--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/python-zstandard/zstd/decompress/zstd_decompress.c Thu Nov 10 21:45:29 2016 -0800
@@ -0,0 +1,1842 @@
+/**
+ * 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 this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+
+/* ***************************************************************
+* Tuning parameters
+*****************************************************************/
+/*!
+ * HEAPMODE :
+ * Select how default decompression function ZSTD_decompress() will allocate memory,
+ * in memory stack (0), or in memory heap (1, requires malloc())
+ */
+#ifndef ZSTD_HEAPMODE
+# define ZSTD_HEAPMODE 1
+#endif
+
+/*!
+* LEGACY_SUPPORT :
+* if set to 1, ZSTD_decompress() can decode older formats (v0.1+)
+*/
+#ifndef ZSTD_LEGACY_SUPPORT
+# define ZSTD_LEGACY_SUPPORT 0
+#endif
+
+/*!
+* MAXWINDOWSIZE_DEFAULT :
+* maximum window size accepted by DStream, by default.
+* Frames requiring more memory will be rejected.
+*/
+#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
+# define ZSTD_MAXWINDOWSIZE_DEFAULT ((1 << ZSTD_WINDOWLOG_MAX) + 1) /* defined within zstd.h */
+#endif
+
+
+/*-*******************************************************
+* Dependencies
+*********************************************************/
+#include <string.h> /* memcpy, memmove, memset */
+#include "mem.h" /* low level memory routines */
+#define XXH_STATIC_LINKING_ONLY /* XXH64_state_t */
+#include "xxhash.h" /* XXH64_* */
+#define FSE_STATIC_LINKING_ONLY
+#include "fse.h"
+#define HUF_STATIC_LINKING_ONLY
+#include "huf.h"
+#include "zstd_internal.h"
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+# include "zstd_legacy.h"
+#endif
+
+
+/*-*************************************
+* Macros
+***************************************/
+#define ZSTD_isError ERR_isError /* for inlining */
+#define FSE_isError ERR_isError
+#define HUF_isError ERR_isError
+
+
+/*_*******************************************************
+* Memory operations
+**********************************************************/
+static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
+
+
+/*-*************************************************************
+* Context management
+***************************************************************/
+typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
+ ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
+ ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
+ ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;
+
+struct ZSTD_DCtx_s
+{
+ const FSE_DTable* LLTptr;
+ const FSE_DTable* MLTptr;
+ const FSE_DTable* OFTptr;
+ const HUF_DTable* HUFptr;
+ 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 */
+ const void* previousDstEnd;
+ const void* base;
+ const void* vBase;
+ const void* dictEnd;
+ size_t expected;
+ U32 rep[ZSTD_REP_NUM];
+ ZSTD_frameParams fParams;
+ blockType_e bType; /* used in ZSTD_decompressContinue(), to transfer blockType between header decoding and block decoding stages */
+ ZSTD_dStage stage;
+ U32 litEntropy;
+ U32 fseEntropy;
+ XXH64_state_t xxhState;
+ size_t headerSize;
+ U32 dictID;
+ const BYTE* litPtr;
+ ZSTD_customMem customMem;
+ size_t litBufSize;
+ size_t litSize;
+ size_t rleSize;
+ BYTE litBuffer[ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
+ BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
+}; /* typedef'd to ZSTD_DCtx within "zstd.h" */
+
+size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) { return (dctx==NULL) ? 0 : sizeof(ZSTD_DCtx); }
+
+size_t ZSTD_estimateDCtxSize(void) { return 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->hufTable[0] = (HUF_DTable)((HufLog)*0x1000001); /* cover both little and big endian */
+ dctx->litEntropy = dctx->fseEntropy = 0;
+ dctx->dictID = 0;
+ MEM_STATIC_ASSERT(sizeof(dctx->rep) == sizeof(repStartValue));
+ memcpy(dctx->rep, repStartValue, sizeof(repStartValue)); /* initial repcodes */
+ dctx->LLTptr = dctx->LLTable;
+ dctx->MLTptr = dctx->MLTable;
+ dctx->OFTptr = dctx->OFTable;
+ dctx->HUFptr = dctx->hufTable;
+ return 0;
+}
+
+ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
+{
+ ZSTD_DCtx* dctx;
+
+ if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
+ if (!customMem.customAlloc || !customMem.customFree) return NULL;
+
+ dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(ZSTD_DCtx), customMem);
+ if (!dctx) return NULL;
+ memcpy(&dctx->customMem, &customMem, sizeof(customMem));
+ ZSTD_decompressBegin(dctx);
+ return dctx;
+}
+
+ZSTD_DCtx* ZSTD_createDCtx(void)
+{
+ return ZSTD_createDCtx_advanced(defaultCustomMem);
+}
+
+size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
+{
+ if (dctx==NULL) return 0; /* support free on NULL */
+ 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_refDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
+{
+ ZSTD_decompressBegin(dstDCtx); /* init */
+ if (srcDCtx) { /* support refDCtx on NULL */
+ dstDCtx->dictEnd = srcDCtx->dictEnd;
+ dstDCtx->vBase = srcDCtx->vBase;
+ dstDCtx->base = srcDCtx->base;
+ dstDCtx->previousDstEnd = srcDCtx->previousDstEnd;
+ dstDCtx->dictID = srcDCtx->dictID;
+ dstDCtx->litEntropy = srcDCtx->litEntropy;
+ dstDCtx->fseEntropy = srcDCtx->fseEntropy;
+ dstDCtx->LLTptr = srcDCtx->LLTable;
+ dstDCtx->MLTptr = srcDCtx->MLTable;
+ dstDCtx->OFTptr = srcDCtx->OFTable;
+ dstDCtx->HUFptr = srcDCtx->hufTable;
+ dstDCtx->rep[0] = srcDCtx->rep[0];
+ dstDCtx->rep[1] = srcDCtx->rep[1];
+ dstDCtx->rep[2] = srcDCtx->rep[2];
+ }
+}
+
+
+/*-*************************************************************
+* Decompression section
+***************************************************************/
+
+/* See compression format details in : doc/zstd_compression_format.md */
+
+/** 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 (MEM_readLE32(src) != ZSTD_MAGICNUMBER) {
+ if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+ if (srcSize < ZSTD_skippableHeaderSize) return ZSTD_skippableHeaderSize; /* magic number + skippable frame length */
+ memset(fparamsPtr, 0, sizeof(*fparamsPtr));
+ fparamsPtr->frameContentSize = MEM_readLE32((const char *)src + 4);
+ fparamsPtr->windowSize = 0; /* windowSize==0 means a frame is skippable */
+ return 0;
+ }
+ return ERROR(prefix_unknown);
+ }
+
+ /* ensure there is enough `srcSize` to fully read/decode frame header */
+ { size_t const fhsize = ZSTD_frameHeaderSize(src, srcSize);
+ if (srcSize < fhsize) return fhsize; }
+
+ { BYTE const fhdByte = ip[4];
+ size_t pos = 5;
+ U32 const dictIDSizeCode = fhdByte&3;
+ U32 const checksumFlag = (fhdByte>>2)&1;
+ U32 const singleSegment = (fhdByte>>5)&1;
+ U32 const fcsID = fhdByte>>6;
+ U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;
+ U32 windowSize = 0;
+ U32 dictID = 0;
+ U64 frameContentSize = 0;
+ if ((fhdByte & 0x08) != 0) return ERROR(frameParameter_unsupported); /* reserved bits, which must be zero */
+ if (!singleSegment) {
+ BYTE const wlByte = ip[pos++];
+ U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
+ if (windowLog > ZSTD_WINDOWLOG_MAX) return ERROR(frameParameter_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 = MEM_readLE16(ip+pos); pos+=2; break;
+ case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
+ }
+ switch(fcsID)
+ {
+ default: /* impossible */
+ case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
+ case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
+ case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
+ case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
+ }
+ if (!windowSize) windowSize = (U32)frameContentSize;
+ if (windowSize > windowSizeMax) return ERROR(frameParameter_windowTooLarge);
+ fparamsPtr->frameContentSize = frameContentSize;
+ fparamsPtr->windowSize = windowSize;
+ fparamsPtr->dictID = dictID;
+ fparamsPtr->checksumFlag = checksumFlag;
+ }
+ return 0;
+}
+
+
+/** ZSTD_getDecompressedSize() :
+* compatible with legacy mode
+* @return : decompressed size if known, 0 otherwise
+ note : 0 can mean any of the following :
+ - decompressed size is not present within frame header
+ - frame header unknown / not supported
+ - frame header not complete (`srcSize` too small) */
+unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
+{
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
+ if (ZSTD_isLegacy(src, srcSize)) return ZSTD_getDecompressedSize_legacy(src, srcSize);
+#endif
+ { ZSTD_frameParams fparams;
+ size_t const frResult = ZSTD_getFrameParams(&fparams, src, srcSize);
+ if (frResult!=0) return 0;
+ return fparams.frameContentSize;
+ }
+}
+
+
+/** ZSTD_decodeFrameHeader() :
+* `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 = MEM_readLE24(src);
+ U32 const cSize = cBlockHeader >> 3;
+ bpPtr->lastBlock = cBlockHeader & 1;
+ bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
+ bpPtr->origSize = cSize; /* only useful for RLE */
+ if (bpPtr->blockType == bt_rle) return 1;
+ if (bpPtr->blockType == bt_reserved) return ERROR(corruption_detected);
+ return cSize;
+ }
+}
+
+
+static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall);
+ memcpy(dst, src, srcSize);
+ return srcSize;
+}
+
+
+static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity, const void* src, size_t srcSize, size_t regenSize)
+{
+ if (srcSize != 1) return ERROR(srcSize_wrong);
+ if (regenSize > dstCapacity) return ERROR(dstSize_tooSmall);
+ memset(dst, *(const BYTE*)src, regenSize);
+ return regenSize;
+}
+
+/*! ZSTD_decodeLiteralsBlock() :
+ @return : nb of bytes read from src (< srcSize ) */
+size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
+ const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
+{
+ if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
+
+ { const BYTE* const istart = (const BYTE*) src;
+ symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
+
+ switch(litEncType)
+ {
+ case set_repeat:
+ if (dctx->litEntropy==0) return ERROR(dictionary_corrupted);
+ /* fall-through */
+ case set_compressed:
+ if (srcSize < 5) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3 */
+ { size_t lhSize, litSize, litCSize;
+ U32 singleStream=0;
+ U32 const lhlCode = (istart[0] >> 2) & 3;
+ U32 const lhc = MEM_readLE32(istart);
+ switch(lhlCode)
+ {
+ case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */
+ /* 2 - 2 - 10 - 10 */
+ singleStream = !lhlCode;
+ lhSize = 3;
+ litSize = (lhc >> 4) & 0x3FF;
+ litCSize = (lhc >> 14) & 0x3FF;
+ break;
+ case 2:
+ /* 2 - 2 - 14 - 14 */
+ lhSize = 4;
+ litSize = (lhc >> 4) & 0x3FFF;
+ litCSize = lhc >> 18;
+ break;
+ case 3:
+ /* 2 - 2 - 18 - 18 */
+ lhSize = 5;
+ litSize = (lhc >> 4) & 0x3FFFF;
+ litCSize = (lhc >> 22) + (istart[4] << 10);
+ break;
+ }
+ if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
+ if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
+
+ if (HUF_isError((litEncType==set_repeat) ?
+ ( singleStream ?
+ HUF_decompress1X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) :
+ HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) ) :
+ ( singleStream ?
+ HUF_decompress1X2_DCtx(dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) :
+ HUF_decompress4X_hufOnly (dctx->hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize)) ))
+ return ERROR(corruption_detected);
+
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
+ dctx->litSize = litSize;
+ dctx->litEntropy = 1;
+ if (litEncType==set_compressed) dctx->HUFptr = dctx->hufTable;
+ return litCSize + lhSize;
+ }
+
+ case set_basic:
+ { size_t litSize, lhSize;
+ U32 const lhlCode = ((istart[0]) >> 2) & 3;
+ switch(lhlCode)
+ {
+ case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
+ lhSize = 1;
+ litSize = istart[0] >> 3;
+ break;
+ case 1:
+ lhSize = 2;
+ litSize = MEM_readLE16(istart) >> 4;
+ break;
+ case 3:
+ lhSize = 3;
+ litSize = MEM_readLE24(istart) >> 4;
+ break;
+ }
+
+ if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */
+ if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
+ memcpy(dctx->litBuffer, istart+lhSize, litSize);
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+8;
+ dctx->litSize = litSize;
+ return lhSize+litSize;
+ }
+ /* direct reference into compressed stream */
+ dctx->litPtr = istart+lhSize;
+ dctx->litBufSize = srcSize-lhSize;
+ dctx->litSize = litSize;
+ return lhSize+litSize;
+ }
+
+ case set_rle:
+ { U32 const lhlCode = ((istart[0]) >> 2) & 3;
+ size_t litSize, lhSize;
+ switch(lhlCode)
+ {
+ case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
+ lhSize = 1;
+ litSize = istart[0] >> 3;
+ break;
+ case 1:
+ lhSize = 2;
+ litSize = MEM_readLE16(istart) >> 4;
+ break;
+ case 3:
+ lhSize = 3;
+ litSize = MEM_readLE24(istart) >> 4;
+ if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
+ break;
+ }
+ if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
+ memset(dctx->litBuffer, istart[lhSize], litSize);
+ dctx->litPtr = dctx->litBuffer;
+ dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
+ dctx->litSize = litSize;
+ return lhSize+1;
+ }
+ default:
+ return ERROR(corruption_detected); /* impossible */
+ }
+ }
+}
+
+
+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)
+{
+ const void* const tmpPtr = defaultTable; /* bypass strict aliasing */
+ switch(type)
+ {
+ case set_rle :
+ if (!srcSize) return ERROR(srcSize_wrong);
+ if ( (*(const BYTE*)src) > max) return ERROR(corruption_detected);
+ FSE_buildDTable_rle(DTableSpace, *(const BYTE*)src);
+ *DTablePtr = DTableSpace;
+ return 1;
+ case set_basic :
+ *DTablePtr = (const FSE_DTable*)tmpPtr;
+ return 0;
+ case set_repeat:
+ if (!flagRepeatTable) return ERROR(corruption_detected);
+ return 0;
+ default : /* impossible */
+ case set_compressed :
+ { U32 tableLog;
+ S16 norm[MaxSeq+1];
+ size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
+ if (FSE_isError(headerSize)) return ERROR(corruption_detected);
+ if (tableLog > maxLog) return ERROR(corruption_detected);
+ FSE_buildDTable(DTableSpace, norm, max, tableLog);
+ *DTablePtr = DTableSpace;
+ return headerSize;
+ } }
+}
+
+size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
+ const void* src, size_t srcSize)
+{
+ const BYTE* const istart = (const BYTE* const)src;
+ const BYTE* const iend = istart + srcSize;
+ const BYTE* ip = istart;
+
+ /* check */
+ if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong);
+
+ /* SeqHead */
+ { int nbSeq = *ip++;
+ if (!nbSeq) { *nbSeqPtr=0; return 1; }
+ if (nbSeq > 0x7F) {
+ if (nbSeq == 0xFF) {
+ if (ip+2 > iend) return ERROR(srcSize_wrong);
+ nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
+ } else {
+ if (ip >= iend) return ERROR(srcSize_wrong);
+ nbSeq = ((nbSeq-0x80)<<8) + *ip++;
+ }
+ }
+ *nbSeqPtr = nbSeq;
+ }
+
+ /* FSE table descriptors */
+ if (ip+4 > iend) return ERROR(srcSize_wrong); /* minimum possible size */
+ { symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
+ symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
+ symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
+ ip++;
+
+ /* Build DTables */
+ { size_t const llhSize = ZSTD_buildSeqTable(dctx->LLTable, &dctx->LLTptr,
+ LLtype, MaxLL, LLFSELog,
+ ip, iend-ip, LL_defaultDTable, dctx->fseEntropy);
+ if (ZSTD_isError(llhSize)) return ERROR(corruption_detected);
+ ip += llhSize;
+ }
+ { size_t const ofhSize = ZSTD_buildSeqTable(dctx->OFTable, &dctx->OFTptr,
+ OFtype, MaxOff, OffFSELog,
+ ip, iend-ip, OF_defaultDTable, dctx->fseEntropy);
+ if (ZSTD_isError(ofhSize)) return ERROR(corruption_detected);
+ ip += ofhSize;
+ }
+ { size_t const mlhSize = ZSTD_buildSeqTable(dctx->MLTable, &dctx->MLTptr,
+ MLtype, MaxML, MLFSELog,
+ ip, iend-ip, ML_defaultDTable, dctx->fseEntropy);
+ if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected);
+ ip += mlhSize;
+ }
+ }
+
+ return ip-istart;
+}
+
+
+typedef struct {
+ size_t litLength;
+ size_t matchLength;
+ size_t offset;
+} seq_t;
+
+typedef struct {
+ BIT_DStream_t DStream;
+ FSE_DState_t stateLL;
+ FSE_DState_t stateOffb;
+ FSE_DState_t stateML;
+ size_t prevOffset[ZSTD_REP_NUM];
+} seqState_t;
+
+
+static seq_t ZSTD_decodeSequence(seqState_t* seqState)
+{
+ seq_t seq;
+
+ U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
+ U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
+ U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb); /* <= maxOff, by table construction */
+
+ U32 const llBits = LL_bits[llCode];
+ U32 const mlBits = ML_bits[mlCode];
+ U32 const ofBits = ofCode;
+ U32 const totalBits = llBits+mlBits+ofBits;
+
+ static const U32 LL_base[MaxLL+1] = {
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 18, 20, 22, 24, 28, 32, 40, 48, 64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
+ 0x2000, 0x4000, 0x8000, 0x10000 };
+
+ static const U32 ML_base[MaxML+1] = {
+ 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
+ 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
+ 35, 37, 39, 41, 43, 47, 51, 59, 67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
+ 0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
+
+ static const U32 OF_base[MaxOff+1] = {
+ 0, 1, 1, 5, 0xD, 0x1D, 0x3D, 0x7D,
+ 0xFD, 0x1FD, 0x3FD, 0x7FD, 0xFFD, 0x1FFD, 0x3FFD, 0x7FFD,
+ 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
+ 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD };
+
+ /* sequence */
+ { size_t offset;
+ if (!ofCode)
+ offset = 0;
+ else {
+ offset = OF_base[ofCode] + BIT_readBits(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
+ }
+
+ if (ofCode <= 1) {
+ offset += (llCode==0);
+ if (offset) {
+ size_t 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_readBits(&seqState->DStream, mlBits) : 0); /* <= 16 bits */
+ if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&seqState->DStream);
+
+ seq.litLength = LL_base[llCode] + ((llCode>15) ? BIT_readBits(&seqState->DStream, llBits) : 0); /* <= 16 bits */
+ if (MEM_32bits() ||
+ (totalBits > 64 - 7 - (LLFSELog+MLFSELog+OffFSELog)) ) BIT_reloadDStream(&seqState->DStream);
+
+ /* ANS state update */
+ FSE_updateState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */
+ FSE_updateState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */
+ FSE_updateState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */
+
+ return seq;
+}
+
+
+FORCE_NOINLINE
+size_t ZSTD_execSequenceLast7(BYTE* op,
+ BYTE* const oend, seq_t sequence,
+ const BYTE** litPtr, const BYTE* const litLimit_w,
+ const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
+{
+ BYTE* const oLitEnd = op + sequence.litLength;
+ size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+ BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+ BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
+ const BYTE* const iLitEnd = *litPtr + sequence.litLength;
+ const BYTE* match = oLitEnd - sequence.offset;
+
+ /* check */
+ if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+ if (iLitEnd > litLimit_w) return ERROR(corruption_detected); /* over-read beyond lit buffer */
+ if (oLitEnd <= oend_w) return ERROR(GENERIC); /* Precondition */
+
+ /* copy literals */
+ if (op < oend_w) {
+ ZSTD_wildcopy(op, *litPtr, oend_w - op);
+ *litPtr += oend_w - op;
+ op = oend_w;
+ }
+ while (op < oLitEnd) *op++ = *(*litPtr)++;
+
+ /* copy Match */
+ if (sequence.offset > (size_t)(oLitEnd - base)) {
+ /* offset beyond prefix */
+ if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
+ match = dictEnd - (base-match);
+ if (match + sequence.matchLength <= dictEnd) {
+ memmove(oLitEnd, match, sequence.matchLength);
+ return sequenceLength;
+ }
+ /* span extDict & currentPrefixSegment */
+ { size_t const length1 = dictEnd - match;
+ memmove(oLitEnd, match, length1);
+ op = oLitEnd + length1;
+ sequence.matchLength -= length1;
+ match = base;
+ } }
+ while (op < oMatchEnd) *op++ = *match++;
+ return sequenceLength;
+}
+
+
+FORCE_INLINE
+size_t ZSTD_execSequence(BYTE* op,
+ BYTE* const oend, seq_t sequence,
+ const BYTE** litPtr, const BYTE* const litLimit_w,
+ const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
+{
+ BYTE* const oLitEnd = op + sequence.litLength;
+ size_t const sequenceLength = sequence.litLength + sequence.matchLength;
+ BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */
+ BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
+ const BYTE* const iLitEnd = *litPtr + sequence.litLength;
+ const BYTE* match = oLitEnd - sequence.offset;
+
+ /* check */
+ if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
+ if (iLitEnd > litLimit_w) return ERROR(corruption_detected); /* over-read beyond lit buffer */
+ if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit_w, 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 - (base-match);
+ if (match + sequence.matchLength <= dictEnd) {
+ memmove(oLitEnd, match, sequence.matchLength);
+ return sequenceLength;
+ }
+ /* span extDict & currentPrefixSegment */
+ { size_t const length1 = dictEnd - match;
+ memmove(oLitEnd, match, length1);
+ op = oLitEnd + length1;
+ sequence.matchLength -= length1;
+ match = base;
+ if (op > oend_w) {
+ U32 i;
+ for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
+ return sequenceLength;
+ }
+ } }
+ /* Requirement: op <= oend_w */
+
+ /* match within prefix */
+ if (sequence.offset < 8) {
+ /* close range match, overlap */
+ static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */
+ static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* substracted */
+ int const sub2 = dec64table[sequence.offset];
+ op[0] = match[0];
+ op[1] = match[1];
+ op[2] = match[2];
+ op[3] = match[3];
+ match += dec32table[sequence.offset];
+ ZSTD_copy4(op+4, match);
+ match -= sub2;
+ } else {
+ ZSTD_copy8(op, match);
+ }
+ op += 8; match += 8;
+
+ if (oMatchEnd > oend-(16-MINMATCH)) {
+ if (op < oend_w) {
+ ZSTD_wildcopy(op, match, oend_w - op);
+ match += oend_w - op;
+ op = oend_w;
+ }
+ while (op < oMatchEnd) *op++ = *match++;
+ } else {
+ ZSTD_wildcopy(op, match, sequence.matchLength-8); /* works even if matchLength < 8 */
+ }
+ return sequenceLength;
+}
+
+
+static size_t ZSTD_decompressSequences(
+ ZSTD_DCtx* dctx,
+ void* dst, size_t maxDstSize,
+ const void* seqStart, size_t seqSize)
+{
+ const BYTE* ip = (const BYTE*)seqStart;
+ const BYTE* const iend = ip + seqSize;
+ BYTE* const ostart = (BYTE* const)dst;
+ BYTE* const oend = ostart + maxDstSize;
+ BYTE* op = ostart;
+ const BYTE* litPtr = dctx->litPtr;
+ const BYTE* const litLimit_w = litPtr + dctx->litBufSize - WILDCOPY_OVERLENGTH;
+ const BYTE* const litEnd = litPtr + dctx->litSize;
+ 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->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, litLimit_w, base, vBase, dictEnd);
+ if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
+ op += oneSeqSize;
+ } }
+
+ /* check if reached exact end */
+ if (nbSeq) return ERROR(corruption_detected);
+ /* save reps for next block */
+ { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->rep[i] = (U32)(seqState.prevOffset[i]); }
+ }
+
+ /* last literal segment */
+ { size_t const lastLLSize = litEnd - litPtr;
+ if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
+ memcpy(op, litPtr, lastLLSize);
+ op += lastLLSize;
+ }
+
+ return op-ostart;
+}
+
+
+static void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst)
+{
+ if (dst != dctx->previousDstEnd) { /* not contiguous */
+ dctx->dictEnd = dctx->previousDstEnd;
+ dctx->vBase = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
+ dctx->base = dst;
+ dctx->previousDstEnd = dst;
+ }
+}
+
+
+static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize)
+{ /* blockType == blockCompressed */
+ const BYTE* ip = (const BYTE*)src;
+
+ if (srcSize >= ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(srcSize_wrong);
+
+ /* Decode literals sub-block */
+ { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
+ if (ZSTD_isError(litCSize)) return litCSize;
+ ip += litCSize;
+ srcSize -= litCSize;
+ }
+ return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize);
+}
+
+
+size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize)
+{
+ size_t dSize;
+ ZSTD_checkContinuity(dctx, dst);
+ dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize);
+ dctx->previousDstEnd = (char*)dst + dSize;
+ return dSize;
+}
+
+
+/** ZSTD_insertBlock() :
+ insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
+ZSTDLIB_API size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
+{
+ ZSTD_checkContinuity(dctx, blockStart);
+ dctx->previousDstEnd = (const char*)blockStart + blockSize;
+ return blockSize;
+}
+
+
+size_t ZSTD_generateNxBytes(void* dst, size_t dstCapacity, BYTE byte, size_t length)
+{
+ if (length > dstCapacity) return ERROR(dstSize_tooSmall);
+ memset(dst, byte, length);
+ return length;
+}
+
+
+/*! ZSTD_decompressFrame() :
+* `dctx` must be properly initialized */
+static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize)
+{
+ const BYTE* ip = (const BYTE*)src;
+ BYTE* const ostart = (BYTE* const)dst;
+ BYTE* const oend = ostart + dstCapacity;
+ BYTE* op = ostart;
+ size_t remainingSize = srcSize;
+
+ /* check */
+ if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+
+ /* Frame Header */
+ { size_t const frameHeaderSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_prefix);
+ if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
+ if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+ CHECK_F(ZSTD_decodeFrameHeader(dctx, src, 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 = MEM_readLE32(ip);
+ if (checkRead != checkCalc) return ERROR(checksum_wrong);
+ remainingSize -= 4;
+ }
+
+ if (remainingSize) return ERROR(srcSize_wrong);
+ return op-ostart;
+}
+
+
+size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict, size_t dictSize)
+{
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
+ if (ZSTD_isLegacy(src, srcSize)) return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, dict, dictSize);
+#endif
+ ZSTD_decompressBegin_usingDict(dctx, dict, dictSize);
+ ZSTD_checkContinuity(dctx, dst);
+ return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
+}
+
+
+size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0);
+}
+
+
+size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE==1)
+ size_t regenSize;
+ ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+ if (dctx==NULL) return ERROR(memory_allocation);
+ regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
+ ZSTD_freeDCtx(dctx);
+ return regenSize;
+#else /* stack mode */
+ ZSTD_DCtx dctx;
+ return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
+#endif
+}
+
+
+/*-**************************************
+* Advanced Streaming Decompression API
+* Bufferless and synchronous
+****************************************/
+size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }
+
+ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
+ switch(dctx->stage)
+ {
+ default: /* should not happen */
+ case ZSTDds_getFrameHeaderSize:
+ case ZSTDds_decodeFrameHeader:
+ return ZSTDnit_frameHeader;
+ case ZSTDds_decodeBlockHeader:
+ return ZSTDnit_blockHeader;
+ case ZSTDds_decompressBlock:
+ return ZSTDnit_block;
+ case ZSTDds_decompressLastBlock:
+ return ZSTDnit_lastBlock;
+ case ZSTDds_checkChecksum:
+ return ZSTDnit_checksum;
+ case ZSTDds_decodeSkippableHeader:
+ case ZSTDds_skipFrame:
+ return ZSTDnit_skippableFrame;
+ }
+}
+
+int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; } /* for zbuff */
+
+/** ZSTD_decompressContinue() :
+* @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
+* or an error code, which can be tested using ZSTD_isError() */
+size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ /* Sanity check */
+ if (srcSize != dctx->expected) return ERROR(srcSize_wrong);
+ if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
+
+ switch (dctx->stage)
+ {
+ case ZSTDds_getFrameHeaderSize :
+ if (srcSize != ZSTD_frameHeaderSize_prefix) return ERROR(srcSize_wrong); /* impossible */
+ if ((MEM_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 = MEM_readLE32(src); /* srcSize == 4, guaranteed by dctx->expected */
+ if (check32 != h32) return ERROR(checksum_wrong);
+ dctx->expected = 0;
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ return 0;
+ }
+ case ZSTDds_decodeSkippableHeader:
+ { memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected);
+ dctx->expected = MEM_readLE32(dctx->headerBuffer + 4);
+ dctx->stage = ZSTDds_skipFrame;
+ return 0;
+ }
+ case ZSTDds_skipFrame:
+ { dctx->expected = 0;
+ dctx->stage = ZSTDds_getFrameHeaderSize;
+ return 0;
+ }
+ default:
+ return ERROR(GENERIC); /* impossible */
+ }
+}
+
+
+static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ dctx->dictEnd = dctx->previousDstEnd;
+ dctx->vBase = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
+ dctx->base = dict;
+ dctx->previousDstEnd = (const char*)dict + dictSize;
+ return 0;
+}
+
+static size_t ZSTD_loadEntropy(ZSTD_DCtx* dctx, const void* const dict, size_t const dictSize)
+{
+ const BYTE* dictPtr = (const BYTE*)dict;
+ const BYTE* const dictEnd = dictPtr + dictSize;
+
+ { size_t const hSize = HUF_readDTableX4(dctx->hufTable, dict, dictSize);
+ if (HUF_isError(hSize)) return ERROR(dictionary_corrupted);
+ dictPtr += hSize;
+ }
+
+ { short offcodeNCount[MaxOff+1];
+ U32 offcodeMaxValue=MaxOff, offcodeLog;
+ 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(dctx->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog), dictionary_corrupted);
+ dictPtr += offcodeHeaderSize;
+ }
+
+ { short matchlengthNCount[MaxML+1];
+ unsigned matchlengthMaxValue = MaxML, matchlengthLog;
+ size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
+ if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
+ if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
+ CHECK_E(FSE_buildDTable(dctx->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog), dictionary_corrupted);
+ dictPtr += matchlengthHeaderSize;
+ }
+
+ { short litlengthNCount[MaxLL+1];
+ unsigned litlengthMaxValue = MaxLL, litlengthLog;
+ size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
+ if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
+ if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
+ CHECK_E(FSE_buildDTable(dctx->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog), dictionary_corrupted);
+ dictPtr += litlengthHeaderSize;
+ }
+
+ if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
+ dctx->rep[0] = MEM_readLE32(dictPtr+0); if (dctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
+ dctx->rep[1] = MEM_readLE32(dictPtr+4); if (dctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
+ dctx->rep[2] = MEM_readLE32(dictPtr+8); if (dctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
+ dictPtr += 12;
+
+ dctx->litEntropy = dctx->fseEntropy = 1;
+ return dictPtr - (const BYTE*)dict;
+}
+
+static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
+ { U32 const magic = MEM_readLE32(dict);
+ if (magic != ZSTD_DICT_MAGIC) {
+ return ZSTD_refDictContent(dctx, dict, dictSize); /* pure content mode */
+ } }
+ dctx->dictID = MEM_readLE32((const char*)dict + 4);
+
+ /* load entropy tables */
+ dict = (const char*)dict + 8;
+ dictSize -= 8;
+ { size_t const eSize = ZSTD_loadEntropy(dctx, dict, dictSize);
+ if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted);
+ dict = (const char*)dict + eSize;
+ dictSize -= eSize;
+ }
+
+ /* reference dictionary content */
+ return ZSTD_refDictContent(dctx, dict, dictSize);
+}
+
+size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
+{
+ 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* dict;
+ size_t dictSize;
+ ZSTD_DCtx* refContext;
+}; /* typedef'd to ZSTD_DDict within "zstd.h" */
+
+ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, ZSTD_customMem customMem)
+{
+ if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
+ if (!customMem.customAlloc || !customMem.customFree) return NULL;
+
+ { ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
+ void* const dictContent = ZSTD_malloc(dictSize, customMem);
+ ZSTD_DCtx* const dctx = ZSTD_createDCtx_advanced(customMem);
+
+ if (!dictContent || !ddict || !dctx) {
+ ZSTD_free(dictContent, customMem);
+ ZSTD_free(ddict, customMem);
+ ZSTD_free(dctx, customMem);
+ return NULL;
+ }
+
+ if (dictSize) {
+ memcpy(dictContent, dict, dictSize);
+ }
+ { size_t const errorCode = ZSTD_decompressBegin_usingDict(dctx, dictContent, dictSize);
+ if (ZSTD_isError(errorCode)) {
+ ZSTD_free(dictContent, customMem);
+ ZSTD_free(ddict, customMem);
+ ZSTD_free(dctx, customMem);
+ return NULL;
+ } }
+
+ ddict->dict = dictContent;
+ ddict->dictSize = dictSize;
+ ddict->refContext = dctx;
+ return ddict;
+ }
+}
+
+/*! ZSTD_createDDict() :
+* Create a digested dictionary, ready to start decompression without startup delay.
+* `dict` can be released after `ZSTD_DDict` creation */
+ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize)
+{
+ ZSTD_customMem const allocator = { NULL, NULL, NULL };
+ return ZSTD_createDDict_advanced(dict, dictSize, allocator);
+}
+
+size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
+{
+ if (ddict==NULL) return 0; /* support free on NULL */
+ { ZSTD_customMem const cMem = ddict->refContext->customMem;
+ ZSTD_freeDCtx(ddict->refContext);
+ ZSTD_free(ddict->dict, cMem);
+ ZSTD_free(ddict, cMem);
+ return 0;
+ }
+}
+
+size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)
+{
+ if (ddict==NULL) return 0; /* support sizeof on NULL */
+ return sizeof(*ddict) + sizeof(ddict->refContext) + ddict->dictSize;
+}
+
+
+/*! 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)
+{
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
+ if (ZSTD_isLegacy(src, srcSize)) return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, ddict->dict, ddict->dictSize);
+#endif
+ ZSTD_refDCtx(dctx, ddict->refContext);
+ ZSTD_checkContinuity(dctx, dst);
+ return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
+}
+
+
+/*=====================================
+* Streaming decompression
+*====================================*/
+
+typedef enum { zdss_init, zdss_loadHeader,
+ zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
+
+/* *** Resource management *** */
+struct ZSTD_DStream_s {
+ ZSTD_DCtx* 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" */
+
+
+ZSTD_DStream* ZSTD_createDStream(void)
+{
+ return ZSTD_createDStream_advanced(defaultCustomMem);
+}
+
+ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
+{
+ ZSTD_DStream* zds;
+
+ if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
+ if (!customMem.customAlloc || !customMem.customFree) return NULL;
+
+ zds = (ZSTD_DStream*) 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;
+}
+
+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);
+ ZSTD_freeDDict(zds->ddictLocal);
+ ZSTD_free(zds->inBuff, cMem);
+ ZSTD_free(zds->outBuff, cMem);
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
+ if (zds->legacyContext)
+ ZSTD_freeLegacyStreamContext(zds->legacyContext, zds->previousLegacyVersion);
+#endif
+ 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_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
+{
+ zds->stage = zdss_loadHeader;
+ zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
+ ZSTD_freeDDict(zds->ddictLocal);
+ if (dict) {
+ zds->ddictLocal = ZSTD_createDDict(dict, dictSize);
+ if (zds->ddictLocal == NULL) return ERROR(memory_allocation);
+ } else zds->ddictLocal = NULL;
+ zds->ddict = zds->ddictLocal;
+ zds->legacyVersion = 0;
+ zds->hostageByte = 0;
+ return ZSTD_frameHeaderSize_prefix;
+}
+
+size_t ZSTD_initDStream(ZSTD_DStream* zds)
+{
+ return ZSTD_initDStream_usingDict(zds, NULL, 0);
+}
+
+size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict) /**< note : ddict will just be referenced, and must outlive decompression session */
+{
+ size_t const initResult = ZSTD_initDStream(zds);
+ zds->ddict = ddict;
+ return initResult;
+}
+
+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;
+}
+
+size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds,
+ ZSTD_DStreamParameter_e paramType, unsigned paramValue)
+{
+ switch(paramType)
+ {
+ default : return ERROR(parameter_unknown);
+ case ZSTDdsp_maxWindowSize : zds->maxWindowSize = paramValue ? paramValue : (U32)(-1); break;
+ }
+ return 0;
+}
+
+
+size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds)
+{
+ if (zds==NULL) return 0; /* support sizeof on NULL */
+ return sizeof(*zds) + ZSTD_sizeof_DCtx(zds->dctx) + ZSTD_sizeof_DDict(zds->ddictLocal) + zds->inBuffSize + zds->outBuffSize;
+}
+
+
+/* ***** Decompression ***** */
+
+MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+{
+ size_t const length = MIN(dstCapacity, srcSize);
+ memcpy(dst, src, length);
+ return length;
+}
+
+
+size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
+{
+ const char* const istart = (const char*)(input->src) + input->pos;
+ const char* const iend = (const char*)(input->src) + input->size;
+ const char* ip = istart;
+ char* const ostart = (char*)(output->dst) + output->pos;
+ char* const oend = (char*)(output->dst) + output->size;
+ char* op = ostart;
+ U32 someMoreWork = 1;
+
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ if (zds->legacyVersion)
+ return ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
+#endif
+
+ while (someMoreWork) {
+ switch(zds->stage)
+ {
+ case zdss_init :
+ return ERROR(init_missing);
+
+ case zdss_loadHeader :
+ { size_t const hSize = ZSTD_getFrameParams(&zds->fParams, zds->headerBuffer, zds->lhSize);
+ if (ZSTD_isError(hSize))
+#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
+ { U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
+ if (legacyVersion) {
+ const void* const dict = zds->ddict ? zds->ddict->dict : NULL;
+ size_t const dictSize = zds->ddict ? zds->ddict->dictSize : 0;
+ CHECK_F(ZSTD_initLegacyStream(&zds->legacyContext, zds->previousLegacyVersion, legacyVersion,
+ dict, dictSize));
+ zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
+ return ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
+ } else {
+ return hSize; /* error */
+ } }
+#else
+ return hSize;
+#endif
+ 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;
+ } }
+
+ /* Consume header */
+ { const ZSTD_DCtx* refContext = zds->ddict ? zds->ddict->refContext : NULL;
+ ZSTD_refDCtx(zds->dctx, refContext);
+ }
+ { 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);
+
+ /* Adapt buffer sizes to frame header instructions */
+ { size_t const blockSize = MIN(zds->fParams.windowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
+ size_t const neededOutSize = zds->fParams.windowSize + blockSize;
+ zds->blockSize = blockSize;
+ if (zds->inBuffSize < blockSize) {
+ ZSTD_free(zds->inBuff, zds->customMem);
+ zds->inBuffSize = blockSize;
+ zds->inBuff = (char*)ZSTD_malloc(blockSize, zds->customMem);
+ if (zds->inBuff == NULL) return ERROR(memory_allocation);
+ }
+ if (zds->outBuffSize < neededOutSize) {
+ ZSTD_free(zds->outBuff, zds->customMem);
+ zds->outBuffSize = neededOutSize;
+ zds->outBuff = (char*)ZSTD_malloc(neededOutSize, zds->customMem);
+ if (zds->outBuff == NULL) return ERROR(memory_allocation);
+ } }
+ 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;
+ }
+}