Compress-LZ4Frame
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CompressLZ4Frame.xs view on Meta::CPAN
MODULE = Compress::LZ4Frame PACKAGE = Compress::LZ4Frame
PROTOTYPES: ENABLE
SV *
compress(sv, level = 0)
SV * sv
int level
ALIAS:
compress_checksum = 1
PREINIT:
LZ4F_preferences_t prefs = { 0 };
char * src, * dest;
size_t src_len, dest_len;
CODE:
SvGETMAGIC(sv);
if (SvROK(sv) && !SvAMAGIC(sv)) {
sv = SvRV(sv);
SvGETMAGIC(sv);
}
if (!SvOK(sv))
XSRETURN_NO;
src = SvPVbyte(sv, src_len);
if (!src_len)
XSRETURN_NO;
prefs.frameInfo.contentChecksumFlag = (ix == 1 ? LZ4F_contentChecksumEnabled : LZ4F_noContentChecksum);
prefs.frameInfo.contentSize = (unsigned long long)src_len;
prefs.compressionLevel = level;
prefs.autoFlush = 1u;
dest_len = LZ4F_compressFrameBound(src_len, &prefs);
RETVAL = newSV(dest_len);
dest = SvPVX(RETVAL);
if (!dest) {
warn("Could not allocate enough memory (%zu Bytes)", dest_len);
SvREFCNT_dec(RETVAL);
XSRETURN_UNDEF;
}
dest_len = LZ4F_compressFrame(dest, dest_len, src, src_len, &prefs);
if (LZ4F_isError(dest_len)) {
warn("Error during compression: %s", LZ4F_getErrorName(dest_len));
SvREFCNT_dec(RETVAL);
XSRETURN_UNDEF;
}
SvCUR_set(RETVAL, dest_len);
SvPOK_on(RETVAL);
OUTPUT:
RETVAL
static const size_t minFHSize = 7;
static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 19 */
static const size_t BHSize = 4;
/*-************************************
* Structures and local types
**************************************/
typedef struct LZ4F_cctx_s
{
LZ4F_preferences_t prefs;
U32 version;
U32 cStage;
const LZ4F_CDict* cdict;
size_t maxBlockSize;
size_t maxBufferSize;
BYTE* tmpBuff;
BYTE* tmpIn;
size_t tmpInSize;
U64 totalInSize;
XXH32_state_t xxh;
if (srcSize <= maxBlockSize)
return proposedBSID;
proposedBSID = (LZ4F_blockSizeID_t)((int)proposedBSID + 1);
maxBlockSize <<= 2;
}
return requestedBSID;
}
/*! LZ4F_compressBound_internal() :
* Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
* prefsPtr is optional : if NULL is provided, preferences will be set to cover worst case scenario.
* @return is always the same for a srcSize and prefsPtr, so it can be relied upon to size reusable buffers.
* When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
*/
static size_t LZ4F_compressBound_internal(size_t srcSize,
const LZ4F_preferences_t* preferencesPtr,
size_t alreadyBuffered)
{
LZ4F_preferences_t prefsNull;
memset(&prefsNull, 0, sizeof(prefsNull));
prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* 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 blockHeaderSize = 4;
size_t const blockCRCSize = 4 * prefsPtr->frameInfo.blockChecksumFlag;
size_t const frameEnd = 4 + (prefsPtr->frameInfo.contentChecksumFlag*4);
return ((blockHeaderSize + blockCRCSize) * nbBlocks) +
(blockSize * nbFullBlocks) + lastBlockSize + frameEnd;
}
}
size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
{
LZ4F_preferences_t prefs;
size_t const headerSize = maxFHSize; /* max header size, including optional fields */
if (preferencesPtr!=NULL) prefs = *preferencesPtr;
else memset(&prefs, 0, sizeof(prefs));
prefs.autoFlush = 1;
return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
}
/*! LZ4F_compressFrame_usingCDict() :
* Compress srcBuffer using a dictionary, in a single step.
* cdict can be NULL, in which case, no dictionary is used.
* dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
* The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
* however, it's the only way to provide a dictID, so it's not recommended.
* @return : number of bytes written into dstBuffer,
* or an error code if it fails (can be tested using LZ4F_isError())
*/
size_t LZ4F_compressFrame_usingCDict(void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
const LZ4F_CDict* cdict,
const LZ4F_preferences_t* preferencesPtr)
{
LZ4F_cctx_t cctxI;
LZ4_stream_t lz4ctx; /* pretty large on stack */
LZ4F_preferences_t prefs;
LZ4F_compressOptions_t options;
BYTE* const dstStart = (BYTE*) dstBuffer;
BYTE* dstPtr = dstStart;
BYTE* const dstEnd = dstStart + dstCapacity;
memset(&cctxI, 0, sizeof(cctxI));
cctxI.version = LZ4F_VERSION;
cctxI.maxBufferSize = 5 MB; /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
if (preferencesPtr!=NULL)
prefs = *preferencesPtr;
else
memset(&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 */
if (prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
cctxI.lz4CtxPtr = &lz4ctx;
cctxI.lz4CtxLevel = 1;
} /* fast compression context pre-created on stack */
memset(&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(&cctxI, dstBuffer, dstCapacity, cdict, &prefs); /* write header */
if (LZ4F_isError(headerSize)) return headerSize;
dstPtr += headerSize; /* header size */ }
{ size_t const cSize = LZ4F_compressUpdate(&cctxI, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options);
if (LZ4F_isError(cSize)) return cSize;
dstPtr += cSize; }
{ size_t const tailSize = LZ4F_compressEnd(&cctxI, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */
if (LZ4F_isError(tailSize)) return tailSize;
dstPtr += tailSize; }
if (prefs.compressionLevel >= LZ4HC_CLEVEL_MIN) /* Ctx allocation only for lz4hc */
FREEMEM(cctxI.lz4CtxPtr);
return (dstPtr - dstStart);
}
/*! LZ4F_compressFrame() :
* Compress an entire srcBuffer into a valid LZ4 frame, in a single step.
* dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
* The LZ4F_preferences_t structure is optional : you can provide NULL as argument. All preferences will be set to default.
const LZ4F_preferences_t* preferencesPtr)
{
LZ4F_preferences_t prefNull;
BYTE* const dstStart = (BYTE*)dstBuffer;
BYTE* dstPtr = dstStart;
BYTE* headerStart;
if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
memset(&prefNull, 0, sizeof(prefNull));
if (preferencesPtr == NULL) preferencesPtr = &prefNull;
cctxPtr->prefs = *preferencesPtr;
/* Ctx Management */
{ U32 const ctxTypeID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2; /* 0:nothing ; 1:LZ4 table ; 2:HC tables */
if (cctxPtr->lz4CtxLevel < ctxTypeID) {
FREEMEM(cctxPtr->lz4CtxPtr);
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
cctxPtr->lz4CtxPtr = (void*)LZ4_createStream();
else
cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC();
if (cctxPtr->lz4CtxPtr == NULL) return err0r(LZ4F_ERROR_allocation_failed);
cctxPtr->lz4CtxLevel = 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 : /* only needs windows size */
cctxPtr->maxBlockSize + ((cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) * 128 KB);
if (cctxPtr->maxBufferSize < requiredBuffSize) {
cctxPtr->maxBufferSize = 0;
FREEMEM(cctxPtr->tmpBuff);
cctxPtr->tmpBuff = (BYTE*)ALLOCATOR(requiredBuffSize);
if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed);
cctxPtr->maxBufferSize = requiredBuffSize;
} }
cctxPtr->tmpIn = cctxPtr->tmpBuff;
cctxPtr->tmpInSize = 0;
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 */
if (cdict) {
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
memcpy(cctxPtr->lz4CtxPtr, cdict->fastCtx, sizeof(*cdict->fastCtx));
} else {
memcpy(cctxPtr->lz4CtxPtr, cdict->HCCtx, sizeof(*cdict->HCCtx));
LZ4_setCompressionLevel((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
}
} else {
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
LZ4_resetStream((LZ4_stream_t*)(cctxPtr->lz4CtxPtr));
else
LZ4_resetStreamHC((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), cctxPtr->prefs.compressionLevel);
}
}
/* Magic Number */
LZ4F_writeLE32(dstPtr, LZ4F_MAGICNUMBER);
dstPtr += 4;
headerStart = dstPtr;
/* FLG Byte */
*dstPtr++ = (BYTE)(((1 & _2BITS) << 6) /* Version('01') */
+ ((cctxPtr->prefs.frameInfo.blockMode & _1BIT ) << 5)
+ ((cctxPtr->prefs.frameInfo.blockChecksumFlag & _1BIT ) << 4)
+ ((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, dstPtr - headerStart);
dstPtr++;
cctxPtr->cStage = 1; /* header written, now request input data block */
return (dstPtr - dstStart);
}
if (level < LZ4HC_CLEVEL_MIN) {
if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlock;
return LZ4F_compressBlock_continue;
}
if (blockMode == LZ4F_blockIndependent) return LZ4F_compressBlockHC;
return LZ4F_compressBlockHC_continue;
}
static int LZ4F_localSaveDict(LZ4F_cctx_t* cctxPtr)
{
if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
return LZ4_saveDict ((LZ4_stream_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
return LZ4_saveDictHC ((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), (char*)(cctxPtr->tmpBuff), 64 KB);
}
typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;
/*! LZ4F_compressUpdate() :
* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
* dstBuffer MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
* LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
const void* srcBuffer, size_t srcSize,
const LZ4F_compressOptions_t* compressOptionsPtr)
{
LZ4F_compressOptions_t cOptionsNull;
size_t const blockSize = cctxPtr->maxBlockSize;
const BYTE* srcPtr = (const BYTE*)srcBuffer;
const BYTE* const srcEnd = srcPtr + srcSize;
BYTE* const dstStart = (BYTE*)dstBuffer;
BYTE* dstPtr = dstStart;
LZ4F_lastBlockStatus lastBlockCompressed = notDone;
compressFunc_t const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC);
if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize)) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
memset(&cOptionsNull, 0, sizeof(cOptionsNull));
if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull;
/* complete tmp buffer */
if (cctxPtr->tmpInSize > 0) { /* some data already within tmp buffer */
size_t const sizeToCopy = blockSize - cctxPtr->tmpInSize;
if (sizeToCopy > srcSize) {
/* add src to tmpIn buffer */
memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, srcSize);
srcPtr = srcEnd;
cctxPtr->tmpInSize += srcSize;
/* still needs some CRC */
} else {
/* complete tmpIn block and then compress it */
lastBlockCompressed = fromTmpBuffer;
memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy);
srcPtr += sizeToCopy;
dstPtr += LZ4F_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, 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 = srcEnd - srcPtr;
memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy);
cctxPtr->tmpInSize = sizeToCopy;
}
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled)
XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize);
cctxPtr->totalInSize += srcSize;
return dstPtr - dstStart;
}
/*! LZ4F_flush() :
* Should you need to create compressed data immediately, without waiting for a block to be filled,
* you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext.
BYTE* const dstStart = (BYTE*)dstBuffer;
BYTE* dstPtr = dstStart;
compressFunc_t compress;
if (cctxPtr->tmpInSize == 0) return 0; /* nothing to flush */
if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC);
if (dstCapacity < (cctxPtr->tmpInSize + 4)) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall); /* +4 : block header(4) */
(void)compressOptionsPtr; /* not yet useful */
/* select compression function */
compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
/* compress tmp buffer */
dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, cctxPtr->tmpInSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += cctxPtr->tmpInSize;
cctxPtr->tmpInSize = 0;
/* keep tmpIn within limits */
if ((cctxPtr->tmpIn + cctxPtr->maxBlockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize)) { /* necessarily LZ4F_blockLinked */
int realDictSize = LZ4F_localSaveDict(cctxPtr);
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
}
return dstPtr - dstStart;
}
BYTE* const dstStart = (BYTE*)dstBuffer;
BYTE* dstPtr = dstStart;
size_t const flushSize = LZ4F_flush(cctxPtr, dstBuffer, dstMaxSize, compressOptionsPtr);
if (LZ4F_isError(flushSize)) return flushSize;
dstPtr += flushSize;
LZ4F_writeLE32(dstPtr, 0);
dstPtr+=4; /* endMark */
if (cctxPtr->prefs.frameInfo.contentChecksumFlag == LZ4F_contentChecksumEnabled) {
U32 const xxh = XXH32_digest(&(cctxPtr->xxh));
LZ4F_writeLE32(dstPtr, xxh);
dstPtr+=4; /* content Checksum */
}
cctxPtr->cStage = 0; /* state is now re-usable (with identical preferences) */
cctxPtr->maxBufferSize = 0; /* reuse HC context */
if (cctxPtr->prefs.frameInfo.contentSize) {
if (cctxPtr->prefs.frameInfo.contentSize != cctxPtr->totalInSize)
return err0r(LZ4F_ERROR_frameSize_wrong);
}
return dstPtr - dstStart;
}
/*-***************************************************
* Frame Decompression
*****************************************************/
LZ4FLIB_API LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
/*---- Compression ----*/
#define LZ4F_HEADER_SIZE_MAX 19
/*! LZ4F_compressBegin() :
* will write the frame header into dstBuffer.
* dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
* `prefsPtr` is optional : you can provide NULL as argument, all preferences will then be set to default.
* @return : number of bytes written into dstBuffer for the header
* or an error code (which can be tested using LZ4F_isError())
*/
LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_preferences_t* prefsPtr);
/*! LZ4F_compressBound() :
* Provides minimum dstCapacity for a given srcSize to guarantee operation success in worst case situations.
* prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario.
* Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
* When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
*/
LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
/*! LZ4F_compressUpdate() :
* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
* An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
* This value is provided by LZ4F_compressBound().
* If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
* LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
* `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
* @return : 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())
lz4frame_static.h view on Meta::CPAN
LZ4FLIB_STATIC_API size_t LZ4F_compressFrame_usingCDict(
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const LZ4F_CDict* cdict,
const LZ4F_preferences_t* preferencesPtr);
/*! LZ4F_compressBegin_usingCDict() :
* Inits streaming dictionary compression, and writes the frame header into dstBuffer.
* dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
* `prefsPtr` is optional : you may provide NULL as argument,
* however, it's the only way to provide dictID in the frame header.
* @return : number of bytes written into dstBuffer for the header,
* or an error code (which can be tested using LZ4F_isError()) */
LZ4FLIB_STATIC_API size_t LZ4F_compressBegin_usingCDict(
LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_CDict* cdict,
const LZ4F_preferences_t* prefsPtr);
/*! 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. */
LZ4FLIB_STATIC_API size_t LZ4F_decompress_usingDict(
LZ4F_dctx* dctxPtr,
void* dstBuffer, size_t* dstSizePtr,
const void* srcBuffer, size_t* srcSizePtr,
( run in 1.398 second using v1.01-cache-2.11-cpan-0bb4e1dffa6 )