| /* |
| zstd - standard compression library |
| Copyright (C) 2014-2016, Yann Collet. |
| |
| BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above |
| copyright notice, this list of conditions and the following disclaimer |
| in the documentation and/or other materials provided with the |
| distribution. |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| You can contact the author at : |
| - zstd homepage : http://www.zstd.net |
| */ |
| |
| /* *************************************************************** |
| * 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 |
| |
| |
| /*! |
| * STREAM_WINDOW_MAX : |
| * maximum window size accepted by DStream. |
| * frames requiring more memory will be rejected. |
| */ |
| #ifndef ZSTD_STREAM_WINDOW_MAX |
| # define ZSTD_STREAM_WINDOW_MAX (257 << 20) /* 257 MB */ |
| #endif |
| |
| |
| /*-******************************************************* |
| * Dependencies |
| *********************************************************/ |
| #include <string.h> /* memcpy, memmove, memset */ |
| #include "mem.h" /* low level memory routines */ |
| #define XXH_STATIC_LINKING_ONLY /* XXH64_state_t */ |
| #include "xxhash.h" /* XXH64_* */ |
| #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 |
| |
| |
| /*-******************************************************* |
| * Compiler specifics |
| *********************************************************/ |
| #ifdef _MSC_VER /* Visual Studio */ |
| # define FORCE_INLINE static __forceinline |
| # include <intrin.h> /* For Visual 2005 */ |
| # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ |
| # pragma warning(disable : 4324) /* disable: C4324: padded structure */ |
| # pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */ |
| #else |
| # ifdef __GNUC__ |
| # define FORCE_INLINE static inline __attribute__((always_inline)) |
| # else |
| # define FORCE_INLINE static inline |
| # endif |
| #endif |
| |
| |
| /*-************************************* |
| * Macros |
| ***************************************/ |
| #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; |
| |
| struct ZSTD_DCtx_s |
| { |
| FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)]; |
| FSE_DTable OffTable[FSE_DTABLE_SIZE_U32(OffFSELog)]; |
| FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)]; |
| HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */ |
| const void* previousDstEnd; |
| const void* base; |
| const void* vBase; |
| const void* dictEnd; |
| size_t expected; |
| U32 rep[ZSTD_REP_NUM]; |
| ZSTD_frameParams fParams; |
| blockType_e bType; /* used in ZSTD_decompressContinue(), to transfer blockType between header decoding and block decoding stages */ |
| ZSTD_dStage stage; |
| U32 litEntropy; |
| U32 fseEntropy; |
| XXH64_state_t xxhState; |
| size_t headerSize; |
| U32 dictID; |
| const BYTE* litPtr; |
| ZSTD_customMem customMem; |
| size_t litBufSize; |
| size_t litSize; |
| size_t rleSize; |
| BYTE litBuffer[ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH]; |
| BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; |
| }; /* typedef'd to ZSTD_DCtx within "zstd_static.h" */ |
| |
| size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) { return sizeof(*dctx); } |
| |
| size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); } |
| |
| size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx) |
| { |
| dctx->expected = ZSTD_frameHeaderSize_min; |
| dctx->stage = ZSTDds_getFrameHeaderSize; |
| dctx->previousDstEnd = NULL; |
| dctx->base = NULL; |
| dctx->vBase = NULL; |
| dctx->dictEnd = NULL; |
| dctx->hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); |
| dctx->litEntropy = dctx->fseEntropy = 0; |
| dctx->dictID = 0; |
| MEM_STATIC_ASSERT(sizeof(dctx->rep)==sizeof(repStartValue)); |
| memcpy(dctx->rep, repStartValue, sizeof(repStartValue)); |
| return 0; |
| } |
| |
| ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) |
| { |
| ZSTD_DCtx* dctx; |
| |
| if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem; |
| if (!customMem.customAlloc || !customMem.customFree) return NULL; |
| |
| dctx = (ZSTD_DCtx*) customMem.customAlloc(customMem.opaque, sizeof(ZSTD_DCtx)); |
| if (!dctx) return NULL; |
| memcpy(&dctx->customMem, &customMem, sizeof(customMem)); |
| ZSTD_decompressBegin(dctx); |
| return dctx; |
| } |
| |
| ZSTD_DCtx* ZSTD_createDCtx(void) |
| { |
| return ZSTD_createDCtx_advanced(defaultCustomMem); |
| } |
| |
| size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx) |
| { |
| if (dctx==NULL) return 0; /* support free on NULL */ |
| dctx->customMem.customFree(dctx->customMem.opaque, dctx); |
| return 0; /* reserved as a potential error code in the future */ |
| } |
| |
| void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx) |
| { |
| size_t const workSpaceSize = (ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH) + ZSTD_frameHeaderSize_max; |
| memcpy(dstDCtx, srcDCtx, sizeof(ZSTD_DCtx) - workSpaceSize); /* no need to copy workspace */ |
| } |
| |
| |
| /*-************************************************************* |
| * Decompression section |
| ***************************************************************/ |
| |
| /* See compression format details in : zstd_compression_format.md */ |
| |
| /** ZSTD_frameHeaderSize() : |
| * srcSize must be >= ZSTD_frameHeaderSize_min. |
| * @return : size of the Frame Header */ |
| static size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize) |
| { |
| if (srcSize < ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong); |
| { BYTE const fhd = ((const BYTE*)src)[4]; |
| U32 const dictID= fhd & 3; |
| U32 const singleSegment = (fhd >> 5) & 1; |
| U32 const fcsId = fhd >> 6; |
| return ZSTD_frameHeaderSize_min + !singleSegment + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId] |
| + (singleSegment && !fcsId); |
| } |
| } |
| |
| |
| /** ZSTD_getFrameParams() : |
| * decode Frame Header, or require larger `srcSize`. |
| * @return : 0, `fparamsPtr` is correctly filled, |
| * >0, `srcSize` is too small, result is expected `srcSize`, |
| * or an error code, which can be tested using ZSTD_isError() */ |
| size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize) |
| { |
| const BYTE* ip = (const BYTE*)src; |
| |
| if (srcSize < ZSTD_frameHeaderSize_min) return ZSTD_frameHeaderSize_min; |
| if (MEM_readLE32(src) != ZSTD_MAGICNUMBER) { |
| if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { |
| if (srcSize < ZSTD_skippableHeaderSize) return ZSTD_skippableHeaderSize; /* magic number + skippable frame length */ |
| memset(fparamsPtr, 0, sizeof(*fparamsPtr)); |
| fparamsPtr->frameContentSize = MEM_readLE32((const char *)src + 4); |
| fparamsPtr->windowSize = 0; /* windowSize==0 means a frame is skippable */ |
| return 0; |
| } |
| return ERROR(prefix_unknown); |
| } |
| |
| /* ensure there is enough `srcSize` to fully read/decode frame header */ |
| { size_t const fhsize = ZSTD_frameHeaderSize(src, srcSize); |
| if (srcSize < fhsize) return fhsize; } |
| |
| { BYTE const fhdByte = ip[4]; |
| size_t pos = 5; |
| U32 const dictIDSizeCode = fhdByte&3; |
| U32 const checksumFlag = (fhdByte>>2)&1; |
| U32 const singleSegment = (fhdByte>>5)&1; |
| U32 const fcsID = fhdByte>>6; |
| U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX; |
| U32 windowSize = 0; |
| U32 dictID = 0; |
| U64 frameContentSize = 0; |
| if ((fhdByte & 0x08) != 0) return ERROR(frameParameter_unsupported); /* reserved bits, which 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_unsupported); |
| windowSize = (1U << windowLog); |
| windowSize += (windowSize >> 3) * (wlByte&7); |
| } |
| |
| switch(dictIDSizeCode) |
| { |
| default: /* 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: /* 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 (!windowSize) windowSize = (U32)frameContentSize; |
| if (windowSize > windowSizeMax) return ERROR(frameParameter_unsupported); |
| fparamsPtr->frameContentSize = frameContentSize; |
| fparamsPtr->windowSize = windowSize; |
| fparamsPtr->dictID = dictID; |
| fparamsPtr->checksumFlag = checksumFlag; |
| } |
| return 0; |
| } |
| |
| |
| /** ZSTD_getDecompressedSize() : |
| * compatible with legacy mode |
| * @return : decompressed size if known, 0 otherwise |
| note : 0 can mean any of the following : |
| - decompressed size is not present within 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) |
| { |
| #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1) |
| if (ZSTD_isLegacy(src, srcSize)) return ZSTD_getDecompressedSize_legacy(src, srcSize); |
| #endif |
| { ZSTD_frameParams fparams; |
| size_t const frResult = ZSTD_getFrameParams(&fparams, src, srcSize); |
| if (frResult!=0) return 0; |
| return fparams.frameContentSize; |
| } |
| } |
| |
| |
| /** ZSTD_decodeFrameHeader() : |
| * `srcSize` 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 srcSize) |
| { |
| size_t const result = ZSTD_getFrameParams(&(dctx->fParams), src, srcSize); |
| if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID)) return ERROR(dictionary_wrong); |
| if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0); |
| return result; |
| } |
| |
| |
| typedef struct |
| { |
| blockType_e blockType; |
| U32 lastBlock; |
| U32 origSize; |
| } blockProperties_t; |
| |
| /*! 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 ) */ |
| 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_ABSOLUTEMAX) 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->hufTable) : |
| HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable) ) : |
| ( singleStream ? |
| HUF_decompress1X2_DCtx(dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) : |
| HUF_decompress4X_hufOnly (dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize)) )) |
| return ERROR(corruption_detected); |
| |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH; |
| dctx->litSize = litSize; |
| dctx->litEntropy = 1; |
| 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->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+8; |
| dctx->litSize = litSize; |
| return lhSize+litSize; |
| } |
| /* direct reference into compressed stream */ |
| dctx->litPtr = istart+lhSize; |
| dctx->litBufSize = srcSize-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_ABSOLUTEMAX) return ERROR(corruption_detected); |
| memset(dctx->litBuffer, istart[lhSize], litSize); |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH; |
| dctx->litSize = litSize; |
| return lhSize+1; |
| } |
| default: |
| return ERROR(corruption_detected); /* impossible */ |
| } |
| |
| } |
| } |
| |
| |
| /*! ZSTD_buildSeqTable() : |
| @return : nb bytes read from src, |
| or an error code if it fails, testable with ZSTD_isError() |
| */ |
| FORCE_INLINE size_t ZSTD_buildSeqTable(FSE_DTable* DTable, symbolEncodingType_e type, U32 max, U32 maxLog, |
| const void* src, size_t srcSize, |
| const S16* defaultNorm, U32 defaultLog, U32 flagRepeatTable) |
| { |
| switch(type) |
| { |
| case set_rle : |
| if (!srcSize) return ERROR(srcSize_wrong); |
| if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected); |
| FSE_buildDTable_rle(DTable, *(const BYTE*)src); /* if *src > max, data is corrupted */ |
| return 1; |
| case set_basic : |
| FSE_buildDTable(DTable, defaultNorm, max, defaultLog); |
| 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(DTable, norm, max, tableLog); |
| return headerSize; |
| } } |
| } |
| |
| |
| size_t ZSTD_decodeSeqHeaders(int* nbSeqPtr, |
| FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb, U32 flagRepeatTable, |
| const void* src, size_t srcSize) |
| { |
| const BYTE* const istart = (const BYTE* const)src; |
| const BYTE* const iend = istart + srcSize; |
| const BYTE* ip = istart; |
| |
| /* 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) |
| nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; |
| else |
| 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(DTableLL, LLtype, MaxLL, LLFSELog, ip, iend-ip, LL_defaultNorm, LL_defaultNormLog, flagRepeatTable); |
| if (ZSTD_isError(llhSize)) return ERROR(corruption_detected); |
| ip += llhSize; |
| } |
| { size_t const ofhSize = ZSTD_buildSeqTable(DTableOffb, OFtype, MaxOff, OffFSELog, ip, iend-ip, OF_defaultNorm, OF_defaultNormLog, flagRepeatTable); |
| if (ZSTD_isError(ofhSize)) return ERROR(corruption_detected); |
| ip += ofhSize; |
| } |
| { size_t const mlhSize = ZSTD_buildSeqTable(DTableML, MLtype, MaxML, MLFSELog, ip, iend-ip, ML_defaultNorm, ML_defaultNormLog, flagRepeatTable); |
| if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected); |
| ip += mlhSize; |
| } } |
| |
| return ip-istart; |
| } |
| |
| |
| typedef struct { |
| size_t litLength; |
| size_t matchLength; |
| size_t offset; |
| } 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]; |
| } seqState_t; |
| |
| |
| static seq_t ZSTD_decodeSequence(seqState_t* seqState) |
| { |
| 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 }; |
| |
| /* sequence */ |
| { size_t offset; |
| if (!ofCode) |
| offset = 0; |
| else { |
| offset = OF_base[ofCode] + BIT_readBits(&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 const temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; |
| 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_readBits(&seqState->DStream, mlBits) : 0); /* <= 16 bits */ |
| if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&seqState->DStream); |
| |
| seq.litLength = LL_base[llCode] + ((llCode>15) ? BIT_readBits(&seqState->DStream, llBits) : 0); /* <= 16 bits */ |
| if (MEM_32bits() || |
| (totalBits > 64 - 7 - (LLFSELog+MLFSELog+OffFSELog)) ) BIT_reloadDStream(&seqState->DStream); |
| |
| /* 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; |
| } |
| |
| |
| FORCE_INLINE |
| size_t ZSTD_execSequence(BYTE* op, |
| BYTE* const oend, seq_t sequence, |
| const BYTE** litPtr, const BYTE* const litLimit_w, |
| 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 ((oLitEnd>oend_w) | (oMatchEnd>oend)) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ |
| if (iLitEnd > litLimit_w) return ERROR(corruption_detected); /* over-read beyond lit buffer */ |
| |
| /* 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); |
| 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; |
| } } |
| |
| /* 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 }; /* substracted */ |
| 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, 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 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 litLimit_w = litPtr + dctx->litBufSize - WILDCOPY_OVERLENGTH; |
| const BYTE* const litEnd = litPtr + dctx->litSize; |
| FSE_DTable* DTableLL = dctx->LLTable; |
| FSE_DTable* DTableML = dctx->MLTable; |
| FSE_DTable* DTableOffb = dctx->OffTable; |
| 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(&nbSeq, DTableLL, DTableML, DTableOffb, dctx->fseEntropy, ip, seqSize); |
| 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->rep[i]; } |
| { size_t const errorCode = BIT_initDStream(&(seqState.DStream), ip, iend-ip); |
| if (ERR_isError(errorCode)) return ERROR(corruption_detected); } |
| FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL); |
| FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb); |
| FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML); |
| |
| for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) { |
| nbSeq--; |
| { seq_t const sequence = ZSTD_decodeSequence(&seqState); |
| size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litLimit_w, base, vBase, dictEnd); |
| if (ZSTD_isError(oneSeqSize)) return oneSeqSize; |
| op += oneSeqSize; |
| } } |
| |
| /* check if reached exact end */ |
| if (nbSeq) return ERROR(corruption_detected); |
| /* save reps for next block */ |
| { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->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 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; |
| } |
| } |
| |
| |
| static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize) |
| { /* blockType == blockCompressed */ |
| const BYTE* ip = (const BYTE*)src; |
| |
| if (srcSize >= ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(srcSize_wrong); |
| |
| /* Decode literals sub-block */ |
| { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize); |
| if (ZSTD_isError(litCSize)) return litCSize; |
| ip += litCSize; |
| srcSize -= litCSize; |
| } |
| return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize); |
| } |
| |
| |
| 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); |
| 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; |
| } |
| |
| |
| 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_decompressFrame() : |
| * `dctx` must be properly initialized */ |
| static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize) |
| { |
| const BYTE* ip = (const BYTE*)src; |
| BYTE* const ostart = (BYTE* const)dst; |
| BYTE* const oend = ostart + dstCapacity; |
| BYTE* op = ostart; |
| size_t remainingSize = srcSize; |
| |
| /* check */ |
| if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); |
| |
| /* Frame Header */ |
| { size_t const frameHeaderSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_min); |
| size_t result; |
| if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize; |
| if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); |
| result = ZSTD_decodeFrameHeader(dctx, src, frameHeaderSize); |
| if (ZSTD_isError(result)) return result; |
| 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); |
| 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.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); |
| remainingSize -= 4; |
| } |
| |
| if (remainingSize) return ERROR(srcSize_wrong); |
| return op-ostart; |
| } |
| |
| |
| /*! ZSTD_decompress_usingPreparedDCtx() : |
| * Same as ZSTD_decompress_usingDict, but using a reference context `preparedDCtx`, where dictionary has been loaded. |
| * It avoids reloading the dictionary each time. |
| * `preparedDCtx` must have been properly initialized using ZSTD_decompressBegin_usingDict(). |
| * Requires 2 contexts : 1 for reference (preparedDCtx), which will not be modified, and 1 to run the decompression operation (dctx) */ |
| size_t ZSTD_decompress_usingPreparedDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* refDCtx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize) |
| { |
| ZSTD_copyDCtx(dctx, refDCtx); |
| ZSTD_checkContinuity(dctx, dst); |
| return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize); |
| } |
| |
| |
| 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) |
| { |
| #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1) |
| if (ZSTD_isLegacy(src, srcSize)) return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, dict, dictSize); |
| #endif |
| ZSTD_decompressBegin_usingDict(dctx, dict, dictSize); |
| ZSTD_checkContinuity(dctx, dst); |
| return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize); |
| } |
| |
| |
| 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 */ |
| 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; |
| } |
| } |
| |
| int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; } /* for zbuff */ |
| |
| /** ZSTD_decompressContinue() : |
| * @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) |
| { |
| /* Sanity check */ |
| if (srcSize != dctx->expected) return ERROR(srcSize_wrong); |
| if (dstCapacity) ZSTD_checkContinuity(dctx, dst); |
| |
| switch (dctx->stage) |
| { |
| case ZSTDds_getFrameHeaderSize : |
| if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong); /* impossible */ |
| if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { |
| memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_min); |
| dctx->expected = ZSTD_skippableHeaderSize - ZSTD_frameHeaderSize_min; /* magic number + skippable frame length */ |
| dctx->stage = ZSTDds_decodeSkippableHeader; |
| return 0; |
| } |
| dctx->headerSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_min); |
| if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize; |
| memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_min); |
| if (dctx->headerSize > ZSTD_frameHeaderSize_min) { |
| dctx->expected = dctx->headerSize - ZSTD_frameHeaderSize_min; |
| dctx->stage = ZSTDds_decodeFrameHeader; |
| return 0; |
| } |
| dctx->expected = 0; /* not necessary to copy more */ |
| |
| case ZSTDds_decodeFrameHeader: |
| { size_t result; |
| memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_min, src, dctx->expected); |
| result = ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize); |
| if (ZSTD_isError(result)) return result; |
| 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 = 3; /* go directly to next header */ |
| dctx->stage = ZSTDds_decodeBlockHeader; |
| } |
| return 0; |
| } |
| case ZSTDds_decompressLastBlock: |
| case ZSTDds_decompressBlock: |
| { size_t rSize; |
| switch(dctx->bType) |
| { |
| case bt_compressed: |
| rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize); |
| 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; |
| if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize); |
| |
| if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */ |
| 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: |
| { U32 const h32 = (U32)XXH64_digest(&dctx->xxhState); |
| U32 const check32 = MEM_readLE32(src); /* srcSize == 4, guaranteed by dctx->expected */ |
| if (check32 != h32) return ERROR(checksum_wrong); |
| dctx->expected = 0; |
| dctx->stage = ZSTDds_getFrameHeaderSize; |
| return 0; |
| } |
| case ZSTDds_decodeSkippableHeader: |
| { memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_min, src, dctx->expected); |
| dctx->expected = MEM_readLE32(dctx->headerBuffer + 4); |
| 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; |
| } |
| |
| static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* const dict, size_t const dictSize) |
| { |
| const BYTE* dictPtr = (const BYTE*)dict; |
| const BYTE* const dictEnd = dictPtr + dictSize; |
| |
| { size_t const hSize = HUF_readDTableX4(dctx->hufTable, dict, dictSize); |
| if (HUF_isError(hSize)) return ERROR(dictionary_corrupted); |
| dictPtr += hSize; |
| } |
| |
| { short offcodeNCount[MaxOff+1]; |
| U32 offcodeMaxValue=MaxOff, offcodeLog=OffFSELog; |
| size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr); |
| if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted); |
| { size_t const errorCode = FSE_buildDTable(dctx->OffTable, offcodeNCount, offcodeMaxValue, offcodeLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); } |
| dictPtr += offcodeHeaderSize; |
| } |
| |
| { short matchlengthNCount[MaxML+1]; |
| unsigned matchlengthMaxValue = MaxML, matchlengthLog = MLFSELog; |
| size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr); |
| if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted); |
| { size_t const errorCode = FSE_buildDTable(dctx->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); } |
| dictPtr += matchlengthHeaderSize; |
| } |
| |
| { short litlengthNCount[MaxLL+1]; |
| unsigned litlengthMaxValue = MaxLL, litlengthLog = LLFSELog; |
| size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr); |
| if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted); |
| { size_t const errorCode = FSE_buildDTable(dctx->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); } |
| dictPtr += litlengthHeaderSize; |
| } |
| |
| if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted); |
| dctx->rep[0] = MEM_readLE32(dictPtr+0); if (dctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted); |
| dctx->rep[1] = MEM_readLE32(dictPtr+4); if (dctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted); |
| dctx->rep[2] = MEM_readLE32(dictPtr+8); if (dctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted); |
| dictPtr += 12; |
| |
| dctx->litEntropy = dctx->fseEntropy = 1; |
| 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_DICT_MAGIC) { |
| return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */ |
| } } |
| dctx->dictID = MEM_readLE32((const char*)dict + 4); |
| |
| /* load entropy tables */ |
| dict = (const char*)dict + 8; |
| dictSize -= 8; |
| { size_t const eSize = ZSTD_loadEntropy(dctx, dict, dictSize); |
| if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted); |
| dict = (const char*)dict + eSize; |
| dictSize -= eSize; |
| } |
| |
| /* reference dictionary content */ |
| return ZSTD_refDictContent(dctx, dict, dictSize); |
| } |
| |
| |
| size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) |
| { |
| { size_t const errorCode = ZSTD_decompressBegin(dctx); |
| if (ZSTD_isError(errorCode)) return errorCode; } |
| |
| if (dict && dictSize) { |
| size_t const errorCode = ZSTD_decompress_insertDictionary(dctx, dict, dictSize); |
| if (ZSTD_isError(errorCode)) return ERROR(dictionary_corrupted); |
| } |
| |
| return 0; |
| } |
| |
| |
| struct ZSTD_DDict_s { |
| void* dict; |
| size_t dictSize; |
| ZSTD_DCtx* refContext; |
| }; /* typedef'd tp ZSTD_CDict within zstd.h */ |
| |
| ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, ZSTD_customMem customMem) |
| { |
| if (!customMem.customAlloc && !customMem.customFree) |
| customMem = defaultCustomMem; |
| |
| if (!customMem.customAlloc || !customMem.customFree) |
| return NULL; |
| |
| { ZSTD_DDict* const ddict = (ZSTD_DDict*) customMem.customAlloc(customMem.opaque, sizeof(*ddict)); |
| void* const dictContent = customMem.customAlloc(customMem.opaque, dictSize); |
| ZSTD_DCtx* const dctx = ZSTD_createDCtx_advanced(customMem); |
| |
| if (!dictContent || !ddict || !dctx) { |
| customMem.customFree(customMem.opaque, dictContent); |
| customMem.customFree(customMem.opaque, ddict); |
| customMem.customFree(customMem.opaque, dctx); |
| return NULL; |
| } |
| |
| memcpy(dictContent, dict, dictSize); |
| { size_t const errorCode = ZSTD_decompressBegin_usingDict(dctx, dictContent, dictSize); |
| if (ZSTD_isError(errorCode)) { |
| customMem.customFree(customMem.opaque, dictContent); |
| customMem.customFree(customMem.opaque, ddict); |
| customMem.customFree(customMem.opaque, dctx); |
| return NULL; |
| } } |
| |
| ddict->dict = dictContent; |
| ddict->dictSize = dictSize; |
| ddict->refContext = dctx; |
| return ddict; |
| } |
| } |
| |
| /*! ZSTD_createDDict() : |
| * Create a digested dictionary, ready to start decompression without startup delay. |
| * `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, allocator); |
| } |
| |
| size_t ZSTD_freeDDict(ZSTD_DDict* ddict) |
| { |
| ZSTD_freeFunction const cFree = ddict->refContext->customMem.customFree; |
| void* const opaque = ddict->refContext->customMem.opaque; |
| ZSTD_freeDCtx(ddict->refContext); |
| cFree(opaque, ddict->dict); |
| cFree(opaque, ddict); |
| return 0; |
| } |
| |
| /*! ZSTD_decompress_usingDDict() : |
| * Decompression using a pre-digested Dictionary |
| * Use dictionary without significant overhead. */ |
| ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize, |
| const ZSTD_DDict* ddict) |
| { |
| #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1) |
| if (ZSTD_isLegacy(src, srcSize)) return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, ddict->dict, ddict->dictSize); |
| #endif |
| return ZSTD_decompress_usingPreparedDCtx(dctx, ddict->refContext, |
| dst, dstCapacity, |
| src, srcSize); |
| } |
| |
| |
| /*===================================== |
| * Streaming decompression |
| *====================================*/ |
| |
| typedef enum { zdss_init, zdss_loadHeader, |
| zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage; |
| |
| /* *** Resource management *** */ |
| struct ZSTD_DStream_s { |
| ZSTD_DCtx* zd; |
| ZSTD_frameParams fParams; |
| ZSTD_dStreamStage stage; |
| char* inBuff; |
| size_t inBuffSize; |
| size_t inPos; |
| char* outBuff; |
| size_t outBuffSize; |
| size_t outStart; |
| size_t outEnd; |
| size_t blockSize; |
| BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; |
| size_t lhSize; |
| ZSTD_customMem customMem; |
| }; /* typedef'd to ZSTD_DStream within "zstd.h" */ |
| |
| |
| ZSTD_DStream* ZSTD_createDStream(void) |
| { |
| return ZSTD_createDStream_advanced(defaultCustomMem); |
| } |
| |
| ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem) |
| { |
| ZSTD_DStream* zds; |
| |
| if (!customMem.customAlloc && !customMem.customFree) |
| customMem = defaultCustomMem; |
| |
| if (!customMem.customAlloc || !customMem.customFree) |
| return NULL; |
| |
| zds = (ZSTD_DStream*)customMem.customAlloc(customMem.opaque, sizeof(ZSTD_DStream)); |
| if (zds==NULL) return NULL; |
| memset(zds, 0, sizeof(ZSTD_DStream)); |
| memcpy(&zds->customMem, &customMem, sizeof(ZSTD_customMem)); |
| zds->zd = ZSTD_createDCtx_advanced(customMem); |
| if (zds->zd == NULL) { ZSTD_freeDStream(zds); return NULL; } |
| zds->stage = zdss_init; |
| return zds; |
| } |
| |
| size_t ZSTD_freeDStream(ZSTD_DStream* zds) |
| { |
| if (zds==NULL) return 0; /* support free on null */ |
| ZSTD_freeDCtx(zds->zd); |
| if (zds->inBuff) zds->customMem.customFree(zds->customMem.opaque, zds->inBuff); |
| if (zds->outBuff) zds->customMem.customFree(zds->customMem.opaque, zds->outBuff); |
| zds->customMem.customFree(zds->customMem.opaque, zds); |
| return 0; |
| } |
| |
| |
| /* *** Initialization *** */ |
| |
| size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX + ZSTD_blockHeaderSize; } |
| size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; } |
| |
| size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize) |
| { |
| zds->stage = zdss_loadHeader; |
| zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; |
| return ZSTD_decompressBegin_usingDict(zds->zd, dict, dictSize); |
| } |
| |
| size_t ZSTD_initDStream(ZSTD_DStream* zds) |
| { |
| return ZSTD_initDStream_usingDict(zds, NULL, 0); |
| } |
| |
| size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds) |
| { |
| return sizeof(*zds) + ZSTD_sizeof_DCtx(zds->zd) + zds->inBuffSize + zds->outBuffSize; |
| } |
| |
| |
| /* *** 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; |
| |
| while (someMoreWork) { |
| switch(zds->stage) |
| { |
| case zdss_init : |
| return ERROR(init_missing); |
| |
| case zdss_loadHeader : |
| { size_t const hSize = ZSTD_getFrameParams(&(zds->fParams), zds->headerBuffer, zds->lhSize); |
| if (ZSTD_isError(hSize)) return hSize; |
| 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 */ |
| memcpy(zds->headerBuffer + zds->lhSize, ip, iend-ip); |
| zds->lhSize += iend-ip; |
| input->pos = input->size; |
| return (hSize - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */ |
| } |
| memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad; |
| break; |
| } } |
| |
| /* Consume header */ |
| { size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zds->zd); /* == ZSTD_frameHeaderSize_min */ |
| size_t const h1Result = ZSTD_decompressContinue(zds->zd, NULL, 0, zds->headerBuffer, h1Size); |
| if (ZSTD_isError(h1Result)) return h1Result; /* should not happen : already checked */ |
| if (h1Size < zds->lhSize) { /* long header */ |
| size_t const h2Size = ZSTD_nextSrcSizeToDecompress(zds->zd); |
| size_t const h2Result = ZSTD_decompressContinue(zds->zd, NULL, 0, zds->headerBuffer+h1Size, h2Size); |
| if (ZSTD_isError(h2Result)) return h2Result; |
| } } |
| |
| zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN); |
| |
| /* Frame header instruct buffer sizes */ |
| { size_t const blockSize = MIN(zds->fParams.windowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX); |
| size_t const neededOutSize = zds->fParams.windowSize + blockSize; |
| if (zds->fParams.windowSize > ZSTD_STREAM_WINDOW_MAX) return ERROR(frameParameter_unsupported); |
| zds->blockSize = blockSize; |
| if (zds->inBuffSize < blockSize) { |
| zds->customMem.customFree(zds->customMem.opaque, zds->inBuff); |
| zds->inBuffSize = blockSize; |
| zds->inBuff = (char*)zds->customMem.customAlloc(zds->customMem.opaque, blockSize); |
| if (zds->inBuff == NULL) return ERROR(memory_allocation); |
| } |
| if (zds->outBuffSize < neededOutSize) { |
| zds->customMem.customFree(zds->customMem.opaque, zds->outBuff); |
| zds->outBuffSize = neededOutSize; |
| zds->outBuff = (char*)zds->customMem.customAlloc(zds->customMem.opaque, neededOutSize); |
| if (zds->outBuff == NULL) return ERROR(memory_allocation); |
| } } |
| zds->stage = zdss_read; |
| /* pass-through */ |
| |
| case zdss_read: |
| { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->zd); |
| if (neededInSize==0) { /* end of frame */ |
| zds->stage = zdss_init; |
| someMoreWork = 0; |
| break; |
| } |
| if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */ |
| const int isSkipFrame = ZSTD_isSkipFrame(zds->zd); |
| size_t const decodedSize = ZSTD_decompressContinue(zds->zd, |
| 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->stage = zdss_flush; |
| break; |
| } |
| if (ip==iend) { someMoreWork = 0; break; } /* no more input */ |
| zds->stage = zdss_load; |
| /* pass-through */ |
| } |
| |
| case zdss_load: |
| { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->zd); |
| 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->zd); |
| size_t const decodedSize = ZSTD_decompressContinue(zds->zd, |
| 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->stage = zdss_read; break; } /* this was just a header */ |
| zds->outEnd = zds->outStart + decodedSize; |
| zds->stage = zdss_flush; |
| /* pass-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->stage = zdss_read; |
| if (zds->outStart + zds->blockSize > zds->outBuffSize) |
| zds->outStart = zds->outEnd = 0; |
| break; |
| } |
| /* cannot flush everything */ |
| 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->zd); |
| if (!nextSrcSizeHint) return (zds->outEnd != zds->outStart); /* return 0 only if fully flushed too */ |
| nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->zd) == ZSTDnit_block); |
| if (zds->inPos > nextSrcSizeHint) return ERROR(GENERIC); /* should never happen */ |
| nextSrcSizeHint -= zds->inPos; /* already loaded*/ |
| return nextSrcSizeHint; |
| } |
| } |