1414 lines
58 KiB
C
1414 lines
58 KiB
C
/*
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LZ4 auto-framing library
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Copyright (C) 2011-2016, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- LZ4 homepage : http://www.lz4.org
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- LZ4 source repository : https://github.com/lz4/lz4
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*/
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/* LZ4F is a stand-alone API to create LZ4-compressed Frames
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* in full conformance with specification v1.5.0
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* All related operations, including memory management, are handled by the library.
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* */
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/*-************************************
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* Compiler Options
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**************************************/
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#ifdef _MSC_VER /* Visual Studio */
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# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
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#endif
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/*-************************************
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* Memory routines
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**************************************/
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#include <stdlib.h> /* malloc, calloc, free */
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#define ALLOCATOR(s) calloc(1,s)
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#define FREEMEM free
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#include <string.h> /* memset, memcpy, memmove */
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#define MEM_INIT memset
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/*-************************************
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* Includes
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**************************************/
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#include "lz4frame_static.h"
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#include "lz4.h"
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#include "lz4hc.h"
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#define XXH_STATIC_LINKING_ONLY
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#include "xxhash.h"
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/*-************************************
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* Common Utils
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**************************************/
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#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
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/*-************************************
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* Basic Types
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**************************************/
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#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
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# include <stdint.h>
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typedef uint8_t BYTE;
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typedef uint16_t U16;
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typedef uint32_t U32;
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typedef int32_t S32;
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typedef uint64_t U64;
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#else
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typedef unsigned char BYTE;
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typedef unsigned short U16;
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typedef unsigned int U32;
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typedef signed int S32;
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typedef unsigned long long U64;
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#endif
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/* unoptimized version; solves endianess & alignment issues */
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static U32 LZ4F_readLE32 (const void* src)
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{
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const BYTE* const srcPtr = (const BYTE*)src;
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U32 value32 = srcPtr[0];
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value32 += (srcPtr[1]<<8);
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value32 += (srcPtr[2]<<16);
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value32 += ((U32)srcPtr[3])<<24;
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return value32;
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}
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static void LZ4F_writeLE32 (void* dst, U32 value32)
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{
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BYTE* const dstPtr = (BYTE*)dst;
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dstPtr[0] = (BYTE)value32;
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dstPtr[1] = (BYTE)(value32 >> 8);
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dstPtr[2] = (BYTE)(value32 >> 16);
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dstPtr[3] = (BYTE)(value32 >> 24);
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}
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static U64 LZ4F_readLE64 (const void* src)
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{
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const BYTE* const srcPtr = (const BYTE*)src;
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U64 value64 = srcPtr[0];
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value64 += ((U64)srcPtr[1]<<8);
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value64 += ((U64)srcPtr[2]<<16);
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value64 += ((U64)srcPtr[3]<<24);
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value64 += ((U64)srcPtr[4]<<32);
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value64 += ((U64)srcPtr[5]<<40);
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value64 += ((U64)srcPtr[6]<<48);
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value64 += ((U64)srcPtr[7]<<56);
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return value64;
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}
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static void LZ4F_writeLE64 (void* dst, U64 value64)
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{
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BYTE* const dstPtr = (BYTE*)dst;
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dstPtr[0] = (BYTE)value64;
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dstPtr[1] = (BYTE)(value64 >> 8);
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dstPtr[2] = (BYTE)(value64 >> 16);
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dstPtr[3] = (BYTE)(value64 >> 24);
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dstPtr[4] = (BYTE)(value64 >> 32);
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dstPtr[5] = (BYTE)(value64 >> 40);
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dstPtr[6] = (BYTE)(value64 >> 48);
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dstPtr[7] = (BYTE)(value64 >> 56);
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}
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/*-************************************
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* Constants
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**************************************/
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#define KB *(1<<10)
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#define MB *(1<<20)
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#define GB *(1<<30)
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#define _1BIT 0x01
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#define _2BITS 0x03
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#define _3BITS 0x07
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#define _4BITS 0x0F
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#define _8BITS 0xFF
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#define LZ4F_MAGIC_SKIPPABLE_START 0x184D2A50U
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#define LZ4F_MAGICNUMBER 0x184D2204U
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#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
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#define LZ4F_BLOCKSIZEID_DEFAULT LZ4F_max64KB
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static const size_t minFHSize = 7;
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static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 15 */
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static const size_t BHSize = 4;
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/*-************************************
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* Structures and local types
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**************************************/
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typedef struct LZ4F_cctx_s
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{
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LZ4F_preferences_t prefs;
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U32 version;
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U32 cStage;
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size_t maxBlockSize;
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size_t maxBufferSize;
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BYTE* tmpBuff;
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BYTE* tmpIn;
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size_t tmpInSize;
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U64 totalInSize;
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XXH32_state_t xxh;
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void* lz4CtxPtr;
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U32 lz4CtxLevel; /* 0: unallocated; 1: LZ4_stream_t; 3: LZ4_streamHC_t */
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} LZ4F_cctx_t;
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/*-************************************
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* Error management
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**************************************/
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#define LZ4F_GENERATE_STRING(STRING) #STRING,
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static const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) };
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unsigned LZ4F_isError(LZ4F_errorCode_t code)
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{
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return (code > (LZ4F_errorCode_t)(-LZ4F_ERROR_maxCode));
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}
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const char* LZ4F_getErrorName(LZ4F_errorCode_t code)
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{
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static const char* codeError = "Unspecified error code";
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if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)];
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return codeError;
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}
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LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult)
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{
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if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError;
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return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult);
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}
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static LZ4F_errorCode_t err0r(LZ4F_errorCodes code)
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{
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LZ4_STATIC_ASSERT(sizeof(ptrdiff_t) >= sizeof(size_t)); /* A compilation error here means sizeof(ptrdiff_t) is not large enough */
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return (LZ4F_errorCode_t)-(ptrdiff_t)code;
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}
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unsigned LZ4F_getVersion(void) { return LZ4F_VERSION; }
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/*-************************************
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* Private functions
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**************************************/
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#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
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static size_t LZ4F_getBlockSize(unsigned blockSizeID)
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{
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static const size_t blockSizes[4] = { 64 KB, 256 KB, 1 MB, 4 MB };
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if (blockSizeID == 0) blockSizeID = LZ4F_BLOCKSIZEID_DEFAULT;
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blockSizeID -= 4;
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if (blockSizeID > 3) return err0r(LZ4F_ERROR_maxBlockSize_invalid);
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return blockSizes[blockSizeID];
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}
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static BYTE LZ4F_headerChecksum (const void* header, size_t length)
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{
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U32 const xxh = XXH32(header, length, 0);
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return (BYTE)(xxh >> 8);
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}
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/*-************************************
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* Simple-pass compression functions
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**************************************/
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static LZ4F_blockSizeID_t LZ4F_optimalBSID(const LZ4F_blockSizeID_t requestedBSID, const size_t srcSize)
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{
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LZ4F_blockSizeID_t proposedBSID = LZ4F_max64KB;
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size_t maxBlockSize = 64 KB;
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while (requestedBSID > proposedBSID) {
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if (srcSize <= maxBlockSize)
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return proposedBSID;
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proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1);
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maxBlockSize <<= 2;
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}
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return requestedBSID;
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}
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/* LZ4F_compressBound() :
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* Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
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* prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario.
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* Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
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* When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
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*/
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static size_t LZ4F_compressBound_internal(size_t srcSize, const LZ4F_preferences_t* preferencesPtr, size_t alreadyBuffered)
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{
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LZ4F_preferences_t prefsNull;
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memset(&prefsNull, 0, sizeof(prefsNull));
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prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* worst case */
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{ const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
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U32 const flush = prefsPtr->autoFlush | (srcSize==0);
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LZ4F_blockSizeID_t const bid = prefsPtr->frameInfo.blockSizeID;
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size_t const blockSize = LZ4F_getBlockSize(bid);
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size_t const maxBuffered = blockSize - 1;
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size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered);
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size_t const maxSrcSize = srcSize + bufferedSize;
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unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize);
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size_t const partialBlockSize = (srcSize - (srcSize==0)) & (blockSize-1); /* 0 => -1 == MAX => blockSize-1 */
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size_t const lastBlockSize = flush ? partialBlockSize : 0;
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unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
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size_t const blockHeaderSize = 4; /* default, without block CRC option (which cannot be generated with current API) */
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size_t const frameEnd = 4 + (prefsPtr->frameInfo.contentChecksumFlag*4);
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return (blockHeaderSize * nbBlocks) + (blockSize * nbFullBlocks) + lastBlockSize + frameEnd;;
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}
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}
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size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
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{
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LZ4F_preferences_t prefs;
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size_t const headerSize = maxFHSize; /* max header size, including magic number and frame content size */
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if (preferencesPtr!=NULL) prefs = *preferencesPtr;
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else memset(&prefs, 0, sizeof(prefs));
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prefs.autoFlush = 1;
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return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
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}
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/*! LZ4F_compressFrame() :
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* Compress an entire srcBuffer into a valid LZ4 frame, as defined by specification v1.5.0, in a single step.
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* The most important rule is that dstBuffer MUST be large enough (dstMaxSize) to ensure compression completion even in worst case.
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* You can get the minimum value of dstMaxSize by using LZ4F_compressFrameBound()
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* If this condition is not respected, LZ4F_compressFrame() will fail (result is an errorCode)
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* The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will then be set to default.
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* The result of the function is the number of bytes written into dstBuffer.
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* The function outputs an error code if it fails (can be tested using LZ4F_isError())
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*/
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size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
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{
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LZ4F_cctx_t cctxI;
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LZ4_stream_t lz4ctx;
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LZ4F_preferences_t prefs;
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LZ4F_compressOptions_t options;
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BYTE* const dstStart = (BYTE*) dstBuffer;
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BYTE* dstPtr = dstStart;
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BYTE* const dstEnd = dstStart + dstCapacity;
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memset(&cctxI, 0, sizeof(cctxI)); /* works because no allocation */
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memset(&options, 0, sizeof(options));
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cctxI.version = LZ4F_VERSION;
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cctxI.maxBufferSize = 5 MB; /* mess with real buffer size to prevent allocation; works because autoflush==1 & stableSrc==1 */
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if (preferencesPtr!=NULL)
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prefs = *preferencesPtr;
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else
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memset(&prefs, 0, sizeof(prefs));
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if (prefs.frameInfo.contentSize != 0)
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prefs.frameInfo.contentSize = (U64)srcSize; /* auto-correct content size if selected (!=0) */
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if (prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
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cctxI.lz4CtxPtr = &lz4ctx;
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cctxI.lz4CtxLevel = 1;
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}
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prefs.frameInfo.blockSizeID = LZ4F_optimalBSID(prefs.frameInfo.blockSizeID, srcSize);
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prefs.autoFlush = 1;
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if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID))
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prefs.frameInfo.blockMode = LZ4F_blockIndependent; /* no need for linked blocks */
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options.stableSrc = 1;
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if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs))
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return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
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{ size_t const headerSize = LZ4F_compressBegin(&cctxI, dstBuffer, dstCapacity, &prefs); /* write header */
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if (LZ4F_isError(headerSize)) return headerSize;
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dstPtr += headerSize; /* header size */ }
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{ size_t const cSize = LZ4F_compressUpdate(&cctxI, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options);
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if (LZ4F_isError(cSize)) return cSize;
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dstPtr += cSize; }
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{ size_t const tailSize = LZ4F_compressEnd(&cctxI, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */
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if (LZ4F_isError(tailSize)) return tailSize;
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dstPtr += tailSize; }
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if (prefs.compressionLevel >= LZ4HC_CLEVEL_MIN) /* no allocation done with lz4 fast */
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FREEMEM(cctxI.lz4CtxPtr);
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return (dstPtr - dstStart);
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}
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/*-*********************************
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* Advanced compression functions
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***********************************/
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/*! LZ4F_createCompressionContext() :
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* The first thing to do is to create a compressionContext object, which will be used in all compression operations.
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* This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
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* The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries.
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* The function will provide a pointer to an allocated LZ4F_compressionContext_t object.
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* If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation.
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* Object can release its memory using LZ4F_freeCompressionContext();
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*/
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LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_compressionContextPtr, unsigned version)
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{
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LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)ALLOCATOR(sizeof(LZ4F_cctx_t));
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if (cctxPtr==NULL) return err0r(LZ4F_ERROR_allocation_failed);
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cctxPtr->version = version;
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cctxPtr->cStage = 0; /* Next stage : write header */
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*LZ4F_compressionContextPtr = (LZ4F_compressionContext_t)cctxPtr;
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return LZ4F_OK_NoError;
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}
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LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_compressionContext)
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{
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LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)LZ4F_compressionContext;
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if (cctxPtr != NULL) { /* null pointers can be safely provided to this function, like free() */
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FREEMEM(cctxPtr->lz4CtxPtr);
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FREEMEM(cctxPtr->tmpBuff);
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FREEMEM(LZ4F_compressionContext);
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}
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return LZ4F_OK_NoError;
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}
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/*! LZ4F_compressBegin() :
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* will write the frame header into dstBuffer.
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* dstBuffer must be large enough to accommodate a header (dstCapacity). Maximum header size is LZ4F_HEADER_SIZE_MAX bytes.
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* @return : number of bytes written into dstBuffer for the header
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* or an error code (can be tested using LZ4F_isError())
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*/
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size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const LZ4F_preferences_t* preferencesPtr)
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{
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LZ4F_preferences_t prefNull;
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BYTE* const dstStart = (BYTE*)dstBuffer;
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BYTE* dstPtr = dstStart;
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BYTE* headerStart;
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size_t requiredBuffSize;
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if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
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if (cctxPtr->cStage != 0) return err0r(LZ4F_ERROR_GENERIC);
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memset(&prefNull, 0, sizeof(prefNull));
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if (preferencesPtr == NULL) preferencesPtr = &prefNull;
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cctxPtr->prefs = *preferencesPtr;
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/* ctx Management */
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{ U32 const tableID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2; /* 0:nothing ; 1:LZ4 table ; 2:HC tables */
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if (cctxPtr->lz4CtxLevel < tableID) {
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FREEMEM(cctxPtr->lz4CtxPtr);
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if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
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cctxPtr->lz4CtxPtr = (void*)LZ4_createStream();
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else
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cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC();
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cctxPtr->lz4CtxLevel = tableID;
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}
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}
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/* 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 == LZ4F_blockLinked) * 128 KB);
|
|
if (preferencesPtr->autoFlush)
|
|
requiredBuffSize = (cctxPtr->prefs.frameInfo.blockMode == LZ4F_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 err0r(LZ4F_ERROR_allocation_failed);
|
|
}
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff;
|
|
cctxPtr->tmpInSize = 0;
|
|
XXH32_reset(&(cctxPtr->xxh), 0);
|
|
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
|
|
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++ = (BYTE)(((1 & _2BITS) << 6) /* Version('01') */
|
|
+ ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5) /* Block mode */
|
|
+ ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2) /* Frame checksum */
|
|
+ ((cctxPtr->prefs.frameInfo.contentSize > 0) << 3)); /* Frame content size */
|
|
/* 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;
|
|
}
|
|
/* CRC Byte */
|
|
*dstPtr = LZ4F_headerChecksum(headerStart, dstPtr - headerStart);
|
|
dstPtr++;
|
|
|
|
cctxPtr->cStage = 1; /* header written, now request input data block */
|
|
|
|
return (dstPtr - dstStart);
|
|
}
|
|
|
|
|
|
/* LZ4F_compressBound() :
|
|
* @ return size of Dst buffer given a srcSize to handle worst case situations.
|
|
* The LZ4F_frameInfo_t structure is optional : if NULL, preferences will be set to cover worst case situations.
|
|
* This function cannot fail.
|
|
*/
|
|
size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
|
|
{
|
|
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);
|
|
|
|
static size_t LZ4F_compressBlock(void* dst, const void* src, size_t srcSize, compressFunc_t compress, void* lz4ctx, int level)
|
|
{
|
|
/* compress a single block */
|
|
BYTE* const cSizePtr = (BYTE*)dst;
|
|
U32 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 dstCapacity, int level)
|
|
{
|
|
(void) level;
|
|
return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, 1);
|
|
}
|
|
|
|
static int LZ4F_localLZ4_compress_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level)
|
|
{
|
|
(void) level;
|
|
return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, 1);
|
|
}
|
|
|
|
static int LZ4F_localLZ4_compressHC_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level)
|
|
{
|
|
(void) level;
|
|
return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstSize);
|
|
}
|
|
|
|
static compressFunc_t LZ4F_selectCompression(LZ4F_blockMode_t blockMode, int level)
|
|
{
|
|
if (level < LZ4HC_CLEVEL_MIN) {
|
|
if (blockMode == LZ4F_blockIndependent) return LZ4F_localLZ4_compress_limitedOutput_withState;
|
|
return LZ4F_localLZ4_compress_limitedOutput_continue;
|
|
}
|
|
if (blockMode == LZ4F_blockIndependent) return LZ4_compress_HC_extStateHC;
|
|
return LZ4F_localLZ4_compressHC_limitedOutput_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.
|
|
* The most important rule is that dstBuffer MUST be large enough (dstCapacity) 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 dstCapacity 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_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);
|
|
|
|
|
|
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);
|
|
memset(&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_compressBlock(dstPtr, cctxPtr->tmpIn, blockSize, compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
|
|
|
|
if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_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==LZ4F_blockLinked) && (lastBlockCompressed==fromSrcBuffer)) {
|
|
if (compressOptionsPtr->stableSrc) {
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff;
|
|
} else {
|
|
int 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 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 = srcEnd - srcPtr;
|
|
memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy);
|
|
cctxPtr->tmpInSize = sizeToCopy;
|
|
}
|
|
|
|
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled)
|
|
XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize);
|
|
|
|
cctxPtr->totalInSize += 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_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 + 4)) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); /* +4 : block header(4) */
|
|
(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==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 realDictSize = LZ4F_localSaveDict(cctxPtr);
|
|
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
|
|
}
|
|
|
|
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_cctx* cctxPtr, void* dstBuffer, size_t dstMaxSize, const LZ4F_compressOptions_t* compressOptionsPtr)
|
|
{
|
|
BYTE* const dstStart = (BYTE*)dstBuffer;
|
|
BYTE* dstPtr = dstStart;
|
|
|
|
size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstMaxSize, compressOptionsPtr);
|
|
if (LZ4F_isError(flushSize)) return flushSize;
|
|
dstPtr += flushSize;
|
|
|
|
LZ4F_writeLE32(dstPtr, 0);
|
|
dstPtr+=4; /* endMark */
|
|
|
|
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) {
|
|
U32 const xxh = XXH32_digest(&(cctxPtr->xxh));
|
|
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 dstPtr - dstStart;
|
|
}
|
|
|
|
|
|
/*-***************************************************
|
|
* Frame Decompression
|
|
*****************************************************/
|
|
|
|
struct LZ4F_dctx_s {
|
|
LZ4F_frameInfo_t frameInfo;
|
|
U32 version;
|
|
U32 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;
|
|
BYTE header[16];
|
|
}; /* 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 dctxPtr = (LZ4F_dctx*)ALLOCATOR(sizeof(LZ4F_dctx));
|
|
if (dctxPtr==NULL) return err0r(LZ4F_ERROR_GENERIC);
|
|
|
|
dctxPtr->version = versionNumber;
|
|
*LZ4F_decompressionContextPtr = dctxPtr;
|
|
return LZ4F_OK_NoError;
|
|
}
|
|
|
|
LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctxPtr)
|
|
{
|
|
LZ4F_errorCode_t result = LZ4F_OK_NoError;
|
|
if (dctxPtr != NULL) { /* can accept NULL input, like free() */
|
|
result = (LZ4F_errorCode_t)dctxPtr->dStage;
|
|
FREEMEM(dctxPtr->tmpIn);
|
|
FREEMEM(dctxPtr->tmpOutBuffer);
|
|
FREEMEM(dctxPtr);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
/*==--- Streaming Decompression operations ---==*/
|
|
|
|
typedef enum { dstage_getHeader=0, dstage_storeHeader,
|
|
dstage_getCBlockSize, dstage_storeCBlockSize,
|
|
dstage_copyDirect,
|
|
dstage_getCBlock, dstage_storeCBlock,
|
|
dstage_decodeCBlock, dstage_decodeCBlock_intoDst,
|
|
dstage_decodeCBlock_intoTmp, dstage_flushOut,
|
|
dstage_getSuffix, dstage_storeSuffix,
|
|
dstage_getSFrameSize, dstage_storeSFrameSize,
|
|
dstage_skipSkippable
|
|
} dStage_t;
|
|
|
|
|
|
/*! LZ4F_headerSize() :
|
|
* @return : size of frame header
|
|
* or an error code, which can be tested using LZ4F_isError()
|
|
*/
|
|
static size_t LZ4F_headerSize(const void* src, size_t srcSize)
|
|
{
|
|
/* minimal srcSize to determine header size */
|
|
if (srcSize < 5) return err0r(LZ4F_ERROR_frameHeader_incomplete);
|
|
|
|
/* special case : skippable frames */
|
|
if ((LZ4F_readLE32(src) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) return 8;
|
|
|
|
/* control magic number */
|
|
if (LZ4F_readLE32(src) != LZ4F_MAGICNUMBER) return err0r(LZ4F_ERROR_frameType_unknown);
|
|
|
|
/* Frame Header Size */
|
|
{ BYTE const FLG = ((const BYTE*)src)[4];
|
|
U32 const contentSizeFlag = (FLG>>3) & _1BIT;
|
|
return contentSizeFlag ? maxFHSize : minFHSize;
|
|
}
|
|
}
|
|
|
|
|
|
/*! LZ4F_decodeHeader() :
|
|
input : `src` points at the **beginning of the frame**
|
|
output : set internal values of dctx, such as
|
|
dctxPtr->frameInfo and dctxPtr->dStage.
|
|
Also allocates internal buffers.
|
|
@return : nb Bytes read from srcVoidPtr (necessarily <= srcSize)
|
|
or an error code (testable with LZ4F_isError())
|
|
*/
|
|
static size_t LZ4F_decodeHeader(LZ4F_dctx* dctxPtr, const void* src, size_t srcSize)
|
|
{
|
|
BYTE FLG, BD;
|
|
unsigned version, blockMode, blockChecksumFlag, contentSizeFlag, contentChecksumFlag, blockSizeID;
|
|
size_t frameHeaderSize;
|
|
const BYTE* srcPtr = (const BYTE*)src;
|
|
|
|
/* need to decode header to get frameInfo */
|
|
if (srcSize < minFHSize) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* minimal frame header size */
|
|
memset(&(dctxPtr->frameInfo), 0, sizeof(dctxPtr->frameInfo));
|
|
|
|
/* special case : skippable frames */
|
|
if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) {
|
|
dctxPtr->frameInfo.frameType = LZ4F_skippableFrame;
|
|
if (src == (void*)(dctxPtr->header)) {
|
|
dctxPtr->tmpInSize = srcSize;
|
|
dctxPtr->tmpInTarget = 8;
|
|
dctxPtr->dStage = dstage_storeSFrameSize;
|
|
return srcSize;
|
|
} else {
|
|
dctxPtr->dStage = dstage_getSFrameSize;
|
|
return 4;
|
|
}
|
|
}
|
|
|
|
/* control magic number */
|
|
if (LZ4F_readLE32(srcPtr) != LZ4F_MAGICNUMBER) return err0r(LZ4F_ERROR_frameType_unknown);
|
|
dctxPtr->frameInfo.frameType = LZ4F_frame;
|
|
|
|
/* Flags */
|
|
FLG = srcPtr[4];
|
|
version = (FLG>>6) & _2BITS;
|
|
blockMode = (FLG>>5) & _1BIT;
|
|
blockChecksumFlag = (FLG>>4) & _1BIT;
|
|
contentSizeFlag = (FLG>>3) & _1BIT;
|
|
contentChecksumFlag = (FLG>>2) & _1BIT;
|
|
|
|
/* Frame Header Size */
|
|
frameHeaderSize = contentSizeFlag ? maxFHSize : minFHSize;
|
|
|
|
if (srcSize < frameHeaderSize) {
|
|
/* not enough input to fully decode frame header */
|
|
if (srcPtr != dctxPtr->header)
|
|
memcpy(dctxPtr->header, srcPtr, srcSize);
|
|
dctxPtr->tmpInSize = srcSize;
|
|
dctxPtr->tmpInTarget = frameHeaderSize;
|
|
dctxPtr->dStage = dstage_storeHeader;
|
|
return srcSize;
|
|
}
|
|
|
|
BD = srcPtr[5];
|
|
blockSizeID = (BD>>4) & _3BITS;
|
|
|
|
/* validate */
|
|
if (version != 1) return err0r(LZ4F_ERROR_headerVersion_wrong); /* Version Number, only supported value */
|
|
if (blockChecksumFlag != 0) return err0r(LZ4F_ERROR_blockChecksum_unsupported); /* Not supported for the time being */
|
|
if (((FLG>>0)&_2BITS) != 0) return err0r(LZ4F_ERROR_reservedFlag_set); /* Reserved bits */
|
|
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 */
|
|
{ BYTE const HC = LZ4F_headerChecksum(srcPtr+4, frameHeaderSize-5);
|
|
if (HC != srcPtr[frameHeaderSize-1]) return err0r(LZ4F_ERROR_headerChecksum_invalid); }
|
|
|
|
/* save */
|
|
dctxPtr->frameInfo.blockMode = (LZ4F_blockMode_t)blockMode;
|
|
dctxPtr->frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)contentChecksumFlag;
|
|
dctxPtr->frameInfo.blockSizeID = (LZ4F_blockSizeID_t)blockSizeID;
|
|
dctxPtr->maxBlockSize = LZ4F_getBlockSize(blockSizeID);
|
|
if (contentSizeFlag)
|
|
dctxPtr->frameRemainingSize = dctxPtr->frameInfo.contentSize = LZ4F_readLE64(srcPtr+6);
|
|
|
|
/* init */
|
|
if (contentChecksumFlag) XXH32_reset(&(dctxPtr->xxh), 0);
|
|
|
|
/* internal buffers allocation */
|
|
{ size_t const bufferNeeded = dctxPtr->maxBlockSize + ((dctxPtr->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB);
|
|
if (bufferNeeded > dctxPtr->maxBufferSize) { /* tmp buffers too small */
|
|
FREEMEM(dctxPtr->tmpIn);
|
|
dctxPtr->tmpIn = (BYTE*)ALLOCATOR(dctxPtr->maxBlockSize);
|
|
if (dctxPtr->tmpIn == NULL) return err0r(LZ4F_ERROR_allocation_failed);
|
|
FREEMEM(dctxPtr->tmpOutBuffer);
|
|
dctxPtr->maxBufferSize = 0;
|
|
dctxPtr->tmpOutBuffer= (BYTE*)ALLOCATOR(bufferNeeded);
|
|
if (dctxPtr->tmpOutBuffer== NULL) return err0r(LZ4F_ERROR_allocation_failed);
|
|
dctxPtr->maxBufferSize = bufferNeeded;
|
|
} }
|
|
dctxPtr->tmpInSize = 0;
|
|
dctxPtr->tmpInTarget = 0;
|
|
dctxPtr->dict = dctxPtr->tmpOutBuffer;
|
|
dctxPtr->dictSize = 0;
|
|
dctxPtr->tmpOut = dctxPtr->tmpOutBuffer;
|
|
dctxPtr->tmpOutStart = 0;
|
|
dctxPtr->tmpOutSize = 0;
|
|
|
|
dctxPtr->dStage = dstage_getCBlockSize;
|
|
|
|
return frameHeaderSize;
|
|
}
|
|
|
|
|
|
/*! LZ4F_getFrameInfo() :
|
|
* Decodes frame header information, such as blockSize. Usage is optional.
|
|
* The objective is to extract header information before receiving decompressed data, typically for allocation purposes.
|
|
* LZ4F_getFrameInfo() can also be used *after* starting decompression, on a valid LZ4F_decompressionContext_t.
|
|
* The number of bytes consumed from srcBuffer will be provided within *srcSizePtr (necessarily <= original value).
|
|
* Decompression must resume from where it stopped (srcBuffer + *srcSizePtr)
|
|
* @return : 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_dctx* dctxPtr, LZ4F_frameInfo_t* frameInfoPtr,
|
|
const void* srcBuffer, size_t* srcSizePtr)
|
|
{
|
|
if (dctxPtr->dStage > dstage_storeHeader) { /* note : requires dstage_* header related to be at beginning of enum */
|
|
/* frameInfo already decoded */
|
|
size_t o=0, i=0;
|
|
*srcSizePtr = 0;
|
|
*frameInfoPtr = dctxPtr->frameInfo;
|
|
return LZ4F_decompress(dctxPtr, NULL, &o, NULL, &i, NULL); /* returns : recommended nb of bytes for LZ4F_decompress() */
|
|
} else {
|
|
size_t nextSrcSize, o=0;
|
|
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); }
|
|
|
|
*srcSizePtr = hSize;
|
|
nextSrcSize = LZ4F_decompress(dctxPtr, NULL, &o, srcBuffer, srcSizePtr, NULL);
|
|
if (dctxPtr->dStage <= dstage_storeHeader) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* should not happen, already checked */
|
|
*frameInfoPtr = dctxPtr->frameInfo;
|
|
return nextSrcSize;
|
|
}
|
|
}
|
|
|
|
|
|
/* trivial redirector, for common prototype */
|
|
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* dctxPtr, const BYTE* dstPtr, size_t dstSize, const BYTE* dstPtr0, unsigned withinTmp)
|
|
{
|
|
if (dctxPtr->dictSize==0)
|
|
dctxPtr->dict = (const 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 = (const 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 */
|
|
size_t const preserveSize = dctxPtr->tmpOut - dctxPtr->tmpOutBuffer;
|
|
size_t copySize = 64 KB - dctxPtr->tmpOutSize;
|
|
const BYTE* const 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;
|
|
}
|
|
|
|
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 const preserveSize = 64 KB - dstSize; /* note : dstSize < 64 KB */
|
|
memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - preserveSize, preserveSize);
|
|
dctxPtr->dictSize = preserveSize;
|
|
}
|
|
memcpy(dctxPtr->tmpOutBuffer + 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 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 the number of bytes read is < number of bytes provided, then the 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.
|
|
* 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, 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* dctxPtr,
|
|
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 + *dstSizePtr;
|
|
BYTE* dstPtr = dstStart;
|
|
const BYTE* selectedIn = NULL;
|
|
unsigned doAnotherStage = 1;
|
|
size_t nextSrcSizeHint = 1;
|
|
|
|
|
|
memset(&optionsNull, 0, sizeof(optionsNull));
|
|
if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull;
|
|
*srcSizePtr = 0;
|
|
*dstSizePtr = 0;
|
|
|
|
/* programmed as a state machine */
|
|
|
|
while (doAnotherStage) {
|
|
|
|
switch(dctxPtr->dStage)
|
|
{
|
|
|
|
case dstage_getHeader:
|
|
if ((size_t)(srcEnd-srcPtr) >= maxFHSize) { /* enough to decode - shortcut */
|
|
LZ4F_errorCode_t const hSize = LZ4F_decodeHeader(dctxPtr, srcPtr, srcEnd-srcPtr);
|
|
if (LZ4F_isError(hSize)) return hSize;
|
|
srcPtr += hSize;
|
|
break;
|
|
}
|
|
dctxPtr->tmpInSize = 0;
|
|
dctxPtr->tmpInTarget = minFHSize; /* minimum to attempt decode */
|
|
dctxPtr->dStage = dstage_storeHeader;
|
|
/* pass-through */
|
|
|
|
case dstage_storeHeader:
|
|
{ size_t sizeToCopy = dctxPtr->tmpInTarget - 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 < dctxPtr->tmpInTarget) {
|
|
nextSrcSizeHint = (dctxPtr->tmpInTarget - dctxPtr->tmpInSize) + BHSize; /* rest of header + nextBlockHeader */
|
|
doAnotherStage = 0; /* not enough src data, ask for some more */
|
|
break;
|
|
}
|
|
{ LZ4F_errorCode_t const hSize = LZ4F_decodeHeader(dctxPtr, dctxPtr->header, dctxPtr->tmpInTarget);
|
|
if (LZ4F_isError(hSize)) return hSize;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case dstage_getCBlockSize:
|
|
if ((size_t)(srcEnd - srcPtr) >= BHSize) {
|
|
selectedIn = srcPtr;
|
|
srcPtr += BHSize;
|
|
} else {
|
|
/* not enough input to read cBlockSize field */
|
|
dctxPtr->tmpInSize = 0;
|
|
dctxPtr->dStage = dstage_storeCBlockSize;
|
|
}
|
|
|
|
if (dctxPtr->dStage == dstage_storeCBlockSize) /* can be skipped */
|
|
case dstage_storeCBlockSize:
|
|
{ size_t sizeToCopy = BHSize - 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 < BHSize) { /* not enough input to get full cBlockSize; wait for more */
|
|
nextSrcSizeHint = BHSize - dctxPtr->tmpInSize;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
selectedIn = dctxPtr->tmpIn;
|
|
}
|
|
|
|
/* case dstage_decodeCBlockSize: */ /* no more direct access, to prevent scan-build warning */
|
|
{ size_t const nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU;
|
|
if (nextCBlockSize==0) { /* frameEnd signal, no more CBlock */
|
|
dctxPtr->dStage = dstage_getSuffix;
|
|
break;
|
|
}
|
|
if (nextCBlockSize > dctxPtr->maxBlockSize) return err0r(LZ4F_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 + BHSize;
|
|
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, sizeToCopy);
|
|
if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= sizeToCopy;
|
|
|
|
/* dictionary management */
|
|
if (dctxPtr->frameInfo.blockMode==LZ4F_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 + BHSize;
|
|
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) + BHSize;
|
|
doAnotherStage=0;
|
|
break;
|
|
}
|
|
selectedIn = dctxPtr->tmpIn;
|
|
dctxPtr->dStage = dstage_decodeCBlock;
|
|
/* pass-through */
|
|
}
|
|
|
|
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 == LZ4F_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 err0r(LZ4F_ERROR_GENERIC); /* decompression failed */
|
|
if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dstPtr, decodedSize);
|
|
if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= decodedSize;
|
|
|
|
/* dictionary management */
|
|
if (dctxPtr->frameInfo.blockMode==LZ4F_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 == LZ4F_blockLinked)
|
|
decoder = LZ4_decompress_safe_usingDict;
|
|
else
|
|
decoder = LZ4F_decompress_safe;
|
|
|
|
/* ensure enough place for tmpOut */
|
|
if (dctxPtr->frameInfo.blockMode == LZ4F_blockLinked) {
|
|
if (dctxPtr->dict == dctxPtr->tmpOutBuffer) {
|
|
if (dctxPtr->dictSize > 128 KB) {
|
|
memcpy(dctxPtr->tmpOutBuffer, dctxPtr->dict + dctxPtr->dictSize - 64 KB, 64 KB);
|
|
dctxPtr->dictSize = 64 KB;
|
|
}
|
|
dctxPtr->tmpOut = dctxPtr->tmpOutBuffer + 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 err0r(LZ4F_ERROR_decompressionFailed); /* decompression failed */
|
|
if (dctxPtr->frameInfo.contentChecksumFlag) XXH32_update(&(dctxPtr->xxh), dctxPtr->tmpOut, decodedSize);
|
|
if (dctxPtr->frameInfo.contentSize) dctxPtr->frameRemainingSize -= 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==LZ4F_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 = BHSize;
|
|
doAnotherStage = 0; /* still some data to flush */
|
|
break;
|
|
}
|
|
|
|
case dstage_getSuffix:
|
|
{ size_t const suffixSize = dctxPtr->frameInfo.contentChecksumFlag * 4;
|
|
if (dctxPtr->frameRemainingSize) return err0r(LZ4F_ERROR_frameSize_wrong); /* incorrect frame size decoded */
|
|
if (suffixSize == 0) { /* frame completed */
|
|
nextSrcSizeHint = 0;
|
|
dctxPtr->dStage = dstage_getHeader;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
if ((srcEnd - srcPtr) < 4) { /* not enough size for entire CRC */
|
|
dctxPtr->tmpInSize = 0;
|
|
dctxPtr->dStage = dstage_storeSuffix;
|
|
} else {
|
|
selectedIn = srcPtr;
|
|
srcPtr += 4;
|
|
}
|
|
}
|
|
|
|
if (dctxPtr->dStage == dstage_storeSuffix) /* can be skipped */
|
|
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;
|
|
}
|
|
|
|
/* case dstage_checkSuffix: */ /* no direct call, to avoid scan-build warning */
|
|
{ U32 const readCRC = LZ4F_readLE32(selectedIn);
|
|
U32 const resultCRC = XXH32_digest(&(dctxPtr->xxh));
|
|
if (readCRC != resultCRC) return err0r(LZ4F_ERROR_contentChecksum_invalid);
|
|
nextSrcSizeHint = 0;
|
|
dctxPtr->dStage = dstage_getHeader;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
|
|
case dstage_getSFrameSize:
|
|
if ((srcEnd - srcPtr) >= 4) {
|
|
selectedIn = srcPtr;
|
|
srcPtr += 4;
|
|
} else {
|
|
/* not enough input to read cBlockSize field */
|
|
dctxPtr->tmpInSize = 4;
|
|
dctxPtr->tmpInTarget = 8;
|
|
dctxPtr->dStage = dstage_storeSFrameSize;
|
|
}
|
|
|
|
if (dctxPtr->dStage == dstage_storeSFrameSize)
|
|
case dstage_storeSFrameSize:
|
|
{
|
|
size_t sizeToCopy = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
|
|
if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
|
|
memcpy(dctxPtr->header + dctxPtr->tmpInSize, srcPtr, sizeToCopy);
|
|
srcPtr += sizeToCopy;
|
|
dctxPtr->tmpInSize += sizeToCopy;
|
|
if (dctxPtr->tmpInSize < dctxPtr->tmpInTarget) { /* not enough input to get full sBlockSize; wait for more */
|
|
nextSrcSizeHint = dctxPtr->tmpInTarget - dctxPtr->tmpInSize;
|
|
doAnotherStage = 0;
|
|
break;
|
|
}
|
|
selectedIn = dctxPtr->header + 4;
|
|
}
|
|
|
|
/* case dstage_decodeSFrameSize: */ /* no direct access */
|
|
{ size_t const SFrameSize = LZ4F_readLE32(selectedIn);
|
|
dctxPtr->frameInfo.contentSize = SFrameSize;
|
|
dctxPtr->tmpInTarget = SFrameSize;
|
|
dctxPtr->dStage = dstage_skipSkippable;
|
|
break;
|
|
}
|
|
|
|
case dstage_skipSkippable:
|
|
{ size_t skipSize = dctxPtr->tmpInTarget;
|
|
if (skipSize > (size_t)(srcEnd-srcPtr)) skipSize = srcEnd-srcPtr;
|
|
srcPtr += skipSize;
|
|
dctxPtr->tmpInTarget -= skipSize;
|
|
doAnotherStage = 0;
|
|
nextSrcSizeHint = dctxPtr->tmpInTarget;
|
|
if (nextSrcSizeHint) break;
|
|
dctxPtr->dStage = dstage_getHeader;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* preserve dictionary within tmp if necessary */
|
|
if ( (dctxPtr->frameInfo.blockMode==LZ4F_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;
|
|
const 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;
|
|
const 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;
|
|
}
|
|
}
|
|
|
|
*srcSizePtr = (srcPtr - srcStart);
|
|
*dstSizePtr = (dstPtr - dstStart);
|
|
return nextSrcSizeHint;
|
|
}
|