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- /*
- * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under both the BSD-style license (found in the
- * LICENSE file in the root directory of this source tree) and the GPLv2 (found
- * in the COPYING file in the root directory of this source tree).
- * You may select, at your option, one of the above-listed licenses.
- */
-
-
- /* ***************************************************************
- * Tuning parameters
- *****************************************************************/
- /*!
- * HEAPMODE :
- * Select how default decompression function ZSTD_decompress() allocates its context,
- * on stack (0), or into heap (1, default; requires malloc()).
- * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected.
- */
- #ifndef ZSTD_HEAPMODE
- # define ZSTD_HEAPMODE 1
- #endif
-
- /*!
- * LEGACY_SUPPORT :
- * if set to 1+, ZSTD_decompress() can decode older formats (v0.1+)
- */
- #ifndef ZSTD_LEGACY_SUPPORT
- # define ZSTD_LEGACY_SUPPORT 0
- #endif
-
- /*!
- * MAXWINDOWSIZE_DEFAULT :
- * maximum window size accepted by DStream __by default__.
- * Frames requiring more memory will be rejected.
- * It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize().
- */
- #ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
- # define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) + 1)
- #endif
-
- /*!
- * NO_FORWARD_PROGRESS_MAX :
- * maximum allowed nb of calls to ZSTD_decompressStream()
- * without any forward progress
- * (defined as: no byte read from input, and no byte flushed to output)
- * before triggering an error.
- */
- #ifndef ZSTD_NO_FORWARD_PROGRESS_MAX
- # define ZSTD_NO_FORWARD_PROGRESS_MAX 16
- #endif
-
-
- /*-*******************************************************
- * Dependencies
- *********************************************************/
- #include <string.h> /* memcpy, memmove, memset */
- #include "cpu.h" /* bmi2 */
- #include "mem.h" /* low level memory routines */
- #define FSE_STATIC_LINKING_ONLY
- #include "fse.h"
- #define HUF_STATIC_LINKING_ONLY
- #include "huf.h"
- #include "zstd_internal.h" /* blockProperties_t */
- #include "zstd_decompress_internal.h" /* ZSTD_DCtx */
- #include "zstd_ddict.h" /* ZSTD_DDictDictContent */
- #include "zstd_decompress_block.h" /* ZSTD_decompressBlock_internal */
-
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
- # include "../legacy/zstd_legacy.h"
- #endif
-
-
- /*-*************************************************************
- * Context management
- ***************************************************************/
- size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
- {
- if (dctx==NULL) return 0; /* support sizeof NULL */
- return sizeof(*dctx)
- + ZSTD_sizeof_DDict(dctx->ddictLocal)
- + dctx->inBuffSize + dctx->outBuffSize;
- }
-
- size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
-
-
- static size_t ZSTD_startingInputLength(ZSTD_format_e format)
- {
- size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format);
- /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
- assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
- return startingInputLength;
- }
-
- static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
- {
- dctx->format = ZSTD_f_zstd1; /* ZSTD_decompressBegin() invokes ZSTD_startingInputLength() with argument dctx->format */
- dctx->staticSize = 0;
- dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
- dctx->ddict = NULL;
- dctx->ddictLocal = NULL;
- dctx->dictEnd = NULL;
- dctx->ddictIsCold = 0;
- dctx->dictUses = ZSTD_dont_use;
- dctx->inBuff = NULL;
- dctx->inBuffSize = 0;
- dctx->outBuffSize = 0;
- dctx->streamStage = zdss_init;
- dctx->legacyContext = NULL;
- dctx->previousLegacyVersion = 0;
- dctx->noForwardProgress = 0;
- dctx->oversizedDuration = 0;
- dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
- dctx->outBufferMode = ZSTD_obm_buffered;
- #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
- dctx->dictContentEndForFuzzing = NULL;
- #endif
- }
-
- ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
- {
- ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace;
-
- if ((size_t)workspace & 7) return NULL; /* 8-aligned */
- if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL; /* minimum size */
-
- ZSTD_initDCtx_internal(dctx);
- dctx->staticSize = workspaceSize;
- dctx->inBuff = (char*)(dctx+1);
- return dctx;
- }
-
- ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
- {
- if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
-
- { ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(*dctx), customMem);
- if (!dctx) return NULL;
- dctx->customMem = customMem;
- ZSTD_initDCtx_internal(dctx);
- return dctx;
- }
- }
-
- ZSTD_DCtx* ZSTD_createDCtx(void)
- {
- DEBUGLOG(3, "ZSTD_createDCtx");
- return ZSTD_createDCtx_advanced(ZSTD_defaultCMem);
- }
-
- static void ZSTD_clearDict(ZSTD_DCtx* dctx)
- {
- ZSTD_freeDDict(dctx->ddictLocal);
- dctx->ddictLocal = NULL;
- dctx->ddict = NULL;
- dctx->dictUses = ZSTD_dont_use;
- }
-
- size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
- {
- if (dctx==NULL) return 0; /* support free on NULL */
- RETURN_ERROR_IF(dctx->staticSize, memory_allocation, "not compatible with static DCtx");
- { ZSTD_customMem const cMem = dctx->customMem;
- ZSTD_clearDict(dctx);
- ZSTD_free(dctx->inBuff, cMem);
- dctx->inBuff = NULL;
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
- if (dctx->legacyContext)
- ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
- #endif
- ZSTD_free(dctx, cMem);
- return 0;
- }
- }
-
- /* no longer useful */
- void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
- {
- size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx);
- memcpy(dstDCtx, srcDCtx, toCopy); /* no need to copy workspace */
- }
-
-
- /*-*************************************************************
- * Frame header decoding
- ***************************************************************/
-
- /*! ZSTD_isFrame() :
- * Tells if the content of `buffer` starts with a valid Frame Identifier.
- * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
- * Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
- * Note 3 : Skippable Frame Identifiers are considered valid. */
- unsigned ZSTD_isFrame(const void* buffer, size_t size)
- {
- if (size < ZSTD_FRAMEIDSIZE) return 0;
- { U32 const magic = MEM_readLE32(buffer);
- if (magic == ZSTD_MAGICNUMBER) return 1;
- if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
- }
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
- if (ZSTD_isLegacy(buffer, size)) return 1;
- #endif
- return 0;
- }
-
- /** ZSTD_frameHeaderSize_internal() :
- * srcSize must be large enough to reach header size fields.
- * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless.
- * @return : size of the Frame Header
- * or an error code, which can be tested with ZSTD_isError() */
- static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
- {
- size_t const minInputSize = ZSTD_startingInputLength(format);
- RETURN_ERROR_IF(srcSize < minInputSize, srcSize_wrong, "");
-
- { BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
- U32 const dictID= fhd & 3;
- U32 const singleSegment = (fhd >> 5) & 1;
- U32 const fcsId = fhd >> 6;
- return minInputSize + !singleSegment
- + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
- + (singleSegment && !fcsId);
- }
- }
-
- /** ZSTD_frameHeaderSize() :
- * srcSize must be >= ZSTD_frameHeaderSize_prefix.
- * @return : size of the Frame Header,
- * or an error code (if srcSize is too small) */
- size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
- {
- return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1);
- }
-
-
- /** ZSTD_getFrameHeader_advanced() :
- * decode Frame Header, or require larger `srcSize`.
- * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
- * @return : 0, `zfhPtr` is correctly filled,
- * >0, `srcSize` is too small, value is wanted `srcSize` amount,
- * or an error code, which can be tested using ZSTD_isError() */
- size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
- {
- const BYTE* ip = (const BYTE*)src;
- size_t const minInputSize = ZSTD_startingInputLength(format);
-
- memset(zfhPtr, 0, sizeof(*zfhPtr)); /* not strictly necessary, but static analyzer do not understand that zfhPtr is only going to be read only if return value is zero, since they are 2 different signals */
- if (srcSize < minInputSize) return minInputSize;
- RETURN_ERROR_IF(src==NULL, GENERIC, "invalid parameter");
-
- if ( (format != ZSTD_f_zstd1_magicless)
- && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) {
- if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
- /* skippable frame */
- if (srcSize < ZSTD_SKIPPABLEHEADERSIZE)
- return ZSTD_SKIPPABLEHEADERSIZE; /* magic number + frame length */
- memset(zfhPtr, 0, sizeof(*zfhPtr));
- zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE);
- zfhPtr->frameType = ZSTD_skippableFrame;
- return 0;
- }
- RETURN_ERROR(prefix_unknown, "");
- }
-
- /* ensure there is enough `srcSize` to fully read/decode frame header */
- { size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format);
- if (srcSize < fhsize) return fhsize;
- zfhPtr->headerSize = (U32)fhsize;
- }
-
- { BYTE const fhdByte = ip[minInputSize-1];
- size_t pos = minInputSize;
- U32 const dictIDSizeCode = fhdByte&3;
- U32 const checksumFlag = (fhdByte>>2)&1;
- U32 const singleSegment = (fhdByte>>5)&1;
- U32 const fcsID = fhdByte>>6;
- U64 windowSize = 0;
- U32 dictID = 0;
- U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN;
- RETURN_ERROR_IF((fhdByte & 0x08) != 0, frameParameter_unsupported,
- "reserved bits, must be zero");
-
- if (!singleSegment) {
- BYTE const wlByte = ip[pos++];
- U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
- RETURN_ERROR_IF(windowLog > ZSTD_WINDOWLOG_MAX, frameParameter_windowTooLarge, "");
- windowSize = (1ULL << windowLog);
- windowSize += (windowSize >> 3) * (wlByte&7);
- }
- switch(dictIDSizeCode)
- {
- default: assert(0); /* impossible */
- case 0 : break;
- case 1 : dictID = ip[pos]; pos++; break;
- case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
- case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
- }
- switch(fcsID)
- {
- default: assert(0); /* impossible */
- case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
- case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
- case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
- case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
- }
- if (singleSegment) windowSize = frameContentSize;
-
- zfhPtr->frameType = ZSTD_frame;
- zfhPtr->frameContentSize = frameContentSize;
- zfhPtr->windowSize = windowSize;
- zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
- zfhPtr->dictID = dictID;
- zfhPtr->checksumFlag = checksumFlag;
- }
- return 0;
- }
-
- /** ZSTD_getFrameHeader() :
- * decode Frame Header, or require larger `srcSize`.
- * note : this function does not consume input, it only reads it.
- * @return : 0, `zfhPtr` is correctly filled,
- * >0, `srcSize` is too small, value is wanted `srcSize` amount,
- * or an error code, which can be tested using ZSTD_isError() */
- size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize)
- {
- return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1);
- }
-
-
- /** ZSTD_getFrameContentSize() :
- * compatible with legacy mode
- * @return : decompressed size of the single frame pointed to be `src` if known, otherwise
- * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
- * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
- unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
- {
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
- if (ZSTD_isLegacy(src, srcSize)) {
- unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize);
- return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret;
- }
- #endif
- { ZSTD_frameHeader zfh;
- if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0)
- return ZSTD_CONTENTSIZE_ERROR;
- if (zfh.frameType == ZSTD_skippableFrame) {
- return 0;
- } else {
- return zfh.frameContentSize;
- } }
- }
-
- static size_t readSkippableFrameSize(void const* src, size_t srcSize)
- {
- size_t const skippableHeaderSize = ZSTD_SKIPPABLEHEADERSIZE;
- U32 sizeU32;
-
- RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, "");
-
- sizeU32 = MEM_readLE32((BYTE const*)src + ZSTD_FRAMEIDSIZE);
- RETURN_ERROR_IF((U32)(sizeU32 + ZSTD_SKIPPABLEHEADERSIZE) < sizeU32,
- frameParameter_unsupported, "");
- {
- size_t const skippableSize = skippableHeaderSize + sizeU32;
- RETURN_ERROR_IF(skippableSize > srcSize, srcSize_wrong, "");
- return skippableSize;
- }
- }
-
- /** 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_startingInputLength(ZSTD_f_zstd1)) {
- U32 const magicNumber = MEM_readLE32(src);
-
- if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
- size_t const skippableSize = readSkippableFrameSize(src, srcSize);
- if (ZSTD_isError(skippableSize)) {
- return ZSTD_CONTENTSIZE_ERROR;
- }
- assert(skippableSize <= srcSize);
-
- src = (const BYTE *)src + skippableSize;
- srcSize -= skippableSize;
- continue;
- }
-
- { unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
- if (ret >= ZSTD_CONTENTSIZE_ERROR) return ret;
-
- /* check for overflow */
- if (totalDstSize + ret < totalDstSize) return ZSTD_CONTENTSIZE_ERROR;
- totalDstSize += ret;
- }
- { size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
- if (ZSTD_isError(frameSrcSize)) {
- return ZSTD_CONTENTSIZE_ERROR;
- }
-
- src = (const BYTE *)src + frameSrcSize;
- srcSize -= frameSrcSize;
- }
- } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
-
- if (srcSize) return ZSTD_CONTENTSIZE_ERROR;
-
- return totalDstSize;
- }
-
- /** ZSTD_getDecompressedSize() :
- * compatible with legacy mode
- * @return : decompressed size if known, 0 otherwise
- note : 0 can mean any of the following :
- - frame content is empty
- - decompressed size field is not present in frame header
- - frame header unknown / not supported
- - frame header not complete (`srcSize` too small) */
- unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
- {
- unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
- ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN);
- return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret;
- }
-
-
- /** ZSTD_decodeFrameHeader() :
- * `headerSize` must be the size provided by ZSTD_frameHeaderSize().
- * @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
- static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize)
- {
- size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
- if (ZSTD_isError(result)) return result; /* invalid header */
- RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small");
- #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
- /* Skip the dictID check in fuzzing mode, because it makes the search
- * harder.
- */
- RETURN_ERROR_IF(dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID),
- dictionary_wrong, "");
- #endif
- if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0);
- return 0;
- }
-
- static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret)
- {
- ZSTD_frameSizeInfo frameSizeInfo;
- frameSizeInfo.compressedSize = ret;
- frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
- return frameSizeInfo;
- }
-
- static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize)
- {
- ZSTD_frameSizeInfo frameSizeInfo;
- memset(&frameSizeInfo, 0, sizeof(ZSTD_frameSizeInfo));
-
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
- if (ZSTD_isLegacy(src, srcSize))
- return ZSTD_findFrameSizeInfoLegacy(src, srcSize);
- #endif
-
- if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
- && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
- frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize);
- assert(ZSTD_isError(frameSizeInfo.compressedSize) ||
- frameSizeInfo.compressedSize <= srcSize);
- return frameSizeInfo;
- } else {
- const BYTE* ip = (const BYTE*)src;
- const BYTE* const ipstart = ip;
- size_t remainingSize = srcSize;
- size_t nbBlocks = 0;
- ZSTD_frameHeader zfh;
-
- /* Extract Frame Header */
- { size_t const ret = ZSTD_getFrameHeader(&zfh, src, srcSize);
- if (ZSTD_isError(ret))
- return ZSTD_errorFrameSizeInfo(ret);
- if (ret > 0)
- return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
- }
-
- ip += zfh.headerSize;
- remainingSize -= zfh.headerSize;
-
- /* Iterate over each block */
- while (1) {
- blockProperties_t blockProperties;
- size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
- if (ZSTD_isError(cBlockSize))
- return ZSTD_errorFrameSizeInfo(cBlockSize);
-
- if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
- return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
-
- ip += ZSTD_blockHeaderSize + cBlockSize;
- remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
- nbBlocks++;
-
- if (blockProperties.lastBlock) break;
- }
-
- /* Final frame content checksum */
- if (zfh.checksumFlag) {
- if (remainingSize < 4)
- return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
- ip += 4;
- }
-
- frameSizeInfo.compressedSize = ip - ipstart;
- frameSizeInfo.decompressedBound = (zfh.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN)
- ? zfh.frameContentSize
- : nbBlocks * zfh.blockSizeMax;
- return frameSizeInfo;
- }
- }
-
- /** 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)
- {
- ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
- return frameSizeInfo.compressedSize;
- }
-
- /** ZSTD_decompressBound() :
- * compatible with legacy mode
- * `src` must point to the start of a ZSTD frame or a skippeable frame
- * `srcSize` must be at least as large as the frame contained
- * @return : the maximum decompressed size of the compressed source
- */
- unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
- {
- unsigned long long bound = 0;
- /* Iterate over each frame */
- while (srcSize > 0) {
- ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
- size_t const compressedSize = frameSizeInfo.compressedSize;
- unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
- if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
- return ZSTD_CONTENTSIZE_ERROR;
- assert(srcSize >= compressedSize);
- src = (const BYTE*)src + compressedSize;
- srcSize -= compressedSize;
- bound += decompressedBound;
- }
- return bound;
- }
-
-
- /*-*************************************************************
- * Frame decoding
- ***************************************************************/
-
- /** 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)
- {
- DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize);
- ZSTD_checkContinuity(dctx, blockStart);
- dctx->previousDstEnd = (const char*)blockStart + blockSize;
- return blockSize;
- }
-
-
- static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
- const void* src, size_t srcSize)
- {
- DEBUGLOG(5, "ZSTD_copyRawBlock");
- if (dst == NULL) {
- if (srcSize == 0) return 0;
- RETURN_ERROR(dstBuffer_null, "");
- }
- RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, "");
- memcpy(dst, src, srcSize);
- return srcSize;
- }
-
- static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
- BYTE b,
- size_t regenSize)
- {
- if (dst == NULL) {
- if (regenSize == 0) return 0;
- RETURN_ERROR(dstBuffer_null, "");
- }
- RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, "");
- memset(dst, b, regenSize);
- return regenSize;
- }
-
-
- /*! ZSTD_decompressFrame() :
- * @dctx must be properly initialized
- * will update *srcPtr and *srcSizePtr,
- * to make *srcPtr progress by one frame. */
- 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 = dstCapacity != 0 ? ostart + dstCapacity : ostart;
- BYTE* op = ostart;
- size_t remainingSrcSize = *srcSizePtr;
-
- DEBUGLOG(4, "ZSTD_decompressFrame (srcSize:%i)", (int)*srcSizePtr);
-
- /* check */
- RETURN_ERROR_IF(
- remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize,
- srcSize_wrong, "");
-
- /* Frame Header */
- { size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal(
- ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format);
- if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
- RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize,
- srcSize_wrong, "");
- FORWARD_IF_ERROR( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) , "");
- ip += frameHeaderSize; remainingSrcSize -= frameHeaderSize;
- }
-
- /* Loop on each block */
- while (1) {
- size_t decodedSize;
- blockProperties_t blockProperties;
- size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSrcSize, &blockProperties);
- if (ZSTD_isError(cBlockSize)) return cBlockSize;
-
- ip += ZSTD_blockHeaderSize;
- remainingSrcSize -= ZSTD_blockHeaderSize;
- RETURN_ERROR_IF(cBlockSize > remainingSrcSize, srcSize_wrong, "");
-
- switch(blockProperties.blockType)
- {
- case bt_compressed:
- decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend-op, ip, cBlockSize, /* frame */ 1);
- break;
- case bt_raw :
- decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize);
- break;
- case bt_rle :
- decodedSize = ZSTD_setRleBlock(op, oend-op, *ip, blockProperties.origSize);
- break;
- case bt_reserved :
- default:
- RETURN_ERROR(corruption_detected, "invalid block type");
- }
-
- if (ZSTD_isError(decodedSize)) return decodedSize;
- if (dctx->fParams.checksumFlag)
- XXH64_update(&dctx->xxhState, op, decodedSize);
- if (decodedSize != 0)
- op += decodedSize;
- assert(ip != NULL);
- ip += cBlockSize;
- remainingSrcSize -= cBlockSize;
- if (blockProperties.lastBlock) break;
- }
-
- if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
- RETURN_ERROR_IF((U64)(op-ostart) != dctx->fParams.frameContentSize,
- corruption_detected, "");
- }
- if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
- U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState);
- U32 checkRead;
- RETURN_ERROR_IF(remainingSrcSize<4, checksum_wrong, "");
- checkRead = MEM_readLE32(ip);
- RETURN_ERROR_IF(checkRead != checkCalc, checksum_wrong, "");
- ip += 4;
- remainingSrcSize -= 4;
- }
-
- /* Allow caller to get size read */
- *srcPtr = ip;
- *srcSizePtr = remainingSrcSize;
- return op-ostart;
- }
-
- 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;
- int moreThan1Frame = 0;
-
- DEBUGLOG(5, "ZSTD_decompressMultiFrame");
- assert(dict==NULL || ddict==NULL); /* either dict or ddict set, not both */
-
- if (ddict) {
- dict = ZSTD_DDict_dictContent(ddict);
- dictSize = ZSTD_DDict_dictSize(ddict);
- }
-
- while (srcSize >= ZSTD_startingInputLength(dctx->format)) {
-
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
- if (ZSTD_isLegacy(src, srcSize)) {
- size_t decodedSize;
- size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
- if (ZSTD_isError(frameSize)) return frameSize;
- RETURN_ERROR_IF(dctx->staticSize, memory_allocation,
- "legacy support is not compatible with static dctx");
-
- decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize);
- if (ZSTD_isError(decodedSize)) return decodedSize;
-
- assert(decodedSize <=- dstCapacity);
- dst = (BYTE*)dst + decodedSize;
- dstCapacity -= decodedSize;
-
- src = (const BYTE*)src + frameSize;
- srcSize -= frameSize;
-
- continue;
- }
- #endif
-
- { U32 const magicNumber = MEM_readLE32(src);
- DEBUGLOG(4, "reading magic number %08X (expecting %08X)",
- (unsigned)magicNumber, ZSTD_MAGICNUMBER);
- if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
- size_t const skippableSize = readSkippableFrameSize(src, srcSize);
- FORWARD_IF_ERROR(skippableSize, "readSkippableFrameSize failed");
- assert(skippableSize <= srcSize);
-
- src = (const BYTE *)src + skippableSize;
- srcSize -= skippableSize;
- continue;
- } }
-
- if (ddict) {
- /* we were called from ZSTD_decompress_usingDDict */
- FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(dctx, ddict), "");
- } else {
- /* this will initialize correctly with no dict if dict == NULL, so
- * use this in all cases but ddict */
- FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize), "");
- }
- ZSTD_checkContinuity(dctx, dst);
-
- { const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
- &src, &srcSize);
- RETURN_ERROR_IF(
- (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown)
- && (moreThan1Frame==1),
- srcSize_wrong,
- "at least one frame successfully completed, but following "
- "bytes are garbage: it's more likely to be a srcSize error, "
- "specifying more bytes than compressed size of frame(s). This "
- "error message replaces ERROR(prefix_unknown), which would be "
- "confusing, as the first header is actually correct. Note that "
- "one could be unlucky, it might be a corruption error instead, "
- "happening right at the place where we expect zstd magic "
- "bytes. But this is _much_ less likely than a srcSize field "
- "error.");
- if (ZSTD_isError(res)) return res;
- assert(res <= dstCapacity);
- if (res != 0)
- dst = (BYTE*)dst + res;
- dstCapacity -= res;
- }
- moreThan1Frame = 1;
- } /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
-
- RETURN_ERROR_IF(srcSize, 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);
- }
-
-
- static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx)
- {
- switch (dctx->dictUses) {
- default:
- assert(0 /* Impossible */);
- /* fall-through */
- case ZSTD_dont_use:
- ZSTD_clearDict(dctx);
- return NULL;
- case ZSTD_use_indefinitely:
- return dctx->ddict;
- case ZSTD_use_once:
- dctx->dictUses = ZSTD_dont_use;
- return dctx->ddict;
- }
- }
-
- size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
- {
- return ZSTD_decompress_usingDDict(dctx, dst, dstCapacity, src, srcSize, ZSTD_getDDict(dctx));
- }
-
-
- size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
- {
- #if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1)
- size_t regenSize;
- ZSTD_DCtx* const dctx = ZSTD_createDCtx();
- RETURN_ERROR_IF(dctx==NULL, memory_allocation, "NULL pointer!");
- regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
- ZSTD_freeDCtx(dctx);
- return regenSize;
- #else /* stack mode */
- ZSTD_DCtx dctx;
- ZSTD_initDCtx_internal(&dctx);
- return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
- #endif
- }
-
-
- /*-**************************************
- * Advanced Streaming Decompression API
- * Bufferless and synchronous
- ****************************************/
- size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }
-
- /**
- * Similar to ZSTD_nextSrcSizeToDecompress(), but when when a block input can be streamed,
- * we allow taking a partial block as the input. Currently only raw uncompressed blocks can
- * be streamed.
- *
- * For blocks that can be streamed, this allows us to reduce the latency until we produce
- * output, and avoid copying the input.
- *
- * @param inputSize - The total amount of input that the caller currently has.
- */
- static size_t ZSTD_nextSrcSizeToDecompressWithInputSize(ZSTD_DCtx* dctx, size_t inputSize) {
- if (!(dctx->stage == ZSTDds_decompressBlock || dctx->stage == ZSTDds_decompressLastBlock))
- return dctx->expected;
- if (dctx->bType != bt_raw)
- return dctx->expected;
- return MIN(MAX(inputSize, 1), dctx->expected);
- }
-
- ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
- switch(dctx->stage)
- {
- default: /* should not happen */
- assert(0);
- case ZSTDds_getFrameHeaderSize:
- case ZSTDds_decodeFrameHeader:
- return ZSTDnit_frameHeader;
- case ZSTDds_decodeBlockHeader:
- return ZSTDnit_blockHeader;
- case ZSTDds_decompressBlock:
- return ZSTDnit_block;
- case ZSTDds_decompressLastBlock:
- return ZSTDnit_lastBlock;
- case ZSTDds_checkChecksum:
- return ZSTDnit_checksum;
- case ZSTDds_decodeSkippableHeader:
- case ZSTDds_skipFrame:
- return ZSTDnit_skippableFrame;
- }
- }
-
- static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }
-
- /** ZSTD_decompressContinue() :
- * srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress())
- * @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
- * or an error code, which can be tested using ZSTD_isError() */
- size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
- {
- DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize);
- /* Sanity check */
- RETURN_ERROR_IF(srcSize != ZSTD_nextSrcSizeToDecompressWithInputSize(dctx, srcSize), srcSize_wrong, "not allowed");
- if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
-
- switch (dctx->stage)
- {
- case ZSTDds_getFrameHeaderSize :
- assert(src != NULL);
- if (dctx->format == ZSTD_f_zstd1) { /* allows header */
- assert(srcSize >= ZSTD_FRAMEIDSIZE); /* to read skippable magic number */
- if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */
- memcpy(dctx->headerBuffer, src, srcSize);
- dctx->expected = ZSTD_SKIPPABLEHEADERSIZE - srcSize; /* remaining to load to get full skippable frame header */
- dctx->stage = ZSTDds_decodeSkippableHeader;
- return 0;
- } }
- dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format);
- if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
- memcpy(dctx->headerBuffer, src, srcSize);
- dctx->expected = dctx->headerSize - srcSize;
- dctx->stage = ZSTDds_decodeFrameHeader;
- return 0;
-
- case ZSTDds_decodeFrameHeader:
- assert(src != NULL);
- memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize);
- FORWARD_IF_ERROR(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;
- RETURN_ERROR_IF(cBlockSize > dctx->fParams.blockSizeMax, corruption_detected, "Block Size Exceeds Maximum");
- dctx->expected = cBlockSize;
- dctx->bType = bp.blockType;
- dctx->rleSize = bp.origSize;
- if (cBlockSize) {
- dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
- return 0;
- }
- /* empty block */
- if (bp.lastBlock) {
- if (dctx->fParams.checksumFlag) {
- dctx->expected = 4;
- dctx->stage = ZSTDds_checkChecksum;
- } else {
- dctx->expected = 0; /* end of frame */
- dctx->stage = ZSTDds_getFrameHeaderSize;
- }
- } else {
- dctx->expected = ZSTD_blockHeaderSize; /* jump to next header */
- dctx->stage = ZSTDds_decodeBlockHeader;
- }
- return 0;
- }
-
- case ZSTDds_decompressLastBlock:
- case ZSTDds_decompressBlock:
- DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock");
- { size_t rSize;
- switch(dctx->bType)
- {
- case bt_compressed:
- DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed");
- rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1);
- dctx->expected = 0; /* Streaming not supported */
- break;
- case bt_raw :
- assert(srcSize <= dctx->expected);
- rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize);
- FORWARD_IF_ERROR(rSize, "ZSTD_copyRawBlock failed");
- assert(rSize == srcSize);
- dctx->expected -= rSize;
- break;
- case bt_rle :
- rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize);
- dctx->expected = 0; /* Streaming not supported */
- break;
- case bt_reserved : /* should never happen */
- default:
- RETURN_ERROR(corruption_detected, "invalid block type");
- }
- FORWARD_IF_ERROR(rSize, "");
- RETURN_ERROR_IF(rSize > dctx->fParams.blockSizeMax, corruption_detected, "Decompressed Block Size Exceeds Maximum");
- DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (unsigned)rSize);
- dctx->decodedSize += rSize;
- if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize);
- dctx->previousDstEnd = (char*)dst + rSize;
-
- /* Stay on the same stage until we are finished streaming the block. */
- if (dctx->expected > 0) {
- return rSize;
- }
-
- if (dctx->stage == ZSTDds_decompressLastBlock) { /* end of frame */
- DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (unsigned)dctx->decodedSize);
- RETURN_ERROR_IF(
- dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
- && dctx->decodedSize != dctx->fParams.frameContentSize,
- corruption_detected, "");
- if (dctx->fParams.checksumFlag) { /* another round for frame checksum */
- dctx->expected = 4;
- dctx->stage = ZSTDds_checkChecksum;
- } else {
- dctx->expected = 0; /* ends here */
- dctx->stage = ZSTDds_getFrameHeaderSize;
- }
- } else {
- dctx->stage = ZSTDds_decodeBlockHeader;
- dctx->expected = ZSTD_blockHeaderSize;
- }
- return rSize;
- }
-
- case ZSTDds_checkChecksum:
- assert(srcSize == 4); /* guaranteed by dctx->expected */
- { U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
- U32 const check32 = MEM_readLE32(src);
- DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32);
- RETURN_ERROR_IF(check32 != h32, checksum_wrong, "");
- dctx->expected = 0;
- dctx->stage = ZSTDds_getFrameHeaderSize;
- return 0;
- }
-
- case ZSTDds_decodeSkippableHeader:
- assert(src != NULL);
- assert(srcSize <= ZSTD_SKIPPABLEHEADERSIZE);
- memcpy(dctx->headerBuffer + (ZSTD_SKIPPABLEHEADERSIZE - srcSize), src, srcSize); /* complete skippable header */
- dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE); /* note : dctx->expected can grow seriously large, beyond local buffer size */
- dctx->stage = ZSTDds_skipFrame;
- return 0;
-
- case ZSTDds_skipFrame:
- dctx->expected = 0;
- dctx->stage = ZSTDds_getFrameHeaderSize;
- return 0;
-
- default:
- assert(0); /* impossible */
- RETURN_ERROR(GENERIC, "impossible to reach"); /* some compiler require default to do something */
- }
- }
-
-
- static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
- {
- dctx->dictEnd = dctx->previousDstEnd;
- dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
- dctx->prefixStart = dict;
- dctx->previousDstEnd = (const char*)dict + dictSize;
- #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
- dctx->dictContentBeginForFuzzing = dctx->prefixStart;
- dctx->dictContentEndForFuzzing = dctx->previousDstEnd;
- #endif
- return 0;
- }
-
- /*! ZSTD_loadDEntropy() :
- * dict : must point at beginning of a valid zstd dictionary.
- * @return : size of entropy tables read */
- size_t
- ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
- const void* const dict, size_t const dictSize)
- {
- const BYTE* dictPtr = (const BYTE*)dict;
- const BYTE* const dictEnd = dictPtr + dictSize;
-
- RETURN_ERROR_IF(dictSize <= 8, dictionary_corrupted, "dict is too small");
- assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY); /* dict must be valid */
- dictPtr += 8; /* skip header = magic + dictID */
-
- ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable));
- ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable));
- ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE);
- { void* const workspace = &entropy->LLTable; /* use fse tables as temporary workspace; implies fse tables are grouped together */
- size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable);
- #ifdef HUF_FORCE_DECOMPRESS_X1
- /* in minimal huffman, we always use X1 variants */
- size_t const hSize = HUF_readDTableX1_wksp(entropy->hufTable,
- dictPtr, dictEnd - dictPtr,
- workspace, workspaceSize);
- #else
- size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable,
- dictPtr, dictEnd - dictPtr,
- workspace, workspaceSize);
- #endif
- RETURN_ERROR_IF(HUF_isError(hSize), dictionary_corrupted, "");
- dictPtr += hSize;
- }
-
- { short offcodeNCount[MaxOff+1];
- unsigned offcodeMaxValue = MaxOff, offcodeLog;
- size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
- RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted, "");
- RETURN_ERROR_IF(offcodeMaxValue > MaxOff, dictionary_corrupted, "");
- RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted, "");
- ZSTD_buildFSETable( entropy->OFTable,
- offcodeNCount, offcodeMaxValue,
- OF_base, OF_bits,
- offcodeLog);
- dictPtr += offcodeHeaderSize;
- }
-
- { short matchlengthNCount[MaxML+1];
- unsigned matchlengthMaxValue = MaxML, matchlengthLog;
- size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
- RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted, "");
- RETURN_ERROR_IF(matchlengthMaxValue > MaxML, dictionary_corrupted, "");
- RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted, "");
- ZSTD_buildFSETable( entropy->MLTable,
- matchlengthNCount, matchlengthMaxValue,
- ML_base, ML_bits,
- matchlengthLog);
- dictPtr += matchlengthHeaderSize;
- }
-
- { short litlengthNCount[MaxLL+1];
- unsigned litlengthMaxValue = MaxLL, litlengthLog;
- size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
- RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted, "");
- RETURN_ERROR_IF(litlengthMaxValue > MaxLL, dictionary_corrupted, "");
- RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted, "");
- ZSTD_buildFSETable( entropy->LLTable,
- litlengthNCount, litlengthMaxValue,
- LL_base, LL_bits,
- litlengthLog);
- dictPtr += litlengthHeaderSize;
- }
-
- RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted, "");
- { int i;
- size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12));
- for (i=0; i<3; i++) {
- U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4;
- RETURN_ERROR_IF(rep==0 || rep > dictContentSize,
- dictionary_corrupted, "");
- entropy->rep[i] = rep;
- } }
-
- return dictPtr - (const BYTE*)dict;
- }
-
- static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
- {
- if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
- { U32 const magic = MEM_readLE32(dict);
- if (magic != ZSTD_MAGIC_DICTIONARY) {
- return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */
- } }
- dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
-
- /* load entropy tables */
- { size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize);
- RETURN_ERROR_IF(ZSTD_isError(eSize), 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(ZSTD_DCtx* dctx)
- {
- assert(dctx != NULL);
- dctx->expected = ZSTD_startingInputLength(dctx->format); /* dctx->format must be properly set */
- dctx->stage = ZSTDds_getFrameHeaderSize;
- dctx->decodedSize = 0;
- dctx->previousDstEnd = NULL;
- dctx->prefixStart = NULL;
- dctx->virtualStart = 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;
- dctx->bType = bt_reserved;
- ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
- memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */
- dctx->LLTptr = dctx->entropy.LLTable;
- dctx->MLTptr = dctx->entropy.MLTable;
- dctx->OFTptr = dctx->entropy.OFTable;
- dctx->HUFptr = dctx->entropy.hufTable;
- return 0;
- }
-
- size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
- {
- FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
- if (dict && dictSize)
- RETURN_ERROR_IF(
- ZSTD_isError(ZSTD_decompress_insertDictionary(dctx, dict, dictSize)),
- dictionary_corrupted, "");
- return 0;
- }
-
-
- /* ====== ZSTD_DDict ====== */
-
- size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
- {
- DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
- assert(dctx != NULL);
- if (ddict) {
- const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict);
- size_t const dictSize = ZSTD_DDict_dictSize(ddict);
- const void* const dictEnd = dictStart + dictSize;
- dctx->ddictIsCold = (dctx->dictEnd != dictEnd);
- DEBUGLOG(4, "DDict is %s",
- dctx->ddictIsCold ? "~cold~" : "hot!");
- }
- FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
- if (ddict) { /* NULL ddict is equivalent to no dictionary */
- ZSTD_copyDDictParameters(dctx, ddict);
- }
- 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 (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0;
- return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
- }
-
- /*! ZSTD_getDictID_fromFrame() :
- * Provides the dictID required to decompress frame stored within `src`.
- * If @return == 0, the dictID could not be decoded.
- * This could for one of the following reasons :
- * - The frame does not require a dictionary (most common case).
- * - The frame was built with dictID intentionally removed.
- * Needed dictionary is a hidden information.
- * Note : this use case also happens when using a non-conformant dictionary.
- * - `srcSize` is too small, and as a result, frame header could not be decoded.
- * Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`.
- * - This is not a Zstandard frame.
- * When identifying the exact failure cause, it's possible to use
- * ZSTD_getFrameHeader(), which will provide a more precise error code. */
- unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
- {
- ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0 };
- size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize);
- if (ZSTD_isError(hError)) return 0;
- return zfp.dictID;
- }
-
-
- /*! ZSTD_decompress_usingDDict() :
- * Decompression using a pre-digested Dictionary
- * Use dictionary without significant overhead. */
- size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const ZSTD_DDict* ddict)
- {
- /* pass content and size in case legacy frames are encountered */
- return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize,
- NULL, 0,
- ddict);
- }
-
-
- /*=====================================
- * Streaming decompression
- *====================================*/
-
- ZSTD_DStream* ZSTD_createDStream(void)
- {
- DEBUGLOG(3, "ZSTD_createDStream");
- return ZSTD_createDStream_advanced(ZSTD_defaultCMem);
- }
-
- ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize)
- {
- return ZSTD_initStaticDCtx(workspace, workspaceSize);
- }
-
- ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
- {
- return ZSTD_createDCtx_advanced(customMem);
- }
-
- size_t ZSTD_freeDStream(ZSTD_DStream* zds)
- {
- return ZSTD_freeDCtx(zds);
- }
-
-
- /* *** Initialization *** */
-
- size_t ZSTD_DStreamInSize(void) { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; }
- size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }
-
- size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx,
- const void* dict, size_t dictSize,
- ZSTD_dictLoadMethod_e dictLoadMethod,
- ZSTD_dictContentType_e dictContentType)
- {
- RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
- ZSTD_clearDict(dctx);
- if (dict && dictSize != 0) {
- dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem);
- RETURN_ERROR_IF(dctx->ddictLocal == NULL, memory_allocation, "NULL pointer!");
- dctx->ddict = dctx->ddictLocal;
- dctx->dictUses = ZSTD_use_indefinitely;
- }
- return 0;
- }
-
- size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
- {
- return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
- }
-
- size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
- {
- return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
- }
-
- size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
- {
- FORWARD_IF_ERROR(ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType), "");
- dctx->dictUses = ZSTD_use_once;
- return 0;
- }
-
- size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize)
- {
- return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent);
- }
-
-
- /* ZSTD_initDStream_usingDict() :
- * return : expected size, aka ZSTD_startingInputLength().
- * this function cannot fail */
- size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
- {
- DEBUGLOG(4, "ZSTD_initDStream_usingDict");
- FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) , "");
- FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) , "");
- return ZSTD_startingInputLength(zds->format);
- }
-
- /* note : this variant can't fail */
- size_t ZSTD_initDStream(ZSTD_DStream* zds)
- {
- DEBUGLOG(4, "ZSTD_initDStream");
- return ZSTD_initDStream_usingDDict(zds, NULL);
- }
-
- /* ZSTD_initDStream_usingDDict() :
- * ddict will just be referenced, and must outlive decompression session
- * this function cannot fail */
- size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
- {
- FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) , "");
- FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) , "");
- return ZSTD_startingInputLength(dctx->format);
- }
-
- /* ZSTD_resetDStream() :
- * return : expected size, aka ZSTD_startingInputLength().
- * this function cannot fail */
- size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
- {
- FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only), "");
- return ZSTD_startingInputLength(dctx->format);
- }
-
-
- size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
- {
- RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
- ZSTD_clearDict(dctx);
- if (ddict) {
- dctx->ddict = ddict;
- dctx->dictUses = ZSTD_use_indefinitely;
- }
- return 0;
- }
-
- /* ZSTD_DCtx_setMaxWindowSize() :
- * note : no direct equivalence in ZSTD_DCtx_setParameter,
- * since this version sets windowSize, and the other sets windowLog */
- size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize)
- {
- ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax);
- size_t const min = (size_t)1 << bounds.lowerBound;
- size_t const max = (size_t)1 << bounds.upperBound;
- RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
- RETURN_ERROR_IF(maxWindowSize < min, parameter_outOfBound, "");
- RETURN_ERROR_IF(maxWindowSize > max, parameter_outOfBound, "");
- dctx->maxWindowSize = maxWindowSize;
- return 0;
- }
-
- size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format)
- {
- return ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, format);
- }
-
- ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam)
- {
- ZSTD_bounds bounds = { 0, 0, 0 };
- switch(dParam) {
- case ZSTD_d_windowLogMax:
- bounds.lowerBound = ZSTD_WINDOWLOG_ABSOLUTEMIN;
- bounds.upperBound = ZSTD_WINDOWLOG_MAX;
- return bounds;
- case ZSTD_d_format:
- bounds.lowerBound = (int)ZSTD_f_zstd1;
- bounds.upperBound = (int)ZSTD_f_zstd1_magicless;
- ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
- return bounds;
- case ZSTD_d_stableOutBuffer:
- bounds.lowerBound = (int)ZSTD_obm_buffered;
- bounds.upperBound = (int)ZSTD_obm_stable;
- return bounds;
- default:;
- }
- bounds.error = ERROR(parameter_unsupported);
- return bounds;
- }
-
- /* ZSTD_dParam_withinBounds:
- * @return 1 if value is within dParam bounds,
- * 0 otherwise */
- static int ZSTD_dParam_withinBounds(ZSTD_dParameter dParam, int value)
- {
- ZSTD_bounds const bounds = ZSTD_dParam_getBounds(dParam);
- if (ZSTD_isError(bounds.error)) return 0;
- if (value < bounds.lowerBound) return 0;
- if (value > bounds.upperBound) return 0;
- return 1;
- }
-
- #define CHECK_DBOUNDS(p,v) { \
- RETURN_ERROR_IF(!ZSTD_dParam_withinBounds(p, v), parameter_outOfBound, ""); \
- }
-
- size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value)
- {
- RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
- switch(dParam) {
- case ZSTD_d_windowLogMax:
- if (value == 0) value = ZSTD_WINDOWLOG_LIMIT_DEFAULT;
- CHECK_DBOUNDS(ZSTD_d_windowLogMax, value);
- dctx->maxWindowSize = ((size_t)1) << value;
- return 0;
- case ZSTD_d_format:
- CHECK_DBOUNDS(ZSTD_d_format, value);
- dctx->format = (ZSTD_format_e)value;
- return 0;
- case ZSTD_d_stableOutBuffer:
- CHECK_DBOUNDS(ZSTD_d_stableOutBuffer, value);
- dctx->outBufferMode = (ZSTD_outBufferMode_e)value;
- return 0;
- default:;
- }
- RETURN_ERROR(parameter_unsupported, "");
- }
-
- size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset)
- {
- if ( (reset == ZSTD_reset_session_only)
- || (reset == ZSTD_reset_session_and_parameters) ) {
- dctx->streamStage = zdss_init;
- dctx->noForwardProgress = 0;
- }
- if ( (reset == ZSTD_reset_parameters)
- || (reset == ZSTD_reset_session_and_parameters) ) {
- RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
- ZSTD_clearDict(dctx);
- dctx->format = ZSTD_f_zstd1;
- dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
- }
- return 0;
- }
-
-
- size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx)
- {
- return ZSTD_sizeof_DCtx(dctx);
- }
-
- size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize)
- {
- size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
- unsigned long long const neededRBSize = windowSize + blockSize + (WILDCOPY_OVERLENGTH * 2);
- unsigned long long const neededSize = MIN(frameContentSize, neededRBSize);
- size_t const minRBSize = (size_t) neededSize;
- RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize,
- frameParameter_windowTooLarge, "");
- return minRBSize;
- }
-
- size_t ZSTD_estimateDStreamSize(size_t windowSize)
- {
- size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
- size_t const inBuffSize = blockSize; /* no block can be larger */
- size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN);
- return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize;
- }
-
- size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
- {
- U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX; /* note : should be user-selectable, but requires an additional parameter (or a dctx) */
- ZSTD_frameHeader zfh;
- size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize);
- if (ZSTD_isError(err)) return err;
- RETURN_ERROR_IF(err>0, srcSize_wrong, "");
- RETURN_ERROR_IF(zfh.windowSize > windowSizeMax,
- frameParameter_windowTooLarge, "");
- return ZSTD_estimateDStreamSize((size_t)zfh.windowSize);
- }
-
-
- /* ***** Decompression ***** */
-
- static int ZSTD_DCtx_isOverflow(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
- {
- return (zds->inBuffSize + zds->outBuffSize) >= (neededInBuffSize + neededOutBuffSize) * ZSTD_WORKSPACETOOLARGE_FACTOR;
- }
-
- static void ZSTD_DCtx_updateOversizedDuration(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
- {
- if (ZSTD_DCtx_isOverflow(zds, neededInBuffSize, neededOutBuffSize))
- zds->oversizedDuration++;
- else
- zds->oversizedDuration = 0;
- }
-
- static int ZSTD_DCtx_isOversizedTooLong(ZSTD_DStream* zds)
- {
- return zds->oversizedDuration >= ZSTD_WORKSPACETOOLARGE_MAXDURATION;
- }
-
- /* Checks that the output buffer hasn't changed if ZSTD_obm_stable is used. */
- static size_t ZSTD_checkOutBuffer(ZSTD_DStream const* zds, ZSTD_outBuffer const* output)
- {
- ZSTD_outBuffer const expect = zds->expectedOutBuffer;
- /* No requirement when ZSTD_obm_stable is not enabled. */
- if (zds->outBufferMode != ZSTD_obm_stable)
- return 0;
- /* Any buffer is allowed in zdss_init, this must be the same for every other call until
- * the context is reset.
- */
- if (zds->streamStage == zdss_init)
- return 0;
- /* The buffer must match our expectation exactly. */
- if (expect.dst == output->dst && expect.pos == output->pos && expect.size == output->size)
- return 0;
- RETURN_ERROR(dstBuffer_wrong, "ZSTD_obm_stable enabled but output differs!");
- }
-
- /* Calls ZSTD_decompressContinue() with the right parameters for ZSTD_decompressStream()
- * and updates the stage and the output buffer state. This call is extracted so it can be
- * used both when reading directly from the ZSTD_inBuffer, and in buffered input mode.
- * NOTE: You must break after calling this function since the streamStage is modified.
- */
- static size_t ZSTD_decompressContinueStream(
- ZSTD_DStream* zds, char** op, char* oend,
- void const* src, size_t srcSize) {
- int const isSkipFrame = ZSTD_isSkipFrame(zds);
- if (zds->outBufferMode == ZSTD_obm_buffered) {
- size_t const dstSize = isSkipFrame ? 0 : zds->outBuffSize - zds->outStart;
- size_t const decodedSize = ZSTD_decompressContinue(zds,
- zds->outBuff + zds->outStart, dstSize, src, srcSize);
- FORWARD_IF_ERROR(decodedSize, "");
- if (!decodedSize && !isSkipFrame) {
- zds->streamStage = zdss_read;
- } else {
- zds->outEnd = zds->outStart + decodedSize;
- zds->streamStage = zdss_flush;
- }
- } else {
- /* Write directly into the output buffer */
- size_t const dstSize = isSkipFrame ? 0 : oend - *op;
- size_t const decodedSize = ZSTD_decompressContinue(zds, *op, dstSize, src, srcSize);
- FORWARD_IF_ERROR(decodedSize, "");
- *op += decodedSize;
- /* Flushing is not needed. */
- zds->streamStage = zdss_read;
- assert(*op <= oend);
- assert(zds->outBufferMode == ZSTD_obm_stable);
- }
- return 0;
- }
-
- size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
- {
- const char* const src = (const char*)input->src;
- const char* const istart = input->pos != 0 ? src + input->pos : src;
- const char* const iend = input->size != 0 ? src + input->size : src;
- const char* ip = istart;
- char* const dst = (char*)output->dst;
- char* const ostart = output->pos != 0 ? dst + output->pos : dst;
- char* const oend = output->size != 0 ? dst + output->size : dst;
- char* op = ostart;
- U32 someMoreWork = 1;
-
- DEBUGLOG(5, "ZSTD_decompressStream");
- RETURN_ERROR_IF(
- input->pos > input->size,
- srcSize_wrong,
- "forbidden. in: pos: %u vs size: %u",
- (U32)input->pos, (U32)input->size);
- RETURN_ERROR_IF(
- output->pos > output->size,
- dstSize_tooSmall,
- "forbidden. out: pos: %u vs size: %u",
- (U32)output->pos, (U32)output->size);
- DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
- FORWARD_IF_ERROR(ZSTD_checkOutBuffer(zds, output), "");
-
- while (someMoreWork) {
- switch(zds->streamStage)
- {
- case zdss_init :
- DEBUGLOG(5, "stage zdss_init => transparent reset ");
- zds->streamStage = zdss_loadHeader;
- zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
- zds->legacyVersion = 0;
- zds->hostageByte = 0;
- zds->expectedOutBuffer = *output;
- /* fall-through */
-
- case zdss_loadHeader :
- DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
- if (zds->legacyVersion) {
- RETURN_ERROR_IF(zds->staticSize, memory_allocation,
- "legacy support is incompatible with static dctx");
- { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
- if (hint==0) zds->streamStage = zdss_init;
- return hint;
- } }
- #endif
- { size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
- DEBUGLOG(5, "header size : %u", (U32)hSize);
- if (ZSTD_isError(hSize)) {
- #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
- U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
- if (legacyVersion) {
- ZSTD_DDict const* const ddict = ZSTD_getDDict(zds);
- const void* const dict = ddict ? ZSTD_DDict_dictContent(ddict) : NULL;
- size_t const dictSize = ddict ? ZSTD_DDict_dictSize(ddict) : 0;
- DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
- RETURN_ERROR_IF(zds->staticSize, memory_allocation,
- "legacy support is incompatible with static dctx");
- FORWARD_IF_ERROR(ZSTD_initLegacyStream(&zds->legacyContext,
- zds->previousLegacyVersion, legacyVersion,
- dict, dictSize), "");
- zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
- { size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input);
- if (hint==0) zds->streamStage = zdss_init; /* or stay in stage zdss_loadHeader */
- return hint;
- } }
- #endif
- return hSize; /* error */
- }
- if (hSize != 0) { /* need more input */
- size_t const toLoad = hSize - zds->lhSize; /* if hSize!=0, hSize > zds->lhSize */
- size_t const remainingInput = (size_t)(iend-ip);
- assert(iend >= ip);
- if (toLoad > remainingInput) { /* not enough input to load full header */
- if (remainingInput > 0) {
- memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput);
- zds->lhSize += remainingInput;
- }
- input->pos = input->size;
- return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize; /* remaining header bytes + next block header */
- }
- assert(ip != NULL);
- memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;
- break;
- } }
-
- /* check for single-pass mode opportunity */
- if (zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
- && zds->fParams.frameType != ZSTD_skippableFrame
- && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
- size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend-istart);
- if (cSize <= (size_t)(iend-istart)) {
- /* shortcut : using single-pass mode */
- size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, oend-op, istart, cSize, ZSTD_getDDict(zds));
- if (ZSTD_isError(decompressedSize)) return decompressedSize;
- DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()")
- ip = istart + cSize;
- op += decompressedSize;
- zds->expected = 0;
- zds->streamStage = zdss_init;
- someMoreWork = 0;
- break;
- } }
-
- /* Check output buffer is large enough for ZSTD_odm_stable. */
- if (zds->outBufferMode == ZSTD_obm_stable
- && zds->fParams.frameType != ZSTD_skippableFrame
- && zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
- && (U64)(size_t)(oend-op) < zds->fParams.frameContentSize) {
- RETURN_ERROR(dstSize_tooSmall, "ZSTD_obm_stable passed but ZSTD_outBuffer is too small");
- }
-
- /* Consume header (see ZSTDds_decodeFrameHeader) */
- DEBUGLOG(4, "Consume header");
- FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)), "");
-
- if ((MEM_readLE32(zds->headerBuffer) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { /* skippable frame */
- zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE);
- zds->stage = ZSTDds_skipFrame;
- } else {
- FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize), "");
- zds->expected = ZSTD_blockHeaderSize;
- zds->stage = ZSTDds_decodeBlockHeader;
- }
-
- /* control buffer memory usage */
- DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)",
- (U32)(zds->fParams.windowSize >>10),
- (U32)(zds->maxWindowSize >> 10) );
- zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
- RETURN_ERROR_IF(zds->fParams.windowSize > zds->maxWindowSize,
- frameParameter_windowTooLarge, "");
-
- /* Adapt buffer sizes to frame header instructions */
- { size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
- size_t const neededOutBuffSize = zds->outBufferMode == ZSTD_obm_buffered
- ? ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize)
- : 0;
-
- ZSTD_DCtx_updateOversizedDuration(zds, neededInBuffSize, neededOutBuffSize);
-
- { int const tooSmall = (zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize);
- int const tooLarge = ZSTD_DCtx_isOversizedTooLong(zds);
-
- if (tooSmall || tooLarge) {
- size_t const bufferSize = neededInBuffSize + neededOutBuffSize;
- DEBUGLOG(4, "inBuff : from %u to %u",
- (U32)zds->inBuffSize, (U32)neededInBuffSize);
- DEBUGLOG(4, "outBuff : from %u to %u",
- (U32)zds->outBuffSize, (U32)neededOutBuffSize);
- if (zds->staticSize) { /* static DCtx */
- DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize);
- assert(zds->staticSize >= sizeof(ZSTD_DCtx)); /* controlled at init */
- RETURN_ERROR_IF(
- bufferSize > zds->staticSize - sizeof(ZSTD_DCtx),
- memory_allocation, "");
- } else {
- ZSTD_free(zds->inBuff, zds->customMem);
- zds->inBuffSize = 0;
- zds->outBuffSize = 0;
- zds->inBuff = (char*)ZSTD_malloc(bufferSize, zds->customMem);
- RETURN_ERROR_IF(zds->inBuff == NULL, memory_allocation, "");
- }
- zds->inBuffSize = neededInBuffSize;
- zds->outBuff = zds->inBuff + zds->inBuffSize;
- zds->outBuffSize = neededOutBuffSize;
- } } }
- zds->streamStage = zdss_read;
- /* fall-through */
-
- case zdss_read:
- DEBUGLOG(5, "stage zdss_read");
- { size_t const neededInSize = ZSTD_nextSrcSizeToDecompressWithInputSize(zds, iend - ip);
- DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize);
- if (neededInSize==0) { /* end of frame */
- zds->streamStage = zdss_init;
- someMoreWork = 0;
- break;
- }
- if ((size_t)(iend-ip) >= neededInSize) { /* decode directly from src */
- FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, ip, neededInSize), "");
- ip += neededInSize;
- /* Function modifies the stage so we must break */
- break;
- } }
- if (ip==iend) { someMoreWork = 0; break; } /* no more input */
- zds->streamStage = zdss_load;
- /* fall-through */
-
- case zdss_load:
- { size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
- size_t const toLoad = neededInSize - zds->inPos;
- int const isSkipFrame = ZSTD_isSkipFrame(zds);
- size_t loadedSize;
- /* At this point we shouldn't be decompressing a block that we can stream. */
- assert(neededInSize == ZSTD_nextSrcSizeToDecompressWithInputSize(zds, iend - ip));
- if (isSkipFrame) {
- loadedSize = MIN(toLoad, (size_t)(iend-ip));
- } else {
- RETURN_ERROR_IF(toLoad > zds->inBuffSize - zds->inPos,
- 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 */
- zds->inPos = 0; /* input is consumed */
- FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, zds->inBuff, neededInSize), "");
- /* Function modifies the stage so we must break */
- break;
- }
- case zdss_flush:
- { size_t const toFlushSize = zds->outEnd - zds->outStart;
- size_t const flushedSize = ZSTD_limitCopy(op, oend-op, zds->outBuff + zds->outStart, toFlushSize);
- op += flushedSize;
- zds->outStart += flushedSize;
- if (flushedSize == toFlushSize) { /* flush completed */
- zds->streamStage = zdss_read;
- if ( (zds->outBuffSize < zds->fParams.frameContentSize)
- && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) {
- DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)",
- (int)(zds->outBuffSize - zds->outStart),
- (U32)zds->fParams.blockSizeMax);
- zds->outStart = zds->outEnd = 0;
- }
- break;
- } }
- /* cannot complete flush */
- someMoreWork = 0;
- break;
-
- default:
- assert(0); /* impossible */
- RETURN_ERROR(GENERIC, "impossible to reach"); /* some compiler require default to do something */
- } }
-
- /* result */
- input->pos = (size_t)(ip - (const char*)(input->src));
- output->pos = (size_t)(op - (char*)(output->dst));
-
- /* Update the expected output buffer for ZSTD_obm_stable. */
- zds->expectedOutBuffer = *output;
-
- if ((ip==istart) && (op==ostart)) { /* no forward progress */
- zds->noForwardProgress ++;
- if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
- RETURN_ERROR_IF(op==oend, dstSize_tooSmall, "");
- RETURN_ERROR_IF(ip==iend, srcSize_wrong, "");
- assert(0);
- }
- } else {
- zds->noForwardProgress = 0;
- }
- { size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds);
- if (!nextSrcSizeHint) { /* frame fully decoded */
- if (zds->outEnd == zds->outStart) { /* output fully flushed */
- if (zds->hostageByte) {
- if (input->pos >= input->size) {
- /* can't release hostage (not present) */
- zds->streamStage = zdss_read;
- return 1;
- }
- input->pos++; /* release hostage */
- } /* zds->hostageByte */
- return 0;
- } /* zds->outEnd == zds->outStart */
- if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
- input->pos--; /* note : pos > 0, otherwise, impossible to finish reading last block */
- zds->hostageByte=1;
- }
- return 1;
- } /* nextSrcSizeHint==0 */
- nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block); /* preload header of next block */
- assert(zds->inPos <= nextSrcSizeHint);
- nextSrcSizeHint -= zds->inPos; /* part already loaded*/
- return nextSrcSizeHint;
- }
- }
-
- size_t ZSTD_decompressStream_simpleArgs (
- ZSTD_DCtx* dctx,
- void* dst, size_t dstCapacity, size_t* dstPos,
- const void* src, size_t srcSize, size_t* srcPos)
- {
- ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
- ZSTD_inBuffer input = { src, srcSize, *srcPos };
- /* ZSTD_compress_generic() will check validity of dstPos and srcPos */
- size_t const cErr = ZSTD_decompressStream(dctx, &output, &input);
- *dstPos = output.pos;
- *srcPos = input.pos;
- return cErr;
- }
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