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Diffstat (limited to 'lib/lz4frame.c')
| -rw-r--r-- | lib/lz4frame.c | 1330 |
1 files changed, 1330 insertions, 0 deletions
diff --git a/lib/lz4frame.c b/lib/lz4frame.c new file mode 100644 index 0000000..aa46152 --- /dev/null +++ b/lib/lz4frame.c @@ -0,0 +1,1330 @@ +/* +LZ4 auto-framing library +Copyright (C) 2011-2014, Yann Collet. +BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +* Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. +* Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +You can contact the author at : +- LZ4 source repository : http://code.google.com/p/lz4/ +- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c +*/ + +/* LZ4F is a stand-alone API to create LZ4-compressed Frames +* fully conformant to specification v1.4.1. +* All related operations, including memory management, are handled by the library. +* */ + + +/************************************** +Compiler Options +**************************************/ +#ifdef _MSC_VER /* Visual Studio */ +# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ +#endif + +#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) +#ifdef __GNUC__ +# pragma GCC diagnostic ignored "-Wmissing-braces" /* GCC bug 53119 : doesn't accept { 0 } as initializer (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119) */ +# pragma GCC diagnostic ignored "-Wmissing-field-initializers" /* GCC bug 53119 : doesn't accept { 0 } as initializer (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119) */ +#endif + + +/************************************** +Memory routines +**************************************/ +#include <stdlib.h> /* malloc, calloc, free */ +#define ALLOCATOR(s) calloc(1,s) +#define FREEMEM free +#include <string.h> /* memset, memcpy, memmove */ +#define MEM_INIT memset + + +/************************************** +Includes +**************************************/ +#include "lz4frame.h" +#include "lz4.h" +#include "lz4hc.h" +#include "xxhash.h" + + +/************************************** +Basic Types +**************************************/ +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */ +# include <stdint.h> +typedef uint8_t BYTE; +typedef uint16_t U16; +typedef uint32_t U32; +typedef int32_t S32; +typedef uint64_t U64; +#else +typedef unsigned char BYTE; +typedef unsigned short U16; +typedef unsigned int U32; +typedef signed int S32; +typedef unsigned long long U64; +#endif + + +/************************************** +Constants +**************************************/ +#define KB *(1<<10) +#define MB *(1<<20) +#define GB *(1<<30) + +#define _1BIT 0x01 +#define _2BITS 0x03 +#define _3BITS 0x07 +#define _4BITS 0x0F +#define _8BITS 0xFF + +#define LZ4F_MAGICNUMBER 0x184D2204U +#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U +#define LZ4F_MAXHEADERFRAME_SIZE 7 +#define LZ4F_BLOCKSIZEID_DEFAULT max64KB + +static const U32 minHClevel = 3; + +/************************************** +Structures and local types +**************************************/ +typedef struct +{ + LZ4F_preferences_t prefs; + U32 version; + U32 cStage; + size_t maxBlockSize; + size_t maxBufferSize; + BYTE* tmpBuff; + BYTE* tmpIn; + size_t tmpInSize; + XXH32_state_t xxh; + void* lz4CtxPtr; + U32 lz4CtxLevel; /* 0: unallocated; 1: LZ4_stream_t; 3: LZ4_streamHC_t */ +} LZ4F_cctx_internal_t; + +typedef struct +{ + LZ4F_frameInfo_t frameInfo; + unsigned version; + unsigned dStage; + size_t maxBlockSize; + size_t maxBufferSize; + const BYTE* srcExpect; + BYTE* tmpIn; + size_t tmpInSize; + size_t tmpInTarget; + BYTE* tmpOutBuffer; + BYTE* dict; + size_t dictSize; + BYTE* tmpOut; + size_t tmpOutSize; + size_t tmpOutStart; + XXH32_state_t xxh; + BYTE header[8]; +} LZ4F_dctx_internal_t; + + +/************************************** +Macros +**************************************/ + + +/************************************** +Error management +**************************************/ +#define LZ4F_GENERATE_STRING(STRING) #STRING, +static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) }; + + +int LZ4F_isError(LZ4F_errorCode_t code) +{ + return (code > (LZ4F_errorCode_t)(-ERROR_maxCode)); +} + +const char* LZ4F_getErrorName(LZ4F_errorCode_t code) +{ + static const char* codeError = "Unspecified error code"; + if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)]; + return codeError; +} + + +/************************************** +Private functions +**************************************/ +static size_t LZ4F_getBlockSize(unsigned blockSizeID) +{ + static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB }; + + if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT; + blockSizeID -= 4; + if (blockSizeID > 3) return (size_t)-ERROR_maxBlockSize_invalid; + return blockSizes[blockSizeID]; +} + + +/* unoptimized version; solves endianess & alignment issues */ +static void LZ4F_writeLE32 (BYTE* dstPtr, U32 value32) +{ + dstPtr[0] = (BYTE)value32; + dstPtr[1] = (BYTE)(value32 >> 8); + dstPtr[2] = (BYTE)(value32 >> 16); + dstPtr[3] = (BYTE)(value32 >> 24); +} + +static U32 LZ4F_readLE32 (const BYTE* srcPtr) +{ + U32 value32 = srcPtr[0]; + value32 += (srcPtr[1]<<8); + value32 += (srcPtr[2]<<16); + value32 += (srcPtr[3]<<24); + return value32; +} + + +static BYTE LZ4F_headerChecksum (const BYTE* header, size_t length) +{ + U32 xxh = XXH32(header, (U32)length, 0); + return (BYTE)(xxh >> 8); +} + + +/************************************** +Simple compression functions +**************************************/ +size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_preferences_t prefs = { 0 }; + size_t headerSize; + size_t streamSize; + + if (preferencesPtr!=NULL) prefs = *preferencesPtr; + { + blockSizeID_t proposedBSID = max64KB; + size_t maxBlockSize = 64 KB; + while (prefs.frameInfo.blockSizeID > proposedBSID) + { + if (srcSize <= maxBlockSize) + { + prefs.frameInfo.blockSizeID = proposedBSID; + break; + } + proposedBSID++; + maxBlockSize <<= 2; + } + } + prefs.autoFlush = 1; + + headerSize = 7; /* basic header size (no option) including magic number */ + streamSize = LZ4F_compressBound(srcSize, &prefs); + + return headerSize + streamSize; +} + + +/* LZ4F_compressFrame() +* Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.4.1, in a single step. +* The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case. +* You can get the minimum value of dstMaxSize by using LZ4F_compressFrameBound() +* If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode) +* The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default. +* The result of the function is the number of bytes written into dstBuffer. +* The function outputs an error code if it fails (can be tested using LZ4F_isError()) +*/ +size_t LZ4F_compressFrame(void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_cctx_internal_t cctxI = { 0 }; /* works because no allocation */ + LZ4F_preferences_t prefs = { 0 }; + LZ4F_compressOptions_t options = { 0 }; + LZ4F_errorCode_t errorCode; + BYTE* const dstStart = (BYTE*) dstBuffer; + BYTE* dstPtr = dstStart; + BYTE* const dstEnd = dstStart + dstMaxSize; + + + cctxI.version = LZ4F_VERSION; + cctxI.maxBufferSize = 5 MB; /* mess with real buffer size to prevent allocation; works because autoflush==1 & stableSrc==1 */ + + if (preferencesPtr!=NULL) prefs = *preferencesPtr; + { + blockSizeID_t proposedBSID = max64KB; + size_t maxBlockSize = 64 KB; + while (prefs.frameInfo.blockSizeID > proposedBSID) + { + if (srcSize <= maxBlockSize) + { + prefs.frameInfo.blockSizeID = proposedBSID; + break; + } + proposedBSID++; + maxBlockSize <<= 2; + } + } + prefs.autoFlush = 1; + if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID)) + prefs.frameInfo.blockMode = blockIndependent; /* no need for linked blocks */ + + options.stableSrc = 1; + + if (dstMaxSize < LZ4F_compressFrameBound(srcSize, &prefs)) + return (size_t)-ERROR_dstMaxSize_tooSmall; + + errorCode = LZ4F_compressBegin(&cctxI, dstBuffer, dstMaxSize, &prefs); /* write header */ + if (LZ4F_isError(errorCode)) return errorCode; + dstPtr += errorCode; /* header size */ + + dstMaxSize -= errorCode; + errorCode = LZ4F_compressUpdate(&cctxI, dstPtr, dstMaxSize, srcBuffer, srcSize, &options); + if (LZ4F_isError(errorCode)) return errorCode; + dstPtr += errorCode; + + errorCode = LZ4F_compressEnd(&cctxI, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */ + if (LZ4F_isError(errorCode)) return errorCode; + dstPtr += errorCode; + + FREEMEM(cctxI.lz4CtxPtr); + + return (dstPtr - dstStart); +} + + +/*********************************** +* Advanced compression functions +* *********************************/ + +/* LZ4F_createCompressionContext() : +* The first thing to do is to create a compressionContext object, which will be used in all compression operations. +* This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure. +* The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries. +* The function will provide a pointer to an allocated LZ4F_compressionContext_t object. +* If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation. +* Object can release its memory using LZ4F_freeCompressionContext(); +*/ +LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_compressionContextPtr, unsigned version) +{ + LZ4F_cctx_internal_t* cctxPtr; + + cctxPtr = (LZ4F_cctx_internal_t*)ALLOCATOR(sizeof(LZ4F_cctx_internal_t)); + if (cctxPtr==NULL) return (LZ4F_errorCode_t)(-ERROR_allocation_failed); + + cctxPtr->version = version; + cctxPtr->cStage = 0; /* Next stage : write header */ + + *LZ4F_compressionContextPtr = (LZ4F_compressionContext_t)cctxPtr; + + return OK_NoError; +} + + +LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_compressionContext) +{ + LZ4F_cctx_internal_t* cctxPtr = (LZ4F_cctx_internal_t*)LZ4F_compressionContext; + + FREEMEM(cctxPtr->lz4CtxPtr); + FREEMEM(cctxPtr->tmpBuff); + FREEMEM(LZ4F_compressionContext); + + return OK_NoError; +} + + +/* LZ4F_compressBegin() : +* will write the frame header into dstBuffer. +* dstBuffer must be large enough to accommodate a header (dstMaxSize). Maximum header size is LZ4F_MAXHEADERFRAME_SIZE bytes. +* The result of the function is the number of bytes written into dstBuffer for the header +* or an error code (can be tested using LZ4F_isError()) +*/ +size_t LZ4F_compressBegin(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_preferences_t prefNull = { 0 }; + LZ4F_cctx_internal_t* cctxPtr = (LZ4F_cctx_internal_t*)compressionContext; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + BYTE* headerStart; + size_t requiredBuffSize; + + if (dstMaxSize < LZ4F_MAXHEADERFRAME_SIZE) return (size_t)-ERROR_dstMaxSize_tooSmall; + if (cctxPtr->cStage != 0) return (size_t)-ERROR_GENERIC; + if (preferencesPtr == NULL) preferencesPtr = &prefNull; + cctxPtr->prefs = *preferencesPtr; + + /* ctx Management */ + { + U32 targetCtxLevel = cctxPtr->prefs.compressionLevel<minHClevel ? 1 : 2; + if (cctxPtr->lz4CtxLevel < targetCtxLevel) + { + FREEMEM(cctxPtr->lz4CtxPtr); + if (cctxPtr->prefs.compressionLevel<minHClevel) + cctxPtr->lz4CtxPtr = (void*)LZ4_createStream(); + else + cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC(); + cctxPtr->lz4CtxLevel = targetCtxLevel; + } + } + + /* Buffer Management */ + if (cctxPtr->prefs.frameInfo.blockSizeID == 0) cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT; + cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID); + + requiredBuffSize = cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == blockLinked) * 128 KB); + if (preferencesPtr->autoFlush) + requiredBuffSize = (cctxPtr->prefs.frameInfo.blockMode == blockLinked) * 64 KB; /* just needs dict */ + + if (cctxPtr->maxBufferSize < requiredBuffSize) + { + cctxPtr->maxBufferSize = requiredBuffSize; + FREEMEM(cctxPtr->tmpBuff); + cctxPtr->tmpBuff = (BYTE*)ALLOCATOR(requiredBuffSize); + if (cctxPtr->tmpBuff == NULL) return (size_t)-ERROR_allocation_failed; + } + cctxPtr->tmpIn = cctxPtr->tmpBuff; + cctxPtr->tmpInSize = 0; + XXH32_reset(&(cctxPtr->xxh), 0); + if (cctxPtr->prefs.compressionLevel<minHClevel) + LZ4_resetStream((LZ4_stream_t*)(cctxPtr->lz4CtxPtr)); + else + LZ4_resetStreamHC((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), cctxPtr->prefs.compressionLevel); + + /* Magic Number */ + LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER); + dstPtr += 4; + headerStart = dstPtr; + + /* FLG Byte */ + *dstPtr++ = ((1 & _2BITS) << 6) /* Version('01') */ + + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5) /* Block mode */ + + (char)((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2); /* Stream checksum */ + /* BD Byte */ + *dstPtr++ = (char)((cctxPtr->prefs.frameInfo.blockSizeID & _3BITS) << 4); + /* CRC Byte */ + *dstPtr++ = LZ4F_headerChecksum(headerStart, 2); + + cctxPtr->cStage = 1; /* header written, wait for data block */ + + return (dstPtr - dstStart); +} + + +/* LZ4F_compressBound() : gives the size of Dst buffer given a srcSize to handle worst case situations. +* The LZ4F_frameInfo_t structure is optional : +* you can provide NULL as argument, all preferences will then be set to default. +* */ +size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr) +{ + const LZ4F_preferences_t prefsNull = { 0 }; + const LZ4F_preferences_t* prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr; + blockSizeID_t bid = prefsPtr->frameInfo.blockSizeID; + size_t blockSize = LZ4F_getBlockSize(bid); + unsigned nbBlocks = (unsigned)(srcSize / blockSize) + 1; + size_t lastBlockSize = prefsPtr->autoFlush ? srcSize % blockSize : blockSize; + size_t blockInfo = 4; /* default, without block CRC option */ + size_t frameEnd = 4 + (prefsPtr->frameInfo.contentChecksumFlag*4); + size_t result = (blockInfo * nbBlocks) + (blockSize * (nbBlocks-1)) + lastBlockSize + frameEnd; + + return result; +} + + +typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level); + +static size_t LZ4F_compressBlock(void* dst, const void* src, size_t srcSize, compressFunc_t compress, void* lz4ctx, int level) +{ + /* compress one block */ + BYTE* cSizePtr = (BYTE*)dst; + U32 cSize; + cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+4), (int)(srcSize), (int)(srcSize-1), level); + LZ4F_writeLE32(cSizePtr, cSize); + if (cSize == 0) /* compression failed */ + { + cSize = (U32)srcSize; + LZ4F_writeLE32(cSizePtr, cSize + LZ4F_BLOCKUNCOMPRESSED_FLAG); + memcpy(cSizePtr+4, src, srcSize); + } + return cSize + 4; +} + + +static int LZ4F_localLZ4_compress_limitedOutput_withState(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level) +{ + (void) level; + return LZ4_compress_limitedOutput_withState(ctx, src, dst, srcSize, dstSize); +} + +static int LZ4F_localLZ4_compress_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level) +{ + (void) level; + return LZ4_compress_limitedOutput_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstSize); +} + +static int LZ4F_localLZ4_compressHC_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level) +{ + (void) level; + return LZ4_compressHC_limitedOutput_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstSize); +} + +static compressFunc_t LZ4F_selectCompression(blockMode_t blockMode, U32 level) +{ + if (level < minHClevel) + { + if (blockMode == blockIndependent) return LZ4F_localLZ4_compress_limitedOutput_withState; + return LZ4F_localLZ4_compress_limitedOutput_continue; + } + if (blockMode == blockIndependent) return LZ4_compressHC2_limitedOutput_withStateHC; + return LZ4F_localLZ4_compressHC_limitedOutput_continue; +} + +static int LZ4F_localSaveDict(LZ4F_cctx_internal_t* cctxPtr) +{ + if (cctxPtr->prefs.compressionLevel < minHClevel) + return LZ4_saveDict ((LZ4_stream_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB); + return LZ4_saveDictHC ((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB); +} + +typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus; + +/* LZ4F_compressUpdate() +* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary. +* The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case. +* If this condition is not respected, LZ4F_compress() will fail (result is an errorCode) +* You can get the minimum value of dstMaxSize by using LZ4F_compressBound() +* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. +* The result of the function is the number of bytes written into dstBuffer : it can be zero, meaning input data was just buffered. +* The function outputs an error code if it fails (can be tested using LZ4F_isError()) +*/ +size_t LZ4F_compressUpdate(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* compressOptionsPtr) +{ + LZ4F_compressOptions_t cOptionsNull = { 0 }; + LZ4F_cctx_internal_t* cctxPtr = (LZ4F_cctx_internal_t*)compressionContext; + size_t blockSize = cctxPtr->maxBlockSize; + const BYTE* srcPtr = (const BYTE*)srcBuffer; + const BYTE* const srcEnd = srcPtr + srcSize; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + LZ4F_lastBlockStatus lastBlockCompressed = notDone; + compressFunc_t compress; + + + if (cctxPtr->cStage != 1) return (size_t)-ERROR_GENERIC; + if (dstMaxSize < LZ4F_compressBound(srcSize, &(cctxPtr->prefs))) return (size_t)-ERROR_dstMaxSize_tooSmall; + if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull; + + /* select compression function */ + compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel); + + /* complete tmp buffer */ + if (cctxPtr->tmpInSize > 0) /* some data already within tmp buffer */ + { + size_t sizeToCopy = blockSize - cctxPtr->tmpInSize; + if (sizeToCopy > srcSize) + { + /* add src to tmpIn buffer */ + memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, srcSize); + srcPtr = srcEnd; + cctxPtr->tmpInSize += srcSize; + /* still needs some CRC */ + } + else + { + /* complete tmpIn block and then compress it */ + lastBlockCompressed = fromTmpBuffer; + memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy); + srcPtr += sizeToCopy; + + dstPtr += LZ4F_compressBlock(dstPtr, cctxPtr->tmpIn, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + + if (cctxPtr->prefs.frameInfo.blockMode==blockLinked) cctxPtr->tmpIn += blockSize; + cctxPtr->tmpInSize = 0; + } + } + + while ((size_t)(srcEnd - srcPtr) >= blockSize) + { + /* compress full block */ + lastBlockCompressed = fromSrcBuffer; + dstPtr += LZ4F_compressBlock(dstPtr, srcPtr, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + srcPtr += blockSize; + } + + if ((cctxPtr->prefs.autoFlush) && (srcPtr < srcEnd)) + { + /* compress remaining input < blockSize */ + lastBlockCompressed = fromSrcBuffer; + dstPtr += LZ4F_compressBlock(dstPtr, srcPtr, srcEnd - srcPtr, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + srcPtr = srcEnd; + } + + /* preserve dictionary if necessary */ + if ((cctxPtr->prefs.frameInfo.blockMode==blockLinked) && (lastBlockCompressed==fromSrcBuffer)) + { + if (compressOptionsPtr->stableSrc) + { + cctxPtr->tmpIn = cctxPtr->tmpBuff; + } + else + { + int realDictSize = LZ4F_localSaveDict(cctxPtr); + if (realDictSize==0) return (size_t)-ERROR_GENERIC; + cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; + } + } + + /* keep tmpIn within limits */ + if ((cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize) /* necessarily blockLinked && lastBlockCompressed==fromTmpBuffer */ + && !(cctxPtr->prefs.autoFlush)) + { + LZ4F_localSaveDict(cctxPtr); + cctxPtr->tmpIn = cctxPtr->tmpBuff + 64 KB; + } + + /* some input data left, necessarily < blockSize */ + if (srcPtr < srcEnd) + { + /* fill tmp buffer */ + size_t sizeToCopy = srcEnd - srcPtr; + memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy); + cctxPtr->tmpInSize = sizeToCopy; + } + + if (cctxPtr->prefs.frameInfo.contentChecksumFlag == contentChecksumEnabled) + XXH32_update(&(cctxPtr->xxh), srcBuffer, (unsigned)srcSize); + + return dstPtr - dstStart; +} + + +/* LZ4F_flush() +* Should you need to create compressed data immediately, without waiting for a block to be filled, +* you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext. +* The result of the function is the number of bytes written into dstBuffer +* (it can be zero, this means there was no data left within compressionContext) +* The function outputs an error code if it fails (can be tested using LZ4F_isError()) +* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. +*/ +size_t LZ4F_flush(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr) +{ + LZ4F_compressOptions_t cOptionsNull = { 0 }; + LZ4F_cctx_internal_t* cctxPtr = (LZ4F_cctx_internal_t*)compressionContext; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + compressFunc_t compress; + + + if (cctxPtr->tmpInSize == 0) return 0; /* nothing to flush */ + if (cctxPtr->cStage != 1) return (size_t)-ERROR_GENERIC; + if (dstMaxSize < (cctxPtr->tmpInSize + 16)) return (size_t)-ERROR_dstMaxSize_tooSmall; + if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull; + (void)compressOptionsPtr; /* not yet useful */ + + /* select compression function */ + compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel); + + /* compress tmp buffer */ + dstPtr += LZ4F_compressBlock(dstPtr, cctxPtr->tmpIn, cctxPtr->tmpInSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + if (cctxPtr->prefs.frameInfo.blockMode==blockLinked) cctxPtr->tmpIn += cctxPtr->tmpInSize; + cctxPtr->tmpInSize = 0; + + /* keep tmpIn within limits */ + if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) /* necessarily blockLinked */ + { + LZ4F_localSaveDict(cctxPtr); + cctxPtr->tmpIn = cctxPtr->tmpBuff + 64 KB; + } + + return dstPtr - dstStart; +} + + +/* LZ4F_compressEnd() +* When you want to properly finish the compressed frame, just call LZ4F_compressEnd(). +* It will flush whatever data remained within compressionContext (like LZ4_flush()) +* but also properly finalize the frame, with an endMark and a checksum. +* The result of the function is the number of bytes written into dstBuffer (necessarily >= 4 (endMark size)) +* The function outputs an error code if it fails (can be tested using LZ4F_isError()) +* The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. +* compressionContext can then be used again, starting with LZ4F_compressBegin(). The preferences will remain the same. +*/ +size_t LZ4F_compressEnd(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr) +{ + LZ4F_cctx_internal_t* cctxPtr = (LZ4F_cctx_internal_t*)compressionContext; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + size_t errorCode; + + errorCode = LZ4F_flush(compressionContext, dstBuffer, dstMaxSize, compressOptionsPtr); + if (LZ4F_isError(errorCode)) return errorCode; + dstPtr += errorCode; + + LZ4F_writeLE32(dstPtr, 0); + dstPtr+=4; /* endMark */ + + if (cctxPtr->prefs.frameInfo.contentChecksumFlag == contentChecksumEnabled) + { + U32 xxh = XXH32_digest(&(cctxPtr->xxh)); + LZ4F_writeLE32(dstPtr, xxh); + dstPtr+=4; /* content Checksum */ + } + + cctxPtr->cStage = 0; /* state is now re-usable (with identical preferences) */ + + return dstPtr - dstStart; +} + + +/*********************************** +* Decompression functions +* *********************************/ + +/* Resource management */ + +/* LZ4F_createDecompressionContext() : +* The first thing to do is to create a decompressionContext object, which will be used in all decompression operations. +* This is achieved using LZ4F_createDecompressionContext(). +* The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext object. +* If the result LZ4F_errorCode_t is not zero, there was an error during context creation. +* Object can release its memory using LZ4F_freeDecompressionContext(); +*/ +LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_compressionContext_t* LZ4F_decompressionContextPtr, unsigned versionNumber) +{ + LZ4F_dctx_internal_t* dctxPtr; + + dctxPtr = ALLOCATOR(sizeof(LZ4F_dctx_internal_t)); + if (dctxPtr==NULL) return (LZ4F_errorCode_t)-ERROR_GENERIC; + + dctxPtr->version = versionNumber; + *LZ4F_decompressionContextPtr = (LZ4F_compressionContext_t)dctxPtr; + return OK_NoError; +} + +LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_compressionContext_t LZ4F_decompressionContext) +{ + LZ4F_dctx_internal_t* dctxPtr = (LZ4F_dctx_internal_t*)LZ4F_decompressionContext; + FREEMEM(dctxPtr->tmpIn); + FREEMEM(dctxPtr->tmpOutBuffer); + FREEMEM(dctxPtr); + return OK_NoError; +} + + +/* Decompression */ + +static size_t LZ4F_decodeHeader(LZ4F_dctx_internal_t* dctxPtr, const BYTE* srcPtr, size_t srcSize) +{ + BYTE FLG, BD, HC; + unsigned version, blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, dictFlag, blockSizeID; + size_t bufferNeeded; + + /* need to decode header to get frameInfo */ + if (srcSize < 7) return (size_t)-ERROR_GENERIC; /* minimal header size */ + + /* control magic number */ + if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) return (size_t)-ERROR_GENERIC; + srcPtr += 4; + + /* Flags */ + FLG = srcPtr[0]; + version = (FLG>>6)&_2BITS; + blockMode = (FLG>>5) & _1BIT; + blockChecksumFlag = (FLG>>4) & _1BIT; + contentSizeFlag = (FLG>>3) & _1BIT; + contentChecksumFlag = (FLG>>2) & _1BIT; + dictFlag = (FLG>>0) & _1BIT; + BD = srcPtr[1]; + blockSizeID = (BD>>4) & _3BITS; + + /* check */ + HC = LZ4F_headerChecksum(srcPtr, 2); + if (HC != srcPtr[2]) return (size_t)-ERROR_GENERIC; /* Bad header checksum error */ + + /* validate */ + if (version != 1) return (size_t)-ERROR_GENERIC; /* Version Number, only supported value */ + if (blockChecksumFlag != 0) return (size_t)-ERROR_GENERIC; /* Only supported value for the time being */ + if (contentSizeFlag != 0) return (size_t)-ERROR_GENERIC; /* Only supported value for the time being */ + if (((FLG>>1)&_1BIT) != 0) return (size_t)-ERROR_GENERIC; /* Reserved bit */ + if (dictFlag != 0) return (size_t)-ERROR_GENERIC; /* Only supported value for the time being */ + if (((BD>>7)&_1BIT) != 0) return (size_t)-ERROR_GENERIC; /* Reserved bit */ + if (blockSizeID < 4) return (size_t)-ERROR_GENERIC; /* Only supported values for the time being */ + if (((BD>>0)&_4BITS) != 0) return (size_t)-ERROR_GENERIC; /* Reserved bits */ + + /* save */ + dctxPtr->frameInfo.blockMode = blockMode; + dctxPtr->frameInfo.contentChecksumFlag = contentChecksumFlag; + dctxPtr->frameInfo.blockSizeID = blockSizeID; + dctxPtr->maxBlockSize = LZ4F_getBlockSize(blockSizeID); + + /* init */ + if (contentChecksumFlag) XXH32_reset(&(dctxPtr->xxh), 0); + + /* alloc */ + bufferNeeded = dctxPtr->maxBlockSize + ((dctxPtr->frameInfo.blockMode==blockLinked) * 128 KB); + if (bufferNeeded > dctxPtr->maxBufferSize) /* tmp buffers too small */ + { + FREEMEM(dctxPtr->tmpIn); + FREEMEM(dctxPtr->tmpOutBuffer); + dctxPtr->maxBufferSize = bufferNeeded; + dctxPtr->tmpIn = ALLOCATOR(dctxPtr->maxBlockSize); + if (dctxPtr->tmpIn == NULL) return (size_t)-ERROR_GENERIC; + dctxPtr->tmpOutBuffer= ALLOCATOR(dctxPtr->maxBufferSize); + if (dctxPtr->tmpOutBuffer== NULL) return (size_t)-ERROR_GENERIC; + } + dctxPtr->tmpInSize = 0; + dctxPtr->tmpInTarget = 0; + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = 0; + dctxPtr->tmpOut = dctxPtr->tmpOutBuffer; + dctxPtr->tmpOutStart = 0; + dctxPtr->tmpOutSize = 0; + + return 7; +} + + +typedef enum { dstage_getHeader=0, dstage_storeHeader, dstage_decodeHeader, + dstage_getCBlockSize, dstage_storeCBlockSize, dstage_decodeCBlockSize, + dstage_copyDirect, + dstage_getCBlock, dstage_storeCBlock, dstage_decodeCBlock, + dstage_decodeCBlock_intoDst, dstage_decodeCBlock_intoTmp, dstage_flushOut, + dstage_getSuffix, dstage_storeSuffix, dstage_checkSuffix +} dStage_t; + + +/* LZ4F_getFrameInfo() +* This function decodes frame header information, such as blockSize. +* It is optional : you could start by calling directly LZ4F_decompress() instead. +* The objective is to extract header information without starting decompression, typically for allocation purposes. +* LZ4F_getFrameInfo() can also be used *after* starting decompression, on a valid LZ4F_decompressionContext_t. +* The number of bytes read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value). +* You are expected to resume decompression from where it stopped (srcBuffer + *srcSizePtr) +* The function result is an hint of the better srcSize to use for next call to LZ4F_decompress, +* or an error code which can be tested using LZ4F_isError(). +*/ +LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_decompressionContext_t decompressionContext, LZ4F_frameInfo_t* frameInfoPtr, const void* srcBuffer, size_t* srcSizePtr) +{ + LZ4F_dctx_internal_t* dctxPtr = (LZ4F_dctx_internal_t*)decompressionContext; + + if (dctxPtr->dStage == dstage_getHeader) + { + LZ4F_errorCode_t errorCode = LZ4F_decodeHeader(dctxPtr, srcBuffer, *srcSizePtr); + if (LZ4F_isError(errorCode)) return errorCode; + *srcSizePtr = errorCode; + *frameInfoPtr = dctxPtr->frameInfo; + dctxPtr->srcExpect = NULL; + dctxPtr->dStage = dstage_getCBlockSize; + return 4; + } + + /* frameInfo already decoded */ + *srcSizePtr = 0; + *frameInfoPtr = dctxPtr->frameInfo; + return 0; +} + + +static int LZ4F_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize) +{ + (void)dictStart; + (void)dictSize; + return LZ4_decompress_safe (source, dest, compressedSize, maxDecompressedSize); +} + + + +static void LZ4F_updateDict(LZ4F_dctx_internal_t* dctxPtr, const BYTE* dstPtr, size_t dstSize, const BYTE* dstPtr0, unsigned withinTmp) +{ + if (dctxPtr->dictSize==0) + dctxPtr->dict = (BYTE*)dstPtr; /* priority to dictionary continuity */ + + if (dctxPtr->dict + dctxPtr->dictSize == dstPtr) /* dictionary continuity */ + { + dctxPtr->dictSize += dstSize; + return; + } + + if (dstPtr - dstPtr0 + dstSize >= 64 KB) /* dstBuffer large enough to become dictionary */ + { + dctxPtr->dict = (BYTE*)dstPtr0; + dctxPtr->dictSize = dstPtr - dstPtr0 + dstSize; + return; + } + + if ((withinTmp) && (dctxPtr->dict == dctxPtr->tmpOutBuffer)) + { + /* assumption : dctxPtr->dict + dctxPtr->dictSize == dctxPtr->tmpOut + dctxPtr->tmpOutStart */ + dctxPtr->dictSize += dstSize; + return; + } + + if (withinTmp) /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */ + { +#if 0 + size_t savedDictSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer; + memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - dctxPtr->tmpOutStart- savedDictSize, savedDictSize); + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = savedDictSize + dctxPtr->tmpOutStart + dstSize; + return; + +#else + + size_t preserveSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer; + size_t copySize = 64 KB - dctxPtr->tmpOutSize; + BYTE* oldDictEnd = dctxPtr->dict + dctxPtr->dictSize - dctxPtr->tmpOutStart; + if (dctxPtr->tmpOutSize > 64 KB) copySize = 0; + if (copySize > preserveSize) copySize = preserveSize; + + memcpy(dctxPtr->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize); + + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = preserveSize + dctxPtr->tmpOutStart + dstSize; + return; +#endif + } + + if (dctxPtr->dict == dctxPtr->tmpOutBuffer) /* copy dst into tmp to complete dict */ + { + if (dctxPtr->dictSize + dstSize > dctxPtr->maxBufferSize) /* tmp buffer not large enough */ + { + size_t preserveSize = 64 KB - dstSize; /* note : dstSize < 64 KB */ + memcpy(dctxPtr->dict, dctxPtr->dict + dctxPtr->dictSize - preserveSize, preserveSize); + dctxPtr->dictSize = preserveSize; + } + memcpy(dctxPtr->dict + dctxPtr->dictSize, dstPtr, dstSize); + dctxPtr->dictSize += dstSize; + return; + } + + /* join dict & dest into tmp */ + { + size_t preserveSize = 64 KB - dstSize; /* note : dstSize < 64 KB */ + if (preserveSize > dctxPtr->dictSize) preserveSize = dctxPtr->dictSize; + memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - preserveSize, preserveSize); + memcpy(dctxPtr->tmpOutBuffer + preserveSize, dstPtr, dstSize); + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = preserveSize + dstSize; + } +} + + + +/* LZ4F_decompress() +* Call this function repetitively to regenerate data compressed within srcBuffer. +* The function will attempt to decode *srcSizePtr from srcBuffer, into dstBuffer of maximum size *dstSizePtr. +* +* The number of bytes regenerated into dstBuffer will be provided within *dstSizePtr (necessarily <= original value). +* +* The number of bytes effectively read from srcBuffer will be provided within *srcSizePtr (necessarily <= original value). +* If the number of bytes read is < number of bytes provided, then the decompression operation is not complete. +* You will have to call it again, continuing from where it stopped. +* +* The function result is an hint of the better srcSize to use for next call to LZ4F_decompress. +* Basically, it's the size of the current (or remaining) compressed block + header of next block. +* Respecting the hint provides some boost to performance, since it allows less buffer shuffling. +* Note that this is just a hint, you can always provide any srcSize you want. +* When a frame is fully decoded, the function result will be 0. +* If decompression failed, function result is an error code which can be tested using LZ4F_isError(). +*/ +size_t LZ4F_decompress(LZ4F_decompressionContext_t decompressionContext, + void* dstBuffer, size_t* dstSizePtr, + const void* srcBuffer, size_t* srcSizePtr, + const LZ4F_decompressOptions_t* decompressOptionsPtr) +{ + LZ4F_dctx_internal_t* dctxPtr = (LZ4F_dctx_internal_t*)decompressionContext; + static const LZ4F_decompressOptions_t optionsNull = { 0 }; + const BYTE* const srcStart = (const BYTE*)srcBuffer; + const BYTE* const srcEnd = srcStart + *srcSizePtr; + const BYTE* srcPtr = srcStart; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* const dstEnd = dstStart + *dstSizePtr; + BYTE* dstPtr = dstStart; + const BYTE* selectedIn=NULL; + unsigned doAnotherStage = 1; + size_t nextSrcSizeHint = 1; + + + if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull; + *srcSizePtr = 0; + *dstSizePtr = 0; + + /* expect to continue decoding src buffer where it left previously */ + if (dctxPtr->srcExpect != NULL) + { + if (srcStart != dctxPtr->srcExpect) return (size_t)-ERROR_GENERIC; + } + + /* programmed as a state machine */ + + while (doAnotherStage) + { + + switch(dctxPtr->dStage) + { + + case dstage_getHeader: + { + if (srcEnd-srcPtr >= 7) + { + selectedIn = srcPtr; + srcPtr += 7; + dctxPtr->dStage = dstage_decodeHeader; + break; + } + dctxPtr->tmpInSize = 0; + dctxPtr->dStage = dstage_storeHeader; + break; + } + + case dstage_storeHeader: + { + size_t sizeToCopy = 7 - dctxPtr->tmpInSize; + if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr; + memcpy(dctxPtr->header + dctxPtr->tmpInSize, srcPtr, sizeToCopy); + dctxPtr->tmpInSize += sizeToCopy; + srcPtr += sizeToCopy; + if (dctxPtr->tmpInSize < 7) + { + nextSrcSizeHint = (7 - dctxPtr->tmpInSize) + 4; + doAnotherStage = 0; /* no enough src, wait to get some more */ + break; + } + selectedIn = dctxPtr->header; + dctxPtr->dStage = dstage_decodeHeader; + break; + } + + case dstage_decodeHeader: + { + LZ4F_errorCode_t errorCode = LZ4F_decodeHeader(dctxPtr, selectedIn, 7); + if (LZ4F_isError(errorCode)) return errorCode; + dctxPtr->dStage = dstage_getCBlockSize; + break; + } + + case dstage_getCBlockSize: + { + if ((srcEnd - srcPtr) >= 4) + { + selectedIn = srcPtr; + srcPtr += 4; + dctxPtr->dStage = dstage_decodeCBlockSize; + break; + } + /* not enough input to read cBlockSize field */ + dctxPtr->tmpInSize = 0; + dctxPtr->dStage = dstage_storeCBlockSize; + break; + } + + case dstage_storeCBlockSize: + { + size_t sizeToCopy = 4 - dctxPtr->tmpInSize; + if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr; + memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy); + srcPtr += sizeToCopy; + dctxPtr->tmpInSize += sizeToCopy; + if (dctxPtr->tmpInSize < 4) /* not enough input to get full cBlockSize; wait for more */ + { + nextSrcSizeHint = 4 - dctxPtr->tmpInSize; + doAnotherStage=0; + break; + } + selectedIn = dctxPtr->tmpIn; + dctxPtr->dStage = dstage_decodeCBlockSize; + break; + } + + case dstage_decodeCBlockSize: + { + size_t nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU; + if (nextCBlockSize==0) /* frameEnd signal, no more CBlock */ + { + dctxPtr->dStage = dstage_getSuffix; + break; + } + if (nextCBlockSize > dctxPtr->maxBlockSize) return (size_t)-ERROR_GENERIC; /* invalid cBlockSize */ + dctxPtr->tmpInTarget = nextCBlockSize; + if (LZ4F_readLE32(selectedIn) & LZ4F_BLOCKUNCOMPRESSED_FLAG) + { + dctxPtr->dStage = dstage_copyDirect; + break; + } + dctxPtr->dStage = dstage_getCBlock; + if (dstPtr==dstEnd) + { + nextSrcSizeHint = nextCBlockSize + 4; + doAnotherStage = 0; + } + break; + } + + case dstage_copyDirect: /* uncompressed block */ + { + size_t sizeToCopy = dctxPtr->tmpInTarget; + if ((size_t)(srcEnd-srcPtr) < sizeToCopy) sizeToCopy = srcEnd - srcPtr; /* not enough input to read full block */ + if ((size_t)(dstEnd-dstPtr) < sizeToCopy) sizeToCopy = dstEnd - dstPtr; + memcpy(dstPtr, srcPtr, sizeToCopy); + if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), srcPtr, (U32)sizeToCopy); + + /* dictionary management */ + if (dctxPtr->frameInfo.blockMode==blockLinked) + LZ4F_updateDict(dctxPtr, dstPtr, sizeToCopy, dstStart, 0); + + srcPtr += sizeToCopy; + dstPtr += sizeToCopy; + if (sizeToCopy == dctxPtr->tmpInTarget) /* all copied */ + { + dctxPtr->dStage = dstage_getCBlockSize; + break; + } + dctxPtr->tmpInTarget -= sizeToCopy; /* still need to copy more */ + nextSrcSizeHint = dctxPtr->tmpInTarget + 4; + doAnotherStage = 0; + break; + } + + case dstage_getCBlock: /* entry from dstage_decodeCBlockSize */ + { + if ((size_t)(srcEnd-srcPtr) < dctxPtr->tmpInTarget) + { + dctxPtr->tmpInSize = 0; + dctxPtr->dStage = dstage_storeCBlock; + break; + } + selectedIn = srcPtr; + srcPtr += dctxPtr->tmpInTarget; + dctxPtr->dStage = dstage_decodeCBlock; + break; + } + + case dstage_storeCBlock: + { + size_t sizeToCopy = dctxPtr->tmpInTarget - dctxPtr->tmpInSize; + if (sizeToCopy > (size_t)(srcEnd-srcPtr)) sizeToCopy = srcEnd-srcPtr; + memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy); + dctxPtr->tmpInSize += sizeToCopy; + srcPtr += sizeToCopy; + if (dctxPtr->tmpInSize < dctxPtr->tmpInTarget) /* need more input */ + { + nextSrcSizeHint = (dctxPtr->tmpInTarget - dctxPtr->tmpInSize) + 4; + doAnotherStage=0; + break; + } + selectedIn = dctxPtr->tmpIn; + dctxPtr->dStage = dstage_decodeCBlock; + break; + } + + case dstage_decodeCBlock: + { + if ((size_t)(dstEnd-dstPtr) < dctxPtr->maxBlockSize) /* not enough place into dst : decode into tmpOut */ + dctxPtr->dStage = dstage_decodeCBlock_intoTmp; + else + dctxPtr->dStage = dstage_decodeCBlock_intoDst; + break; + } + + case dstage_decodeCBlock_intoDst: + { + int (*decoder)(const char*, char*, int, int, const char*, int); + int decodedSize; + + if (dctxPtr->frameInfo.blockMode == blockLinked) + decoder = LZ4_decompress_safe_usingDict; + else + decoder = LZ4F_decompress_safe; + + decodedSize = decoder((const char*)selectedIn, (char*)dstPtr, (int)dctxPtr->tmpInTarget, (int)dctxPtr->maxBlockSize, (const char*)dctxPtr->dict, (int)dctxPtr->dictSize); + if (decodedSize < 0) return (size_t)-ERROR_GENERIC; /* decompression failed */ + if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dstPtr, decodedSize); + + /* dictionary management */ + if (dctxPtr->frameInfo.blockMode==blockLinked) + LZ4F_updateDict(dctxPtr, dstPtr, decodedSize, dstStart, 0); + + dstPtr += decodedSize; + dctxPtr->dStage = dstage_getCBlockSize; + break; + } + + case dstage_decodeCBlock_intoTmp: + { + /* not enough place into dst : decode into tmpOut */ + int (*decoder)(const char*, char*, int, int, const char*, int); + int decodedSize; + + if (dctxPtr->frameInfo.blockMode == blockLinked) + decoder = LZ4_decompress_safe_usingDict; + else + decoder = LZ4F_decompress_safe; + + /* ensure enough place for tmpOut */ + if (dctxPtr->frameInfo.blockMode == blockLinked) + { + if (dctxPtr->dict == dctxPtr->tmpOutBuffer) + { + if (dctxPtr->dictSize > 128 KB) + { + memcpy(dctxPtr->dict, dctxPtr->dict + dctxPtr->dictSize - 64 KB, 64 KB); + dctxPtr->dictSize = 64 KB; + } + dctxPtr->tmpOut = dctxPtr->dict + dctxPtr->dictSize; + } + else /* dict not within tmp */ + { + size_t reservedDictSpace = dctxPtr->dictSize; + if (reservedDictSpace > 64 KB) reservedDictSpace = 64 KB; + dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + reservedDictSpace; + } + } + + /* Decode */ + decodedSize = decoder((const char*)selectedIn, (char*)dctxPtr->tmpOut, (int)dctxPtr->tmpInTarget, (int)dctxPtr->maxBlockSize, (const char*)dctxPtr->dict, (int)dctxPtr->dictSize); + if (decodedSize < 0) return (size_t)-ERROR_decompressionFailed; /* decompression failed */ + if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dctxPtr->tmpOut, decodedSize); + dctxPtr->tmpOutSize = decodedSize; + dctxPtr->tmpOutStart = 0; + dctxPtr->dStage = dstage_flushOut; + break; + } + + case dstage_flushOut: /* flush decoded data from tmpOut to dstBuffer */ + { + size_t sizeToCopy = dctxPtr->tmpOutSize - dctxPtr->tmpOutStart; + if (sizeToCopy > (size_t)(dstEnd-dstPtr)) sizeToCopy = dstEnd-dstPtr; + memcpy(dstPtr, dctxPtr->tmpOut + dctxPtr->tmpOutStart, sizeToCopy); + + /* dictionary management */ + if (dctxPtr->frameInfo.blockMode==blockLinked) + LZ4F_updateDict(dctxPtr, dstPtr, sizeToCopy, dstStart, 1); + + dctxPtr->tmpOutStart += sizeToCopy; + dstPtr += sizeToCopy; + + /* end of flush ? */ + if (dctxPtr->tmpOutStart == dctxPtr->tmpOutSize) + { + dctxPtr->dStage = dstage_getCBlockSize; + break; + } + nextSrcSizeHint = 4; + doAnotherStage = 0; /* still some data to flush */ + break; + } + + case dstage_getSuffix: + { + size_t suffixSize = dctxPtr->frameInfo.contentChecksumFlag * 4; + if (suffixSize == 0) /* frame completed */ + { + nextSrcSizeHint = 0; + dctxPtr->dStage = dstage_getHeader; + doAnotherStage = 0; + break; + } + if ((srcEnd - srcPtr) >= 4) /* CRC present */ + { + selectedIn = srcPtr; + srcPtr += 4; + dctxPtr->dStage = dstage_checkSuffix; + break; + } + dctxPtr->tmpInSize = 0; + dctxPtr->dStage = dstage_storeSuffix; + break; + } + + case dstage_storeSuffix: + { + size_t sizeToCopy = 4 - dctxPtr->tmpInSize; + if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr; + memcpy(dctxPtr->tmpIn + dctxPtr->tmpInSize, srcPtr, sizeToCopy); + srcPtr += sizeToCopy; + dctxPtr->tmpInSize += sizeToCopy; + if (dctxPtr->tmpInSize < 4) /* not enough input to read complete suffix */ + { + nextSrcSizeHint = 4 - dctxPtr->tmpInSize; + doAnotherStage=0; + break; + } + selectedIn = dctxPtr->tmpIn; + dctxPtr->dStage = dstage_checkSuffix; + break; + } + + case dstage_checkSuffix: + { + U32 readCRC = LZ4F_readLE32(selectedIn); + U32 resultCRC = XXH32_digest(&(dctxPtr->xxh)); + if (readCRC != resultCRC) return (size_t)-ERROR_checksum_invalid; + nextSrcSizeHint = 0; + dctxPtr->dStage = dstage_getHeader; + doAnotherStage = 0; + break; + } + } + } + + /* preserve dictionary within tmp if necessary */ + if ( (dctxPtr->frameInfo.blockMode==blockLinked) + &&(dctxPtr->dict != dctxPtr->tmpOutBuffer) + &&(!decompressOptionsPtr->stableDst) + &&((unsigned)(dctxPtr->dStage-1) < (unsigned)(dstage_getSuffix-1)) + ) + { + if (dctxPtr->dStage == dstage_flushOut) + { + size_t preserveSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer; + size_t copySize = 64 KB - dctxPtr->tmpOutSize; + BYTE* oldDictEnd = dctxPtr->dict + dctxPtr->dictSize - dctxPtr->tmpOutStart; + if (dctxPtr->tmpOutSize > 64 KB) copySize = 0; + if (copySize > preserveSize) copySize = preserveSize; + + memcpy(dctxPtr->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize); + + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = preserveSize + dctxPtr->tmpOutStart; + } + else + { + size_t newDictSize = dctxPtr->dictSize; + BYTE* oldDictEnd = dctxPtr->dict + dctxPtr->dictSize; + if ((newDictSize) > 64 KB) newDictSize = 64 KB; + + memcpy(dctxPtr->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize); + + dctxPtr->dict = dctxPtr->tmpOutBuffer; + dctxPtr->dictSize = newDictSize; + dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + newDictSize; + } + } + + if (srcPtr<srcEnd) /* function must be called again with following source data */ + dctxPtr->srcExpect = srcPtr; + else + dctxPtr->srcExpect = NULL; + *srcSizePtr = (srcPtr - srcStart); + *dstSizePtr = (dstPtr - dstStart); + return nextSrcSizeHint; +} |