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Diffstat (limited to 'lib/zstd/decompress.c')
| -rw-r--r-- | lib/zstd/decompress.c | 2528 |
1 files changed, 2528 insertions, 0 deletions
diff --git a/lib/zstd/decompress.c b/lib/zstd/decompress.c new file mode 100644 index 000000000000..b17846725ca0 --- /dev/null +++ b/lib/zstd/decompress.c @@ -0,0 +1,2528 @@ +/** + * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of https://github.com/facebook/zstd. + * An additional grant of patent rights can be found in the PATENTS file in the + * same directory. + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License version 2 as published by the + * Free Software Foundation. This program is dual-licensed; you may select + * either version 2 of the GNU General Public License ("GPL") or BSD license + * ("BSD"). + */ + +/* *************************************************************** +* Tuning parameters +*****************************************************************/ +/*! +* MAXWINDOWSIZE_DEFAULT : +* maximum window size accepted by DStream, by default. +* Frames requiring more memory will be rejected. +*/ +#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT +#define ZSTD_MAXWINDOWSIZE_DEFAULT ((1 << ZSTD_WINDOWLOG_MAX) + 1) /* defined within zstd.h */ +#endif + +/*-******************************************************* +* Dependencies +*********************************************************/ +#include "fse.h" +#include "huf.h" +#include "mem.h" /* low level memory routines */ +#include "zstd_internal.h" +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/string.h> /* memcpy, memmove, memset */ + +#define ZSTD_PREFETCH(ptr) __builtin_prefetch(ptr, 0, 0) + +/*-************************************* +* 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; + +typedef struct { + FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)]; + FSE_DTable OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)]; + FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)]; + HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)]; /* can accommodate HUF_decompress4X */ + U64 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32 / 2]; + U32 rep[ZSTD_REP_NUM]; +} ZSTD_entropyTables_t; + +struct ZSTD_DCtx_s { + const FSE_DTable *LLTptr; + const FSE_DTable *MLTptr; + const FSE_DTable *OFTptr; + const HUF_DTable *HUFptr; + ZSTD_entropyTables_t entropy; + const void *previousDstEnd; /* detect continuity */ + const void *base; /* start of curr segment */ + const void *vBase; /* virtual start of previous segment if it was just before curr one */ + const void *dictEnd; /* end of previous segment */ + size_t expected; + 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; + struct xxh64_state xxhState; + size_t headerSize; + U32 dictID; + const BYTE *litPtr; + ZSTD_customMem customMem; + 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.h" */ + +size_t ZSTD_DCtxWorkspaceBound(void) { return ZSTD_ALIGN(sizeof(ZSTD_stack)) + ZSTD_ALIGN(sizeof(ZSTD_DCtx)); } + +size_t ZSTD_decompressBegin(ZSTD_DCtx *dctx) +{ + dctx->expected = ZSTD_frameHeaderSize_prefix; + dctx->stage = ZSTDds_getFrameHeaderSize; + dctx->previousDstEnd = NULL; + dctx->base = NULL; + dctx->vBase = NULL; + dctx->dictEnd = NULL; + dctx->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ + dctx->litEntropy = dctx->fseEntropy = 0; + dctx->dictID = 0; + ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue)); + memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */ + dctx->LLTptr = dctx->entropy.LLTable; + dctx->MLTptr = dctx->entropy.MLTable; + dctx->OFTptr = dctx->entropy.OFTable; + dctx->HUFptr = dctx->entropy.hufTable; + return 0; +} + +ZSTD_DCtx *ZSTD_createDCtx_advanced(ZSTD_customMem customMem) +{ + ZSTD_DCtx *dctx; + + if (!customMem.customAlloc || !customMem.customFree) + return NULL; + + dctx = (ZSTD_DCtx *)ZSTD_malloc(sizeof(ZSTD_DCtx), customMem); + if (!dctx) + return NULL; + memcpy(&dctx->customMem, &customMem, sizeof(customMem)); + ZSTD_decompressBegin(dctx); + return dctx; +} + +ZSTD_DCtx *ZSTD_initDCtx(void *workspace, size_t workspaceSize) +{ + ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize); + return ZSTD_createDCtx_advanced(stackMem); +} + +size_t ZSTD_freeDCtx(ZSTD_DCtx *dctx) +{ + if (dctx == NULL) + return 0; /* support free on NULL */ + ZSTD_free(dctx, dctx->customMem); + 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 */ +} + +static void ZSTD_refDDict(ZSTD_DCtx *dstDCtx, const ZSTD_DDict *ddict); + +/*-************************************************************* +* Decompression section +***************************************************************/ + +/*! ZSTD_isFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled. + * Note 3 : Skippable Frame Identifiers are considered valid. */ +unsigned ZSTD_isFrame(const void *buffer, size_t size) +{ + if (size < 4) + return 0; + { + U32 const magic = ZSTD_readLE32(buffer); + if (magic == ZSTD_MAGICNUMBER) + return 1; + if ((magic & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) + return 1; + } + return 0; +} + +/** ZSTD_frameHeaderSize() : +* srcSize must be >= ZSTD_frameHeaderSize_prefix. +* @return : size of the Frame Header */ +static size_t ZSTD_frameHeaderSize(const void *src, size_t srcSize) +{ + if (srcSize < ZSTD_frameHeaderSize_prefix) + 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_prefix + !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_prefix) + return ZSTD_frameHeaderSize_prefix; + if (ZSTD_readLE32(src) != ZSTD_MAGICNUMBER) { + if ((ZSTD_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 = ZSTD_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_windowTooLarge); /* avoids issue with 1 << windowLog */ + 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 = ZSTD_readLE16(ip + pos); + pos += 2; + break; + case 3: + dictID = ZSTD_readLE32(ip + pos); + pos += 4; + break; + } + switch (fcsID) { + default: /* impossible */ + case 0: + if (singleSegment) + frameContentSize = ip[pos]; + break; + case 1: frameContentSize = ZSTD_readLE16(ip + pos) + 256; break; + case 2: frameContentSize = ZSTD_readLE32(ip + pos); break; + case 3: frameContentSize = ZSTD_readLE64(ip + pos); break; + } + if (!windowSize) + windowSize = (U32)frameContentSize; + if (windowSize > windowSizeMax) + return ERROR(frameParameter_windowTooLarge); + fparamsPtr->frameContentSize = frameContentSize; + fparamsPtr->windowSize = windowSize; + fparamsPtr->dictID = dictID; + fparamsPtr->checksumFlag = checksumFlag; + } + return 0; +} + +/** ZSTD_getFrameContentSize() : +* compatible with legacy mode +* @return : decompressed size of the single frame pointed to be `src` if known, otherwise +* - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined +* - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */ +unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize) +{ + { + ZSTD_frameParams fParams; + if (ZSTD_getFrameParams(&fParams, src, srcSize) != 0) + return ZSTD_CONTENTSIZE_ERROR; + if (fParams.windowSize == 0) { + /* Either skippable or empty frame, size == 0 either way */ + return 0; + } else if (fParams.frameContentSize != 0) { + return fParams.frameContentSize; + } else { + return ZSTD_CONTENTSIZE_UNKNOWN; + } + } +} + +/** ZSTD_findDecompressedSize() : + * compatible with legacy mode + * `srcSize` must be the exact length of some number of ZSTD compressed and/or + * skippable frames + * @return : decompressed size of the frames contained */ +unsigned long long ZSTD_findDecompressedSize(const void *src, size_t srcSize) +{ + { + unsigned long long totalDstSize = 0; + while (srcSize >= ZSTD_frameHeaderSize_prefix) { + const U32 magicNumber = ZSTD_readLE32(src); + + if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + size_t skippableSize; + if (srcSize < ZSTD_skippableHeaderSize) + return ERROR(srcSize_wrong); + skippableSize = ZSTD_readLE32((const BYTE *)src + 4) + ZSTD_skippableHeaderSize; + if (srcSize < skippableSize) { + return ZSTD_CONTENTSIZE_ERROR; + } + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; + } + + { + unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize); + if (ret >= ZSTD_CONTENTSIZE_ERROR) + return ret; + + /* check for overflow */ + if (totalDstSize + ret < totalDstSize) + return ZSTD_CONTENTSIZE_ERROR; + totalDstSize += ret; + } + { + size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize); + if (ZSTD_isError(frameSrcSize)) { + return ZSTD_CONTENTSIZE_ERROR; + } + + src = (const BYTE *)src + frameSrcSize; + srcSize -= frameSrcSize; + } + } + + if (srcSize) { + return ZSTD_CONTENTSIZE_ERROR; + } + + return totalDstSize; + } +} + +/** ZSTD_decodeFrameHeader() : +* `headerSize` must be the size provided by ZSTD_frameHeaderSize(). +* @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */ +static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx *dctx, const void *src, size_t headerSize) +{ + size_t const result = ZSTD_getFrameParams(&(dctx->fParams), src, headerSize); + if (ZSTD_isError(result)) + return result; /* invalid header */ + if (result > 0) + return ERROR(srcSize_wrong); /* headerSize too small */ + if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID)) + return ERROR(dictionary_wrong); + if (dctx->fParams.checksumFlag) + xxh64_reset(&dctx->xxhState, 0); + return 0; +} + +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 = ZSTD_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 = ZSTD_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->HUFptr) + : HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart + lhSize, litCSize, dctx->HUFptr)) + : (singleStream + ? HUF_decompress1X2_DCtx_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart + lhSize, litCSize, + dctx->entropy.workspace, sizeof(dctx->entropy.workspace)) + : HUF_decompress4X_hufOnly_wksp(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart + lhSize, litCSize, + dctx->entropy.workspace, sizeof(dctx->entropy.workspace))))) + return ERROR(corruption_detected); + + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + dctx->litEntropy = 1; + if (litEncType == set_compressed) + dctx->HUFptr = dctx->entropy.hufTable; + memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); + return litCSize + lhSize; + } + + case set_basic: { + size_t litSize, lhSize; + U32 const lhlCode = ((istart[0]) >> 2) & 3; + switch (lhlCode) { + case 0: + case 2: + default: /* note : default is impossible, since lhlCode into [0..3] */ + lhSize = 1; + litSize = istart[0] >> 3; + break; + case 1: + lhSize = 2; + litSize = ZSTD_readLE16(istart) >> 4; + break; + case 3: + lhSize = 3; + litSize = ZSTD_readLE24(istart) >> 4; + break; + } + + if (lhSize + litSize + WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */ + if (litSize + lhSize > srcSize) + return ERROR(corruption_detected); + memcpy(dctx->litBuffer, istart + lhSize, litSize); + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); + return lhSize + litSize; + } + /* direct reference into compressed stream */ + dctx->litPtr = istart + lhSize; + dctx->litSize = litSize; + return lhSize + litSize; + } + + case set_rle: { + U32 const lhlCode = ((istart[0]) >> 2) & 3; + size_t litSize, lhSize; + switch (lhlCode) { + case 0: + case 2: + default: /* note : default is impossible, since lhlCode into [0..3] */ + lhSize = 1; + litSize = istart[0] >> 3; + break; + case 1: + lhSize = 2; + litSize = ZSTD_readLE16(istart) >> 4; + break; + case 3: + lhSize = 3; + litSize = ZSTD_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 + WILDCOPY_OVERLENGTH); + dctx->litPtr = dctx->litBuffer; + dctx->litSize = litSize; + return lhSize + 1; + } + default: + return ERROR(corruption_detected); /* impossible */ + } + } +} + +typedef union { + FSE_decode_t realData; + U32 alignedBy4; +} FSE_decode_t4; + +static const FSE_decode_t4 LL_defaultDTable[(1 << LL_DEFAULTNORMLOG) + 1] = { + {{LL_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */ + {{0, 0, 4}}, /* 0 : base, symbol, bits */ + {{16, 0, 4}}, + {{32, 1, 5}}, + {{0, 3, 5}}, + {{0, 4, 5}}, + {{0, 6, 5}}, + {{0, 7, 5}}, + {{0, 9, 5}}, + {{0, 10, 5}}, + {{0, 12, 5}}, + {{0, 14, 6}}, + {{0, 16, 5}}, + {{0, 18, 5}}, + {{0, 19, 5}}, + {{0, 21, 5}}, + {{0, 22, 5}}, + {{0, 24, 5}}, + {{32, 25, 5}}, + {{0, 26, 5}}, + {{0, 27, 6}}, + {{0, 29, 6}}, + {{0, 31, 6}}, + {{32, 0, 4}}, + {{0, 1, 4}}, + {{0, 2, 5}}, + {{32, 4, 5}}, + {{0, 5, 5}}, + {{32, 7, 5}}, + {{0, 8, 5}}, + {{32, 10, 5}}, + {{0, 11, 5}}, + {{0, 13, 6}}, + {{32, 16, 5}}, + {{0, 17, 5}}, + {{32, 19, 5}}, + {{0, 20, 5}}, + {{32, 22, 5}}, + {{0, 23, 5}}, + {{0, 25, 4}}, + {{16, 25, 4}}, + {{32, 26, 5}}, + {{0, 28, 6}}, + {{0, 30, 6}}, + {{48, 0, 4}}, + {{16, 1, 4}}, + {{32, 2, 5}}, + {{32, 3, 5}}, + {{32, 5, 5}}, + {{32, 6, 5}}, + {{32, 8, 5}}, + {{32, 9, 5}}, + {{32, 11, 5}}, + {{32, 12, 5}}, + {{0, 15, 6}}, + {{32, 17, 5}}, + {{32, 18, 5}}, + {{32, 20, 5}}, + {{32, 21, 5}}, + {{32, 23, 5}}, + {{32, 24, 5}}, + {{0, 35, 6}}, + {{0, 34, 6}}, + {{0, 33, 6}}, + {{0, 32, 6}}, +}; /* LL_defaultDTable */ + +static const FSE_decode_t4 ML_defaultDTable[(1 << ML_DEFAULTNORMLOG) + 1] = { + {{ML_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */ + {{0, 0, 6}}, /* 0 : base, symbol, bits */ + {{0, 1, 4}}, + {{32, 2, 5}}, + {{0, 3, 5}}, + {{0, 5, 5}}, + {{0, 6, 5}}, + {{0, 8, 5}}, + {{0, 10, 6}}, + {{0, 13, 6}}, + {{0, 16, 6}}, + {{0, 19, 6}}, + {{0, 22, 6}}, + {{0, 25, 6}}, + {{0, 28, 6}}, + {{0, 31, 6}}, + {{0, 33, 6}}, + {{0, 35, 6}}, + {{0, 37, 6}}, + {{0, 39, 6}}, + {{0, 41, 6}}, + {{0, 43, 6}}, + {{0, 45, 6}}, + {{16, 1, 4}}, + {{0, 2, 4}}, + {{32, 3, 5}}, + {{0, 4, 5}}, + {{32, 6, 5}}, + {{0, 7, 5}}, + {{0, 9, 6}}, + {{0, 12, 6}}, + {{0, 15, 6}}, + {{0, 18, 6}}, + {{0, 21, 6}}, + {{0, 24, 6}}, + {{0, 27, 6}}, + {{0, 30, 6}}, + {{0, 32, 6}}, + {{0, 34, 6}}, + {{0, 36, 6}}, + {{0, 38, 6}}, + {{0, 40, 6}}, + {{0, 42, 6}}, + {{0, 44, 6}}, + {{32, 1, 4}}, + {{48, 1, 4}}, + {{16, 2, 4}}, + {{32, 4, 5}}, + {{32, 5, 5}}, + {{32, 7, 5}}, + {{32, 8, 5}}, + {{0, 11, 6}}, + {{0, 14, 6}}, + {{0, 17, 6}}, + {{0, 20, 6}}, + {{0, 23, 6}}, + {{0, 26, 6}}, + {{0, 29, 6}}, + {{0, 52, 6}}, + {{0, 51, 6}}, + {{0, 50, 6}}, + {{0, 49, 6}}, + {{0, 48, 6}}, + {{0, 47, 6}}, + {{0, 46, 6}}, +}; /* ML_defaultDTable */ + +static const FSE_decode_t4 OF_defaultDTable[(1 << OF_DEFAULTNORMLOG) + 1] = { + {{OF_DEFAULTNORMLOG, 1, 1}}, /* header : tableLog, fastMode, fastMode */ + {{0, 0, 5}}, /* 0 : base, symbol, bits */ + {{0, 6, 4}}, + {{0, 9, 5}}, + {{0, 15, 5}}, + {{0, 21, 5}}, + {{0, 3, 5}}, + {{0, 7, 4}}, + {{0, 12, 5}}, + {{0, 18, 5}}, + {{0, 23, 5}}, + {{0, 5, 5}}, + {{0, 8, 4}}, + {{0, 14, 5}}, + {{0, 20, 5}}, + {{0, 2, 5}}, + {{16, 7, 4}}, + {{0, 11, 5}}, + {{0, 17, 5}}, + {{0, 22, 5}}, + {{0, 4, 5}}, + {{16, 8, 4}}, + {{0, 13, 5}}, + {{0, 19, 5}}, + {{0, 1, 5}}, + {{16, 6, 4}}, + {{0, 10, 5}}, + {{0, 16, 5}}, + {{0, 28, 5}}, + {{0, 27, 5}}, + {{0, 26, 5}}, + {{0, 25, 5}}, + {{0, 24, 5}}, +}; /* OF_defaultDTable */ + +/*! ZSTD_buildSeqTable() : + @return : nb bytes read from src, + or an error code if it fails, testable with ZSTD_isError() +*/ +static size_t ZSTD_buildSeqTable(FSE_DTable *DTableSpace, const FSE_DTable **DTablePtr, symbolEncodingType_e type, U32 max, U32 maxLog, const void *src, + size_t srcSize, const FSE_decode_t4 *defaultTable, U32 flagRepeatTable, void *workspace, size_t workspaceSize) +{ + const void *const tmpPtr = defaultTable; /* bypass strict aliasing */ + switch (type) { + case set_rle: + if (!srcSize) + return ERROR(srcSize_wrong); + if ((*(const BYTE *)src) > max) + return ERROR(corruption_detected); + FSE_buildDTable_rle(DTableSpace, *(const BYTE *)src); + *DTablePtr = DTableSpace; + return 1; + case set_basic: *DTablePtr = (const FSE_DTable *)tmpPtr; return 0; + case set_repeat: + if (!flagRepeatTable) + return ERROR(corruption_detected); + return 0; + default: /* impossible */ + case set_compressed: { + U32 tableLog; + S16 *norm = (S16 *)workspace; + size_t const spaceUsed32 = ALIGN(sizeof(S16) * (MaxSeq + 1), sizeof(U32)) >> 2; + + if ((spaceUsed32 << 2) > workspaceSize) + return ERROR(GENERIC); + workspace = (U32 *)workspace + spaceUsed32; + workspaceSize -= (spaceUsed32 << 2); + { + 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_wksp(DTableSpace, norm, max, tableLog, workspace, workspaceSize); + *DTablePtr = DTableSpace; + return headerSize; + } + } + } +} + +size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx *dctx, int *nbSeqPtr, const void *src, size_t srcSize) +{ + const BYTE *const istart = (const BYTE *const)src; + const BYTE *const iend = istart + srcSize; + const BYTE *ip = istart; + + /* check */ + if (srcSize < MIN_SEQUENCES_SIZE) + return ERROR(srcSize_wrong); + + /* SeqHead */ + { + int nbSeq = *ip++; + if (!nbSeq) { + *nbSeqPtr = 0; + return 1; + } + if (nbSeq > 0x7F) { + if (nbSeq == 0xFF) { + if (ip + 2 > iend) + return ERROR(srcSize_wrong); + nbSeq = ZSTD_readLE16(ip) + LONGNBSEQ, ip += 2; + } else { + if (ip >= iend) + return ERROR(srcSize_wrong); + nbSeq = ((nbSeq - 0x80) << 8) + *ip++; + } + } + *nbSeqPtr = nbSeq; + } + + /* FSE table descriptors */ + if (ip + 4 > iend) + return ERROR(srcSize_wrong); /* minimum possible size */ + { + symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6); + symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3); + symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3); + ip++; + + /* Build DTables */ + { + size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr, LLtype, MaxLL, LLFSELog, ip, iend - ip, + LL_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace)); + if (ZSTD_isError(llhSize)) + return ERROR(corruption_detected); + ip += llhSize; + } + { + size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr, OFtype, MaxOff, OffFSELog, ip, iend - ip, + OF_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace)); + if (ZSTD_isError(ofhSize)) + return ERROR(corruption_detected); + ip += ofhSize; + } + { + size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr, MLtype, MaxML, MLFSELog, ip, iend - ip, + ML_defaultDTable, dctx->fseEntropy, dctx->entropy.workspace, sizeof(dctx->entropy.workspace)); + if (ZSTD_isError(mlhSize)) + return ERROR(corruption_detected); + ip += mlhSize; + } + } + + return ip - istart; +} + +typedef struct { + size_t litLength; + size_t matchLength; + size_t offset; + const BYTE *match; +} seq_t; + +typedef struct { + BIT_DStream_t DStream; + FSE_DState_t stateLL; + FSE_DState_t stateOffb; + FSE_DState_t stateML; + size_t prevOffset[ZSTD_REP_NUM]; + const BYTE *base; + size_t pos; + uPtrDiff gotoDict; +} seqState_t; + +FORCE_NOINLINE +size_t ZSTD_execSequenceLast7(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base, + const BYTE *const vBase, const BYTE *const dictEnd) +{ + BYTE *const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ + BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH; + const BYTE *const iLitEnd = *litPtr + sequence.litLength; + const BYTE *match = oLitEnd - sequence.offset; + + /* check */ + if (oMatchEnd > oend) + return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ + if (iLitEnd > litLimit) + return ERROR(corruption_detected); /* over-read beyond lit buffer */ + if (oLitEnd <= oend_w) + return ERROR(GENERIC); /* Precondition */ + + /* copy literals */ + if (op < oend_w) { + ZSTD_wildcopy(op, *litPtr, oend_w - op); + *litPtr += oend_w - op; + op = oend_w; + } + while (op < oLitEnd) + *op++ = *(*litPtr)++; + + /* copy Match */ + if (sequence.offset > (size_t)(oLitEnd - base)) { + /* offset beyond prefix */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) + return ERROR(corruption_detected); + match = dictEnd - (base - match); + if (match + sequence.matchLength <= dictEnd) { + memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currPrefixSegment */ + { + size_t const length1 = dictEnd - match; + memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = base; + } + } + while (op < oMatchEnd) + *op++ = *match++; + return sequenceLength; +} + +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_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ + if (ZSTD_32bits()) + BIT_reloadDStream(&seqState->DStream); + } + + if (ofCode <= 1) { + offset += (llCode == 0); + if (offset) { + size_t temp = (offset == 3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; + temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ + if (offset != 1) + seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset = temp; + } else { + offset = seqState->prevOffset[0]; + } + } else { + seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset; + } + seq.offset = offset; + } + + seq.matchLength = ML_base[mlCode] + ((mlCode > 31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <= 16 bits */ + if (ZSTD_32bits() && (mlBits + llBits > 24)) + BIT_reloadDStream(&seqState->DStream); + + seq.litLength = LL_base[llCode] + ((llCode > 15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */ + if (ZSTD_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 (ZSTD_32bits()) + BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ + FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ + + seq.match = NULL; + + return seq; +} + +FORCE_INLINE +size_t ZSTD_execSequence(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base, + const BYTE *const vBase, const BYTE *const dictEnd) +{ + BYTE *const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ + BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH; + const BYTE *const iLitEnd = *litPtr + sequence.litLength; + const BYTE *match = oLitEnd - sequence.offset; + + /* check */ + if (oMatchEnd > oend) + return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ + if (iLitEnd > litLimit) + return ERROR(corruption_detected); /* over-read beyond lit buffer */ + if (oLitEnd > oend_w) + return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd); + + /* copy Literals */ + ZSTD_copy8(op, *litPtr); + if (sequence.litLength > 8) + ZSTD_wildcopy(op + 8, (*litPtr) + 8, + sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ + op = oLitEnd; + *litPtr = iLitEnd; /* update for next sequence */ + + /* copy Match */ + if (sequence.offset > (size_t)(oLitEnd - base)) { + /* offset beyond prefix */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) + return ERROR(corruption_detected); + match = dictEnd + (match - base); + if (match + sequence.matchLength <= dictEnd) { + memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currPrefixSegment */ + { + size_t const length1 = dictEnd - match; + memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = base; + if (op > oend_w || sequence.matchLength < MINMATCH) { + U32 i; + for (i = 0; i < sequence.matchLength; ++i) + op[i] = match[i]; + return sequenceLength; + } + } + } + /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */ + + /* match within prefix */ + if (sequence.offset < 8) { + /* close range match, overlap */ + static const U32 dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4}; /* added */ + static const int dec64table[] = {8, 8, 8, 7, 8, 9, 10, 11}; /* subtracted */ + int const sub2 = dec64table[sequence.offset]; + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += dec32table[sequence.offset]; + ZSTD_copy4(op + 4, match); + match -= sub2; + } else { + ZSTD_copy8(op, match); + } + op += 8; + match += 8; + + if (oMatchEnd > oend - (16 - MINMATCH)) { + if (op < oend_w) { + ZSTD_wildcopy(op, match, oend_w - op); + match += oend_w - op; + op = oend_w; + } + while (op < oMatchEnd) + *op++ = *match++; + } else { + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8); /* works even if matchLength < 8 */ + } + return sequenceLength; +} + +static size_t ZSTD_decompressSequences(ZSTD_DCtx *dctx, void *dst, size_t maxDstSize, const void *seqStart, size_t seqSize) +{ + const BYTE *ip = (const BYTE *)seqStart; + const BYTE *const iend = ip + seqSize; + BYTE *const ostart = (BYTE * const)dst; + BYTE *const oend = ostart + maxDstSize; + BYTE *op = ostart; + const BYTE *litPtr = dctx->litPtr; + const BYTE *const litEnd = litPtr + dctx->litSize; + const BYTE *const base = (const BYTE *)(dctx->base); + const BYTE *const vBase = (const BYTE *)(dctx->vBase); + const BYTE *const dictEnd = (const BYTE *)(dctx->dictEnd); + int nbSeq; + + /* Build Decoding Tables */ + { + size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize); + if (ZSTD_isError(seqHSize)) + return seqHSize; + ip += seqHSize; + } + + /* Regen sequences */ + if (nbSeq) { + seqState_t seqState; + dctx->fseEntropy = 1; + { + U32 i; + for (i = 0; i < ZSTD_REP_NUM; i++) + seqState.prevOffset[i] = dctx->entropy.rep[i]; + } + CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend - ip), corruption_detected); + FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + + for (; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq;) { + nbSeq--; + { + seq_t const sequence = ZSTD_decodeSequence(&seqState); + size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, 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->entropy.rep[i] = (U32)(seqState.prevOffset[i]); + } + } + + /* last literal segment */ + { + size_t const lastLLSize = litEnd - litPtr; + if (lastLLSize > (size_t)(oend - op)) + return ERROR(dstSize_tooSmall); + memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } + + return op - ostart; +} + +FORCE_INLINE seq_t ZSTD_decodeSequenceLong_generic(seqState_t *seqState, int const longOffsets) +{ + seq_t seq; + + U32 const llCode = FSE_peekSymbol(&seqState->stateLL); + U32 const mlCode = FSE_peekSymbol(&seqState->stateML); + U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= maxOff, by table construction */ + + U32 const llBits = LL_bits[llCode]; + U32 const mlBits = ML_bits[mlCode]; + U32 const ofBits = ofCode; + U32 const totalBits = llBits + mlBits + ofBits; + + static const U32 LL_base[MaxLL + 1] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, + 20, 22, 24, 28, 32, 40, 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000, 0x10000}; + + static const U32 ML_base[MaxML + 1] = {3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, + 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 39, 41, + 43, 47, 51, 59, 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803, 0x1003, 0x2003, 0x4003, 0x8003, 0x10003}; + + static const U32 OF_base[MaxOff + 1] = {0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D, 0xFD, 0x1FD, + 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD, 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, + 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD, 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD}; + + /* sequence */ + { + size_t offset; + if (!ofCode) + offset = 0; + else { + if (longOffsets) { + int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN); + offset = OF_base[ofCode] + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); + if (ZSTD_32bits() || extraBits) + BIT_reloadDStream(&seqState->DStream); + if (extraBits) + offset += BIT_readBitsFast(&seqState->DStream, extraBits); + } else { + offset = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ + if (ZSTD_32bits()) + BIT_reloadDStream(&seqState->DStream); + } + } + + if (ofCode <= 1) { + offset += (llCode == 0); + if (offset) { + size_t temp = (offset == 3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; + temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ + if (offset != 1) + seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset = temp; + } else { + offset = seqState->prevOffset[0]; + } + } else { + seqState->prevOffset[2] = seqState->prevOffset[1]; + seqState->prevOffset[1] = seqState->prevOffset[0]; + seqState->prevOffset[0] = offset; + } + seq.offset = offset; + } + + seq.matchLength = ML_base[mlCode] + ((mlCode > 31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <= 16 bits */ + if (ZSTD_32bits() && (mlBits + llBits > 24)) + BIT_reloadDStream(&seqState->DStream); + + seq.litLength = LL_base[llCode] + ((llCode > 15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */ + if (ZSTD_32bits() || (totalBits > 64 - 7 - (LLFSELog + MLFSELog + OffFSELog))) + BIT_reloadDStream(&seqState->DStream); + + { + size_t const pos = seqState->pos + seq.litLength; + seq.match = seqState->base + pos - seq.offset; /* single memory segment */ + if (seq.offset > pos) + seq.match += seqState->gotoDict; /* separate memory segment */ + seqState->pos = pos + seq.matchLength; + } + + /* ANS state update */ + FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ + FSE_updateState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ + if (ZSTD_32bits()) + BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ + FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ + + return seq; +} + +static seq_t ZSTD_decodeSequenceLong(seqState_t *seqState, unsigned const windowSize) +{ + if (ZSTD_highbit32(windowSize) > STREAM_ACCUMULATOR_MIN) { + return ZSTD_decodeSequenceLong_generic(seqState, 1); + } else { + return ZSTD_decodeSequenceLong_generic(seqState, 0); + } +} + +FORCE_INLINE +size_t ZSTD_execSequenceLong(BYTE *op, BYTE *const oend, seq_t sequence, const BYTE **litPtr, const BYTE *const litLimit, const BYTE *const base, + const BYTE *const vBase, const BYTE *const dictEnd) +{ + BYTE *const oLitEnd = op + sequence.litLength; + size_t const sequenceLength = sequence.litLength + sequence.matchLength; + BYTE *const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ + BYTE *const oend_w = oend - WILDCOPY_OVERLENGTH; + const BYTE *const iLitEnd = *litPtr + sequence.litLength; + const BYTE *match = sequence.match; + + /* check */ + if (oMatchEnd > oend) + return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */ + if (iLitEnd > litLimit) + return ERROR(corruption_detected); /* over-read beyond lit buffer */ + if (oLitEnd > oend_w) + return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd); + + /* copy Literals */ + ZSTD_copy8(op, *litPtr); + if (sequence.litLength > 8) + ZSTD_wildcopy(op + 8, (*litPtr) + 8, + sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ + op = oLitEnd; + *litPtr = iLitEnd; /* update for next sequence */ + + /* copy Match */ + if (sequence.offset > (size_t)(oLitEnd - base)) { + /* offset beyond prefix */ + if (sequence.offset > (size_t)(oLitEnd - vBase)) + return ERROR(corruption_detected); + if (match + sequence.matchLength <= dictEnd) { + memmove(oLitEnd, match, sequence.matchLength); + return sequenceLength; + } + /* span extDict & currPrefixSegment */ + { + size_t const length1 = dictEnd - match; + memmove(oLitEnd, match, length1); + op = oLitEnd + length1; + sequence.matchLength -= length1; + match = base; + if (op > oend_w || sequence.matchLength < MINMATCH) { + U32 i; + for (i = 0; i < sequence.matchLength; ++i) + op[i] = match[i]; + return sequenceLength; + } + } + } + /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */ + + /* match within prefix */ + if (sequence.offset < 8) { + /* close range match, overlap */ + static const U32 dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4}; /* added */ + static const int dec64table[] = {8, 8, 8, 7, 8, 9, 10, 11}; /* subtracted */ + int const sub2 = dec64table[sequence.offset]; + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += dec32table[sequence.offset]; + ZSTD_copy4(op + 4, match); + match -= sub2; + } else { + ZSTD_copy8(op, match); + } + op += 8; + match += 8; + + if (oMatchEnd > oend - (16 - MINMATCH)) { + if (op < oend_w) { + ZSTD_wildcopy(op, match, oend_w - op); + match += oend_w - op; + op = oend_w; + } + while (op < oMatchEnd) + *op++ = *match++; + } else { + ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8); /* works even if matchLength < 8 */ + } + return sequenceLength; +} + +static size_t ZSTD_decompressSequencesLong(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 litEnd = litPtr + dctx->litSize; + const BYTE *const base = (const BYTE *)(dctx->base); + const BYTE *const vBase = (const BYTE *)(dctx->vBase); + const BYTE *const dictEnd = (const BYTE *)(dctx->dictEnd); + unsigned const windowSize = dctx->fParams.windowSize; + int nbSeq; + + /* Build Decoding Tables */ + { + size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize); + if (ZSTD_isError(seqHSize)) + return seqHSize; + ip += seqHSize; + } + + /* Regen sequences */ + if (nbSeq) { +#define STORED_SEQS 4 +#define STOSEQ_MASK (STORED_SEQS - 1) +#define ADVANCED_SEQS 4 + seq_t *sequences = (seq_t *)dctx->entropy.workspace; + int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS); + seqState_t seqState; + int seqNb; + ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.workspace) >= sizeof(seq_t) * STORED_SEQS); + dctx->fseEntropy = 1; + { + U32 i; + for (i = 0; i < ZSTD_REP_NUM; i++) + seqState.prevOffset[i] = dctx->entropy.rep[i]; + } + seqState.base = base; + seqState.pos = (size_t)(op - base); + seqState.gotoDict = (uPtrDiff)dictEnd - (uPtrDiff)base; /* cast to avoid undefined behaviour */ + CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend - ip), corruption_detected); + FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); + FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); + FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); + + /* prepare in advance */ + for (seqNb = 0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && seqNb < seqAdvance; seqNb++) { + sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, windowSize); + } + if (seqNb < seqAdvance) + return ERROR(corruption_detected); + + /* decode and decompress */ + for (; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && seqNb < nbSeq; seqNb++) { + seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, windowSize); + size_t const oneSeqSize = + ZSTD_execSequenceLong(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd); + if (ZSTD_isError(oneSeqSize)) + return oneSeqSize; + ZSTD_PREFETCH(sequence.match); + sequences[seqNb & STOSEQ_MASK] = sequence; + op += oneSeqSize; + } + if (seqNb < nbSeq) + return ERROR(corruption_detected); + + /* finish queue */ + seqNb -= seqAdvance; + for (; seqNb < nbSeq; seqNb++) { + size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb & STOSEQ_MASK], &litPtr, litEnd, base, vBase, dictEnd); + if (ZSTD_isError(oneSeqSize)) + return oneSeqSize; + op += oneSeqSize; + } + + /* save reps for next block */ + { + U32 i; + for (i = 0; i < ZSTD_REP_NUM; i++) + dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); + } + } + + /* last literal segment */ + { + size_t const lastLLSize = litEnd - litPtr; + if (lastLLSize > (size_t)(oend - op)) + return ERROR(dstSize_tooSmall); + memcpy(op, litPtr, lastLLSize); + op += lastLLSize; + } + + return op - ostart; +} + +static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize) +{ /* blockType == blockCompressed */ + const BYTE *ip = (const BYTE *)src; + + if (srcSize >= ZSTD_BLOCKSIZE_ABSOLUTEMAX) + return ERROR(srcSize_wrong); + + /* Decode literals section */ + { + size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize); + if (ZSTD_isError(litCSize)) + return litCSize; + ip += litCSize; + srcSize -= litCSize; + } + if (sizeof(size_t) > 4) /* do not enable prefetching on 32-bits x86, as it's performance detrimental */ + /* likely because of register pressure */ + /* if that's the correct cause, then 32-bits ARM should be affected differently */ + /* it would be good to test this on ARM real hardware, to see if prefetch version improves speed */ + if (dctx->fParams.windowSize > (1 << 23)) + return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize); + return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize); +} + +static void ZSTD_checkContinuity(ZSTD_DCtx *dctx, const void *dst) +{ + if (dst != dctx->previousDstEnd) { /* not contiguous */ + dctx->dictEnd = dctx->previousDstEnd; + dctx->vBase = (const char *)dst - ((const char *)(dctx->previousDstEnd) - (const char *)(dctx->base)); + dctx->base = dst; + dctx->previousDstEnd = dst; + } +} + +size_t ZSTD_decompressBlock(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize) +{ + size_t dSize; + ZSTD_checkContinuity(dctx, dst); + dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize); + dctx->previousDstEnd = (char *)dst + dSize; + return dSize; +} + +/** ZSTD_insertBlock() : + insert `src` block into `dctx` history. Useful to track uncompressed blocks. */ +size_t ZSTD_insertBlock(ZSTD_DCtx *dctx, const void *blockStart, size_t blockSize) +{ + ZSTD_checkContinuity(dctx, blockStart); + dctx->previousDstEnd = (const char *)blockStart + blockSize; + return blockSize; +} + +size_t ZSTD_generateNxBytes(void *dst, size_t dstCapacity, BYTE byte, size_t length) +{ + if (length > dstCapacity) + return ERROR(dstSize_tooSmall); + memset(dst, byte, length); + return length; +} + +/** ZSTD_findFrameCompressedSize() : + * compatible with legacy mode + * `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame + * `srcSize` must be at least as large as the frame contained + * @return : the compressed size of the frame starting at `src` */ +size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize) +{ + if (srcSize >= ZSTD_skippableHeaderSize && (ZSTD_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + return ZSTD_skippableHeaderSize + ZSTD_readLE32((const BYTE *)src + 4); + } else { + const BYTE *ip = (const BYTE *)src; + const BYTE *const ipstart = ip; + size_t remainingSize = srcSize; + ZSTD_frameParams fParams; + + size_t const headerSize = ZSTD_frameHeaderSize(ip, remainingSize); + if (ZSTD_isError(headerSize)) + return headerSize; + + /* Frame Header */ + { + size_t const ret = ZSTD_getFrameParams(&fParams, ip, remainingSize); + if (ZSTD_isError(ret)) + return ret; + if (ret > 0) + return ERROR(srcSize_wrong); + } + + ip += headerSize; + remainingSize -= headerSize; + + /* Loop on each block */ + while (1) { + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) + return cBlockSize; + + if (ZSTD_blockHeaderSize + cBlockSize > remainingSize) + return ERROR(srcSize_wrong); + + ip += ZSTD_blockHeaderSize + cBlockSize; + remainingSize -= ZSTD_blockHeaderSize + cBlockSize; + + if (blockProperties.lastBlock) + break; + } + + if (fParams.checksumFlag) { /* Frame content checksum */ + if (remainingSize < 4) + return ERROR(srcSize_wrong); + ip += 4; + remainingSize -= 4; + } + + return ip - ipstart; + } +} + +/*! ZSTD_decompressFrame() : +* @dctx must be properly initialized */ +static size_t ZSTD_decompressFrame(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void **srcPtr, size_t *srcSizePtr) +{ + const BYTE *ip = (const BYTE *)(*srcPtr); + BYTE *const ostart = (BYTE * const)dst; + BYTE *const oend = ostart + dstCapacity; + BYTE *op = ostart; + size_t remainingSize = *srcSizePtr; + + /* check */ + if (remainingSize < ZSTD_frameHeaderSize_min + ZSTD_blockHeaderSize) + return ERROR(srcSize_wrong); + + /* Frame Header */ + { + size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_frameHeaderSize_prefix); + if (ZSTD_isError(frameHeaderSize)) + return frameHeaderSize; + if (remainingSize < frameHeaderSize + ZSTD_blockHeaderSize) + return ERROR(srcSize_wrong); + CHECK_F(ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize)); + ip += frameHeaderSize; + remainingSize -= frameHeaderSize; + } + + /* Loop on each block */ + while (1) { + size_t decodedSize; + blockProperties_t blockProperties; + size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties); + if (ZSTD_isError(cBlockSize)) + return cBlockSize; + + ip += ZSTD_blockHeaderSize; + remainingSize -= ZSTD_blockHeaderSize; + if (cBlockSize > remainingSize) + return ERROR(srcSize_wrong); + + switch (blockProperties.blockType) { + case bt_compressed: decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend - op, ip, cBlockSize); 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 = ZSTD_readLE32(ip); + if (checkRead != checkCalc) + return ERROR(checksum_wrong); + ip += 4; + remainingSize -= 4; + } + + /* Allow caller to get size read */ + *srcPtr = ip; + *srcSizePtr = remainingSize; + return op - ostart; +} + +static const void *ZSTD_DDictDictContent(const ZSTD_DDict *ddict); +static size_t ZSTD_DDictDictSize(const ZSTD_DDict *ddict); + +static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const void *dict, size_t dictSize, + const ZSTD_DDict *ddict) +{ + void *const dststart = dst; + + if (ddict) { + if (dict) { + /* programmer error, these two cases should be mutually exclusive */ + return ERROR(GENERIC); + } + + dict = ZSTD_DDictDictContent(ddict); + dictSize = ZSTD_DDictDictSize(ddict); + } + + while (srcSize >= ZSTD_frameHeaderSize_prefix) { + U32 magicNumber; + + magicNumber = ZSTD_readLE32(src); + if (magicNumber != ZSTD_MAGICNUMBER) { + if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { + size_t skippableSize; + if (srcSize < ZSTD_skippableHeaderSize) + return ERROR(srcSize_wrong); + skippableSize = ZSTD_readLE32((const BYTE *)src + 4) + ZSTD_skippableHeaderSize; + if (srcSize < skippableSize) { + return ERROR(srcSize_wrong); + } + + src = (const BYTE *)src + skippableSize; + srcSize -= skippableSize; + continue; + } else { + return ERROR(prefix_unknown); + } + } + + if (ddict) { + /* we were called from ZSTD_decompress_usingDDict */ + ZSTD_refDDict(dctx, ddict); + } else { + /* this will initialize correctly with no dict if dict == NULL, so + * use this in all cases but ddict */ + CHECK_F(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize)); + } + ZSTD_checkContinuity(dctx, dst); + + { + const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity, &src, &srcSize); + if (ZSTD_isError(res)) + return res; + /* don't need to bounds check this, ZSTD_decompressFrame will have + * already */ + dst = (BYTE *)dst + res; + dstCapacity -= res; + } + } + + if (srcSize) + return ERROR(srcSize_wrong); /* input not entirely consumed */ + + return (BYTE *)dst - (BYTE *)dststart; +} + +size_t ZSTD_decompress_usingDict(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const void *dict, size_t dictSize) +{ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL); +} + +size_t ZSTD_decompressDCtx(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize) +{ + return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0); +} + +/*-************************************** +* 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_prefix) + return ERROR(srcSize_wrong); /* impossible */ + if ((ZSTD_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */ + memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix); + dctx->expected = ZSTD_skippableHeaderSize - ZSTD_frameHeaderSize_prefix; /* magic number + skippable frame length */ + dctx->stage = ZSTDds_decodeSkippableHeader; + return 0; + } + dctx->headerSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_prefix); + if (ZSTD_isError(dctx->headerSize)) + return dctx->headerSize; + memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix); + if (dctx->headerSize > ZSTD_frameHeaderSize_prefix) { + dctx->expected = dctx->headerSize - ZSTD_frameHeaderSize_prefix; + dctx->stage = ZSTDds_decodeFrameHeader; + return 0; + } + dctx->expected = 0; /* not necessary to copy more */ + + case ZSTDds_decodeFrameHeader: + memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected); + CHECK_F(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize)); + dctx->expected = ZSTD_blockHeaderSize; + dctx->stage = ZSTDds_decodeBlockHeader; + return 0; + + case ZSTDds_decodeBlockHeader: { + blockProperties_t bp; + size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp); + if (ZSTD_isError(cBlockSize)) + return cBlockSize; + dctx->expected = cBlockSize; + dctx->bType = bp.blockType; + dctx->rleSize = bp.origSize; + if (cBlockSize) { + dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock; + return 0; + } + /* empty block */ + if (bp.lastBlock) { + if (dctx->fParams.checksumFlag) { + dctx->expected = 4; + dctx->stage = ZSTDds_checkChecksum; + } else { + dctx->expected = 0; /* end of frame */ + dctx->stage = ZSTDds_getFrameHeaderSize; + } + } else { + dctx->expected = 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 = ZSTD_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_prefix, src, dctx->expected); + dctx->expected = ZSTD_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; +} + +/* ZSTD_loadEntropy() : + * dict : must point at beginning of a valid zstd dictionary + * @return : size of entropy tables read */ +static size_t ZSTD_loadEntropy(ZSTD_entropyTables_t *entropy, const void *const dict, size_t const dictSize) +{ + const BYTE *dictPtr = (const BYTE *)dict; + const BYTE *const dictEnd = dictPtr + dictSize; + + if (dictSize <= 8) + return ERROR(dictionary_corrupted); + dictPtr += 8; /* skip header = magic + dictID */ + + { + size_t const hSize = HUF_readDTableX4_wksp(entropy->hufTable, dictPtr, dictEnd - dictPtr, entropy->workspace, sizeof(entropy->workspace)); + if (HUF_isError(hSize)) + return ERROR(dictionary_corrupted); + dictPtr += hSize; + } + + { + short offcodeNCount[MaxOff + 1]; + U32 offcodeMaxValue = MaxOff, offcodeLog; + size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd - dictPtr); + if (FSE_isError(offcodeHeaderSize)) + return ERROR(dictionary_corrupted); + if (offcodeLog > OffFSELog) + return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable_wksp(entropy->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted); + dictPtr += offcodeHeaderSize; + } + + { + short matchlengthNCount[MaxML + 1]; + unsigned matchlengthMaxValue = MaxML, matchlengthLog; + size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd - dictPtr); + if (FSE_isError(matchlengthHeaderSize)) + return ERROR(dictionary_corrupted); + if (matchlengthLog > MLFSELog) + return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable_wksp(entropy->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted); + dictPtr += matchlengthHeaderSize; + } + + { + short litlengthNCount[MaxLL + 1]; + unsigned litlengthMaxValue = MaxLL, litlengthLog; + size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd - dictPtr); + if (FSE_isError(litlengthHeaderSize)) + return ERROR(dictionary_corrupted); + if (litlengthLog > LLFSELog) + return ERROR(dictionary_corrupted); + CHECK_E(FSE_buildDTable_wksp(entropy->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog, entropy->workspace, sizeof(entropy->workspace)), dictionary_corrupted); + dictPtr += litlengthHeaderSize; + } + + if (dictPtr + 12 > dictEnd) + return ERROR(dictionary_corrupted); + { + int i; + size_t const dictContentSize = (size_t)(dictEnd - (dictPtr + 12)); + for (i = 0; i < 3; i++) { + U32 const rep = ZSTD_readLE32(dictPtr); + dictPtr += 4; + if (rep == 0 || rep >= dictContentSize) + return ERROR(dictionary_corrupted); + entropy->rep[i] = rep; + } + } + + return dictPtr - (const BYTE *)dict; +} + +static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx *dctx, const void *dict, size_t dictSize) +{ + if (dictSize < 8) + return ZSTD_refDictContent(dctx, dict, dictSize); + { + U32 const magic = ZSTD_readLE32(dict); + if (magic != ZSTD_DICT_MAGIC) { + return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */ + } + } + dctx->dictID = ZSTD_readLE32((const char *)dict + 4); + + /* load entropy tables */ + { + size_t const eSize = ZSTD_loadEntropy(&dctx->entropy, dict, dictSize); + if (ZSTD_isError(eSize)) + return ERROR(dictionary_corrupted); + dict = (const char *)dict + eSize; + dictSize -= eSize; + } + dctx->litEntropy = dctx->fseEntropy = 1; + + /* reference dictionary content */ + return ZSTD_refDictContent(dctx, dict, dictSize); +} + +size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx *dctx, const void *dict, size_t dictSize) +{ + CHECK_F(ZSTD_decompressBegin(dctx)); + if (dict && dictSize) + CHECK_E(ZSTD_decompress_insertDictionary(dctx, dict, dictSize), dictionary_corrupted); + return 0; +} + +/* ====== ZSTD_DDict ====== */ + +struct ZSTD_DDict_s { + void *dictBuffer; + const void *dictContent; + size_t dictSize; + ZSTD_entropyTables_t entropy; + U32 dictID; + U32 entropyPresent; + ZSTD_customMem cMem; +}; /* typedef'd to ZSTD_DDict within "zstd.h" */ + +size_t ZSTD_DDictWorkspaceBound(void) { return ZSTD_ALIGN(sizeof(ZSTD_stack)) + ZSTD_ALIGN(sizeof(ZSTD_DDict)); } + +static const void *ZSTD_DDictDictContent(const ZSTD_DDict *ddict) { return ddict->dictContent; } + +static size_t ZSTD_DDictDictSize(const ZSTD_DDict *ddict) { return ddict->dictSize; } + +static void ZSTD_refDDict(ZSTD_DCtx *dstDCtx, const ZSTD_DDict *ddict) +{ + ZSTD_decompressBegin(dstDCtx); /* init */ + if (ddict) { /* support refDDict on NULL */ + dstDCtx->dictID = ddict->dictID; + dstDCtx->base = ddict->dictContent; + dstDCtx->vBase = ddict->dictContent; + dstDCtx->dictEnd = (const BYTE *)ddict->dictContent + ddict->dictSize; + dstDCtx->previousDstEnd = dstDCtx->dictEnd; + if (ddict->entropyPresent) { + dstDCtx->litEntropy = 1; + dstDCtx->fseEntropy = 1; + dstDCtx->LLTptr = ddict->entropy.LLTable; + dstDCtx->MLTptr = ddict->entropy.MLTable; + dstDCtx->OFTptr = ddict->entropy.OFTable; + dstDCtx->HUFptr = ddict->entropy.hufTable; + dstDCtx->entropy.rep[0] = ddict->entropy.rep[0]; + dstDCtx->entropy.rep[1] = ddict->entropy.rep[1]; + dstDCtx->entropy.rep[2] = ddict->entropy.rep[2]; + } else { + dstDCtx->litEntropy = 0; + dstDCtx->fseEntropy = 0; + } + } +} + +static size_t ZSTD_loadEntropy_inDDict(ZSTD_DDict *ddict) +{ + ddict->dictID = 0; + ddict->entropyPresent = 0; + if (ddict->dictSize < 8) + return 0; + { + U32 const magic = ZSTD_readLE32(ddict->dictContent); + if (magic != ZSTD_DICT_MAGIC) + return 0; /* pure content mode */ + } + ddict->dictID = ZSTD_readLE32((const char *)ddict->dictContent + 4); + + /* load entropy tables */ + CHECK_E(ZSTD_loadEntropy(&ddict->entropy, ddict->dictContent, ddict->dictSize), dictionary_corrupted); + ddict->entropyPresent = 1; + return 0; +} + +static ZSTD_DDict *ZSTD_createDDict_advanced(const void *dict, size_t dictSize, unsigned byReference, ZSTD_customMem customMem) +{ + if (!customMem.customAlloc || !customMem.customFree) + return NULL; + + { + ZSTD_DDict *const ddict = (ZSTD_DDict *)ZSTD_malloc(sizeof(ZSTD_DDict), customMem); + if (!ddict) + return NULL; + ddict->cMem = customMem; + + if ((byReference) || (!dict) || (!dictSize)) { + ddict->dictBuffer = NULL; + ddict->dictContent = dict; + } else { + void *const internalBuffer = ZSTD_malloc(dictSize, customMem); + if (!internalBuffer) { + ZSTD_freeDDict(ddict); + return NULL; + } + memcpy(internalBuffer, dict, dictSize); + ddict->dictBuffer = internalBuffer; + ddict->dictContent = internalBuffer; + } + ddict->dictSize = dictSize; + ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */ + /* parse dictionary content */ + { + size_t const errorCode = ZSTD_loadEntropy_inDDict(ddict); + if (ZSTD_isError(errorCode)) { + ZSTD_freeDDict(ddict); + return NULL; + } + } + + return ddict; + } +} + +/*! ZSTD_initDDict() : +* Create a digested dictionary, to start decompression without startup delay. +* `dict` content is copied inside DDict. +* Consequently, `dict` can be released after `ZSTD_DDict` creation */ +ZSTD_DDict *ZSTD_initDDict(const void *dict, size_t dictSize, void *workspace, size_t workspaceSize) +{ + ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize); + return ZSTD_createDDict_advanced(dict, dictSize, 1, stackMem); +} + +size_t ZSTD_freeDDict(ZSTD_DDict *ddict) +{ + if (ddict == NULL) + return 0; /* support free on NULL */ + { + ZSTD_customMem const cMem = ddict->cMem; + ZSTD_free(ddict->dictBuffer, cMem); + ZSTD_free(ddict, cMem); + return 0; + } +} + +/*! ZSTD_getDictID_fromDict() : + * Provides the dictID stored within dictionary. + * if @return == 0, the dictionary is not conformant with Zstandard specification. + * It can still be loaded, but as a content-only dictionary. */ +unsigned ZSTD_getDictID_fromDict(const void *dict, size_t dictSize) +{ + if (dictSize < 8) + return 0; + if (ZSTD_readLE32(dict) != ZSTD_DICT_MAGIC) + return 0; + return ZSTD_readLE32((const char *)dict + 4); +} + +/*! ZSTD_getDictID_fromDDict() : + * Provides the dictID of the dictionary loaded into `ddict`. + * If @return == 0, the dictionary is not conformant to Zstandard specification, or empty. + * Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */ +unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict *ddict) +{ + if (ddict == NULL) + return 0; + return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize); +} + +/*! ZSTD_getDictID_fromFrame() : + * Provides the dictID required to decompressed the frame stored within `src`. + * If @return == 0, the dictID could not be decoded. + * This could for one of the following reasons : + * - The frame does not require a dictionary to be decoded (most common case). + * - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information. + * Note : this use case also happens when using a non-conformant dictionary. + * - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`). + * - This is not a Zstandard frame. + * When identifying the exact failure cause, it's possible to used ZSTD_getFrameParams(), which will provide a more precise error code. */ +unsigned ZSTD_getDictID_fromFrame(const void *src, size_t srcSize) +{ + ZSTD_frameParams zfp = {0, 0, 0, 0}; + size_t const hError = ZSTD_getFrameParams(&zfp, src, srcSize); + if (ZSTD_isError(hError)) + return 0; + return zfp.dictID; +} + +/*! ZSTD_decompress_usingDDict() : +* Decompression using a pre-digested Dictionary +* Use dictionary without significant overhead. */ +size_t ZSTD_decompress_usingDDict(ZSTD_DCtx *dctx, void *dst, size_t dstCapacity, const void *src, size_t srcSize, const ZSTD_DDict *ddict) +{ + /* pass content and size in case legacy frames are encountered */ + return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, NULL, 0, ddict); +} + +/*===================================== +* Streaming decompression +*====================================*/ + +typedef enum { zdss_init, zdss_loadHeader, zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage; + +/* *** Resource management *** */ +struct ZSTD_DStream_s { + ZSTD_DCtx *dctx; + ZSTD_DDict *ddictLocal; + const ZSTD_DDict *ddict; + ZSTD_frameParams fParams; + ZSTD_dStreamStage stage; + char *inBuff; + size_t inBuffSize; + size_t inPos; + size_t maxWindowSize; + char *outBuff; + size_t outBuffSize; + size_t outStart; + size_t outEnd; + size_t blockSize; + BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX]; /* tmp buffer to store frame header */ + size_t lhSize; + ZSTD_customMem customMem; + void *legacyContext; + U32 previousLegacyVersion; + U32 legacyVersion; + U32 hostageByte; +}; /* typedef'd to ZSTD_DStream within "zstd.h" */ + +size_t ZSTD_DStreamWorkspaceBound(size_t maxWindowSize) +{ + size_t const blockSize = MIN(maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX); + size_t const inBuffSize = blockSize; + size_t const outBuffSize = maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2; + return ZSTD_DCtxWorkspaceBound() + ZSTD_ALIGN(sizeof(ZSTD_DStream)) + ZSTD_ALIGN(inBuffSize) + ZSTD_ALIGN(outBuffSize); +} + +static ZSTD_DStream *ZSTD_createDStream_advanced(ZSTD_customMem customMem) +{ + ZSTD_DStream *zds; + + if (!customMem.customAlloc || !customMem.customFree) + return NULL; + + zds = (ZSTD_DStream *)ZSTD_malloc(sizeof(ZSTD_DStream), customMem); + if (zds == NULL) + return NULL; + memset(zds, 0, sizeof(ZSTD_DStream)); + memcpy(&zds->customMem, &customMem, sizeof(ZSTD_customMem)); + zds->dctx = ZSTD_createDCtx_advanced(customMem); + if (zds->dctx == NULL) { + ZSTD_freeDStream(zds); + return NULL; + } + zds->stage = zdss_init; + zds->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT; + return zds; +} + +ZSTD_DStream *ZSTD_initDStream(size_t maxWindowSize, void *workspace, size_t workspaceSize) +{ + ZSTD_customMem const stackMem = ZSTD_initStack(workspace, workspaceSize); + ZSTD_DStream *zds = ZSTD_createDStream_advanced(stackMem); + if (!zds) { + return NULL; + } + + zds->maxWindowSize = maxWindowSize; + zds->stage = zdss_loadHeader; + zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; + ZSTD_freeDDict(zds->ddictLocal); + zds->ddictLocal = NULL; + zds->ddict = zds->ddictLocal; + zds->legacyVersion = 0; + zds->hostageByte = 0; + + { + size_t const blockSize = MIN(zds->maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX); + size_t const neededOutSize = zds->maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2; + + zds->inBuff = (char *)ZSTD_malloc(blockSize, zds->customMem); + zds->inBuffSize = blockSize; + zds->outBuff = (char *)ZSTD_malloc(neededOutSize, zds->customMem); + zds->outBuffSize = neededOutSize; + if (zds->inBuff == NULL || zds->outBuff == NULL) { + ZSTD_freeDStream(zds); + return NULL; + } + } + return zds; +} + +ZSTD_DStream *ZSTD_initDStream_usingDDict(size_t maxWindowSize, const ZSTD_DDict *ddict, void *workspace, size_t workspaceSize) +{ + ZSTD_DStream *zds = ZSTD_initDStream(maxWindowSize, workspace, workspaceSize); + if (zds) { + zds->ddict = ddict; + } + return zds; +} + +size_t ZSTD_freeDStream(ZSTD_DStream *zds) +{ + if (zds == NULL) + return 0; /* support free on null */ + { + ZSTD_customMem const cMem = zds->customMem; + ZSTD_freeDCtx(zds->dctx); + zds->dctx = NULL; + ZSTD_freeDDict(zds->ddictLocal); + zds->ddictLocal = NULL; + ZSTD_free(zds->inBuff, cMem); + zds->inBuff = NULL; + ZSTD_free(zds->outBuff, cMem); + zds->outBuff = NULL; + ZSTD_free(zds, cMem); + 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_resetDStream(ZSTD_DStream *zds) +{ + zds->stage = zdss_loadHeader; + zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; + zds->legacyVersion = 0; + zds->hostageByte = 0; + return ZSTD_frameHeaderSize_prefix; +} + +/* ***** Decompression ***** */ + +ZSTD_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: + ZSTD_resetDStream(zds); /* transparent reset on starting decoding a new frame */ + /* fall-through */ + + 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 (MAX(ZSTD_frameHeaderSize_min, hSize) - zds->lhSize) + + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */ + } + memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); + zds->lhSize = hSize; + ip += toLoad; + break; + } + + /* check for single-pass mode opportunity */ + if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */ + && (U64)(size_t)(oend - op) >= zds->fParams.frameContentSize) { + size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend - istart); + if (cSize <= (size_t)(iend - istart)) { + size_t const decompressedSize = ZSTD_decompress_usingDDict(zds->dctx, op, oend - op, istart, cSize, zds->ddict); + if (ZSTD_isError(decompressedSize)) + return decompressedSize; + ip = istart + cSize; + op += decompressedSize; + zds->dctx->expected = 0; + zds->stage = zdss_init; + someMoreWork = 0; + break; + } + } + + /* Consume header */ + ZSTD_refDDict(zds->dctx, zds->ddict); + { + size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zds->dctx); /* == ZSTD_frameHeaderSize_prefix */ + CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer, h1Size)); + { + size_t const h2Size = ZSTD_nextSrcSizeToDecompress(zds->dctx); + CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer + h1Size, h2Size)); + } + } + + zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN); + if (zds->fParams.windowSize > zds->maxWindowSize) + return ERROR(frameParameter_windowTooLarge); + + /* Buffers are preallocated, but double check */ + { + size_t const blockSize = MIN(zds->maxWindowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX); + size_t const neededOutSize = zds->maxWindowSize + blockSize + WILDCOPY_OVERLENGTH * 2; + if (zds->inBuffSize < blockSize) { + return ERROR(GENERIC); + } + if (zds->outBuffSize < neededOutSize) { + return ERROR(GENERIC); + } + zds->blockSize = blockSize; + } + zds->stage = zdss_read; + } + /* pass-through */ + + case zdss_read: { + size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx); + 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->dctx); + size_t const decodedSize = ZSTD_decompressContinue(zds->dctx, 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->dctx); + 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->dctx); + size_t const decodedSize = ZSTD_decompressContinue(zds->dctx, 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 complete flush */ + someMoreWork = 0; + break; + } + default: + return ERROR(GENERIC); /* impossible */ + } + } + + /* result */ + input->pos += (size_t)(ip - istart); + output->pos += (size_t)(op - ostart); + { + size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds->dctx); + if (!nextSrcSizeHint) { /* frame fully decoded */ + if (zds->outEnd == zds->outStart) { /* output fully flushed */ + if (zds->hostageByte) { + if (input->pos >= input->size) { + zds->stage = zdss_read; + return 1; + } /* can't release hostage (not present) */ + input->pos++; /* release hostage */ + } + return 0; + } + if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */ + input->pos--; /* note : pos > 0, otherwise, impossible to finish reading last block */ + zds->hostageByte = 1; + } + return 1; + } + nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->dctx) == ZSTDnit_block); /* preload header of next block */ + if (zds->inPos > nextSrcSizeHint) + return ERROR(GENERIC); /* should never happen */ + nextSrcSizeHint -= zds->inPos; /* already loaded*/ + return nextSrcSizeHint; + } +} + +EXPORT_SYMBOL(ZSTD_DCtxWorkspaceBound); +EXPORT_SYMBOL(ZSTD_initDCtx); +EXPORT_SYMBOL(ZSTD_decompressDCtx); +EXPORT_SYMBOL(ZSTD_decompress_usingDict); + +EXPORT_SYMBOL(ZSTD_DDictWorkspaceBound); +EXPORT_SYMBOL(ZSTD_initDDict); +EXPORT_SYMBOL(ZSTD_decompress_usingDDict); + +EXPORT_SYMBOL(ZSTD_DStreamWorkspaceBound); +EXPORT_SYMBOL(ZSTD_initDStream); +EXPORT_SYMBOL(ZSTD_initDStream_usingDDict); +EXPORT_SYMBOL(ZSTD_resetDStream); +EXPORT_SYMBOL(ZSTD_decompressStream); +EXPORT_SYMBOL(ZSTD_DStreamInSize); +EXPORT_SYMBOL(ZSTD_DStreamOutSize); + +EXPORT_SYMBOL(ZSTD_findFrameCompressedSize); +EXPORT_SYMBOL(ZSTD_getFrameContentSize); +EXPORT_SYMBOL(ZSTD_findDecompressedSize); + +EXPORT_SYMBOL(ZSTD_isFrame); +EXPORT_SYMBOL(ZSTD_getDictID_fromDict); +EXPORT_SYMBOL(ZSTD_getDictID_fromDDict); +EXPORT_SYMBOL(ZSTD_getDictID_fromFrame); + +EXPORT_SYMBOL(ZSTD_getFrameParams); +EXPORT_SYMBOL(ZSTD_decompressBegin); +EXPORT_SYMBOL(ZSTD_decompressBegin_usingDict); +EXPORT_SYMBOL(ZSTD_copyDCtx); +EXPORT_SYMBOL(ZSTD_nextSrcSizeToDecompress); +EXPORT_SYMBOL(ZSTD_decompressContinue); +EXPORT_SYMBOL(ZSTD_nextInputType); + +EXPORT_SYMBOL(ZSTD_decompressBlock); +EXPORT_SYMBOL(ZSTD_insertBlock); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_DESCRIPTION("Zstd Decompressor"); |