } else { + ZSTD_free(zds->inBuff, zds->customMem); + zds->inBuffSize = 0; + zds->outBuffSize = 0; + zds->inBuff = (char*)ZSTD_malloc(bufferSize, zds->customMem); + if (zds->inBuff == NULL) return ERROR(memory_allocation); + } + zds->inBuffSize = neededInBuffSize; + zds->outBuff = zds->inBuff + zds->inBuffSize; + zds->outBuffSize = neededOutBuffSize; + } } + zds->streamStage = zdss_read; + /* fall-through */ + + case zdss_read: + DEBUGLOG(5, "stage zdss_read"); + { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds); + DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize); + if (neededInSize==0) { /* end of frame */ + zds->streamStage = zdss_init; + someMoreWork = 0; + break; + } + if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */ + int const isSkipFrame = ZSTD_isSkipFrame(zds); + size_t const decodedSize = ZSTD_decompressContinue(zds, + zds->outBuff + zds->outStart, (isSkipFrame ? 0 : zds->outBuffSize - zds->outStart), + ip, neededInSize); + if (ZSTD_isError(decodedSize)) return decodedSize; + ip += neededInSize; + if (!decodedSize && !isSkipFrame) break; /* this was just a header */ + zds->outEnd = zds->outStart + decodedSize; + zds->streamStage = zdss_flush; + break; + } } + if (ip==iend) { someMoreWork = 0; break; } /* no more input */ + zds->streamStage = zdss_load; + /* fall-through */ + case zdss_load: + { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds); + size_t const toLoad = neededInSize - zds->inPos; /* should always be <= remaining space within inBuff */ + size_t loadedSize; + if (toLoad > zds->inBuffSize - zds->inPos) return ERROR(corruption_detected); /* should never happen */ + loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, iend-ip); + ip += loadedSize; + zds->inPos += loadedSize; + if (loadedSize < toLoad) { someMoreWork = 0; break; } /* not enough input, wait for more */ + + /* decode loaded input */ + { const int isSkipFrame = ZSTD_isSkipFrame(zds); + size_t const decodedSize = ZSTD_decompressContinue(zds, + zds->outBuff + zds->outStart, zds->outBuffSize - zds->outStart, + zds->inBuff, neededInSize); + if (ZSTD_isError(decodedSize)) return decodedSize; + zds->inPos = 0; /* input is consumed */ + if (!decodedSize && !isSkipFrame) { zds->streamStage = zdss_read; break; } /* this was just a header */ + zds->outEnd = zds->outStart + decodedSize; + } } + zds->streamStage = zdss_flush; + /* fall-through */ + case zdss_flush: + { size_t const toFlushSize = zds->outEnd - zds->outStart; + size_t const flushedSize = ZSTD_limitCopy(op, oend-op, zds->outBuff + zds->outStart, toFlushSize); + op += flushedSize; + zds->outStart += flushedSize; + if (flushedSize == toFlushSize) { /* flush completed */ + zds->streamStage = zdss_read; + if ( (zds->outBuffSize < zds->fParams.frameContentSize) + && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) { + DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)", + (int)(zds->outBuffSize - zds->outStart), + (U32)zds->fParams.blockSizeMax); + zds->outStart = zds->outEnd = 0; + } + break; + } } + /* cannot complete flush */ + someMoreWork = 0; + break; + + default: return ERROR(GENERIC); /* impossible */ + } } + + /* result */ + input->pos += (size_t)(ip-istart); + output->pos += (size_t)(op-ostart); + { size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds); + if (!nextSrcSizeHint) { /* frame fully decoded */ + if (zds->outEnd == zds->outStart) { /* output fully flushed */ + if (zds->hostageByte) { + if (input->pos >= input->size) { + /* can't release hostage (not present) */ + zds->streamStage = zdss_read; + return 1; + } + input->pos++; /* release hostage */ + } /* zds->hostageByte */ + return 0; + } /* zds->outEnd == zds->outStart */ + if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */ + input->pos--; /* note : pos > 0, otherwise, impossible to finish reading last block */ + zds->hostageByte=1; + } + return 1; + } /* nextSrcSizeHint==0 */ + nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block); /* preload header of next block */ + if (zds->inPos > nextSrcSizeHint) return ERROR(GENERIC); /* should never happen */ + nextSrcSizeHint -= zds->inPos; /* already loaded*/ + return nextSrcSizeHint; + } +} + + +size_t ZSTD_decompress_generic(ZSTD_DCtx* dctx, ZSTD_outBuffer* output, ZSTD_inBuffer* input) +{ + return ZSTD_decompressStream(dctx, output, input); +} + +size_t ZSTD_decompress_generic_simpleArgs ( + ZSTD_DCtx* dctx, + void* dst, size_t dstCapacity, size_t* dstPos, + const void* src, size_t srcSize, size_t* srcPos) +{ + ZSTD_outBuffer output = { dst, dstCapacity, *dstPos }; + ZSTD_inBuffer input = { src, srcSize, *srcPos }; + /* ZSTD_compress_generic() will check validity of dstPos and srcPos */ + size_t const cErr = ZSTD_decompress_generic(dctx, &output, &input); + *dstPos = output.pos; + *srcPos = input.pos; + return cErr; +} + +void ZSTD_DCtx_reset(ZSTD_DCtx* dctx) +{ + (void)ZSTD_initDStream(dctx); + dctx->format = ZSTD_f_zstd1; + dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT; +} |