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changed BLOCKSIZE into ZSTD_BLOCKSIZE_MAX

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This commit is contained in:
Yann Collet
2016-03-16 15:26:51 +01:00
parent 69afc716d3
commit 569b81adb1
7 changed files with 104 additions and 107 deletions
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lib/zbuff.c
+30 -29
View File
@@ -40,15 +40,16 @@
***************************************/
#include <stdlib.h>
#include "error_private.h"
#include "zstd_internal.h"
#include "zstd_internal.h" /* MIN, ZSTD_blockHeaderSize */
#include "zstd_static.h" /* ZSTD_BLOCKSIZE_MAX */
#include "zbuff_static.h"
/* *************************************
* Constants
***************************************/
static size_t ZBUFF_blockHeaderSize = 3;
static size_t ZBUFF_endFrameSize = 3;
static size_t const ZBUFF_endFrameSize = ZSTD_BLOCKHEADERSIZE;
/*_**************************************************
* Streaming compression
@@ -59,28 +60,28 @@ static size_t ZBUFF_endFrameSize = 3;
* ZBUFF_CCtx objects can be reused multiple times.
*
* Use ZBUFF_compressContinue() repetitively to consume your input.
* *srcSizePtr and *maxDstSizePtr can be any size.
* The function will report how many bytes were read or written by modifying *srcSizePtr and *maxDstSizePtr.
* *srcSizePtr and *dstCapacityPtr can be any size.
* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
* Note that it may not consume the entire input, in which case it's up to the caller to call again the function with remaining input.
* The content of dst will be overwritten (up to *maxDstSizePtr) at each function call, so save its content if it matters or change dst .
* The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
* or an error code, which can be tested using ZBUFF_isError().
*
* ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
* Note that it will not output more than *maxDstSizePtr.
* Note that it will not output more than *dstCapacityPtr.
* Therefore, some content might still be left into its internal buffer if dst buffer is too small.
* @return : nb of bytes still present into internal buffer (0 if it's empty)
* or an error code, which can be tested using ZBUFF_isError().
*
* ZBUFF_compressEnd() instructs to finish a frame.
* It will perform a flush and write frame epilogue.
* Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *maxDstSizePtr is too small.
* Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
* @return : nb of bytes still present into internal buffer (0 if it's empty)
* or an error code, which can be tested using ZBUFF_isError().
*
* Hint : recommended buffer sizes (not compulsory)
* input : 128 KB block size is the internal unit, it improves latency to use this value.
* output : ZSTD_compressBound(128 KB) + 3 + 3 : ensures it's always possible to write/flush/end a full block at best speed.
* input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
* output : ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize : ensures it's always possible to write/flush/end a full block at best speed.
* **************************************************/
typedef enum { ZBUFFcs_init, ZBUFFcs_load, ZBUFFcs_flush } ZBUFF_cStage;
@@ -137,7 +138,7 @@ size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc, const void* dict, size_t dic
zbc->inBuff = (char*)malloc(neededInBuffSize);
if (zbc->inBuff == NULL) return ERROR(memory_allocation);
}
zbc->blockSize = MIN(BLOCKSIZE, zbc->inBuffSize);
zbc->blockSize = MIN(ZSTD_BLOCKSIZE_MAX, zbc->inBuffSize);
if (zbc->outBuffSize < ZSTD_compressBound(zbc->blockSize)+1) {
zbc->outBuffSize = ZSTD_compressBound(zbc->blockSize)+1;
free(zbc->outBuff); /* should not be necessary */
@@ -178,7 +179,7 @@ static size_t ZBUFF_limitCopy(void* dst, size_t dstCapacity, const void* src, si
}
static size_t ZBUFF_compressContinue_generic(ZBUFF_CCtx* zbc,
void* dst, size_t* maxDstSizePtr,
void* dst, size_t* dstCapacityPtr,
const void* src, size_t* srcSizePtr,
int flush) /* aggregate : wait for full block before compressing */
{
@@ -188,7 +189,7 @@ static size_t ZBUFF_compressContinue_generic(ZBUFF_CCtx* zbc,
const char* const iend = istart + *srcSizePtr;
char* const ostart = (char*)dst;
char* op = ostart;
char* const oend = ostart + *maxDstSizePtr;
char* const oend = ostart + *dstCapacityPtr;
while (notDone) {
switch(zbc->stage)
@@ -248,7 +249,7 @@ static size_t ZBUFF_compressContinue_generic(ZBUFF_CCtx* zbc,
}
*srcSizePtr = ip - istart;
*maxDstSizePtr = op - ostart;
*dstCapacityPtr = op - ostart;
{
size_t hintInSize = zbc->inBuffTarget - zbc->inBuffPos;
if (hintInSize==0) hintInSize = zbc->blockSize;
@@ -257,30 +258,30 @@ static size_t ZBUFF_compressContinue_generic(ZBUFF_CCtx* zbc,
}
size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
void* dst, size_t* maxDstSizePtr,
void* dst, size_t* dstCapacityPtr,
const void* src, size_t* srcSizePtr)
{
return ZBUFF_compressContinue_generic(zbc, dst, maxDstSizePtr, src, srcSizePtr, 0);
return ZBUFF_compressContinue_generic(zbc, dst, dstCapacityPtr, src, srcSizePtr, 0);
}
/* *** Finalize *** */
size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* maxDstSizePtr)
size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
{
size_t srcSize = 0;
ZBUFF_compressContinue_generic(zbc, dst, maxDstSizePtr, &srcSize, &srcSize, 1); /* use a valid src address instead of NULL, as some sanitizer don't like it */
ZBUFF_compressContinue_generic(zbc, dst, dstCapacityPtr, &srcSize, &srcSize, 1); /* use a valid src address instead of NULL, as some sanitizer don't like it */
return zbc->outBuffContentSize - zbc->outBuffFlushedSize;
}
size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* maxDstSizePtr)
size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
{
BYTE* const ostart = (BYTE*)dst;
BYTE* op = ostart;
BYTE* const oend = ostart + *maxDstSizePtr;
size_t outSize = *maxDstSizePtr;
BYTE* const oend = ostart + *dstCapacityPtr;
size_t outSize = *dstCapacityPtr;
size_t epilogueSize, remaining;
ZBUFF_compressFlush(zbc, dst, &outSize); /* flush any remaining inBuff */
op += outSize;
@@ -291,7 +292,7 @@ size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* maxDstSizePtr)
remaining = ZBUFF_compressFlush(zbc, op, &outSize); /* attempt to flush epilogue into dst */
op += outSize;
if (!remaining) zbc->stage = ZBUFFcs_init; /* close only if nothing left to flush */
*maxDstSizePtr = op-ostart; /* tells how many bytes were written */
*dstCapacityPtr = op-ostart; /* tells how many bytes were written */
return remaining;
}
@@ -406,7 +407,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc,
} }
/* Frame header provides buffer sizes */
{ size_t const neededInSize = BLOCKSIZE; /* a block is never > BLOCKSIZE */
{ size_t const neededInSize = ZSTD_BLOCKSIZE_MAX; /* a block is never > ZSTD_BLOCKSIZE_MAX */
if (zbc->inBuffSize < neededInSize) {
free(zbc->inBuff);
zbc->inBuffSize = neededInSize;
@@ -476,7 +477,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc,
zbc->outStart += flushedSize;
if (flushedSize == toFlushSize) {
zbc->stage = ZBUFFds_read;
if (zbc->outStart + BLOCKSIZE > zbc->outBuffSize)
if (zbc->outStart + ZSTD_BLOCKSIZE_MAX > zbc->outBuffSize)
zbc->outStart = zbc->outEnd = 0;
break;
}
@@ -492,7 +493,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc,
*dstCapacityPtr = op-ostart;
{
size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zbc->zc);
if (nextSrcSizeHint > ZBUFF_blockHeaderSize) nextSrcSizeHint+= ZBUFF_blockHeaderSize; /* get following block header too */
if (nextSrcSizeHint > ZSTD_blockHeaderSize) nextSrcSizeHint+= ZSTD_blockHeaderSize; /* get following block header too */
nextSrcSizeHint -= zbc->inPos; /* already loaded*/
return nextSrcSizeHint;
}
@@ -506,7 +507,7 @@ size_t ZBUFF_decompressContinue(ZBUFF_DCtx* zbc,
unsigned ZBUFF_isError(size_t errorCode) { return ERR_isError(errorCode); }
const char* ZBUFF_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
size_t ZBUFF_recommendedCInSize(void) { return BLOCKSIZE; }
size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_compressBound(BLOCKSIZE) + ZBUFF_blockHeaderSize + ZBUFF_endFrameSize; }
size_t ZBUFF_recommendedDInSize(void) { return BLOCKSIZE + ZBUFF_blockHeaderSize /* block header size*/ ; }
size_t ZBUFF_recommendedDOutSize(void) { return BLOCKSIZE; }
size_t ZBUFF_recommendedCInSize(void) { return ZSTD_BLOCKSIZE_MAX; }
size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize; }
size_t ZBUFF_recommendedDInSize(void) { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize /* block header size*/ ; }
size_t ZBUFF_recommendedDOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }
lib/zdict.c
+4 -4
View File
@@ -587,7 +587,7 @@ typedef struct
{
ZSTD_CCtx* ref;
ZSTD_CCtx* zc;
void* workPlace; /* must be BLOCKSIZE allocated */
void* workPlace; /* must be ZSTD_BLOCKSIZE_MAX allocated */
} EStats_ress_t;
@@ -599,9 +599,9 @@ static void ZDICT_countEStats(EStats_ress_t esr,
const U32* u32Ptr;
seqStore_t seqStore;
if (srcSize > BLOCKSIZE) srcSize = BLOCKSIZE; /* protection vs large samples */
if (srcSize > ZSTD_BLOCKSIZE_MAX) srcSize = ZSTD_BLOCKSIZE_MAX; /* protection vs large samples */
ZSTD_copyCCtx(esr.zc, esr.ref);
ZSTD_compressBlock(esr.zc, esr.workPlace, BLOCKSIZE, src, srcSize);
ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_MAX, src, srcSize);
seqStore = ZSTD_copySeqStore(esr.zc);
/* count stats */
@@ -654,7 +654,7 @@ static size_t ZDICT_analyzeEntropy(void* dstBuffer, size_t maxDstSize,
for (u=0; u<=MaxLL; u++) litlengthCount[u]=1;
esr.ref = ZSTD_createCCtx();
esr.zc = ZSTD_createCCtx();
esr.workPlace = malloc(BLOCKSIZE);
esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX);
if (!esr.ref || !esr.zc || !esr.workPlace) {
eSize = ERROR(memory_allocation);
DISPLAYLEVEL(1, "Not enough memory");
lib/zstd_compress.c
+3 -3
View File
@@ -169,7 +169,7 @@ void ZSTD_validateParams(ZSTD_parameters* params)
size_t ZSTD_sizeofCCtx(ZSTD_parameters params) /* hidden interface, for paramagrill */
{ /* copy / pasted from ZSTD_resetCCtx_advanced */
const size_t blockSize = MIN(BLOCKSIZE, (size_t)1 << params.windowLog);
const size_t blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << params.windowLog);
const U32 contentLog = (params.strategy == ZSTD_fast) ? 1 : params.contentLog;
const U32 divider = (params.searchLength==3) ? 3 : 4;
const size_t maxNbSeq = blockSize / divider;
@@ -186,7 +186,7 @@ size_t ZSTD_sizeofCCtx(ZSTD_parameters params) /* hidden interface, for parama
static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
ZSTD_parameters params)
{ /* note : params considered validated here */
const size_t blockSize = MIN(BLOCKSIZE, (size_t)1 << params.windowLog);
const size_t blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << params.windowLog);
const U32 contentLog = (params.strategy == ZSTD_fast) ? 1 : params.contentLog;
const U32 divider = (params.searchLength==3) ? 3 : 4;
const size_t maxNbSeq = blockSize / divider;
@@ -2079,7 +2079,7 @@ size_t ZSTD_compressContinue (ZSTD_CCtx* zc,
size_t ZSTD_compressBlock(ZSTD_CCtx* zc, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
if (srcSize > BLOCKSIZE) return ERROR(srcSize_wrong);
if (srcSize > ZSTD_BLOCKSIZE_MAX) return ERROR(srcSize_wrong);
zc->params.searchLength = MINMATCH; /* force ZSTD_btopt to MINMATCH in block mode */
ZSTD_LOG_BLOCK("%p: ZSTD_compressBlock searchLength=%d\n", zc->base, zc->params.searchLength);
return ZSTD_compressContinue_internal(zc, dst, dstCapacity, src, srcSize, 0);
lib/zstd_decompress.c
+9 -9
View File
@@ -143,7 +143,7 @@ struct ZSTD_DCtx_s
const BYTE* litPtr;
size_t litBufSize;
size_t litSize;
BYTE litBuffer[BLOCKSIZE + WILDCOPY_OVERLENGTH];
BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
}; /* typedef'd to ZSTD_DCtx within "zstd_static.h" */
@@ -181,7 +181,7 @@ size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
{
memcpy(dstDCtx, srcDCtx,
sizeof(ZSTD_DCtx) - (BLOCKSIZE+WILDCOPY_OVERLENGTH + ZSTD_frameHeaderSize_max)); /* no need to copy workspace */
sizeof(ZSTD_DCtx) - (ZSTD_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH + ZSTD_frameHeaderSize_max)); /* no need to copy workspace */
}
@@ -411,7 +411,7 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
litCSize = ((istart[2] & 3) << 16) + (istart[3] << 8) + istart[4];
break;
}
if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
if (HUF_isError(singleStream ?
HUF_decompress1X2(dctx->litBuffer, litSize, istart+lhSize, litCSize) :
@@ -419,7 +419,7 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+8;
dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+8;
dctx->litSize = litSize;
return litCSize + lhSize;
}
@@ -442,7 +442,7 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
if (HUF_isError(errorCode)) return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+WILDCOPY_OVERLENGTH;
dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
return litCSize + lhSize;
}
@@ -468,7 +468,7 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
memcpy(dctx->litBuffer, istart+lhSize, litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+8;
dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+8;
dctx->litSize = litSize;
return lhSize+litSize;
}
@@ -495,10 +495,10 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2];
break;
}
if (litSize > BLOCKSIZE) return ERROR(corruption_detected);
if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
memset(dctx->litBuffer, istart[lhSize], litSize);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = BLOCKSIZE+WILDCOPY_OVERLENGTH;
dctx->litBufSize = ZSTD_BLOCKSIZE_MAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
return lhSize+1;
}
@@ -892,7 +892,7 @@ static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
const BYTE* ip = (const BYTE*)src;
size_t litCSize;
if (srcSize >= BLOCKSIZE) return ERROR(srcSize_wrong);
if (srcSize >= ZSTD_BLOCKSIZE_MAX) return ERROR(srcSize_wrong);
ZSTD_LOG_BLOCK("%p: ZSTD_decompressBlock_internal searchLength=%d\n", dctx->base, dctx->params.searchLength);
lib/zstd_internal.h
+3 -4
View File
@@ -27,7 +27,7 @@
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
You can contact the author at :
- zstd source repository : https://github.com/Cyan4973/zstd
- zstd homepage : https://www.zstd.net
*/
#ifndef ZSTD_CCOMMON_H_MODULE
#define ZSTD_CCOMMON_H_MODULE
@@ -71,9 +71,8 @@
#define MB *(1 <<20)
#define GB *(1U<<30)
#define BLOCKSIZE (128 KB) /* define, for static allocation */
static const size_t ZSTD_blockHeaderSize = 3;
#define ZSTD_BLOCKHEADERSIZE 3 /* because C standard does not allow a static const value to be defined using another static const value .... :( */
static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
#define BIT7 128
#define BIT6 64
lib/zstd_static.h
+16 -15
View File
@@ -93,8 +93,8 @@ ZSTDLIB_API unsigned ZSTD_maxCLevel (void);
/*! ZSTD_getParams() :
* @return ZSTD_parameters structure for a selected compression level and srcSize.
* `srcSizeHint` value is optional, select 0 if not known */
ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, U64 srcSizeHint);
* `srcSize` value is optional, select 0 if not known */
ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, U64 srcSize);
/*! ZSTD_validateParams() :
* correct params value to remain within authorized range */
@@ -112,7 +112,7 @@ ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
* Same as ZSTD_compress_usingDict, but using a reference context `preparedCCtx`, where dictionary has been loaded.
* It avoids reloading the dictionary each time.
* `preparedCCtx` must have been properly initialized using ZSTD_compressBegin_usingDict() or ZSTD_compressBegin_advanced().
* Requires 2 contexts : 1 for reference, which will not be modified, and 1 to run the compression operation */
* Requires 2 contexts : 1 for reference (preparedCCtx) which will not be modified, and 1 to run the compression operation (cctx) */
ZSTDLIB_API size_t ZSTD_compress_usingPreparedCCtx(
ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx,
void* dst, size_t dstCapacity,
@@ -124,19 +124,19 @@ ZSTDLIB_API size_t ZSTD_compress_usingPreparedCCtx(
* Same as ZSTD_decompress_usingDict, but using a reference context `preparedDCtx`, where dictionary has been loaded.
* It avoids reloading the dictionary each time.
* `preparedDCtx` must have been properly initialized using ZSTD_decompressBegin_usingDict().
* Requires 2 contexts : 1 for reference, which will not be modified, and 1 to run the decompression operation */
* Requires 2 contexts : 1 for reference (preparedDCtx), which will not be modified, and 1 to run the decompression operation (dctx) */
ZSTDLIB_API size_t ZSTD_decompress_usingPreparedDCtx(
ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize);
ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize);
/* **************************************
* Streaming functions (direct mode)
****************************************/
ZSTDLIB_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict,size_t dictSize, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict,size_t dictSize, ZSTD_parameters params);
ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params);
ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx);
ZSTDLIB_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
@@ -187,11 +187,11 @@ ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t ds
A ZSTD_DCtx object can be re-used multiple times.
First optional operation is to retrieve frame parameters, using ZSTD_getFrameParams().
It can provide the minimum size of buffer required to properly decompress data,
It can provide the minimum size of rolling buffer required to properly decompress data,
and optionally the final size of uncompressed content.
(Note : content size is an optional info that may not be present. 0 means : content size unknown)
It is done by reading a certain amount of the beginning of compressed frame.
The amount of data to read is variable, from ZSTD_frameHeaderSize_min to ZSTD_frameHeaderSize_max.
Frame parameters are extracted from the beginning of compressed frame.
The amount of data to read is variable, from ZSTD_frameHeaderSize_min to ZSTD_frameHeaderSize_max (so if `srcSize` >= ZSTD_frameHeaderSize_max, it will always work)
If `srcSize` is too small for operation to succeed, function will return the minimum size it requires to produce a result.
Result : 0 when successful, it means the ZSTD_frameParams structure has been filled.
>0 : means there is not enough data into `src`. Provides the expected size to successfully decode header.
@@ -206,7 +206,7 @@ ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t ds
ZSTD_decompressContinue() needs previous data blocks during decompression, up to (1 << windowlog).
They should preferably be located contiguously, prior to current block. Alternatively, a round buffer is also possible.
@result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst'.
@result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity)
It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
@@ -218,10 +218,10 @@ ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t ds
* Block functions
****************************************/
/*! Block functions produce and decode raw zstd blocks, without frame metadata.
User will have to take in charge required information to regenerate data, such as block sizes.
User will have to take in charge required information to regenerate data, such as compressed and content sizes.
A few rules to respect :
- Uncompressed block size must be <= 128 KB
- Uncompressed block size must be <= ZSTD_BLOCKSIZE_MAX (128 KB)
- Compressing or decompressing requires a context structure
+ Use ZSTD_createCCtx() and ZSTD_createDCtx()
- It is necessary to init context before starting
@@ -235,6 +235,7 @@ ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t ds
+ ZSTD_decompressBlock() doesn't accept uncompressed data as input !!
*/
#define ZSTD_BLOCKSIZE_MAX (128 * 1024) /* define, for static allocation */
size_t ZSTD_compressBlock (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);