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Diffstat (limited to 'libbutl/lz4frame.c')
| -rw-r--r-- | libbutl/lz4frame.c | 1899 |
1 files changed, 1899 insertions, 0 deletions
diff --git a/libbutl/lz4frame.c b/libbutl/lz4frame.c new file mode 100644 index 0000000..ec02c92 --- /dev/null +++ b/libbutl/lz4frame.c @@ -0,0 +1,1899 @@ +/* + * LZ4 auto-framing library + * Copyright (C) 2011-2016, Yann Collet. + * + * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * You can contact the author at : + * - LZ4 homepage : http://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 + */ + +/* LZ4F is a stand-alone API to create LZ4-compressed Frames + * in full conformance with specification v1.6.1 . + * This library rely upon memory management capabilities (malloc, free) + * provided either by <stdlib.h>, + * or redirected towards another library of user's choice + * (see Memory Routines below). + */ + + +/*-************************************ +* Compiler Options +**************************************/ +#ifdef _MSC_VER /* Visual Studio */ +# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ +#endif + + +/*-************************************ +* Tuning parameters +**************************************/ +/* + * LZ4F_HEAPMODE : + * Select how default compression functions will allocate memory for their hash table, + * in memory stack (0:default, fastest), or in memory heap (1:requires malloc()). + */ +#ifndef LZ4F_HEAPMODE +# define LZ4F_HEAPMODE 0 +#endif + + +/*-************************************ +* Memory routines +**************************************/ +/* + * User may redirect invocations of + * malloc(), calloc() and free() + * towards another library or solution of their choice + * by modifying below section. + */ +#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */ +# include <stdlib.h> /* malloc, calloc, free */ +# define ALLOC(s) malloc(s) +# define ALLOC_AND_ZERO(s) calloc(1,(s)) +# define FREEMEM(p) free(p) +#endif + +#include <string.h> /* memset, memcpy, memmove */ +#ifndef LZ4_SRC_INCLUDED /* avoid redefinition when sources are coalesced */ +# define MEM_INIT(p,v,s) memset((p),(v),(s)) +#endif + + +/*-************************************ +* Library declarations +**************************************/ +#define LZ4F_STATIC_LINKING_ONLY +#include "lz4frame.h" +#define LZ4_STATIC_LINKING_ONLY +#include "lz4.h" +#define LZ4_HC_STATIC_LINKING_ONLY +#include "lz4hc.h" +#define XXH_STATIC_LINKING_ONLY +#include "xxhash.h" + + +/*-************************************ +* Debug +**************************************/ +#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1) +# include <assert.h> +#else +# ifndef assert +# define assert(condition) ((void)0) +# endif +#endif + +#define LZ4F_STATIC_ASSERT(c) { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */ + +#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) && !defined(DEBUGLOG) +# include <stdio.h> +static int g_debuglog_enable = 1; +# define DEBUGLOG(l, ...) { \ + if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \ + fprintf(stderr, __FILE__ ": "); \ + fprintf(stderr, __VA_ARGS__); \ + fprintf(stderr, " \n"); \ + } } +#else +# define DEBUGLOG(l, ...) {} /* disabled */ +#endif + + +/*-************************************ +* Basic Types +**************************************/ +#if !defined (__VMS) && (defined (__cplusplus) || (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 + + +/* unoptimized version; solves endianess & alignment issues */ +static U32 LZ4F_readLE32 (const void* src) +{ + const BYTE* const srcPtr = (const BYTE*)src; + U32 value32 = srcPtr[0]; + value32 += ((U32)srcPtr[1])<< 8; + value32 += ((U32)srcPtr[2])<<16; + value32 += ((U32)srcPtr[3])<<24; + return value32; +} + +static void LZ4F_writeLE32 (void* dst, U32 value32) +{ + BYTE* const dstPtr = (BYTE*)dst; + dstPtr[0] = (BYTE)value32; + dstPtr[1] = (BYTE)(value32 >> 8); + dstPtr[2] = (BYTE)(value32 >> 16); + dstPtr[3] = (BYTE)(value32 >> 24); +} + +static U64 LZ4F_readLE64 (const void* src) +{ + const BYTE* const srcPtr = (const BYTE*)src; + U64 value64 = srcPtr[0]; + value64 += ((U64)srcPtr[1]<<8); + value64 += ((U64)srcPtr[2]<<16); + value64 += ((U64)srcPtr[3]<<24); + value64 += ((U64)srcPtr[4]<<32); + value64 += ((U64)srcPtr[5]<<40); + value64 += ((U64)srcPtr[6]<<48); + value64 += ((U64)srcPtr[7]<<56); + return value64; +} + +static void LZ4F_writeLE64 (void* dst, U64 value64) +{ + BYTE* const dstPtr = (BYTE*)dst; + dstPtr[0] = (BYTE)value64; + dstPtr[1] = (BYTE)(value64 >> 8); + dstPtr[2] = (BYTE)(value64 >> 16); + dstPtr[3] = (BYTE)(value64 >> 24); + dstPtr[4] = (BYTE)(value64 >> 32); + dstPtr[5] = (BYTE)(value64 >> 40); + dstPtr[6] = (BYTE)(value64 >> 48); + dstPtr[7] = (BYTE)(value64 >> 56); +} + + +/*-************************************ +* Constants +**************************************/ +#ifndef LZ4_SRC_INCLUDED /* avoid double definition */ +# define KB *(1<<10) +# define MB *(1<<20) +# define GB *(1<<30) +#endif + +#define _1BIT 0x01 +#define _2BITS 0x03 +#define _3BITS 0x07 +#define _4BITS 0x0F +#define _8BITS 0xFF + +#define LZ4F_MAGIC_SKIPPABLE_START 0x184D2A50U +#define LZ4F_MAGICNUMBER 0x184D2204U +#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U +#define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB + +static const size_t minFHSize = LZ4F_HEADER_SIZE_MIN; /* 7 */ +static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 19 */ +static const size_t BHSize = LZ4F_BLOCK_HEADER_SIZE; /* block header : size, and compress flag */ +static const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE; /* block footer : checksum (optional) */ + + +/*-************************************ +* Structures and local types +**************************************/ +typedef struct LZ4F_cctx_s +{ + LZ4F_preferences_t prefs; + U32 version; + U32 cStage; + const LZ4F_CDict* cdict; + size_t maxBlockSize; + size_t maxBufferSize; + BYTE* tmpBuff; + BYTE* tmpIn; + size_t tmpInSize; + U64 totalInSize; + XXH32_state_t xxh; + void* lz4CtxPtr; + U16 lz4CtxAlloc; /* sized for: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */ + U16 lz4CtxState; /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */ +} LZ4F_cctx_t; + + +/*-************************************ +* Error management +**************************************/ +#define LZ4F_GENERATE_STRING(STRING) #STRING, +static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) }; + + +unsigned LZ4F_isError(LZ4F_errorCode_t code) +{ + return (code > (LZ4F_errorCode_t)(-LZ4F_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; +} + +LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult) +{ + if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError; + return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult); +} + +static LZ4F_errorCode_t err0r(LZ4F_errorCodes code) +{ + /* A compilation error here means sizeof(ptrdiff_t) is not large enough */ + LZ4F_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t)); + return (LZ4F_errorCode_t)-(ptrdiff_t)code; +} + +unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; } + +int LZ4F_compressionLevel_max(void) { return LZ4HC_CLEVEL_MAX; } + +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; + if (blockSizeID < LZ4F_max64KB || blockSizeID > LZ4F_max4MB) + return err0r(LZ4F_ERROR_maxBlockSize_invalid); + blockSizeID -= LZ4F_max64KB; + return blockSizes[blockSizeID]; +} + +/*-************************************ +* Private functions +**************************************/ +#define MIN(a,b) ( (a) < (b) ? (a) : (b) ) + +static BYTE LZ4F_headerChecksum (const void* header, size_t length) +{ + U32 const xxh = XXH32(header, length, 0); + return (BYTE)(xxh >> 8); +} + + +/*-************************************ +* Simple-pass compression functions +**************************************/ +static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID, + const size_t srcSize) +{ + LZ4F_blockSizeID_t proposedBSID = LZ4F_max64KB; + size_t maxBlockSize = 64 KB; + while (requestedBSID > proposedBSID) { + if (srcSize <= maxBlockSize) + return proposedBSID; + proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1); + maxBlockSize <<= 2; + } + return requestedBSID; +} + +/*! LZ4F_compressBound_internal() : + * Provides dstCapacity given a srcSize to guarantee operation success in worst case situations. + * prefsPtr is optional : if NULL is provided, preferences will be set to cover worst case scenario. + * @return is always the same for a srcSize and prefsPtr, so it can be relied upon to size reusable buffers. + * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations. + */ +static size_t LZ4F_compressBound_internal(size_t srcSize, + const LZ4F_preferences_t* preferencesPtr, + size_t alreadyBuffered) +{ + LZ4F_preferences_t prefsNull = LZ4F_INIT_PREFERENCES; + prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* worst case */ + prefsNull.frameInfo.blockChecksumFlag = LZ4F_blockChecksumEnabled; /* worst case */ + { const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr; + U32 const flush = prefsPtr->autoFlush | (srcSize==0); + LZ4F_blockSizeID_t const blockID = prefsPtr->frameInfo.blockSizeID; + size_t const blockSize = LZ4F_getBlockSize(blockID); + size_t const maxBuffered = blockSize - 1; + size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered); + size_t const maxSrcSize = srcSize + bufferedSize; + unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize); + size_t const partialBlockSize = maxSrcSize & (blockSize-1); + size_t const lastBlockSize = flush ? partialBlockSize : 0; + unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0); + + size_t const blockCRCSize = BFSize * prefsPtr->frameInfo.blockChecksumFlag; + size_t const frameEnd = BHSize + (prefsPtr->frameInfo.contentChecksumFlag*BFSize); + + return ((BHSize + blockCRCSize) * nbBlocks) + + (blockSize * nbFullBlocks) + lastBlockSize + frameEnd; + } +} + +size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_preferences_t prefs; + size_t const headerSize = maxFHSize; /* max header size, including optional fields */ + + if (preferencesPtr!=NULL) prefs = *preferencesPtr; + else MEM_INIT(&prefs, 0, sizeof(prefs)); + prefs.autoFlush = 1; + + return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);; +} + + +/*! LZ4F_compressFrame_usingCDict() : + * Compress srcBuffer using a dictionary, in a single step. + * cdict can be NULL, in which case, no dictionary is used. + * dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr). + * The LZ4F_preferences_t structure is optional : you may provide NULL as argument, + * however, it's the only way to provide a dictID, so it's not recommended. + * @return : number of bytes written into dstBuffer, + * or an error code if it fails (can be tested using LZ4F_isError()) + */ +size_t LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx, + void* dstBuffer, size_t dstCapacity, + const void* srcBuffer, size_t srcSize, + const LZ4F_CDict* cdict, + const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_preferences_t prefs; + LZ4F_compressOptions_t options; + BYTE* const dstStart = (BYTE*) dstBuffer; + BYTE* dstPtr = dstStart; + BYTE* const dstEnd = dstStart + dstCapacity; + + if (preferencesPtr!=NULL) + prefs = *preferencesPtr; + else + MEM_INIT(&prefs, 0, sizeof(prefs)); + if (prefs.frameInfo.contentSize != 0) + prefs.frameInfo.contentSize = (U64)srcSize; /* auto-correct content size if selected (!=0) */ + + prefs.frameInfo.blockSizeID = LZ4F_optimalBSID(prefs.frameInfo.blockSizeID, srcSize); + prefs.autoFlush = 1; + if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID)) + prefs.frameInfo.blockMode = LZ4F_blockIndependent; /* only one block => no need for inter-block link */ + + MEM_INIT(&options, 0, sizeof(options)); + options.stableSrc = 1; + + if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs)) /* condition to guarantee success */ + return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + + { size_t const headerSize = LZ4F_compressBegin_usingCDict(cctx, dstBuffer, dstCapacity, cdict, &prefs); /* write header */ + if (LZ4F_isError(headerSize)) return headerSize; + dstPtr += headerSize; /* header size */ } + + assert(dstEnd >= dstPtr); + { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, (size_t)(dstEnd-dstPtr), srcBuffer, srcSize, &options); + if (LZ4F_isError(cSize)) return cSize; + dstPtr += cSize; } + + assert(dstEnd >= dstPtr); + { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, (size_t)(dstEnd-dstPtr), &options); /* flush last block, and generate suffix */ + if (LZ4F_isError(tailSize)) return tailSize; + dstPtr += tailSize; } + + assert(dstEnd >= dstStart); + return (size_t)(dstPtr - dstStart); +} + + +/*! LZ4F_compressFrame() : + * Compress an entire srcBuffer into a valid LZ4 frame, in a single step. + * dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr). + * The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default. + * @return : number of bytes written into dstBuffer. + * or an error code if it fails (can be tested using LZ4F_isError()) + */ +size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, + const void* srcBuffer, size_t srcSize, + const LZ4F_preferences_t* preferencesPtr) +{ + size_t result; +#if (LZ4F_HEAPMODE) + LZ4F_cctx_t *cctxPtr; + result = LZ4F_createCompressionContext(&cctxPtr, LZ4F_VERSION); + if (LZ4F_isError(result)) return result; +#else + LZ4F_cctx_t cctx; + LZ4_stream_t lz4ctx; + LZ4F_cctx_t *cctxPtr = &cctx; + + DEBUGLOG(4, "LZ4F_compressFrame"); + MEM_INIT(&cctx, 0, sizeof(cctx)); + cctx.version = LZ4F_VERSION; + cctx.maxBufferSize = 5 MB; /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */ + if (preferencesPtr == NULL || + preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN) + { + LZ4_initStream(&lz4ctx, sizeof(lz4ctx)); + cctxPtr->lz4CtxPtr = &lz4ctx; + cctxPtr->lz4CtxAlloc = 1; + cctxPtr->lz4CtxState = 1; + } +#endif + + result = LZ4F_compressFrame_usingCDict(cctxPtr, dstBuffer, dstCapacity, + srcBuffer, srcSize, + NULL, preferencesPtr); + +#if (LZ4F_HEAPMODE) + LZ4F_freeCompressionContext(cctxPtr); +#else + if (preferencesPtr != NULL && + preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) + { + FREEMEM(cctxPtr->lz4CtxPtr); + } +#endif + return result; +} + + +/*-*************************************************** +* Dictionary compression +*****************************************************/ + +struct LZ4F_CDict_s { + void* dictContent; + LZ4_stream_t* fastCtx; + LZ4_streamHC_t* HCCtx; +}; /* typedef'd to LZ4F_CDict within lz4frame_static.h */ + +/*! LZ4F_createCDict() : + * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once. + * LZ4F_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay. + * LZ4F_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only. + * `dictBuffer` can be released after LZ4F_CDict creation, since its content is copied within CDict + * @return : digested dictionary for compression, or NULL if failed */ +LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize) +{ + const char* dictStart = (const char*)dictBuffer; + LZ4F_CDict* cdict = (LZ4F_CDict*) ALLOC(sizeof(*cdict)); + DEBUGLOG(4, "LZ4F_createCDict"); + if (!cdict) return NULL; + if (dictSize > 64 KB) { + dictStart += dictSize - 64 KB; + dictSize = 64 KB; + } + cdict->dictContent = ALLOC(dictSize); + cdict->fastCtx = LZ4_createStream(); + cdict->HCCtx = LZ4_createStreamHC(); + if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) { + LZ4F_freeCDict(cdict); + return NULL; + } + memcpy(cdict->dictContent, dictStart, dictSize); + LZ4_loadDict (cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize); + LZ4_setCompressionLevel(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT); + LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize); + return cdict; +} + +void LZ4F_freeCDict(LZ4F_CDict* cdict) +{ + if (cdict==NULL) return; /* support free on NULL */ + FREEMEM(cdict->dictContent); + LZ4_freeStream(cdict->fastCtx); + LZ4_freeStreamHC(cdict->HCCtx); + FREEMEM(cdict); +} + + +/*-********************************* +* 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 incompatible 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_cctx** LZ4F_compressionContextPtr, unsigned version) +{ + LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)ALLOC_AND_ZERO(sizeof(LZ4F_cctx_t)); + if (cctxPtr==NULL) return err0r(LZ4F_ERROR_allocation_failed); + + cctxPtr->version = version; + cctxPtr->cStage = 0; /* Next stage : init stream */ + + *LZ4F_compressionContextPtr = cctxPtr; + + return LZ4F_OK_NoError; +} + + +LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctxPtr) +{ + if (cctxPtr != NULL) { /* support free on NULL */ + FREEMEM(cctxPtr->lz4CtxPtr); /* note: LZ4_streamHC_t and LZ4_stream_t are simple POD types */ + FREEMEM(cctxPtr->tmpBuff); + FREEMEM(cctxPtr); + } + + return LZ4F_OK_NoError; +} + + +/** + * This function prepares the internal LZ4(HC) stream for a new compression, + * resetting the context and attaching the dictionary, if there is one. + * + * It needs to be called at the beginning of each independent compression + * stream (i.e., at the beginning of a frame in blockLinked mode, or at the + * beginning of each block in blockIndependent mode). + */ +static void LZ4F_initStream(void* ctx, + const LZ4F_CDict* cdict, + int level, + LZ4F_blockMode_t blockMode) { + if (level < LZ4HC_CLEVEL_MIN) { + if (cdict != NULL || blockMode == LZ4F_blockLinked) { + /* In these cases, we will call LZ4_compress_fast_continue(), + * which needs an already reset context. Otherwise, we'll call a + * one-shot API. The non-continued APIs internally perform their own + * resets at the beginning of their calls, where they know what + * tableType they need the context to be in. So in that case this + * would be misguided / wasted work. */ + LZ4_resetStream_fast((LZ4_stream_t*)ctx); + } + LZ4_attach_dictionary((LZ4_stream_t *)ctx, cdict ? cdict->fastCtx : NULL); + } else { + LZ4_resetStreamHC_fast((LZ4_streamHC_t*)ctx, level); + LZ4_attach_HC_dictionary((LZ4_streamHC_t *)ctx, cdict ? cdict->HCCtx : NULL); + } +} + + +/*! LZ4F_compressBegin_usingCDict() : + * init streaming compression and writes frame header into dstBuffer. + * dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes. + * @return : number of bytes written into dstBuffer for the header + * or an error code (can be tested using LZ4F_isError()) + */ +size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_CDict* cdict, + const LZ4F_preferences_t* preferencesPtr) +{ + LZ4F_preferences_t prefNull; + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + BYTE* headerStart; + + if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + MEM_INIT(&prefNull, 0, sizeof(prefNull)); + if (preferencesPtr == NULL) preferencesPtr = &prefNull; + cctxPtr->prefs = *preferencesPtr; + + /* Ctx Management */ + { U16 const ctxTypeID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2; + if (cctxPtr->lz4CtxAlloc < ctxTypeID) { + FREEMEM(cctxPtr->lz4CtxPtr); + if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) { + cctxPtr->lz4CtxPtr = LZ4_createStream(); + } else { + cctxPtr->lz4CtxPtr = LZ4_createStreamHC(); + } + if (cctxPtr->lz4CtxPtr == NULL) + return err0r(LZ4F_ERROR_allocation_failed); + cctxPtr->lz4CtxAlloc = ctxTypeID; + cctxPtr->lz4CtxState = ctxTypeID; + } else if (cctxPtr->lz4CtxState != ctxTypeID) { + /* otherwise, a sufficient buffer is allocated, but we need to + * reset it to the correct context type */ + if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) { + LZ4_initStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr, sizeof (LZ4_stream_t)); + } else { + LZ4_initStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, sizeof(LZ4_streamHC_t)); + LZ4_setCompressionLevel((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel); + } + cctxPtr->lz4CtxState = ctxTypeID; + } + } + + /* Buffer Management */ + if (cctxPtr->prefs.frameInfo.blockSizeID == 0) + cctxPtr->prefs.frameInfo.blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT; + cctxPtr->maxBlockSize = LZ4F_getBlockSize(cctxPtr->prefs.frameInfo.blockSizeID); + + { size_t const requiredBuffSize = preferencesPtr->autoFlush ? + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 64 KB : 0) : /* only needs past data up to window size */ + cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) ? 128 KB : 0); + + if (cctxPtr->maxBufferSize < requiredBuffSize) { + cctxPtr->maxBufferSize = 0; + FREEMEM(cctxPtr->tmpBuff); + cctxPtr->tmpBuff = (BYTE*)ALLOC_AND_ZERO(requiredBuffSize); + if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed); + cctxPtr->maxBufferSize = requiredBuffSize; + } } + cctxPtr->tmpIn = cctxPtr->tmpBuff; + cctxPtr->tmpInSize = 0; + (void)XXH32_reset(&(cctxPtr->xxh), 0); + + /* context init */ + cctxPtr->cdict = cdict; + if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) { + /* frame init only for blockLinked : blockIndependent will be init at each block */ + LZ4F_initStream(cctxPtr->lz4CtxPtr, cdict, cctxPtr->prefs.compressionLevel, LZ4F_blockLinked); + } + if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) { + LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed); + } + + /* Magic Number */ + LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER); + dstPtr += 4; + headerStart = dstPtr; + + /* FLG Byte */ + *dstPtr++ = (BYTE)(((1 & _2BITS) << 6) /* Version('01') */ + + ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5) + + ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4) + + ((unsigned)(cctxPtr->prefs.frameInfo.contentSize > 0) << 3) + + ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2) + + (cctxPtr->prefs.frameInfo.dictID > 0) ); + /* BD Byte */ + *dstPtr++ = (BYTE)((cctxPtr->prefs.frameInfo.blockSizeID & _3BITS) << 4); + /* Optional Frame content size field */ + if (cctxPtr->prefs.frameInfo.contentSize) { + LZ4F_writeLE64(dstPtr, cctxPtr->prefs.frameInfo.contentSize); + dstPtr += 8; + cctxPtr->totalInSize = 0; + } + /* Optional dictionary ID field */ + if (cctxPtr->prefs.frameInfo.dictID) { + LZ4F_writeLE32(dstPtr, cctxPtr->prefs.frameInfo.dictID); + dstPtr += 4; + } + /* Header CRC Byte */ + *dstPtr = LZ4F_headerChecksum(headerStart, (size_t)(dstPtr - headerStart)); + dstPtr++; + + cctxPtr->cStage = 1; /* header written, now request input data block */ + return (size_t)(dstPtr - dstStart); +} + + +/*! LZ4F_compressBegin() : + * init streaming compression and writes frame header into dstBuffer. + * dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes. + * preferencesPtr can be NULL, in which case default parameters are selected. + * @return : number of bytes written into dstBuffer for the header + * or an error code (can be tested using LZ4F_isError()) + */ +size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_preferences_t* preferencesPtr) +{ + return LZ4F_compressBegin_usingCDict(cctxPtr, dstBuffer, dstCapacity, + NULL, preferencesPtr); +} + + +/* LZ4F_compressBound() : + * @return minimum capacity of dstBuffer for a given srcSize to handle worst case scenario. + * LZ4F_preferences_t structure is optional : if NULL, preferences will be set to cover worst case scenario. + * This function cannot fail. + */ +size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr) +{ + if (preferencesPtr && preferencesPtr->autoFlush) { + return LZ4F_compressBound_internal(srcSize, preferencesPtr, 0); + } + return LZ4F_compressBound_internal(srcSize, preferencesPtr, (size_t)-1); +} + + +typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level, const LZ4F_CDict* cdict); + + +/*! LZ4F_makeBlock(): + * compress a single block, add header and optional checksum. + * assumption : dst buffer capacity is >= BHSize + srcSize + crcSize + */ +static size_t LZ4F_makeBlock(void* dst, + const void* src, size_t srcSize, + compressFunc_t compress, void* lz4ctx, int level, + const LZ4F_CDict* cdict, + LZ4F_blockChecksum_t crcFlag) +{ + BYTE* const cSizePtr = (BYTE*)dst; + U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize), + (int)(srcSize), (int)(srcSize-1), + level, cdict); + if (cSize == 0) { /* compression failed */ + DEBUGLOG(5, "LZ4F_makeBlock: compression failed, creating a raw block (size %u)", (U32)srcSize); + cSize = (U32)srcSize; + LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG); + memcpy(cSizePtr+BHSize, src, srcSize); + } else { + LZ4F_writeLE32(cSizePtr, cSize); + } + if (crcFlag) { + U32 const crc32 = XXH32(cSizePtr+BHSize, cSize, 0); /* checksum of compressed data */ + LZ4F_writeLE32(cSizePtr+BHSize+cSize, crc32); + } + return BHSize + cSize + ((U32)crcFlag)*BFSize; +} + + +static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict) +{ + int const acceleration = (level < 0) ? -level + 1 : 1; + LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent); + if (cdict) { + return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration); + } else { + return LZ4_compress_fast_extState_fastReset(ctx, src, dst, srcSize, dstCapacity, acceleration); + } +} + +static int LZ4F_compressBlock_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict) +{ + int const acceleration = (level < 0) ? -level + 1 : 1; + (void)cdict; /* init once at beginning of frame */ + return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration); +} + +static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict) +{ + LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent); + if (cdict) { + return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity); + } + return LZ4_compress_HC_extStateHC_fastReset(ctx, src, dst, srcSize, dstCapacity, level); +} + +static int LZ4F_compressBlockHC_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict) +{ + (void)level; (void)cdict; /* init once at beginning of frame */ + return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity); +} + +static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level) +{ + if (level < LZ4HC_CLEVEL_MIN) { + if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock; + return LZ4F_compressBlock_continue; + } + if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC; + return LZ4F_compressBlockHC_continue; +} + +static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr) +{ + if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) + 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. + * dstBuffer MUST be >= LZ4F_compressBound(srcSize, preferencesPtr). + * LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. + * @return : the number of bytes written into dstBuffer. It can be zero, meaning input data was just buffered. + * or an error code if it fails (which can be tested using LZ4F_isError()) + */ +size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const void* srcBuffer, size_t srcSize, + const LZ4F_compressOptions_t* compressOptionsPtr) +{ + LZ4F_compressOptions_t cOptionsNull; + size_t const 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 const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel); + + DEBUGLOG(4, "LZ4F_compressUpdate (srcSize=%zu)", srcSize); + + if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC); + if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize)) + return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + MEM_INIT(&cOptionsNull, 0, sizeof(cOptionsNull)); + if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull; + + /* complete tmp buffer */ + if (cctxPtr->tmpInSize > 0) { /* some data already within tmp buffer */ + size_t const 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_makeBlock(dstPtr, + cctxPtr->tmpIn, blockSize, + compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); + + if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize; + cctxPtr->tmpInSize = 0; + } + } + + while ((size_t)(srcEnd - srcPtr) >= blockSize) { + /* compress full blocks */ + lastBlockCompressed = fromSrcBuffer; + dstPtr += LZ4F_makeBlock(dstPtr, + srcPtr, blockSize, + compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); + srcPtr += blockSize; + } + + if ((cctxPtr->prefs.autoFlush) && (srcPtr < srcEnd)) { + /* compress remaining input < blockSize */ + lastBlockCompressed = fromSrcBuffer; + dstPtr += LZ4F_makeBlock(dstPtr, + srcPtr, (size_t)(srcEnd - srcPtr), + compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); + srcPtr = srcEnd; + } + + /* preserve dictionary if necessary */ + if ((cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) && (lastBlockCompressed==fromSrcBuffer)) { + if (compressOptionsPtr->stableSrc) { + cctxPtr->tmpIn = cctxPtr->tmpBuff; + } else { + int const realDictSize = LZ4F_localSaveDict(cctxPtr); + if (realDictSize==0) return err0r(LZ4F_ERROR_GENERIC); + cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; + } + } + + /* keep tmpIn within limits */ + if ((cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize) /* necessarily LZ4F_blockLinked && lastBlockCompressed==fromTmpBuffer */ + && !(cctxPtr->prefs.autoFlush)) + { + int const realDictSize = LZ4F_localSaveDict(cctxPtr); + cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; + } + + /* some input data left, necessarily < blockSize */ + if (srcPtr < srcEnd) { + /* fill tmp buffer */ + size_t const sizeToCopy = (size_t)(srcEnd - srcPtr); + memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy); + cctxPtr->tmpInSize = sizeToCopy; + } + + if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) + (void)XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize); + + cctxPtr->totalInSize += srcSize; + return (size_t)(dstPtr - dstStart); +} + + +/*! LZ4F_flush() : + * When compressed data must be sent immediately, without waiting for a block to be filled, + * invoke LZ4_flush(), which will immediately compress any remaining data stored within LZ4F_cctx. + * 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 LZ4F_cctx. + * The function outputs an error code if it fails (can be tested using LZ4F_isError()) + * LZ4F_compressOptions_t* is optional. NULL is a valid argument. + */ +size_t LZ4F_flush(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_compressOptions_t* compressOptionsPtr) +{ + 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 err0r(LZ4F_ERROR_GENERIC); + if (dstCapacity < (cctxPtr->tmpInSize + BHSize + BFSize)) + return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + (void)compressOptionsPtr; /* not yet useful */ + + /* select compression function */ + compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel); + + /* compress tmp buffer */ + dstPtr += LZ4F_makeBlock(dstPtr, + cctxPtr->tmpIn, cctxPtr->tmpInSize, + compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel, + cctxPtr->cdict, + cctxPtr->prefs.frameInfo.blockChecksumFlag); + assert(((void)"flush overflows dstBuffer!", (size_t)(dstPtr - dstStart) <= dstCapacity)); + + if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) + cctxPtr->tmpIn += cctxPtr->tmpInSize; + cctxPtr->tmpInSize = 0; + + /* keep tmpIn within limits */ + if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) { /* necessarily LZ4F_blockLinked */ + int const realDictSize = LZ4F_localSaveDict(cctxPtr); + cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; + } + + return (size_t)(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 an (optional) checksum. + * LZ4F_compressOptions_t structure is optional : you can provide NULL as argument. + * @return: the number of bytes written into dstBuffer (necessarily >= 4 (endMark size)) + * or an error code if it fails (can be tested using LZ4F_isError()) + * The context can then be used again to compress a new frame, starting with LZ4F_compressBegin(). + */ +size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr, + void* dstBuffer, size_t dstCapacity, + const LZ4F_compressOptions_t* compressOptionsPtr) +{ + BYTE* const dstStart = (BYTE*)dstBuffer; + BYTE* dstPtr = dstStart; + + size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr); + DEBUGLOG(5,"LZ4F_compressEnd: dstCapacity=%u", (unsigned)dstCapacity); + if (LZ4F_isError(flushSize)) return flushSize; + dstPtr += flushSize; + + assert(flushSize <= dstCapacity); + dstCapacity -= flushSize; + + if (dstCapacity < 4) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + LZ4F_writeLE32(dstPtr, 0); + dstPtr += 4; /* endMark */ + + if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) { + U32 const xxh = XXH32_digest(&(cctxPtr->xxh)); + if (dstCapacity < 8) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); + DEBUGLOG(5,"Writing 32-bit content checksum"); + LZ4F_writeLE32(dstPtr, xxh); + dstPtr+=4; /* content Checksum */ + } + + cctxPtr->cStage = 0; /* state is now re-usable (with identical preferences) */ + cctxPtr->maxBufferSize = 0; /* reuse HC context */ + + if (cctxPtr->prefs.frameInfo.contentSize) { + if (cctxPtr->prefs.frameInfo.contentSize != cctxPtr->totalInSize) + return err0r(LZ4F_ERROR_frameSize_wrong); + } + + return (size_t)(dstPtr - dstStart); +} + + +/*-*************************************************** +* Frame Decompression +*****************************************************/ + +typedef enum { + dstage_getFrameHeader=0, dstage_storeFrameHeader, + dstage_init, + dstage_getBlockHeader, dstage_storeBlockHeader, + dstage_copyDirect, dstage_getBlockChecksum, + dstage_getCBlock, dstage_storeCBlock, + dstage_flushOut, + dstage_getSuffix, dstage_storeSuffix, + dstage_getSFrameSize, dstage_storeSFrameSize, + dstage_skipSkippable +} dStage_t; + +struct LZ4F_dctx_s { + LZ4F_frameInfo_t frameInfo; + U32 version; + dStage_t dStage; + U64 frameRemainingSize; + size_t maxBlockSize; + size_t maxBufferSize; + BYTE* tmpIn; + size_t tmpInSize; + size_t tmpInTarget; + BYTE* tmpOutBuffer; + const BYTE* dict; + size_t dictSize; + BYTE* tmpOut; + size_t tmpOutSize; + size_t tmpOutStart; + XXH32_state_t xxh; + XXH32_state_t blockChecksum; + BYTE header[LZ4F_HEADER_SIZE_MAX]; +}; /* typedef'd to LZ4F_dctx in lz4frame.h */ + + +/*! LZ4F_createDecompressionContext() : + * Create a decompressionContext object, which will track all decompression operations. + * Provides a pointer to a fully allocated and initialized LZ4F_decompressionContext object. + * Object can later be released using LZ4F_freeDecompressionContext(). + * @return : if != 0, there was an error during context creation. + */ +LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber) +{ + LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOC_AND_ZERO(sizeof(LZ4F_dctx)); + if (dctx == NULL) { /* failed allocation */ + *LZ4F_decompressionContextPtr = NULL; + return err0r(LZ4F_ERROR_allocation_failed); + } + + dctx->version = versionNumber; + *LZ4F_decompressionContextPtr = dctx; + return LZ4F_OK_NoError; +} + +LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx) +{ + LZ4F_errorCode_t result = LZ4F_OK_NoError; + if (dctx != NULL) { /* can accept NULL input, like free() */ + result = (LZ4F_errorCode_t)dctx->dStage; + FREEMEM(dctx->tmpIn); + FREEMEM(dctx->tmpOutBuffer); + FREEMEM(dctx); + } + return result; +} + + +/*==--- Streaming Decompression operations ---==*/ + +void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx) +{ + dctx->dStage = dstage_getFrameHeader; + dctx->dict = NULL; + dctx->dictSize = 0; +} + + +/*! LZ4F_decodeHeader() : + * input : `src` points at the **beginning of the frame** + * output : set internal values of dctx, such as + * dctx->frameInfo and dctx->dStage. + * Also allocates internal buffers. + * @return : nb Bytes read from src (necessarily <= srcSize) + * or an error code (testable with LZ4F_isError()) + */ +static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize) +{ + unsigned blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, dictIDFlag, blockSizeID; + size_t frameHeaderSize; + const BYTE* srcPtr = (const BYTE*)src; + + DEBUGLOG(5, "LZ4F_decodeHeader"); + /* need to decode header to get frameInfo */ + if (srcSize < minFHSize) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* minimal frame header size */ + MEM_INIT(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo)); + + /* special case : skippable frames */ + if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) { + dctx->frameInfo.frameType = LZ4F_skippableFrame; + if (src == (void*)(dctx->header)) { + dctx->tmpInSize = srcSize; + dctx->tmpInTarget = 8; + dctx->dStage = dstage_storeSFrameSize; + return srcSize; + } else { + dctx->dStage = dstage_getSFrameSize; + return 4; + } + } + + /* control magic number */ +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) { + DEBUGLOG(4, "frame header error : unknown magic number"); + return err0r(LZ4F_ERROR_frameType_unknown); + } +#endif + dctx->frameInfo.frameType = LZ4F_frame; + + /* Flags */ + { U32 const FLG = srcPtr[4]; + U32 const version = (FLG>>6) & _2BITS; + blockChecksumFlag = (FLG>>4) & _1BIT; + blockMode = (FLG>>5) & _1BIT; + contentSizeFlag = (FLG>>3) & _1BIT; + contentChecksumFlag = (FLG>>2) & _1BIT; + dictIDFlag = FLG & _1BIT; + /* validate */ + if (((FLG>>1)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */ + if (version != 1) return err0r(LZ4F_ERROR_headerVersion_wrong); /* Version Number, only supported value */ + } + + /* Frame Header Size */ + frameHeaderSize = minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0); + + if (srcSize < frameHeaderSize) { + /* not enough input to fully decode frame header */ + if (srcPtr != dctx->header) + memcpy(dctx->header, srcPtr, srcSize); + dctx->tmpInSize = srcSize; + dctx->tmpInTarget = frameHeaderSize; + dctx->dStage = dstage_storeFrameHeader; + return srcSize; + } + + { U32 const BD = srcPtr[5]; + blockSizeID = (BD>>4) & _3BITS; + /* validate */ + if (((BD>>7)&_1BIT) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bit */ + if (blockSizeID < 4) return err0r(LZ4F_ERROR_maxBlockSize_invalid); /* 4-7 only supported values for the time being */ + if (((BD>>0)&_4BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bits */ + } + + /* check header */ + assert(frameHeaderSize > 5); +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + { BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5); + if (HC != srcPtr[frameHeaderSize-1]) + return err0r(LZ4F_ERROR_headerChecksum_invalid); + } +#endif + + /* save */ + dctx->frameInfo.blockMode = (LZ4F_blockMode_t)blockMode; + dctx->frameInfo.blockChecksumFlag = (LZ4F_blockChecksum_t)blockChecksumFlag; + dctx->frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)contentChecksumFlag; + dctx->frameInfo.blockSizeID = (LZ4F_blockSizeID_t)blockSizeID; + dctx->maxBlockSize = LZ4F_getBlockSize(blockSizeID); + if (contentSizeFlag) + dctx->frameRemainingSize = + dctx->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6); + if (dictIDFlag) + dctx->frameInfo.dictID = LZ4F_readLE32(srcPtr + frameHeaderSize - 5); + + dctx->dStage = dstage_init; + + return frameHeaderSize; +} + + +/*! LZ4F_headerSize() : + * @return : size of frame header + * or an error code, which can be tested using LZ4F_isError() + */ +size_t LZ4F_headerSize(const void* src, size_t srcSize) +{ + if (src == NULL) return err0r(LZ4F_ERROR_srcPtr_wrong); + + /* minimal srcSize to determine header size */ + if (srcSize < LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH) + return err0r(LZ4F_ERROR_frameHeader_incomplete); + + /* special case : skippable frames */ + if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) + return 8; + + /* control magic number */ +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER) + return err0r(LZ4F_ERROR_frameType_unknown); +#endif + + /* Frame Header Size */ + { BYTE const FLG = ((const BYTE*)src)[4]; + U32 const contentSizeFlag = (FLG>>3) & _1BIT; + U32 const dictIDFlag = FLG & _1BIT; + return minFHSize + (contentSizeFlag?8:0) + (dictIDFlag?4:0); + } +} + +/*! LZ4F_getFrameInfo() : + * This function extracts frame parameters (max blockSize, frame checksum, etc.). + * Usage is optional. Objective is to provide relevant information for allocation purposes. + * This function works in 2 situations : + * - At the beginning of a new frame, in which case it will decode this information from `srcBuffer`, and start the decoding process. + * Amount of input data provided must be large enough to successfully decode the frame header. + * A header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes. It's possible to provide more input data than this minimum. + * - After decoding has been started. In which case, no input is read, frame parameters are extracted from dctx. + * The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value). + * Decompression must resume from (srcBuffer + *srcSizePtr). + * @return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call, + * or an error code which can be tested using LZ4F_isError() + * note 1 : in case of error, dctx is not modified. Decoding operations can resume from where they stopped. + * note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure. + */ +LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, + LZ4F_frameInfo_t* frameInfoPtr, + const void* srcBuffer, size_t* srcSizePtr) +{ + LZ4F_STATIC_ASSERT(dstage_getFrameHeader < dstage_storeFrameHeader); + if (dctx->dStage > dstage_storeFrameHeader) { + /* frameInfo already decoded */ + size_t o=0, i=0; + *srcSizePtr = 0; + *frameInfoPtr = dctx->frameInfo; + /* returns : recommended nb of bytes for LZ4F_decompress() */ + return LZ4F_decompress(dctx, NULL, &o, NULL, &i, NULL); + } else { + if (dctx->dStage == dstage_storeFrameHeader) { + /* frame decoding already started, in the middle of header => automatic fail */ + *srcSizePtr = 0; + return err0r(LZ4F_ERROR_frameDecoding_alreadyStarted); + } else { + size_t const hSize = LZ4F_headerSize(srcBuffer, *srcSizePtr); + if (LZ4F_isError(hSize)) { *srcSizePtr=0; return hSize; } + if (*srcSizePtr < hSize) { + *srcSizePtr=0; + return err0r(LZ4F_ERROR_frameHeader_incomplete); + } + + { size_t decodeResult = LZ4F_decodeHeader(dctx, srcBuffer, hSize); + if (LZ4F_isError(decodeResult)) { + *srcSizePtr = 0; + } else { + *srcSizePtr = decodeResult; + decodeResult = BHSize; /* block header size */ + } + *frameInfoPtr = dctx->frameInfo; + return decodeResult; + } } } +} + + +/* LZ4F_updateDict() : + * only used for LZ4F_blockLinked mode + * Condition : dstPtr != NULL + */ +static void LZ4F_updateDict(LZ4F_dctx* dctx, + const BYTE* dstPtr, size_t dstSize, const BYTE* dstBufferStart, + unsigned withinTmp) +{ + assert(dstPtr != NULL); + if (dctx->dictSize==0) { + dctx->dict = (const BYTE*)dstPtr; /* priority to prefix mode */ + } + assert(dctx->dict != NULL); + + if (dctx->dict + dctx->dictSize == dstPtr) { /* prefix mode, everything within dstBuffer */ + dctx->dictSize += dstSize; + return; + } + + assert(dstPtr >= dstBufferStart); + if ((size_t)(dstPtr - dstBufferStart) + dstSize >= 64 KB) { /* history in dstBuffer becomes large enough to become dictionary */ + dctx->dict = (const BYTE*)dstBufferStart; + dctx->dictSize = (size_t)(dstPtr - dstBufferStart) + dstSize; + return; + } + + assert(dstSize < 64 KB); /* if dstSize >= 64 KB, dictionary would be set into dstBuffer directly */ + + /* dstBuffer does not contain whole useful history (64 KB), so it must be saved within tmpOutBuffer */ + assert(dctx->tmpOutBuffer != NULL); + + if (withinTmp && (dctx->dict == dctx->tmpOutBuffer)) { /* continue history within tmpOutBuffer */ + /* withinTmp expectation : content of [dstPtr,dstSize] is same as [dict+dictSize,dstSize], so we just extend it */ + assert(dctx->dict + dctx->dictSize == dctx->tmpOut + dctx->tmpOutStart); + dctx->dictSize += dstSize; + return; + } + + if (withinTmp) { /* copy relevant dict portion in front of tmpOut within tmpOutBuffer */ + size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer); + size_t copySize = 64 KB - dctx->tmpOutSize; + const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart; + if (dctx->tmpOutSize > 64 KB) copySize = 0; + if (copySize > preserveSize) copySize = preserveSize; + + memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize); + + dctx->dict = dctx->tmpOutBuffer; + dctx->dictSize = preserveSize + dctx->tmpOutStart + dstSize; + return; + } + + if (dctx->dict == dctx->tmpOutBuffer) { /* copy dst into tmp to complete dict */ + if (dctx->dictSize + dstSize > dctx->maxBufferSize) { /* tmp buffer not large enough */ + size_t const preserveSize = 64 KB - dstSize; + memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize); + dctx->dictSize = preserveSize; + } + memcpy(dctx->tmpOutBuffer + dctx->dictSize, dstPtr, dstSize); + dctx->dictSize += dstSize; + return; + } + + /* join dict & dest into tmp */ + { size_t preserveSize = 64 KB - dstSize; + if (preserveSize > dctx->dictSize) preserveSize = dctx->dictSize; + memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize); + memcpy(dctx->tmpOutBuffer + preserveSize, dstPtr, dstSize); + dctx->dict = dctx->tmpOutBuffer; + dctx->dictSize = preserveSize + dstSize; + } +} + + + +/*! LZ4F_decompress() : + * Call this function repetitively to regenerate compressed data in srcBuffer. + * The function will attempt to decode up to *srcSizePtr bytes from srcBuffer + * into dstBuffer of capacity *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 number of bytes read is < number of bytes provided, then decompression operation is not complete. + * Remaining data will have to be presented again in a subsequent invocation. + * + * The function result is an hint of the better srcSize to use for next call to LZ4F_decompress. + * Schematically, it's the size of the current (or remaining) compressed block + header of next block. + * Respecting the hint provides a small boost to performance, since it allows less buffer shuffling. + * Note that this is just a hint, and it's always possible to any srcSize value. + * When a frame is fully decoded, @return will be 0. + * If decompression failed, @return is an error code which can be tested using LZ4F_isError(). + */ +size_t LZ4F_decompress(LZ4F_dctx* dctx, + void* dstBuffer, size_t* dstSizePtr, + const void* srcBuffer, size_t* srcSizePtr, + const LZ4F_decompressOptions_t* decompressOptionsPtr) +{ + LZ4F_decompressOptions_t optionsNull; + 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 ? dstStart + *dstSizePtr : NULL; + BYTE* dstPtr = dstStart; + const BYTE* selectedIn = NULL; + unsigned doAnotherStage = 1; + size_t nextSrcSizeHint = 1; + + + DEBUGLOG(5, "LZ4F_decompress : %p,%u => %p,%u", + srcBuffer, (unsigned)*srcSizePtr, dstBuffer, (unsigned)*dstSizePtr); + if (dstBuffer == NULL) assert(*dstSizePtr == 0); + MEM_INIT(&optionsNull, 0, sizeof(optionsNull)); + if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull; + *srcSizePtr = 0; + *dstSizePtr = 0; + assert(dctx != NULL); + + /* behaves as a state machine */ + + while (doAnotherStage) { + + switch(dctx->dStage) + { + + case dstage_getFrameHeader: + DEBUGLOG(6, "dstage_getFrameHeader"); + if ((size_t)(srcEnd-srcPtr) >= maxFHSize) { /* enough to decode - shortcut */ + size_t const hSize = LZ4F_decodeHeader(dctx, srcPtr, (size_t)(srcEnd-srcPtr)); /* will update dStage appropriately */ + if (LZ4F_isError(hSize)) return hSize; + srcPtr += hSize; + break; + } + dctx->tmpInSize = 0; + if (srcEnd-srcPtr == 0) return minFHSize; /* 0-size input */ + dctx->tmpInTarget = minFHSize; /* minimum size to decode header */ + dctx->dStage = dstage_storeFrameHeader; + /* fall-through */ + + case dstage_storeFrameHeader: + DEBUGLOG(6, "dstage_storeFrameHeader"); + { size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, (size_t)(srcEnd - srcPtr)); + memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy); + dctx->tmpInSize += sizeToCopy; + srcPtr += sizeToCopy; + } + if (dctx->tmpInSize < dctx->tmpInTarget) { + nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize; /* rest of header + nextBlockHeader */ + doAnotherStage = 0; /* not enough src data, ask for some more */ + break; + } + { size_t const hSize = LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget); /* will update dStage appropriately */ + if (LZ4F_isError(hSize)) return hSize; + } + break; + + case dstage_init: + DEBUGLOG(6, "dstage_init"); + if (dctx->frameInfo.contentChecksumFlag) (void)XXH32_reset(&(dctx->xxh), 0); + /* internal buffers allocation */ + { size_t const bufferNeeded = dctx->maxBlockSize + + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) ? 128 KB : 0); + if (bufferNeeded > dctx->maxBufferSize) { /* tmp buffers too small */ + dctx->maxBufferSize = 0; /* ensure allocation will be re-attempted on next entry*/ + FREEMEM(dctx->tmpIn); + dctx->tmpIn = (BYTE*)ALLOC(dctx->maxBlockSize + BFSize /* block checksum */); + if (dctx->tmpIn == NULL) + return err0r(LZ4F_ERROR_allocation_failed); + FREEMEM(dctx->tmpOutBuffer); + dctx->tmpOutBuffer= (BYTE*)ALLOC(bufferNeeded); + if (dctx->tmpOutBuffer== NULL) + return err0r(LZ4F_ERROR_allocation_failed); + dctx->maxBufferSize = bufferNeeded; + } } + dctx->tmpInSize = 0; + dctx->tmpInTarget = 0; + dctx->tmpOut = dctx->tmpOutBuffer; + dctx->tmpOutStart = 0; + dctx->tmpOutSize = 0; + + dctx->dStage = dstage_getBlockHeader; + /* fall-through */ + + case dstage_getBlockHeader: + if ((size_t)(srcEnd - srcPtr) >= BHSize) { + selectedIn = srcPtr; + srcPtr += BHSize; + } else { + /* not enough input to read cBlockSize field */ + dctx->tmpInSize = 0; + dctx->dStage = dstage_storeBlockHeader; + } + + if (dctx->dStage == dstage_storeBlockHeader) /* can be skipped */ + case dstage_storeBlockHeader: + { size_t const remainingInput = (size_t)(srcEnd - srcPtr); + size_t const wantedData = BHSize - dctx->tmpInSize; + size_t const sizeToCopy = MIN(wantedData, remainingInput); + memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy); + srcPtr += sizeToCopy; + dctx->tmpInSize += sizeToCopy; + + if (dctx->tmpInSize < BHSize) { /* not enough input for cBlockSize */ + nextSrcSizeHint = BHSize - dctx->tmpInSize; + doAnotherStage = 0; + break; + } + selectedIn = dctx->tmpIn; + } /* if (dctx->dStage == dstage_storeBlockHeader) */ + + /* decode block header */ + { U32 const blockHeader = LZ4F_readLE32(selectedIn); + size_t const nextCBlockSize = blockHeader & 0x7FFFFFFFU; + size_t const crcSize = dctx->frameInfo.blockChecksumFlag * BFSize; + if (blockHeader==0) { /* frameEnd signal, no more block */ + DEBUGLOG(5, "end of frame"); + dctx->dStage = dstage_getSuffix; + break; + } + if (nextCBlockSize > dctx->maxBlockSize) { + return err0r(LZ4F_ERROR_maxBlockSize_invalid); + } + if (blockHeader & LZ4F_BLOCKUNCOMPRESSED_FLAG) { + /* next block is uncompressed */ + dctx->tmpInTarget = nextCBlockSize; + DEBUGLOG(5, "next block is uncompressed (size %u)", (U32)nextCBlockSize); + if (dctx->frameInfo.blockChecksumFlag) { + (void)XXH32_reset(&dctx->blockChecksum, 0); + } + dctx->dStage = dstage_copyDirect; + break; + } + /* next block is a compressed block */ + dctx->tmpInTarget = nextCBlockSize + crcSize; + dctx->dStage = dstage_getCBlock; + if (dstPtr==dstEnd || srcPtr==srcEnd) { + nextSrcSizeHint = BHSize + nextCBlockSize + crcSize; + doAnotherStage = 0; + } + break; + } + + case dstage_copyDirect: /* uncompressed block */ + DEBUGLOG(6, "dstage_copyDirect"); + { size_t sizeToCopy; + if (dstPtr == NULL) { + sizeToCopy = 0; + } else { + size_t const minBuffSize = MIN((size_t)(srcEnd-srcPtr), (size_t)(dstEnd-dstPtr)); + sizeToCopy = MIN(dctx->tmpInTarget, minBuffSize); + memcpy(dstPtr, srcPtr, sizeToCopy); + if (dctx->frameInfo.blockChecksumFlag) { + (void)XXH32_update(&dctx->blockChecksum, srcPtr, sizeToCopy); + } + if (dctx->frameInfo.contentChecksumFlag) + (void)XXH32_update(&dctx->xxh, srcPtr, sizeToCopy); + if (dctx->frameInfo.contentSize) + dctx->frameRemainingSize -= sizeToCopy; + + /* history management (linked blocks only)*/ + if (dctx->frameInfo.blockMode == LZ4F_blockLinked) { + LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 0); + } } + + srcPtr += sizeToCopy; + dstPtr += sizeToCopy; + if (sizeToCopy == dctx->tmpInTarget) { /* all done */ + if (dctx->frameInfo.blockChecksumFlag) { + dctx->tmpInSize = 0; + dctx->dStage = dstage_getBlockChecksum; + } else + dctx->dStage = dstage_getBlockHeader; /* new block */ + break; + } + dctx->tmpInTarget -= sizeToCopy; /* need to copy more */ + } + nextSrcSizeHint = dctx->tmpInTarget + + +(dctx->frameInfo.blockChecksumFlag ? BFSize : 0) + + BHSize /* next header size */; + doAnotherStage = 0; + break; + + /* check block checksum for recently transferred uncompressed block */ + case dstage_getBlockChecksum: + DEBUGLOG(6, "dstage_getBlockChecksum"); + { const void* crcSrc; + if ((srcEnd-srcPtr >= 4) && (dctx->tmpInSize==0)) { + crcSrc = srcPtr; + srcPtr += 4; + } else { + size_t const stillToCopy = 4 - dctx->tmpInSize; + size_t const sizeToCopy = MIN(stillToCopy, (size_t)(srcEnd-srcPtr)); + memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy); + dctx->tmpInSize += sizeToCopy; + srcPtr += sizeToCopy; + if (dctx->tmpInSize < 4) { /* all input consumed */ + doAnotherStage = 0; + break; + } + crcSrc = dctx->header; + } + { U32 const readCRC = LZ4F_readLE32(crcSrc); + U32 const calcCRC = XXH32_digest(&dctx->blockChecksum); +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + DEBUGLOG(6, "compare block checksum"); + if (readCRC != calcCRC) { + DEBUGLOG(4, "incorrect block checksum: %08X != %08X", + readCRC, calcCRC); + return err0r(LZ4F_ERROR_blockChecksum_invalid); + } +#else + (void)readCRC; + (void)calcCRC; +#endif + } } + dctx->dStage = dstage_getBlockHeader; /* new block */ + break; + + case dstage_getCBlock: + DEBUGLOG(6, "dstage_getCBlock"); + if ((size_t)(srcEnd-srcPtr) < dctx->tmpInTarget) { + dctx->tmpInSize = 0; + dctx->dStage = dstage_storeCBlock; + break; + } + /* input large enough to read full block directly */ + selectedIn = srcPtr; + srcPtr += dctx->tmpInTarget; + + if (0) /* always jump over next block */ + case dstage_storeCBlock: + { size_t const wantedData = dctx->tmpInTarget - dctx->tmpInSize; + size_t const inputLeft = (size_t)(srcEnd-srcPtr); + size_t const sizeToCopy = MIN(wantedData, inputLeft); + memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy); + dctx->tmpInSize += sizeToCopy; + srcPtr += sizeToCopy; + if (dctx->tmpInSize < dctx->tmpInTarget) { /* need more input */ + nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + + (dctx->frameInfo.blockChecksumFlag ? BFSize : 0) + + BHSize /* next header size */; + doAnotherStage = 0; + break; + } + selectedIn = dctx->tmpIn; + } + + /* At this stage, input is large enough to decode a block */ + if (dctx->frameInfo.blockChecksumFlag) { + dctx->tmpInTarget -= 4; + assert(selectedIn != NULL); /* selectedIn is defined at this stage (either srcPtr, or dctx->tmpIn) */ + { U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget); + U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0); +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + if (readBlockCrc != calcBlockCrc) + return err0r(LZ4F_ERROR_blockChecksum_invalid); +#else + (void)readBlockCrc; + (void)calcBlockCrc; +#endif + } } + + if ((size_t)(dstEnd-dstPtr) >= dctx->maxBlockSize) { + const char* dict = (const char*)dctx->dict; + size_t dictSize = dctx->dictSize; + int decodedSize; + assert(dstPtr != NULL); + if (dict && dictSize > 1 GB) { + /* the dictSize param is an int, avoid truncation / sign issues */ + dict += dictSize - 64 KB; + dictSize = 64 KB; + } + /* enough capacity in `dst` to decompress directly there */ + decodedSize = LZ4_decompress_safe_usingDict( + (const char*)selectedIn, (char*)dstPtr, + (int)dctx->tmpInTarget, (int)dctx->maxBlockSize, + dict, (int)dictSize); + if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC); /* decompression failed */ + if (dctx->frameInfo.contentChecksumFlag) + XXH32_update(&(dctx->xxh), dstPtr, (size_t)decodedSize); + if (dctx->frameInfo.contentSize) + dctx->frameRemainingSize -= (size_t)decodedSize; + + /* dictionary management */ + if (dctx->frameInfo.blockMode==LZ4F_blockLinked) { + LZ4F_updateDict(dctx, dstPtr, (size_t)decodedSize, dstStart, 0); + } + + dstPtr += decodedSize; + dctx->dStage = dstage_getBlockHeader; + break; + } + + /* not enough place into dst : decode into tmpOut */ + /* ensure enough place for tmpOut */ + if (dctx->frameInfo.blockMode == LZ4F_blockLinked) { + if (dctx->dict == dctx->tmpOutBuffer) { + if (dctx->dictSize > 128 KB) { + memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - 64 KB, 64 KB); + dctx->dictSize = 64 KB; + } + dctx->tmpOut = dctx->tmpOutBuffer + dctx->dictSize; + } else { /* dict not within tmp */ + size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB); + dctx->tmpOut = dctx->tmpOutBuffer + reservedDictSpace; + } } + + /* Decode block */ + { const char* dict = (const char*)dctx->dict; + size_t dictSize = dctx->dictSize; + int decodedSize; + if (dict && dictSize > 1 GB) { + /* the dictSize param is an int, avoid truncation / sign issues */ + dict += dictSize - 64 KB; + dictSize = 64 KB; + } + decodedSize = LZ4_decompress_safe_usingDict( + (const char*)selectedIn, (char*)dctx->tmpOut, + (int)dctx->tmpInTarget, (int)dctx->maxBlockSize, + dict, (int)dictSize); + if (decodedSize < 0) /* decompression failed */ + return err0r(LZ4F_ERROR_decompressionFailed); + if (dctx->frameInfo.contentChecksumFlag) + XXH32_update(&(dctx->xxh), dctx->tmpOut, (size_t)decodedSize); + if (dctx->frameInfo.contentSize) + dctx->frameRemainingSize -= (size_t)decodedSize; + dctx->tmpOutSize = (size_t)decodedSize; + dctx->tmpOutStart = 0; + dctx->dStage = dstage_flushOut; + } + /* fall-through */ + + case dstage_flushOut: /* flush decoded data from tmpOut to dstBuffer */ + DEBUGLOG(6, "dstage_flushOut"); + if (dstPtr != NULL) { + size_t const sizeToCopy = MIN(dctx->tmpOutSize - dctx->tmpOutStart, (size_t)(dstEnd-dstPtr)); + memcpy(dstPtr, dctx->tmpOut + dctx->tmpOutStart, sizeToCopy); + + /* dictionary management */ + if (dctx->frameInfo.blockMode == LZ4F_blockLinked) + LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1 /*withinTmp*/); + + dctx->tmpOutStart += sizeToCopy; + dstPtr += sizeToCopy; + } + if (dctx->tmpOutStart == dctx->tmpOutSize) { /* all flushed */ + dctx->dStage = dstage_getBlockHeader; /* get next block */ + break; + } + /* could not flush everything : stop there, just request a block header */ + doAnotherStage = 0; + nextSrcSizeHint = BHSize; + break; + + case dstage_getSuffix: + if (dctx->frameRemainingSize) + return err0r(LZ4F_ERROR_frameSize_wrong); /* incorrect frame size decoded */ + if (!dctx->frameInfo.contentChecksumFlag) { /* no checksum, frame is completed */ + nextSrcSizeHint = 0; + LZ4F_resetDecompressionContext(dctx); + doAnotherStage = 0; + break; + } + if ((srcEnd - srcPtr) < 4) { /* not enough size for entire CRC */ + dctx->tmpInSize = 0; + dctx->dStage = dstage_storeSuffix; + } else { + selectedIn = srcPtr; + srcPtr += 4; + } + + if (dctx->dStage == dstage_storeSuffix) /* can be skipped */ + case dstage_storeSuffix: + { size_t const remainingInput = (size_t)(srcEnd - srcPtr); + size_t const wantedData = 4 - dctx->tmpInSize; + size_t const sizeToCopy = MIN(wantedData, remainingInput); + memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy); + srcPtr += sizeToCopy; + dctx->tmpInSize += sizeToCopy; + if (dctx->tmpInSize < 4) { /* not enough input to read complete suffix */ + nextSrcSizeHint = 4 - dctx->tmpInSize; + doAnotherStage=0; + break; + } + selectedIn = dctx->tmpIn; + } /* if (dctx->dStage == dstage_storeSuffix) */ + + /* case dstage_checkSuffix: */ /* no direct entry, avoid initialization risks */ + { U32 const readCRC = LZ4F_readLE32(selectedIn); + U32 const resultCRC = XXH32_digest(&(dctx->xxh)); +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + if (readCRC != resultCRC) + return err0r(LZ4F_ERROR_contentChecksum_invalid); +#else + (void)readCRC; + (void)resultCRC; +#endif + nextSrcSizeHint = 0; + LZ4F_resetDecompressionContext(dctx); + doAnotherStage = 0; + break; + } + + case dstage_getSFrameSize: + if ((srcEnd - srcPtr) >= 4) { + selectedIn = srcPtr; + srcPtr += 4; + } else { + /* not enough input to read cBlockSize field */ + dctx->tmpInSize = 4; + dctx->tmpInTarget = 8; + dctx->dStage = dstage_storeSFrameSize; + } + + if (dctx->dStage == dstage_storeSFrameSize) + case dstage_storeSFrameSize: + { size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, + (size_t)(srcEnd - srcPtr) ); + memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy); + srcPtr += sizeToCopy; + dctx->tmpInSize += sizeToCopy; + if (dctx->tmpInSize < dctx->tmpInTarget) { + /* not enough input to get full sBlockSize; wait for more */ + nextSrcSizeHint = dctx->tmpInTarget - dctx->tmpInSize; + doAnotherStage = 0; + break; + } + selectedIn = dctx->header + 4; + } /* if (dctx->dStage == dstage_storeSFrameSize) */ + + /* case dstage_decodeSFrameSize: */ /* no direct entry */ + { size_t const SFrameSize = LZ4F_readLE32(selectedIn); + dctx->frameInfo.contentSize = SFrameSize; + dctx->tmpInTarget = SFrameSize; + dctx->dStage = dstage_skipSkippable; + break; + } + + case dstage_skipSkippable: + { size_t const skipSize = MIN(dctx->tmpInTarget, (size_t)(srcEnd-srcPtr)); + srcPtr += skipSize; + dctx->tmpInTarget -= skipSize; + doAnotherStage = 0; + nextSrcSizeHint = dctx->tmpInTarget; + if (nextSrcSizeHint) break; /* still more to skip */ + /* frame fully skipped : prepare context for a new frame */ + LZ4F_resetDecompressionContext(dctx); + break; + } + } /* switch (dctx->dStage) */ + } /* while (doAnotherStage) */ + + /* preserve history within tmp whenever necessary */ + LZ4F_STATIC_ASSERT((unsigned)dstage_init == 2); + if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked) /* next block will use up to 64KB from previous ones */ + && (dctx->dict != dctx->tmpOutBuffer) /* dictionary is not already within tmp */ + && (dctx->dict != NULL) /* dictionary exists */ + && (!decompressOptionsPtr->stableDst) /* cannot rely on dst data to remain there for next call */ + && ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) ) /* valid stages : [init ... getSuffix[ */ + { + if (dctx->dStage == dstage_flushOut) { + size_t const preserveSize = (size_t)(dctx->tmpOut - dctx->tmpOutBuffer); + size_t copySize = 64 KB - dctx->tmpOutSize; + const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart; + if (dctx->tmpOutSize > 64 KB) copySize = 0; + if (copySize > preserveSize) copySize = preserveSize; + assert(dctx->tmpOutBuffer != NULL); + + memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize); + + dctx->dict = dctx->tmpOutBuffer; + dctx->dictSize = preserveSize + dctx->tmpOutStart; + } else { + const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize; + size_t const newDictSize = MIN(dctx->dictSize, 64 KB); + + memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize); + + dctx->dict = dctx->tmpOutBuffer; + dctx->dictSize = newDictSize; + dctx->tmpOut = dctx->tmpOutBuffer + newDictSize; + } + } + + *srcSizePtr = (size_t)(srcPtr - srcStart); + *dstSizePtr = (size_t)(dstPtr - dstStart); + return nextSrcSizeHint; +} + +/*! LZ4F_decompress_usingDict() : + * Same as LZ4F_decompress(), using a predefined dictionary. + * Dictionary is used "in place", without any preprocessing. + * It must remain accessible throughout the entire frame decoding. + */ +size_t LZ4F_decompress_usingDict(LZ4F_dctx* dctx, + void* dstBuffer, size_t* dstSizePtr, + const void* srcBuffer, size_t* srcSizePtr, + const void* dict, size_t dictSize, + const LZ4F_decompressOptions_t* decompressOptionsPtr) +{ + if (dctx->dStage <= dstage_init) { + dctx->dict = (const BYTE*)dict; + dctx->dictSize = dictSize; + } + return LZ4F_decompress(dctx, dstBuffer, dstSizePtr, + srcBuffer, srcSizePtr, + decompressOptionsPtr); +} |