| /* |
| 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 |
| |
| |
| /*-******************************************************* |
| * Dependencies |
| *********************************************************/ |
| #include <stdlib.h> /* calloc */ |
| #include <string.h> /* memcpy, memmove */ |
| #include <stdio.h> /* debug only : printf */ |
| #include "mem.h" /* low level memory routines */ |
| #include "zstd_internal.h" |
| #include "fse_static.h" |
| #include "huff0_static.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 */ |
| #else |
| # ifdef __GNUC__ |
| # define FORCE_INLINE static inline __attribute__((always_inline)) |
| # else |
| # define FORCE_INLINE static inline |
| # endif |
| #endif |
| |
| |
| /*_******************************************************* |
| * Memory operations |
| **********************************************************/ |
| static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); } |
| |
| |
| /*-************************************* |
| * Error Management |
| ***************************************/ |
| unsigned ZSTD_versionNumber (void) { return ZSTD_VERSION_NUMBER; } |
| |
| /*! ZSTD_isError() : |
| * tells if a return value is an error code */ |
| unsigned ZSTD_isError(size_t code) { return ERR_isError(code); } |
| |
| /*! ZSTD_getError() : |
| * convert a `size_t` function result into a proper ZSTD_errorCode enum */ |
| ZSTD_ErrorCode ZSTD_getError(size_t code) { return ERR_getError(code); } |
| |
| /*! ZSTD_getErrorName() : |
| * provides error code string (useful for debugging) */ |
| const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); } |
| |
| |
| /*-************************************************************* |
| * Context management |
| ***************************************************************/ |
| typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader, |
| ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock } 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)]; |
| unsigned hufTableX4[HUF_DTABLE_SIZE(HufLog)]; |
| const void* previousDstEnd; |
| const void* base; |
| const void* vBase; |
| const void* dictEnd; |
| size_t expected; |
| size_t headerSize; |
| ZSTD_frameParams fParams; |
| blockType_t bType; /* used in ZSTD_decompressContinue(), to transfer blockType between header decoding and block decoding stages */ |
| ZSTD_dStage stage; |
| U32 flagStaticTables; |
| const BYTE* litPtr; |
| size_t litBufSize; |
| size_t litSize; |
| BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH]; |
| BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; |
| }; /* typedef'd to ZSTD_DCtx within "zstd_static.h" */ |
| |
| size_t sizeofDCtx (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->hufTableX4[0] = HufLog; |
| dctx->flagStaticTables = 0; |
| dctx->fParams.mml = MINMATCH; /* overwritten by frame but forces ZSTD_btopt to MINMATCH in block mode */ |
| ZSTD_LOG_BLOCK("%p: ZSTD_decompressBegin searchLength=%d\n", dctx->base, dctx->params.searchLength); |
| return 0; |
| } |
| |
| ZSTD_DCtx* ZSTD_createDCtx(void) |
| { |
| ZSTD_DCtx* dctx = (ZSTD_DCtx*)malloc(sizeof(ZSTD_DCtx)); |
| if (dctx==NULL) return NULL; |
| ZSTD_decompressBegin(dctx); |
| return dctx; |
| } |
| |
| size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx) |
| { |
| free(dctx); |
| return 0; /* reserved as a potential error code in the future */ |
| } |
| |
| void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx) |
| { |
| memcpy(dstDCtx, srcDCtx, |
| sizeof(ZSTD_DCtx) - (ZSTD_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH + ZSTD_frameHeaderSize_max)); /* no need to copy workspace */ |
| } |
| |
| |
| /*-************************************************************* |
| * Decompression section |
| ***************************************************************/ |
| |
| /* Frame format description |
| Frame Header - [ Block Header - Block ] - Frame End |
| 1) Frame Header |
| - 4 bytes - Magic Number : ZSTD_MAGICNUMBER (defined within zstd_static.h) |
| - 1 byte - Frame Descriptor |
| 2) Block Header |
| - 3 bytes, starting with a 2-bits descriptor |
| Uncompressed, Compressed, Frame End, unused |
| 3) Block |
| See Block Format Description |
| 4) Frame End |
| - 3 bytes, compatible with Block Header |
| */ |
| |
| |
| /* Frame descriptor |
| |
| 1 byte, using : |
| bit 0-3 : windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN (see zstd_internal.h) |
| bit 4 : minmatch 4(0) or 3(1) |
| bit 5 : reserved (must be zero) |
| bit 6-7 : Frame content size : unknown, 1 byte, 2 bytes, 8 bytes |
| |
| Optional : content size (0, 1, 2 or 8 bytes) |
| 0 : unknown |
| 1 : 0-255 bytes |
| 2 : 256 - 65535+256 |
| 8 : up to 16 exa |
| */ |
| |
| |
| /* Compressed Block, format description |
| |
| Block = Literal Section - Sequences Section |
| Prerequisite : size of (compressed) block, maximum size of regenerated data |
| |
| 1) Literal Section |
| |
| 1.1) Header : 1-5 bytes |
| flags: 2 bits |
| 00 compressed by Huff0 |
| 01 unused |
| 10 is Raw (uncompressed) |
| 11 is Rle |
| Note : using 01 => Huff0 with precomputed table ? |
| Note : delta map ? => compressed ? |
| |
| 1.1.1) Huff0-compressed literal block : 3-5 bytes |
| srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream |
| srcSize < 1 KB => 3 bytes (2-2-10-10) |
| srcSize < 16KB => 4 bytes (2-2-14-14) |
| else => 5 bytes (2-2-18-18) |
| big endian convention |
| |
| 1.1.2) Raw (uncompressed) literal block header : 1-3 bytes |
| size : 5 bits: (IS_RAW<<6) + (0<<4) + size |
| 12 bits: (IS_RAW<<6) + (2<<4) + (size>>8) |
| size&255 |
| 20 bits: (IS_RAW<<6) + (3<<4) + (size>>16) |
| size>>8&255 |
| size&255 |
| |
| 1.1.3) Rle (repeated single byte) literal block header : 1-3 bytes |
| size : 5 bits: (IS_RLE<<6) + (0<<4) + size |
| 12 bits: (IS_RLE<<6) + (2<<4) + (size>>8) |
| size&255 |
| 20 bits: (IS_RLE<<6) + (3<<4) + (size>>16) |
| size>>8&255 |
| size&255 |
| |
| 1.1.4) Huff0-compressed literal block, using precomputed CTables : 3-5 bytes |
| srcSize < 1 KB => 3 bytes (2-2-10-10) => single stream |
| srcSize < 1 KB => 3 bytes (2-2-10-10) |
| srcSize < 16KB => 4 bytes (2-2-14-14) |
| else => 5 bytes (2-2-18-18) |
| big endian convention |
| |
| 1- CTable available (stored into workspace ?) |
| 2- Small input (fast heuristic ? Full comparison ? depend on clevel ?) |
| |
| |
| 1.2) Literal block content |
| |
| 1.2.1) Huff0 block, using sizes from header |
| See Huff0 format |
| |
| 1.2.2) Huff0 block, using prepared table |
| |
| 1.2.3) Raw content |
| |
| 1.2.4) single byte |
| |
| |
| 2) Sequences section |
| TO DO |
| */ |
| |
| /** 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) |
| { |
| U32 fcsId; |
| if (srcSize < ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong); |
| fcsId = (((const BYTE*)src)[4]) >> 6; |
| return ZSTD_frameHeaderSize_min + ZSTD_fcs_fieldSize[fcsId]; |
| } |
| |
| |
| /** ZSTD_getFrameParams() : |
| * decode Frame Header, or provide expected `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) 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; } |
| |
| memset(fparamsPtr, 0, sizeof(*fparamsPtr)); |
| { BYTE const frameDesc = ip[4]; |
| fparamsPtr->windowLog = (frameDesc & 0xF) + ZSTD_WINDOWLOG_ABSOLUTEMIN; |
| fparamsPtr->mml = (frameDesc & 0x10) ? MINMATCH-1 : MINMATCH; |
| if ((frameDesc & 0x20) != 0) return ERROR(frameParameter_unsupported); /* reserved 1 bit */ |
| switch(frameDesc >> 6) /* fcsId */ |
| { |
| default: /* impossible */ |
| case 0 : fparamsPtr->frameContentSize = 0; break; |
| case 1 : fparamsPtr->frameContentSize = ip[5]; break; |
| case 2 : fparamsPtr->frameContentSize = MEM_readLE16(ip+5)+256; break; |
| case 3 : fparamsPtr->frameContentSize = MEM_readLE64(ip+5); break; |
| } } |
| return 0; |
| } |
| |
| |
| /** 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* zc, const void* src, size_t srcSize) |
| { |
| size_t const result = ZSTD_getFrameParams(&(zc->fParams), src, srcSize); |
| if ((MEM_32bits()) && (zc->fParams.windowLog > 25)) return ERROR(frameParameter_unsupportedBy32bits); |
| return result; |
| } |
| |
| |
| typedef struct |
| { |
| blockType_t blockType; |
| 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) |
| { |
| const BYTE* const in = (const BYTE* const)src; |
| U32 cSize; |
| |
| if (srcSize < ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); |
| |
| bpPtr->blockType = (blockType_t)((*in) >> 6); |
| cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16); |
| bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0; |
| |
| if (bpPtr->blockType == bt_end) return 0; |
| if (bpPtr->blockType == bt_rle) return 1; |
| 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; |
| } |
| |
| |
| /*! 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 */ |
| { |
| const BYTE* const istart = (const BYTE*) src; |
| |
| /* any compressed block with literals segment must be at least this size */ |
| if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected); |
| |
| switch(istart[0]>> 6) |
| { |
| case IS_HUF: |
| { |
| size_t litSize, litCSize, singleStream=0; |
| U32 lhSize = ((istart[0]) >> 4) & 3; |
| switch(lhSize) |
| { |
| case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */ |
| /* 2 - 2 - 10 - 10 */ |
| lhSize=3; |
| singleStream = istart[0] & 16; |
| litSize = ((istart[0] & 15) << 6) + (istart[1] >> 2); |
| litCSize = ((istart[1] & 3) << 8) + istart[2]; |
| break; |
| case 2: |
| /* 2 - 2 - 14 - 14 */ |
| lhSize=4; |
| litSize = ((istart[0] & 15) << 10) + (istart[1] << 2) + (istart[2] >> 6); |
| litCSize = ((istart[2] & 63) << 8) + istart[3]; |
| break; |
| case 3: |
| /* 2 - 2 - 18 - 18 */ |
| lhSize=5; |
| litSize = ((istart[0] & 15) << 14) + (istart[1] << 6) + (istart[2] >> 2); |
| litCSize = ((istart[2] & 3) << 16) + (istart[3] << 8) + istart[4]; |
| break; |
| } |
| if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected); |
| |
| if (HUF_isError(singleStream ? |
| HUF_decompress1X2(dctx->litBuffer, litSize, istart+lhSize, litCSize) : |
| HUF_decompress (dctx->litBuffer, litSize, istart+lhSize, litCSize) )) |
| return ERROR(corruption_detected); |
| |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+8; |
| dctx->litSize = litSize; |
| return litCSize + lhSize; |
| } |
| case IS_PCH: |
| { |
| size_t errorCode; |
| size_t litSize, litCSize; |
| U32 lhSize = ((istart[0]) >> 4) & 3; |
| if (lhSize != 1) /* only case supported for now : small litSize, single stream */ |
| return ERROR(corruption_detected); |
| if (!dctx->flagStaticTables) |
| return ERROR(dictionary_corrupted); |
| |
| /* 2 - 2 - 10 - 10 */ |
| lhSize=3; |
| litSize = ((istart[0] & 15) << 6) + (istart[1] >> 2); |
| litCSize = ((istart[1] & 3) << 8) + istart[2]; |
| |
| errorCode = HUF_decompress1X4_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTableX4); |
| if (HUF_isError(errorCode)) return ERROR(corruption_detected); |
| |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH; |
| dctx->litSize = litSize; |
| return litCSize + lhSize; |
| } |
| case IS_RAW: |
| { |
| size_t litSize; |
| U32 lhSize = ((istart[0]) >> 4) & 3; |
| switch(lhSize) |
| { |
| case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */ |
| lhSize=1; |
| litSize = istart[0] & 31; |
| break; |
| case 2: |
| litSize = ((istart[0] & 15) << 8) + istart[1]; |
| break; |
| case 3: |
| litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2]; |
| 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_MAX+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 IS_RLE: |
| { |
| size_t litSize; |
| U32 lhSize = ((istart[0]) >> 4) & 3; |
| switch(lhSize) |
| { |
| case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */ |
| lhSize = 1; |
| litSize = istart[0] & 31; |
| break; |
| case 2: |
| litSize = ((istart[0] & 15) << 8) + istart[1]; |
| break; |
| case 3: |
| litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2]; |
| break; |
| } |
| if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected); |
| memset(dctx->litBuffer, istart[lhSize], litSize); |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+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, U32 type, U32 rawBits, U32 maxLog, |
| const void* src, size_t srcSize) |
| { |
| U32 max = (1<<rawBits)-1; |
| switch(type) |
| { |
| case FSE_ENCODING_RLE : |
| if (!srcSize) return ERROR(srcSize_wrong); |
| FSE_buildDTable_rle(DTable, (*(const BYTE*)src) & max); /* if *src > max, data is corrupted */ |
| return 1; |
| case FSE_ENCODING_RAW : |
| FSE_buildDTable_raw(DTable, rawBits); |
| return 0; |
| case FSE_ENCODING_STATIC: |
| return 0; |
| default : /* impossible */ |
| case FSE_ENCODING_DYNAMIC : |
| { 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; |
| } } |
| } |
| |
| |
| FORCE_INLINE size_t ZSTD_buildSeqTableLL(FSE_DTable* DTable, U32 type, U32 max, U32 maxLog, |
| const void* src, size_t srcSize) |
| { |
| switch(type) |
| { |
| case FSE_ENCODING_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 FSE_ENCODING_RAW : |
| FSE_buildDTable(DTable, LL_defaultNorm, max, LL_defaultNormLog); |
| return 0; |
| case FSE_ENCODING_STATIC: |
| return 0; |
| default : /* impossible */ |
| case FSE_ENCODING_DYNAMIC : |
| { 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; |
| } } |
| } |
| |
| |
| FORCE_INLINE size_t ZSTD_buildSeqTableML(FSE_DTable* DTable, U32 type, U32 max, U32 maxLog, |
| const void* src, size_t srcSize) |
| { |
| switch(type) |
| { |
| case FSE_ENCODING_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 FSE_ENCODING_RAW : |
| FSE_buildDTable(DTable, ML_defaultNorm, max, ML_defaultNormLog); |
| return 0; |
| case FSE_ENCODING_STATIC: |
| return 0; |
| default : /* impossible */ |
| case FSE_ENCODING_DYNAMIC : |
| { 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* nbSeq, |
| FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb, |
| const void* src, size_t srcSize) |
| { |
| const BYTE* const istart = (const BYTE* const)src; |
| const BYTE* ip = istart; |
| const BYTE* const iend = istart + srcSize; |
| U32 LLtype, Offtype, MLtype; |
| |
| /* check */ |
| if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong); |
| |
| /* SeqHead */ |
| *nbSeq = *ip++; |
| if (*nbSeq==0) return 1; |
| if (*nbSeq >= 0x7F) { |
| if (*nbSeq == 0xFF) |
| *nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; |
| else |
| *nbSeq = ((nbSeq[0]-0x80)<<8) + *ip++; |
| } |
| |
| /* FSE table descriptors */ |
| LLtype = *ip >> 6; |
| Offtype = (*ip >> 4) & 3; |
| MLtype = (*ip >> 2) & 3; |
| ip++; |
| |
| /* check */ |
| if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */ |
| |
| /* Build DTables */ |
| { size_t const bhSize = ZSTD_buildSeqTableLL(DTableLL, LLtype, MaxLL, LLFSELog, ip, iend-ip); |
| if (ZSTD_isError(bhSize)) return ERROR(corruption_detected); |
| ip += bhSize; |
| } |
| { size_t const bhSize = ZSTD_buildSeqTable(DTableOffb, Offtype, Offbits, OffFSELog, ip, iend-ip); |
| if (ZSTD_isError(bhSize)) return ERROR(corruption_detected); |
| ip += bhSize; |
| } |
| { size_t const bhSize = ZSTD_buildSeqTableML(DTableML, MLtype, MaxML, MLFSELog, ip, iend-ip); |
| if (ZSTD_isError(bhSize)) return ERROR(corruption_detected); |
| ip += bhSize; |
| } |
| |
| 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; |
| } seqState_t; |
| |
| |
| static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls) |
| { |
| /* Literal length */ |
| U32 const litCode = FSE_peakSymbol(&(seqState->stateLL)); |
| { 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 }; |
| seq->litLength = LL_base[litCode] + BIT_readBits(&(seqState->DStream), LL_bits[litCode]); |
| } |
| |
| /* Offset */ |
| { static const U32 offsetPrefix[MaxOff+1] = { |
| 1 /*fake*/, 1, 2, 4, 8, 0x10, 0x20, 0x40, |
| 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, |
| 0x8000, 0x10000, 0x20000, 0x40000, 0x80000, 0x100000, 0x200000, 0x400000, |
| 0x800000, 0x1000000, 0x2000000, 0x4000000, /*fake*/ 1, 1, 1, 1 }; |
| U32 const offsetCode = FSE_peakSymbol(&(seqState->stateOffb)); /* <= maxOff, by table construction */ |
| U32 const nbBits = offsetCode ? offsetCode-1 : 0; |
| size_t const offset = offsetCode ? offsetPrefix[offsetCode] + BIT_readBits(&(seqState->DStream), nbBits) : |
| litCode ? seq->offset : seqState->prevOffset; |
| if (offsetCode | !litCode) seqState->prevOffset = seq->offset; /* cmove */ |
| seq->offset = offset; |
| if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream)); |
| } |
| |
| { static const U32 ML_base[MaxML+1] = { |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, |
| 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, |
| 32, 34, 36, 38, 40, 44, 48, 56, 64, 80, 96, 0x80, 0x100, 0x200, 0x400, 0x800, |
| 0x1000, 0x2000, 0x4000, 0x8000, 0x10000 }; |
| U32 const mlCode = FSE_peakSymbol(&(seqState->stateML)); |
| seq->matchLength = ML_base[mlCode] + BIT_readBits(&(seqState->DStream), ML_bits[mlCode]) + mls; |
| } |
| |
| /* ANS update */ |
| FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream)); /* update */ |
| if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream)); |
| |
| FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream)); /* update */ |
| if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream)); |
| |
| FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream)); /* update */ |
| if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream)); |
| |
| #if 0 /* debug */ |
| { |
| static U64 totalDecoded = 0; |
| printf("pos %6u : %3u literals & match %3u bytes at distance %6u \n", |
| (U32)(totalDecoded), (U32)litLength, (U32)matchLength, (U32)offset); |
| totalDecoded += litLength + matchLength; |
| } |
| #endif |
| } |
| |
| |
| FORCE_INLINE size_t ZSTD_execSequence(BYTE* op, |
| BYTE* const oend, seq_t sequence, |
| const BYTE** litPtr, const BYTE* const litLimit_8, |
| const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd) |
| { |
| static const int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ |
| static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* substracted */ |
| BYTE* const oLitEnd = op + sequence.litLength; |
| const size_t sequenceLength = sequence.litLength + sequence.matchLength; |
| BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ |
| BYTE* const oend_8 = oend-8; |
| const BYTE* const litEnd = *litPtr + sequence.litLength; |
| const BYTE* match = oLitEnd - sequence.offset; |
| |
| /* check */ |
| if (oLitEnd > oend_8) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of 8 from oend */ |
| if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* overwrite beyond dst buffer */ |
| if (litEnd > litLimit_8) return ERROR(corruption_detected); /* risk read beyond lit buffer */ |
| |
| /* copy Literals */ |
| ZSTD_wildcopy(op, *litPtr, sequence.litLength); /* note : oLitEnd <= oend-8 : no risk of overwrite beyond oend */ |
| op = oLitEnd; |
| *litPtr = litEnd; /* 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 */ |
| const int 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-(16-3)) { // 3 = MINMATCH |
| if (op < oend_8) { |
| ZSTD_wildcopy(op, match, oend_8 - op); |
| match += oend_8 - op; |
| op = oend_8; |
| } |
| 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* op = ostart; |
| BYTE* const oend = ostart + maxDstSize; |
| const BYTE* litPtr = dctx->litPtr; |
| const BYTE* const litLimit_8 = litPtr + dctx->litBufSize - 8; |
| const BYTE* const litEnd = litPtr + dctx->litSize; |
| int nbSeq; |
| U32* DTableLL = dctx->LLTable; |
| U32* DTableML = dctx->MLTable; |
| U32* 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); |
| const U32 mls = dctx->fParams.mml; |
| |
| /* Build Decoding Tables */ |
| { size_t const errorCode = ZSTD_decodeSeqHeaders(&nbSeq, |
| DTableLL, DTableML, DTableOffb, |
| ip, seqSize); |
| if (ZSTD_isError(errorCode)) return errorCode; |
| ip += errorCode; |
| } |
| |
| /* Regen sequences */ |
| if (nbSeq) { |
| seq_t sequence; |
| seqState_t seqState; |
| |
| memset(&sequence, 0, sizeof(sequence)); |
| sequence.offset = REPCODE_STARTVALUE; |
| seqState.prevOffset = REPCODE_STARTVALUE; |
| { 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 ; ) { |
| size_t oneSeqSize; |
| nbSeq--; |
| ZSTD_decodeSequence(&sequence, &seqState, mls); |
| #if 0 /* for debug */ |
| { U32 pos = (U32)(op-base); |
| if ((pos > 10354000) && (pos < 10355000)) |
| printf("pos %6u : %3u literals & match %3u bytes at distance %6u \n", |
| pos, (U32)sequence.litLength, (U32)sequence.matchLength, (U32)sequence.offset); |
| } |
| #endif |
| oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litLimit_8, base, vBase, dictEnd); |
| if (ZSTD_isError(oneSeqSize)) return oneSeqSize; |
| op += oneSeqSize; |
| } |
| |
| /* check if reached exact end */ |
| if (nbSeq) return ERROR(corruption_detected); |
| } |
| |
| /* last literal segment */ |
| { size_t const lastLLSize = litEnd - litPtr; |
| if (litPtr > litEnd) return ERROR(corruption_detected); /* too many literals already used */ |
| if (op+lastLLSize > oend) 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_MAX) return ERROR(srcSize_wrong); |
| |
| ZSTD_LOG_BLOCK("%p: ZSTD_decompressBlock_internal searchLength=%d\n", dctx->base, dctx->params.searchLength); |
| |
| /* 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) |
| { |
| ZSTD_checkContinuity(dctx, dst); |
| return ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize); |
| } |
| |
| |
| /*! ZSTD_decompress_continueDCtx() : |
| * `dctx` must have been 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; |
| const BYTE* iend = ip + srcSize; |
| BYTE* const ostart = (BYTE* const)dst; |
| BYTE* op = ostart; |
| BYTE* const oend = ostart + dstCapacity; |
| size_t remainingSize = srcSize; |
| blockProperties_t blockProperties; |
| |
| /* check */ |
| if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); |
| #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1) |
| { const U32 magicNumber = MEM_readLE32(src); |
| if (ZSTD_isLegacy(magicNumber)) |
| return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, magicNumber); |
| } |
| #endif |
| |
| /* Frame Header */ |
| { size_t const frameHeaderSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_min); |
| if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize; |
| if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong); |
| if (ZSTD_decodeFrameHeader(dctx, src, frameHeaderSize)) return ERROR(corruption_detected); |
| ip += frameHeaderSize; remainingSize -= frameHeaderSize; |
| } |
| |
| /* Loop on each block */ |
| while (1) { |
| size_t decodedSize=0; |
| size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &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 : |
| return ERROR(GENERIC); /* not yet supported */ |
| break; |
| case bt_end : |
| /* end of frame */ |
| if (remainingSize) return ERROR(srcSize_wrong); |
| break; |
| default: |
| return ERROR(GENERIC); /* impossible */ |
| } |
| if (cBlockSize == 0) break; /* bt_end */ |
| |
| if (ZSTD_isError(decodedSize)) return decodedSize; |
| op += decodedSize; |
| ip += cBlockSize; |
| remainingSize -= cBlockSize; |
| } |
| |
| return op-ostart; |
| } |
| |
| |
| 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) |
| { |
| ZSTD_decompressBegin_usingDict(dctx, dict, dictSize); |
| ZSTD_LOG_BLOCK("%p: ZSTD_decompressBegin_usingDict searchLength=%d\n", dctx->base, dctx->params.searchLength); |
| 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* dctx = ZSTD_createDCtx(); |
| if (dctx==NULL) return ERROR(memory_allocation); |
| regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize); |
| ZSTD_freeDCtx(dctx); |
| return regenSize; |
| #else |
| ZSTD_DCtx dctx; |
| return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize); |
| #endif |
| } |
| |
| |
| /*_****************************** |
| * Streaming Decompression API |
| ********************************/ |
| size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) |
| { |
| return dctx->expected; |
| } |
| |
| size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize) |
| { |
| /* Sanity check */ |
| if (srcSize != dctx->expected) return ERROR(srcSize_wrong); |
| ZSTD_checkContinuity(dctx, dst); |
| |
| /* Decompress : frame header; part 1 */ |
| switch (dctx->stage) |
| { |
| case ZSTDds_getFrameHeaderSize : |
| { |
| /* get frame header size */ |
| if (srcSize != ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong); /* impossible */ |
| 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: |
| { |
| /* get frame header */ |
| 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: |
| { |
| /* Decode block header */ |
| blockProperties_t bp; |
| size_t blockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp); |
| if (ZSTD_isError(blockSize)) return blockSize; |
| if (bp.blockType == bt_end) { |
| dctx->expected = 0; |
| dctx->stage = ZSTDds_getFrameHeaderSize; |
| } |
| else { |
| dctx->expected = blockSize; |
| dctx->bType = bp.blockType; |
| dctx->stage = ZSTDds_decompressBlock; |
| } |
| return 0; |
| } |
| case ZSTDds_decompressBlock: |
| { |
| /* Decompress : block content */ |
| size_t rSize; |
| switch(dctx->bType) |
| { |
| case bt_compressed: |
| rSize = ZSTD_decompressBlock_internal(dctx, dst, maxDstSize, src, srcSize); |
| break; |
| case bt_raw : |
| rSize = ZSTD_copyRawBlock(dst, maxDstSize, src, srcSize); |
| break; |
| case bt_rle : |
| return ERROR(GENERIC); /* not yet handled */ |
| break; |
| case bt_end : /* should never happen (filtered at phase 1) */ |
| rSize = 0; |
| break; |
| default: |
| return ERROR(GENERIC); /* impossible */ |
| } |
| dctx->stage = ZSTDds_decodeBlockHeader; |
| dctx->expected = ZSTD_blockHeaderSize; |
| dctx->previousDstEnd = (char*)dst + rSize; |
| return rSize; |
| } |
| default: |
| return ERROR(GENERIC); /* impossible */ |
| } |
| } |
| |
| |
| static void 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; |
| } |
| |
| static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) |
| { |
| size_t hSize, offcodeHeaderSize, matchlengthHeaderSize, errorCode, litlengthHeaderSize; |
| short offcodeNCount[MaxOff+1]; |
| U32 offcodeMaxValue=MaxOff, offcodeLog=OffFSELog; |
| short matchlengthNCount[MaxML+1]; |
| unsigned matchlengthMaxValue = MaxML, matchlengthLog = MLFSELog; |
| short litlengthNCount[MaxLL+1]; |
| unsigned litlengthMaxValue = MaxLL, litlengthLog = LLFSELog; |
| |
| hSize = HUF_readDTableX4(dctx->hufTableX4, dict, dictSize); |
| if (HUF_isError(hSize)) return ERROR(dictionary_corrupted); |
| dict = (const char*)dict + hSize; |
| dictSize -= hSize; |
| |
| offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dict, dictSize); |
| if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted); |
| errorCode = FSE_buildDTable(dctx->OffTable, offcodeNCount, offcodeMaxValue, offcodeLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); |
| dict = (const char*)dict + offcodeHeaderSize; |
| dictSize -= offcodeHeaderSize; |
| |
| matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dict, dictSize); |
| if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted); |
| errorCode = FSE_buildDTable(dctx->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); |
| dict = (const char*)dict + matchlengthHeaderSize; |
| dictSize -= matchlengthHeaderSize; |
| |
| litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dict, dictSize); |
| if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted); |
| errorCode = FSE_buildDTable(dctx->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog); |
| if (FSE_isError(errorCode)) return ERROR(dictionary_corrupted); |
| |
| dctx->flagStaticTables = 1; |
| return hSize + offcodeHeaderSize + matchlengthHeaderSize + litlengthHeaderSize; |
| } |
| |
| static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) |
| { |
| size_t eSize; |
| U32 magic = MEM_readLE32(dict); |
| if (magic != ZSTD_DICT_MAGIC) { |
| /* pure content mode */ |
| ZSTD_refDictContent(dctx, dict, dictSize); |
| return 0; |
| } |
| /* load entropy tables */ |
| dict = (const char*)dict + 4; |
| dictSize -= 4; |
| eSize = ZSTD_loadEntropy(dctx, dict, dictSize); |
| if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted); |
| |
| /* reference dictionary content */ |
| dict = (const char*)dict + eSize; |
| dictSize -= eSize; |
| ZSTD_refDictContent(dctx, dict, dictSize); |
| |
| return 0; |
| } |
| |
| |
| size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize) |
| { |
| size_t errorCode; |
| errorCode = ZSTD_decompressBegin(dctx); |
| if (ZSTD_isError(errorCode)) return errorCode; |
| |
| if (dict && dictSize) { |
| errorCode = ZSTD_decompress_insertDictionary(dctx, dict, dictSize); |
| if (ZSTD_isError(errorCode)) return ERROR(dictionary_corrupted); |
| } |
| |
| return 0; |
| } |
| |
