lz4frame.c File Reference

#include <stdlib.h>
#include <string.h>
#include "lz4frame.h"
#include "lz4.h"
#include "lz4hc.h"
#include "xxhash.h"

Go to the source code of this file.

Classes
struct	LZ4F_cctx_s
struct	LZ4F_CDict_s
struct	LZ4F_dctx_s

Macros
#define	LZ4F_HEAPMODE   0
#define	ALLOC(s)   malloc(s)
#define	ALLOC_AND_ZERO(s)   calloc(1,(s))
#define	FREEMEM(p)   free(p)
#define	MEM_INIT(p, v, s)   memset((p),(v),(s))
#define	LZ4F_STATIC_LINKING_ONLY
#define	LZ4_STATIC_LINKING_ONLY
#define	LZ4_HC_STATIC_LINKING_ONLY
#define	XXH_STATIC_LINKING_ONLY
#define	assert(condition)   ((void)0)
#define	LZ4F_STATIC_ASSERT(c)   { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
#define	DEBUGLOG(l, ...)   {} /* disabled */
#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
#define	LZ4F_GENERATE_STRING(STRING)   #STRING,
#define	MIN(a, b)   ( (a) < (b) ? (a) : (b) )

Typedefs
typedef unsigned char	BYTE
typedef unsigned short	U16
typedef unsigned int	U32
typedef signed int	S32
typedef unsigned long long	U64
typedef struct LZ4F_cctx_s	LZ4F_cctx_t
typedef int(*	compressFunc_t) (void *ctx, const char *src, char *dst, int srcSize, int dstSize, int level, const LZ4F_CDict *cdict)

Enumerations
enum	LZ4F_lastBlockStatus { notDone , fromTmpBuffer , fromSrcBuffer }
enum	dStage_t {   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 }

Functions
static U32	LZ4F_readLE32 (const void *src)
static void	LZ4F_writeLE32 (void *dst, U32 value32)
static U64	LZ4F_readLE64 (const void *src)
static void	LZ4F_writeLE64 (void *dst, U64 value64)
unsigned	LZ4F_isError (LZ4F_errorCode_t code)
const char *	LZ4F_getErrorName (LZ4F_errorCode_t code)
LZ4F_errorCodes	LZ4F_getErrorCode (size_t functionResult)
static LZ4F_errorCode_t	err0r (LZ4F_errorCodes code)
unsigned	LZ4F_getVersion (void)
int	LZ4F_compressionLevel_max (void)
size_t	LZ4F_getBlockSize (unsigned blockSizeID)
static BYTE	LZ4F_headerChecksum (const void *header, size_t length)
static LZ4F_blockSizeID_t	LZ4F_optimalBSID (const LZ4F_blockSizeID_t requestedBSID, const size_t srcSize)
static size_t	LZ4F_compressBound_internal (size_t srcSize, const LZ4F_preferences_t *preferencesPtr, size_t alreadyBuffered)
size_t	LZ4F_compressFrameBound (size_t srcSize, const LZ4F_preferences_t *preferencesPtr)
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)
size_t	LZ4F_compressFrame (void *dstBuffer, size_t dstCapacity, const void *srcBuffer, size_t srcSize, const LZ4F_preferences_t *preferencesPtr)
LZ4F_CDict *	LZ4F_createCDict (const void *dictBuffer, size_t dictSize)
void	LZ4F_freeCDict (LZ4F_CDict *cdict)
LZ4F_errorCode_t	LZ4F_createCompressionContext (LZ4F_cctx **LZ4F_compressionContextPtr, unsigned version)
LZ4F_errorCode_t	LZ4F_freeCompressionContext (LZ4F_cctx *cctxPtr)
static void	LZ4F_initStream (void *ctx, const LZ4F_CDict *cdict, int level, LZ4F_blockMode_t blockMode)
size_t	LZ4F_compressBegin_usingCDict (LZ4F_cctx *cctxPtr, void *dstBuffer, size_t dstCapacity, const LZ4F_CDict *cdict, const LZ4F_preferences_t *preferencesPtr)
size_t	LZ4F_compressBegin (LZ4F_cctx *cctxPtr, void *dstBuffer, size_t dstCapacity, const LZ4F_preferences_t *preferencesPtr)
size_t	LZ4F_compressBound (size_t srcSize, const LZ4F_preferences_t *preferencesPtr)
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)
static int	LZ4F_compressBlock (void *ctx, const char *src, char *dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict *cdict)
static int	LZ4F_compressBlock_continue (void *ctx, const char *src, char *dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict *cdict)
static int	LZ4F_compressBlockHC (void *ctx, const char *src, char *dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict *cdict)
static int	LZ4F_compressBlockHC_continue (void *ctx, const char *src, char *dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict *cdict)
static compressFunc_t	LZ4F_selectCompression (LZ4F_blockMode_t blockMode, int level)
static int	LZ4F_localSaveDict (LZ4F_cctx_t *cctxPtr)
size_t	LZ4F_compressUpdate (LZ4F_cctx *cctxPtr, void *dstBuffer, size_t dstCapacity, const void *srcBuffer, size_t srcSize, const LZ4F_compressOptions_t *compressOptionsPtr)
size_t	LZ4F_flush (LZ4F_cctx *cctxPtr, void *dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t *compressOptionsPtr)
size_t	LZ4F_compressEnd (LZ4F_cctx *cctxPtr, void *dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t *compressOptionsPtr)
LZ4F_errorCode_t	LZ4F_createDecompressionContext (LZ4F_dctx **LZ4F_decompressionContextPtr, unsigned versionNumber)
LZ4F_errorCode_t	LZ4F_freeDecompressionContext (LZ4F_dctx *dctx)
void	LZ4F_resetDecompressionContext (LZ4F_dctx *dctx)
static size_t	LZ4F_decodeHeader (LZ4F_dctx *dctx, const void *src, size_t srcSize)
size_t	LZ4F_headerSize (const void *src, size_t srcSize)
LZ4F_errorCode_t	LZ4F_getFrameInfo (LZ4F_dctx *dctx, LZ4F_frameInfo_t *frameInfoPtr, const void *srcBuffer, size_t *srcSizePtr)
static void	LZ4F_updateDict (LZ4F_dctx *dctx, const BYTE *dstPtr, size_t dstSize, const BYTE *dstBufferStart, unsigned withinTmp)
size_t	LZ4F_decompress (LZ4F_dctx *dctx, void *dstBuffer, size_t *dstSizePtr, const void *srcBuffer, size_t *srcSizePtr, const LZ4F_decompressOptions_t *decompressOptionsPtr)
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)

Variables
static const size_t	minFHSize = LZ4F_HEADER_SIZE_MIN
static const size_t	maxFHSize = LZ4F_HEADER_SIZE_MAX
static const size_t	BHSize = LZ4F_BLOCK_HEADER_SIZE
static const size_t	BFSize = LZ4F_BLOCK_CHECKSUM_SIZE
static const char *	LZ4F_errorStrings [] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) }

Macro Definition Documentation

_1BIT

#define _1BIT   0x01

Definition at line 203 of file lz4frame.c.

_2BITS

#define _2BITS   0x03

Definition at line 204 of file lz4frame.c.

_3BITS

#define _3BITS   0x07

Definition at line 205 of file lz4frame.c.

_4BITS

#define _4BITS   0x0F

Definition at line 206 of file lz4frame.c.

_8BITS

#define _8BITS   0xFF

Definition at line 207 of file lz4frame.c.

ALLOC

#define ALLOC

(

s

)

malloc(s)

Definition at line 76 of file lz4frame.c.

ALLOC_AND_ZERO

#define ALLOC_AND_ZERO

(

s

)

calloc(1,(s))

Definition at line 77 of file lz4frame.c.

assert

#define assert

(

condition

)

((void)0)

Definition at line 107 of file lz4frame.c.

DEBUGLOG

#define DEBUGLOG	(		l,
			...
	)		{} /* disabled */

Definition at line 123 of file lz4frame.c.

FREEMEM

#define FREEMEM

(

p

)

free(p)

Definition at line 78 of file lz4frame.c.

LZ4_HC_STATIC_LINKING_ONLY

#define LZ4_HC_STATIC_LINKING_ONLY

Definition at line 94 of file lz4frame.c.

LZ4_STATIC_LINKING_ONLY

#define LZ4_STATIC_LINKING_ONLY

Definition at line 92 of file lz4frame.c.

LZ4F_BLOCKSIZEID_DEFAULT

#define LZ4F_BLOCKSIZEID_DEFAULT   LZ4F_max64KB

Definition at line 212 of file lz4frame.c.

LZ4F_BLOCKUNCOMPRESSED_FLAG

#define LZ4F_BLOCKUNCOMPRESSED_FLAG   0x80000000U

Definition at line 211 of file lz4frame.c.

LZ4F_GENERATE_STRING

#define LZ4F_GENERATE_STRING

(

STRING

)

#STRING,

Definition at line 245 of file lz4frame.c.

LZ4F_HEAPMODE

#define LZ4F_HEAPMODE   0

Definition at line 61 of file lz4frame.c.

LZ4F_MAGIC_SKIPPABLE_START

#define LZ4F_MAGIC_SKIPPABLE_START   0x184D2A50U

Definition at line 209 of file lz4frame.c.

LZ4F_MAGICNUMBER

#define LZ4F_MAGICNUMBER   0x184D2204U

Definition at line 210 of file lz4frame.c.

LZ4F_STATIC_ASSERT

#define LZ4F_STATIC_ASSERT

(

c

)

{ enum { LZ4F_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */

Definition at line 111 of file lz4frame.c.

LZ4F_STATIC_LINKING_ONLY

#define LZ4F_STATIC_LINKING_ONLY

Definition at line 90 of file lz4frame.c.

MEM_INIT

#define MEM_INIT	(		p,
			v,
			s
	)		memset((p),(v),(s))

Definition at line 83 of file lz4frame.c.

MIN

#define MIN	(		a,
			b
	)		( (a) < (b) ? (a) : (b) )

Definition at line 292 of file lz4frame.c.

XXH_STATIC_LINKING_ONLY

#define XXH_STATIC_LINKING_ONLY

Definition at line 96 of file lz4frame.c.

Typedef Documentation

BYTE

typedef unsigned char BYTE

Definition at line 138 of file lz4frame.c.

compressFunc_t

typedef int(* compressFunc_t) (void *ctx, const char *src, char *dst, int srcSize, int dstSize, int level, const LZ4F_CDict *cdict)

Definition at line 733 of file lz4frame.c.

LZ4F_cctx_t

typedef struct LZ4F_cctx_s LZ4F_cctx_t

S32

typedef signed int S32

Definition at line 141 of file lz4frame.c.

U16

typedef unsigned short U16

Definition at line 139 of file lz4frame.c.

U32

typedef unsigned int U32

Definition at line 140 of file lz4frame.c.

U64

typedef unsigned long long U64

Definition at line 142 of file lz4frame.c.

Enumeration Type Documentation

dStage_t

enum dStage_t

Enumerator
dstage_getFrameHeader
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

Definition at line 1029 of file lz4frame.c.

             {
    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;

LZ4F_lastBlockStatus

enum LZ4F_lastBlockStatus

Enumerator
notDone
fromTmpBuffer
fromSrcBuffer

Definition at line 816 of file lz4frame.c.

{ notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;

Function Documentation

err0r()

static LZ4F_errorCode_t err0r ( LZ4F_errorCodes  code )

static

Definition at line 267 of file lz4frame.c.

{
    /* 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;
}

References LZ4F_STATIC_ASSERT.

Referenced by LZ4F_compressBegin_usingCDict(), LZ4F_compressEnd(), LZ4F_compressFrame_usingCDict(), LZ4F_compressUpdate(), LZ4F_createCompressionContext(), LZ4F_createDecompressionContext(), LZ4F_decodeHeader(), LZ4F_decompress(), LZ4F_flush(), LZ4F_getBlockSize(), LZ4F_getFrameInfo(), and LZ4F_headerSize().

LZ4F_compressBegin()

size_t LZ4F_compressBegin	(	LZ4F_cctx *	cctxPtr,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_preferences_t *	preferencesPtr
	)

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.

Returns

: number of bytes written into dstBuffer for the header or an error code (can be tested using LZ4F_isError())

Definition at line 710 of file lz4frame.c.

{
    return LZ4F_compressBegin_usingCDict(cctxPtr, dstBuffer, dstCapacity,
                                         NULL, preferencesPtr);
}

References LZ4F_compressBegin_usingCDict(), and NULL.

Referenced by basicTests(), compress_file_internal(), and fuzzerTests().

LZ4F_compressBegin_usingCDict()

size_t LZ4F_compressBegin_usingCDict	(	LZ4F_cctx *	cctxPtr,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_CDict *	cdict,
		const LZ4F_preferences_t *	preferencesPtr
	)

LZ4F_compressBegin_usingCDict() : init streaming compression and writes frame header into dstBuffer. dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.

Returns

: number of bytes written into dstBuffer for the header or an error code (can be tested using LZ4F_isError())

Definition at line 598 of file lz4frame.c.

{
    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);
}

References _1BIT, _2BITS, _3BITS, ALLOC_AND_ZERO, LZ4F_preferences_t::autoFlush, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockMode, LZ4F_frameInfo_t::blockSizeID, LZ4F_cctx_s::cdict, LZ4F_preferences_t::compressionLevel, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_frameInfo_t::contentSize, LZ4F_cctx_s::cStage, LZ4F_frameInfo_t::dictID, err0r(), LZ4F_preferences_t::favorDecSpeed, LZ4F_preferences_t::frameInfo, FREEMEM, KB, LZ4_createStream(), LZ4_createStreamHC(), LZ4_favorDecompressionSpeed(), LZ4_initStream(), LZ4_initStreamHC(), LZ4_setCompressionLevel(), LZ4F_cctx_s::lz4CtxAlloc, LZ4F_cctx_s::lz4CtxPtr, LZ4F_cctx_s::lz4CtxState, LZ4F_blockLinked, LZ4F_BLOCKSIZEID_DEFAULT, LZ4F_getBlockSize(), LZ4F_headerChecksum(), LZ4F_initStream(), LZ4F_MAGICNUMBER, LZ4F_writeLE32(), LZ4F_writeLE64(), LZ4HC_CLEVEL_MIN, LZ4F_cctx_s::maxBlockSize, LZ4F_cctx_s::maxBufferSize, maxFHSize, MEM_INIT, NULL, LZ4F_cctx_s::prefs, LZ4F_cctx_s::tmpBuff, LZ4F_cctx_s::tmpIn, LZ4F_cctx_s::tmpInSize, LZ4F_cctx_s::totalInSize, unsigned, LZ4F_cctx_s::xxh, and XXH32_reset().

Referenced by LZ4F_compressBegin(), LZ4F_compressFrame_usingCDict(), and LZ4IO_compressFilename_extRess().

LZ4F_compressBlock()

static int LZ4F_compressBlock ( void *  ctx, const char *  src, char *  dst, int  srcSize, int  dstCapacity, int  level, const LZ4F_CDict *  cdict  )

static

Definition at line 766 of file lz4frame.c.

{
    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);
    }
}

References dst, level, LZ4_compress_fast_continue(), LZ4_compress_fast_extState_fastReset(), LZ4F_blockIndependent, LZ4F_initStream(), src, and srcSize.

Referenced by LZ4F_selectCompression().

LZ4F_compressBlock_continue()

static int LZ4F_compressBlock_continue ( void *  ctx, const char *  src, char *  dst, int  srcSize, int  dstCapacity, int  level, const LZ4F_CDict *  cdict  )

static

Definition at line 777 of file lz4frame.c.

{
    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);
}

References dst, level, LZ4_compress_fast_continue(), src, and srcSize.

Referenced by LZ4F_selectCompression().

LZ4F_compressBlockHC()

static int LZ4F_compressBlockHC ( void *  ctx, const char *  src, char *  dst, int  srcSize, int  dstCapacity, int  level, const LZ4F_CDict *  cdict  )

static

Definition at line 784 of file lz4frame.c.

{
    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);
}

References dst, level, LZ4_compress_HC_continue(), LZ4_compress_HC_extStateHC_fastReset(), LZ4F_blockIndependent, LZ4F_initStream(), src, and srcSize.

Referenced by LZ4F_selectCompression().

LZ4F_compressBlockHC_continue()

static int LZ4F_compressBlockHC_continue ( void *  ctx, const char *  src, char *  dst, int  srcSize, int  dstCapacity, int  level, const LZ4F_CDict *  cdict  )

static

Definition at line 793 of file lz4frame.c.

{
    (void)level; (void)cdict; /* init once at beginning of frame */
    return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
}

References dst, level, LZ4_compress_HC_continue(), src, and srcSize.

Referenced by LZ4F_selectCompression().

LZ4F_compressBound()

size_t LZ4F_compressBound	(	size_t	srcSize,
		const LZ4F_preferences_t *	prefsPtr
	)

LZ4F_compressBound() : Provides minimum dstCapacity required to guarantee success of LZ4F_compressUpdate(), given a srcSize and preferences, for a worst case scenario. When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() instead. Note that the result is only valid for a single invocation of LZ4F_compressUpdate(). When invoking LZ4F_compressUpdate() multiple times, if the output buffer is gradually filled up instead of emptied and re-used from its start, one must check if there is enough remaining capacity before each invocation, using LZ4F_compressBound().

Returns

is always the same for a srcSize and prefsPtr. prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario. tech details :

if automatic flushing is not enabled, includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes. It also includes frame footer (ending + checksum), since it might be generated by LZ4F_compressEnd().

doesn't include frame header, as it was already generated by LZ4F_compressBegin().

Definition at line 724 of file lz4frame.c.

{
    if (preferencesPtr && preferencesPtr->autoFlush) {
        return LZ4F_compressBound_internal(srcSize, preferencesPtr, 0);
    }
    return LZ4F_compressBound_internal(srcSize, preferencesPtr, (size_t)-1);
}

References LZ4F_preferences_t::autoFlush, LZ4F_compressBound_internal(), and srcSize.

Referenced by basicTests(), compress_file(), compress_file_internal(), and fuzzerTests().

LZ4F_compressBound_internal()

static size_t LZ4F_compressBound_internal ( size_t  srcSize, const LZ4F_preferences_t *  preferencesPtr, size_t  alreadyBuffered  )

static

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.

Returns

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.

Definition at line 324 of file lz4frame.c.

{
    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;
    }
}

References LZ4F_preferences_t::autoFlush, BFSize, BHSize, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockSizeID, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_preferences_t::frameInfo, LZ4F_blockChecksumEnabled, LZ4F_contentChecksumEnabled, LZ4F_getBlockSize(), LZ4F_INIT_PREFERENCES, MIN, NULL, srcSize, and unsigned.

Referenced by LZ4F_compressBound(), LZ4F_compressFrameBound(), and LZ4F_compressUpdate().

LZ4F_compressEnd()

size_t LZ4F_compressEnd	(	LZ4F_cctx *	cctxPtr,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_compressOptions_t *	compressOptionsPtr
	)

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.

Returns

: 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().

Definition at line 986 of file lz4frame.c.

{
    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);
}

References assert, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_frameInfo_t::contentSize, LZ4F_cctx_s::cStage, DEBUGLOG, err0r(), LZ4F_preferences_t::frameInfo, LZ4F_contentChecksumEnabled, LZ4F_flush(), LZ4F_isError(), LZ4F_writeLE32(), LZ4F_cctx_s::maxBufferSize, LZ4F_cctx_s::prefs, LZ4F_cctx_s::totalInSize, LZ4F_cctx_s::xxh, and XXH32_digest().

Referenced by basicTests(), compress_file_internal(), fuzzerTests(), LZ4F_compressFrame_usingCDict(), and LZ4IO_compressFilename_extRess().

LZ4F_compressFrame()

size_t LZ4F_compressFrame	(	void *	dstBuffer,
		size_t	dstCapacity,
		const void *	srcBuffer,
		size_t	srcSize,
		const LZ4F_preferences_t *	preferencesPtr
	)

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.

Returns

: number of bytes written into dstBuffer. or an error code if it fails (can be tested using LZ4F_isError())

Definition at line 429 of file lz4frame.c.

{
    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;
}

References LZ4F_preferences_t::compressionLevel, DEBUGLOG, FREEMEM, LZ4_initStream(), LZ4F_cctx_s::lz4CtxAlloc, LZ4F_cctx_s::lz4CtxPtr, LZ4F_cctx_s::lz4CtxState, LZ4F_compressFrame_usingCDict(), LZ4F_createCompressionContext(), LZ4F_freeCompressionContext(), LZ4F_isError(), LZ4F_VERSION, LZ4HC_CLEVEL_MIN, LZ4F_cctx_s::maxBufferSize, MB, MEM_INIT, NULL, srcSize, and LZ4F_cctx_s::version.

Referenced by basicTests(), fullSpeedBench(), fuzzerTests(), LLVMFuzzerTestOneInput(), and local_LZ4F_compressFrame().

LZ4F_compressFrame_usingCDict()

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_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.

Returns

: number of bytes written into dstBuffer, or an error code if it fails (can be tested using LZ4F_isError())

Definition at line 373 of file lz4frame.c.

{
    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);
}

References assert, LZ4F_preferences_t::autoFlush, LZ4F_frameInfo_t::blockMode, LZ4F_frameInfo_t::blockSizeID, LZ4F_frameInfo_t::contentSize, err0r(), LZ4F_preferences_t::frameInfo, LZ4F_blockIndependent, LZ4F_compressBegin_usingCDict(), LZ4F_compressEnd(), LZ4F_compressFrameBound(), LZ4F_compressUpdate(), LZ4F_getBlockSize(), LZ4F_isError(), LZ4F_optimalBSID(), MEM_INIT, NULL, options, and srcSize.

Referenced by basicTests(), LZ4F_compressFrame(), and LZ4IO_compressFilename_extRess().

LZ4F_compressFrameBound()

size_t LZ4F_compressFrameBound	(	size_t	srcSize,
		const LZ4F_preferences_t *	preferencesPtr
	)

LZ4F_compressFrameBound() : Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences. preferencesPtr is optional. It can be replaced by NULL, in which case, the function will assume default preferences. Note : this result is only usable with LZ4F_compressFrame(). It may also be used with LZ4F_compressUpdate() if no flush() operation is performed.

Definition at line 351 of file lz4frame.c.

{
    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);;
}

References LZ4F_preferences_t::autoFlush, LZ4F_compressBound_internal(), maxFHSize, MEM_INIT, NULL, and srcSize.

Referenced by basicTests(), fuzzerTests(), LLVMFuzzerTestOneInput(), local_LZ4F_compressFrame(), LZ4F_compressFrame_usingCDict(), and LZ4IO_createCResources().

LZ4F_compressionLevel_max()

int LZ4F_compressionLevel_max

(

void

)

Definition at line 276 of file lz4frame.c.

{ return LZ4HC_CLEVEL_MAX; }

References LZ4HC_CLEVEL_MAX.

Referenced by basicTests().

LZ4F_compressUpdate()

size_t LZ4F_compressUpdate	(	LZ4F_cctx *	cctxPtr,
		void *	dstBuffer,
		size_t	dstCapacity,
		const void *	srcBuffer,
		size_t	srcSize,
		const LZ4F_compressOptions_t *	compressOptionsPtr
	)

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.

Returns

: 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())

Definition at line 825 of file lz4frame.c.

{
    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);
}

References LZ4F_preferences_t::autoFlush, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockMode, LZ4F_cctx_s::cdict, compress(), LZ4F_preferences_t::compressionLevel, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_cctx_s::cStage, DEBUGLOG, err0r(), LZ4F_preferences_t::frameInfo, fromSrcBuffer, fromTmpBuffer, LZ4F_cctx_s::lz4CtxPtr, LZ4F_blockLinked, LZ4F_compressBound_internal(), LZ4F_contentChecksumEnabled, LZ4F_localSaveDict(), LZ4F_makeBlock(), LZ4F_selectCompression(), LZ4F_cctx_s::maxBlockSize, LZ4F_cctx_s::maxBufferSize, MEM_INIT, memcpy(), notDone, NULL, LZ4F_cctx_s::prefs, srcSize, LZ4F_compressOptions_t::stableSrc, LZ4F_cctx_s::tmpBuff, LZ4F_cctx_s::tmpIn, LZ4F_cctx_s::tmpInSize, LZ4F_cctx_s::totalInSize, LZ4F_cctx_s::xxh, and XXH32_update().

Referenced by basicTests(), compress_file_internal(), fuzzerTests(), LZ4F_compressFrame_usingCDict(), and LZ4IO_compressFilename_extRess().

LZ4F_createCDict()

LZ4F_CDict* LZ4F_createCDict	(	const void *	dictBuffer,
		size_t	dictSize
	)

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

Returns

: digested dictionary for compression, or NULL if failed

Definition at line 490 of file lz4frame.c.

{
    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;
}

References ALLOC, DEBUGLOG, KB, LZ4_createStream(), LZ4_createStreamHC(), LZ4_loadDict(), LZ4_loadDictHC(), LZ4_setCompressionLevel(), LZ4F_freeCDict(), LZ4HC_CLEVEL_DEFAULT, memcpy(), and NULL.

Referenced by basicTests(), and LZ4IO_createCDict().

LZ4F_createCompressionContext()

LZ4F_errorCode_t LZ4F_createCompressionContext	(	LZ4F_cctx **	LZ4F_compressionContextPtr,
		unsigned	version
	)

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();

Definition at line 536 of file lz4frame.c.

{
    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;
}

References ALLOC_AND_ZERO, LZ4F_cctx_s::cStage, err0r(), NULL, LZ4F_cctx_s::version, and version.

Referenced by basicTests(), compress_file(), fuzzerTests(), LZ4F_compressFrame(), and LZ4IO_createCResources().

LZ4F_createDecompressionContext()

LZ4F_errorCode_t LZ4F_createDecompressionContext	(	LZ4F_dctx **	LZ4F_decompressionContextPtr,
		unsigned	versionNumber
	)

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().

Returns

: if != 0, there was an error during context creation.

Definition at line 1069 of file lz4frame.c.

{
    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;
}

References ALLOC_AND_ZERO, err0r(), NULL, and LZ4F_dctx_s::version.

Referenced by basicTests(), createCResources(), decompress_file(), fullSpeedBench(), FUZZ_decompressFrame(), fuzzerTests(), LLVMFuzzerTestOneInput(), LZ4IO_createDResources(), and LZ4IO_getCompressedFileInfo().

LZ4F_decodeHeader()

static size_t LZ4F_decodeHeader ( LZ4F_dctx *  dctx, const void *  src, size_t  srcSize  )

static

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.

Returns

: nb Bytes read from src (necessarily <= srcSize) or an error code (testable with LZ4F_isError())

Definition at line 1113 of file lz4frame.c.

{
    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;
}

References _1BIT, _2BITS, _3BITS, _4BITS, assert, BD, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockMode, LZ4F_frameInfo_t::blockSizeID, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_frameInfo_t::contentSize, DEBUGLOG, LZ4F_frameInfo_t::dictID, LZ4F_dctx_s::dStage, dstage_getSFrameSize, dstage_init, dstage_storeFrameHeader, dstage_storeSFrameSize, err0r(), FLG, LZ4F_dctx_s::frameInfo, LZ4F_dctx_s::frameRemainingSize, LZ4F_frameInfo_t::frameType, LZ4F_dctx_s::header, LZ4F_frame, LZ4F_getBlockSize(), LZ4F_headerChecksum(), LZ4F_MAGIC_SKIPPABLE_START, LZ4F_MAGICNUMBER, LZ4F_readLE32(), LZ4F_readLE64(), LZ4F_skippableFrame, LZ4F_dctx_s::maxBlockSize, MEM_INIT, memcpy(), minFHSize, src, srcSize, LZ4F_dctx_s::tmpInSize, and LZ4F_dctx_s::tmpInTarget.

Referenced by LZ4F_decompress(), and LZ4F_getFrameInfo().

LZ4F_decompress()

size_t LZ4F_decompress	(	LZ4F_dctx *	dctx,
		void *	dstBuffer,
		size_t *	dstSizePtr,
		const void *	srcBuffer,
		size_t *	srcSizePtr,
		const LZ4F_decompressOptions_t *	decompressOptionsPtr
	)

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,

Returns

will be 0. If decompression failed,

is an error code which can be tested using LZ4F_isError().

Definition at line 1384 of file lz4frame.c.

{
    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;
}

References ALLOC, assert, BFSize, BHSize, LZ4F_dctx_s::blockChecksum, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockMode, LZ4F_frameInfo_t::contentChecksumFlag, LZ4F_frameInfo_t::contentSize, DEBUGLOG, LZ4F_dctx_s::dict, LZ4F_dctx_s::dictSize, LZ4F_dctx_s::dStage, dstage_copyDirect, dstage_flushOut, dstage_getBlockChecksum, dstage_getBlockHeader, dstage_getCBlock, dstage_getFrameHeader, dstage_getSFrameSize, dstage_getSuffix, dstage_init, dstage_skipSkippable, dstage_storeBlockHeader, dstage_storeCBlock, dstage_storeFrameHeader, dstage_storeSFrameSize, dstage_storeSuffix, err0r(), LZ4F_dctx_s::frameInfo, LZ4F_dctx_s::frameRemainingSize, FREEMEM, GB, LZ4F_dctx_s::header, if(), KB, LZ4_decompress_safe_usingDict(), LZ4F_blockLinked, LZ4F_BLOCKUNCOMPRESSED_FLAG, LZ4F_decodeHeader(), LZ4F_isError(), LZ4F_readLE32(), LZ4F_resetDecompressionContext(), LZ4F_STATIC_ASSERT, LZ4F_updateDict(), LZ4F_dctx_s::maxBlockSize, LZ4F_dctx_s::maxBufferSize, maxFHSize, MEM_INIT, memcpy(), MIN, minFHSize, NULL, LZ4F_decompressOptions_t::stableDst, LZ4F_dctx_s::tmpIn, LZ4F_dctx_s::tmpInSize, LZ4F_dctx_s::tmpInTarget, LZ4F_dctx_s::tmpOut, LZ4F_dctx_s::tmpOutBuffer, LZ4F_dctx_s::tmpOutSize, LZ4F_dctx_s::tmpOutStart, LZ4F_dctx_s::xxh, XXH32(), XXH32_digest(), XXH32_reset(), and XXH32_update().

Referenced by basicTests(), decompress(), decompress_file_internal(), frameCheck(), FUZZ_decompressFrame(), local_LZ4F_decompress(), local_LZ4F_decompress_followHint(), local_LZ4F_decompress_noHint(), LZ4F_decompress_usingDict(), LZ4F_getFrameInfo(), and test_lz4f_decompression_wBuffers().

LZ4F_decompress_usingDict()

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
	)

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.

Definition at line 1886 of file lz4frame.c.

{
    if (dctx->dStage <= dstage_init) {
        dctx->dict = (const BYTE*)dict;
        dctx->dictSize = dictSize;
    }
    return LZ4F_decompress(dctx, dstBuffer, dstSizePtr,
                           srcBuffer, srcSizePtr,
                           decompressOptionsPtr);
}

References LZ4F_dctx_s::dict, LZ4F_dctx_s::dictSize, LZ4F_dctx_s::dStage, dstage_init, and LZ4F_decompress().

Referenced by basicTests(), decompress(), and LZ4IO_decompressLZ4F().

LZ4F_flush()

size_t LZ4F_flush	(	LZ4F_cctx *	cctxPtr,
		void *	dstBuffer,
		size_t	dstCapacity,
		const LZ4F_compressOptions_t *	compressOptionsPtr
	)

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.

Definition at line 938 of file lz4frame.c.

{
    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);
}

References assert, BFSize, BHSize, LZ4F_frameInfo_t::blockChecksumFlag, LZ4F_frameInfo_t::blockMode, LZ4F_cctx_s::cdict, compress(), LZ4F_preferences_t::compressionLevel, LZ4F_cctx_s::cStage, err0r(), LZ4F_preferences_t::frameInfo, LZ4F_cctx_s::lz4CtxPtr, LZ4F_blockLinked, LZ4F_localSaveDict(), LZ4F_makeBlock(), LZ4F_selectCompression(), LZ4F_cctx_s::maxBlockSize, LZ4F_cctx_s::maxBufferSize, LZ4F_cctx_s::prefs, LZ4F_cctx_s::tmpBuff, LZ4F_cctx_s::tmpIn, and LZ4F_cctx_s::tmpInSize.

Referenced by fuzzerTests(), and LZ4F_compressEnd().

LZ4F_freeCDict()

void LZ4F_freeCDict

(

LZ4F_CDict *

cdict

)

Definition at line 514 of file lz4frame.c.

{
    if (cdict==NULL) return;  /* support free on NULL */
    FREEMEM(cdict->dictContent);
    LZ4_freeStream(cdict->fastCtx);
    LZ4_freeStreamHC(cdict->HCCtx);
    FREEMEM(cdict);
}

References FREEMEM, LZ4_freeStream(), LZ4_freeStreamHC(), and NULL.

Referenced by basicTests(), LZ4F_createCDict(), and LZ4IO_freeCResources().

LZ4F_freeCompressionContext()

LZ4F_errorCode_t LZ4F_freeCompressionContext

(

LZ4F_cctx *

cctxPtr

)

Definition at line 550 of file lz4frame.c.

{
    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;
}

References FREEMEM, LZ4F_cctx_s::lz4CtxPtr, NULL, and LZ4F_cctx_s::tmpBuff.

Referenced by basicTests(), compress_file(), fuzzerTests(), LZ4F_compressFrame(), and LZ4IO_freeCResources().

LZ4F_freeDecompressionContext()

LZ4F_errorCode_t LZ4F_freeDecompressionContext

(

LZ4F_dctx *

dctx

)

Definition at line 1082 of file lz4frame.c.

{
    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;
}

References LZ4F_dctx_s::dStage, FREEMEM, NULL, LZ4F_dctx_s::tmpIn, and LZ4F_dctx_s::tmpOutBuffer.

Referenced by basicTests(), decompress_file(), freeCResources(), fullSpeedBench(), FUZZ_decompressFrame(), fuzzerTests(), LLVMFuzzerTestOneInput(), LZ4IO_freeDResources(), and LZ4IO_getCompressedFileInfo().

LZ4F_getBlockSize()

size_t LZ4F_getBlockSize

(

unsigned

blockSizeID

)

Definition at line 278 of file lz4frame.c.

{
    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];
}

References err0r(), KB, LZ4F_BLOCKSIZEID_DEFAULT, LZ4F_max4MB, LZ4F_max64KB, and MB.

Referenced by basicTests(), LZ4F_compressBegin_usingCDict(), LZ4F_compressBound_internal(), LZ4F_compressFrame_usingCDict(), and LZ4F_decodeHeader().

LZ4F_getErrorCode()

LZ4F_errorCodes LZ4F_getErrorCode

(

size_t

functionResult

)

Definition at line 261 of file lz4frame.c.

{
    if (!LZ4F_isError(functionResult)) return LZ4F_OK_NoError;
    return (LZ4F_errorCodes)(-(ptrdiff_t)functionResult);
}

References LZ4F_isError().

Referenced by basicTests(), and test_lz4f_decompression_wBuffers().

LZ4F_getErrorName()

const char* LZ4F_getErrorName

(

LZ4F_errorCode_t

code

)

return error code string; for debugging

Definition at line 254 of file lz4frame.c.

{
    static const char* codeError = "Unspecified error code";
    if (LZ4F_isError(code)) return LZ4F_errorStrings[-(int)(code)];
    return codeError;
}

References int, LZ4F_errorStrings, and LZ4F_isError().

Referenced by basicTests(), decompress_file(), decompress_file_allocDst(), decompress_file_internal(), frameCheck(), fuzzerTests(), LZ4IO_compressFilename_extRess(), LZ4IO_createCResources(), LZ4IO_createDResources(), LZ4IO_decompressLZ4F(), LZ4IO_freeCResources(), and LZ4IO_freeDResources().

LZ4F_getFrameInfo()

LZ4F_errorCode_t LZ4F_getFrameInfo	(	LZ4F_dctx *	dctx,
		LZ4F_frameInfo_t *	frameInfoPtr,
		const void *	srcBuffer,
		size_t *	srcSizePtr
	)

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).

  Returns

  : 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.

Definition at line 1253 of file lz4frame.c.

{
    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;
    }   }   }
}

References BHSize, LZ4F_dctx_s::dStage, dstage_getFrameHeader, dstage_storeFrameHeader, err0r(), LZ4F_dctx_s::frameInfo, i, LZ4F_decodeHeader(), LZ4F_decompress(), LZ4F_headerSize(), LZ4F_isError(), LZ4F_STATIC_ASSERT, and NULL.

Referenced by basicTests(), decompress_file_allocDst(), frameCheck(), and LZ4IO_getCompressedFileInfo().

LZ4F_getVersion()

unsigned LZ4F_getVersion

(

void

)

Definition at line 274 of file lz4frame.c.

{ return LZ4F_VERSION; }

References LZ4F_VERSION.

LZ4F_headerChecksum()

static BYTE LZ4F_headerChecksum ( const void *  header, size_t  length  )

static

Definition at line 294 of file lz4frame.c.

{
    U32 const xxh = XXH32(header, length, 0);
    return (BYTE)(xxh >> 8);
}

References header, length, and XXH32().

Referenced by LZ4F_compressBegin_usingCDict(), and LZ4F_decodeHeader().

LZ4F_headerSize()

size_t LZ4F_headerSize	(	const void *	src,
		size_t	srcSize
	)

LZ4F_headerSize() :

Returns

: size of frame header or an error code, which can be tested using LZ4F_isError()

Definition at line 1212 of file lz4frame.c.

{
    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);
    }
}

References _1BIT, err0r(), FLG, LZ4F_MAGIC_SKIPPABLE_START, LZ4F_MAGICNUMBER, LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH, LZ4F_readLE32(), minFHSize, NULL, src, and srcSize.

Referenced by basicTests(), LZ4F_getFrameInfo(), and LZ4IO_getCompressedFileInfo().

LZ4F_initStream()

static void LZ4F_initStream ( void *  ctx, const LZ4F_CDict *  cdict, int  level, LZ4F_blockMode_t  blockMode  )

static

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).

Definition at line 570 of file lz4frame.c.

                                                        {
    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);
    }
}

References level, LZ4_attach_dictionary(), LZ4_attach_HC_dictionary(), LZ4_resetStream_fast(), LZ4_resetStreamHC_fast(), LZ4F_blockLinked, LZ4HC_CLEVEL_MIN, and NULL.

Referenced by LZ4F_compressBegin_usingCDict(), LZ4F_compressBlock(), and LZ4F_compressBlockHC().

LZ4F_isError()

unsigned LZ4F_isError

(

LZ4F_errorCode_t

code

)

tells when a function result is an error code

Definition at line 249 of file lz4frame.c.

{
    return (code > (LZ4F_errorCode_t)(-LZ4F_ERROR_maxCode));
}

Referenced by basicTests(), compress_file(), compress_file_internal(), createCResources(), decompress_file(), decompress_file_allocDst(), decompress_file_internal(), frameCheck(), fullSpeedBench(), FUZZ_decompressFrame(), fuzzerTests(), LLVMFuzzerTestOneInput(), local_LZ4F_decompress_followHint(), local_LZ4F_decompress_noHint(), LZ4F_compressEnd(), LZ4F_compressFrame(), LZ4F_compressFrame_usingCDict(), LZ4F_decompress(), LZ4F_getErrorCode(), LZ4F_getErrorName(), LZ4F_getFrameInfo(), LZ4IO_compressFilename_extRess(), LZ4IO_createCResources(), LZ4IO_createDResources(), LZ4IO_decompressLZ4F(), LZ4IO_freeCResources(), LZ4IO_freeDResources(), LZ4IO_getCompressedFileInfo(), and test_lz4f_decompression_wBuffers().

LZ4F_localSaveDict()

static int LZ4F_localSaveDict ( LZ4F_cctx_t *  cctxPtr )

static

Definition at line 809 of file lz4frame.c.

{
    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);
}

References LZ4F_preferences_t::compressionLevel, KB, LZ4_saveDict(), LZ4_saveDictHC(), LZ4F_cctx_s::lz4CtxPtr, LZ4HC_CLEVEL_MIN, LZ4F_cctx_s::prefs, and LZ4F_cctx_s::tmpBuff.

Referenced by LZ4F_compressUpdate(), and LZ4F_flush().

LZ4F_makeBlock()

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  )

static

LZ4F_makeBlock(): compress a single block, add header and optional checksum. assumption : dst buffer capacity is >= BHSize + srcSize + crcSize

Definition at line 740 of file lz4frame.c.

{
    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;
}

References BFSize, BHSize, compress(), crc32(), DEBUGLOG, dst, int, level, LZ4F_BLOCKUNCOMPRESSED_FLAG, LZ4F_writeLE32(), memcpy(), src, srcSize, and XXH32().

Referenced by LZ4F_compressUpdate(), and LZ4F_flush().

LZ4F_optimalBSID()

static LZ4F_blockSizeID_t LZ4F_optimalBSID ( const LZ4F_blockSizeID_t  requestedBSID, const size_t  srcSize  )

static

Definition at line 304 of file lz4frame.c.

{
    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;
}

References KB, LZ4F_max64KB, and srcSize.

Referenced by LZ4F_compressFrame_usingCDict().

LZ4F_readLE32()

static U32 LZ4F_readLE32 ( const void *  src )

static

Definition at line 147 of file lz4frame.c.

{
    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;
}

References src.

Referenced by LZ4F_decodeHeader(), LZ4F_decompress(), and LZ4F_headerSize().

LZ4F_readLE64()

static U64 LZ4F_readLE64 ( const void *  src )

static

Definition at line 166 of file lz4frame.c.

{
    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;
}

References src.

Referenced by LZ4F_decodeHeader().

LZ4F_resetDecompressionContext()

void LZ4F_resetDecompressionContext

(

LZ4F_dctx *

dctx

)

LZ4F_resetDecompressionContext() : added in v1.8.0 In case of an error, the context is left in "undefined" state. In which case, it's necessary to reset it, before re-using it. This method can also be used to abruptly stop any unfinished decompression, and start a new one using same context resources.

Definition at line 1097 of file lz4frame.c.

{
    dctx->dStage = dstage_getFrameHeader;
    dctx->dict = NULL;
    dctx->dictSize = 0;
}

References LZ4F_dctx_s::dict, LZ4F_dctx_s::dictSize, LZ4F_dctx_s::dStage, dstage_getFrameHeader, and NULL.

Referenced by basicTests(), decompress(), fuzzerTests(), and LZ4F_decompress().

LZ4F_selectCompression()

static compressFunc_t LZ4F_selectCompression ( LZ4F_blockMode_t  blockMode, int  level  )

static

Definition at line 799 of file lz4frame.c.

{
    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;
}

References level, LZ4F_blockIndependent, LZ4F_compressBlock(), LZ4F_compressBlock_continue(), LZ4F_compressBlockHC(), LZ4F_compressBlockHC_continue(), and LZ4HC_CLEVEL_MIN.

Referenced by LZ4F_compressUpdate(), and LZ4F_flush().

LZ4F_updateDict()

static void LZ4F_updateDict ( LZ4F_dctx *  dctx, const BYTE *  dstPtr, size_t  dstSize, const BYTE *  dstBufferStart, unsigned  withinTmp  )

static

Definition at line 1295 of file lz4frame.c.

{
    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;
    }
}

References assert, LZ4F_dctx_s::dict, LZ4F_dctx_s::dictSize, KB, LZ4F_dctx_s::maxBufferSize, memcpy(), NULL, LZ4F_dctx_s::tmpOut, LZ4F_dctx_s::tmpOutBuffer, LZ4F_dctx_s::tmpOutSize, and LZ4F_dctx_s::tmpOutStart.

Referenced by LZ4F_decompress().

LZ4F_writeLE32()

static void LZ4F_writeLE32 ( void *  dst, U32  value32  )

static

Definition at line 157 of file lz4frame.c.

{
    BYTE* const dstPtr = (BYTE*)dst;
    dstPtr[0] = (BYTE)value32;
    dstPtr[1] = (BYTE)(value32 >> 8);
    dstPtr[2] = (BYTE)(value32 >> 16);
    dstPtr[3] = (BYTE)(value32 >> 24);
}

References dst.

Referenced by LZ4F_compressBegin_usingCDict(), LZ4F_compressEnd(), and LZ4F_makeBlock().

LZ4F_writeLE64()

static void LZ4F_writeLE64 ( void *  dst, U64  value64  )

static

Definition at line 180 of file lz4frame.c.

{
    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);
}

References dst.

Referenced by LZ4F_compressBegin_usingCDict().

Variable Documentation

BFSize

const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE

static

Definition at line 217 of file lz4frame.c.

Referenced by LZ4F_compressBound_internal(), LZ4F_decompress(), LZ4F_flush(), and LZ4F_makeBlock().

BHSize

const size_t BHSize = LZ4F_BLOCK_HEADER_SIZE

static

Definition at line 216 of file lz4frame.c.

Referenced by LZ4F_compressBound_internal(), LZ4F_decompress(), LZ4F_flush(), LZ4F_getFrameInfo(), and LZ4F_makeBlock().

LZ4F_errorStrings

const char* LZ4F_errorStrings[] = { LZ4F_LIST_ERRORS(LZ4F_GENERATE_STRING) }

static

Definition at line 246 of file lz4frame.c.

Referenced by LZ4F_getErrorName().

maxFHSize

const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX

static

Definition at line 215 of file lz4frame.c.

Referenced by LZ4F_compressBegin_usingCDict(), LZ4F_compressFrameBound(), and LZ4F_decompress().

minFHSize

const size_t minFHSize = LZ4F_HEADER_SIZE_MIN

static

Definition at line 214 of file lz4frame.c.

Referenced by LZ4F_decodeHeader(), LZ4F_decompress(), and LZ4F_headerSize().