/*
-* This API consists of small unitary functions, which highly benefit from being inlined.
+* This API consists of small unitary functions, which must be inlined for best performance.
* Since link-time-optimization is not available for all compilers,
* these functions are defined into a .h to be included.
*/
MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC);
MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC);
-/*Start by initCStream, providing the size of buffer to write into.
-* bitStream will never write outside of this buffer.
-* `dstCapacity` must be >= sizeof(size_t), otherwise @return will be an error code.
+/* Start with initCStream, providing the size of buffer to write into.
+* bitStream will never write outside of this buffer.
+* `dstCapacity` must be >= sizeof(size_t), otherwise @return will be an error code.
*
-* bits are first added to a local register.
-* Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
-* Writing data into memory is an explicit operation, performed by the flushBits function.
-* Hence keep track how many bits are potentially stored into local register to avoid register overflow.
-* After a flushBits, a maximum of 7 bits might still be stored into local register.
+* bits are first added to a local register.
+* Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
+* Writing data into memory is an explicit operation, performed by the flushBits function.
+* Hence keep track how many bits are potentially stored into local register to avoid register overflow.
+* After a flushBits, a maximum of 7 bits might still be stored into local register.
*
-* Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
+* Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
*
-* Last operation is to close the bitStream.
-* The function returns the final size of CStream in bytes.
-* If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
+* Last operation is to close the bitStream.
+* The function returns the final size of CStream in bytes.
+* If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
*/
MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
-/*Start by invoking BIT_initDStream().
-* A chunk of the bitStream is then stored into a local register.
-* Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
-* You can then retrieve bitFields stored into the local register, **in reverse order**.
-* Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
-* A reload guarantee a minimum of ((8*sizeof(size_t))-7) bits when its result is BIT_DStream_unfinished.
-* Otherwise, it can be less than that, so proceed accordingly.
-* Checking if DStream has reached its end can be performed with BIT_endOfDStream()
+/* Start by invoking BIT_initDStream().
+* A chunk of the bitStream is then stored into a local register.
+* Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
+* You can then retrieve bitFields stored into the local register, **in reverse order**.
+* Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
+* A reload guarantee a minimum of ((8*sizeof(size_t))-7) bits when its result is BIT_DStream_unfinished.
+* Otherwise, it can be less than that, so proceed accordingly.
+* Checking if DStream has reached its end can be performed with BIT_endOfDStream()
*/
/*-**************************************************************
* bitStream encoding
****************************************************************/
-MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* startPtr, size_t maxSize)
+/*! BIT_initCStream() :
+ * `dstCapacity` must be > sizeof(void*)
+ * @return : 0 if success,
+ otherwise an error code (can be tested using ERR_isError() ) */
+MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* startPtr, size_t dstCapacity)
{
bitC->bitContainer = 0;
bitC->bitPos = 0;
bitC->startPtr = (char*)startPtr;
bitC->ptr = bitC->startPtr;
- bitC->endPtr = bitC->startPtr + maxSize - sizeof(bitC->ptr);
- if (maxSize < sizeof(bitC->ptr)) return ERROR(dstSize_tooSmall);
+ bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->ptr);
+ if (dstCapacity <= sizeof(bitC->ptr)) return ERROR(dstSize_tooSmall);
return 0;
}
+/*! BIT_addBits() :
+ can add up to 26 bits into `bitC`.
+ Does not check for register overflow ! */
MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits)
{
static const unsigned mask[] = { 0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0x1FFFF, 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF, 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF }; /* up to 26 bits */
bitC->bitContainer >>= nbBytes*8; /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
}
+/*! BIT_flushBits() :
+ * safe version; check for buffer overflow, and prevents it.
+ * note : does not signal buffer overflow. This will be revealed later on using BIT_closeCStream() */
MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
{
size_t nbBytes = bitC->bitPos >> 3;
}
/*! BIT_closeCStream() :
- * @return : size of CStream, in bytes, or 0 if it cannot fit into dstBuffer */
+ * @return : size of CStream, in bytes,
+ or 0 if it could not fit into dstBuffer */
MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
{
- char* endPtr;
-
BIT_addBitsFast(bitC, 1, 1); /* endMark */
BIT_flushBits(bitC);
- if (bitC->ptr >= bitC->endPtr) /* too close to buffer's end */
- return 0; /* not storable */
-
- endPtr = bitC->ptr;
- endPtr += bitC->bitPos > 0; /* remaining bits (incomplete byte) */
+ if (bitC->ptr >= bitC->endPtr) return 0; /* doesn't fit within authorized budget : cancel */
- return (endPtr - bitC->startPtr);
+ return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
}
/*-********************************************************
* bitStream decoding
**********************************************************/
-/*!BIT_initDStream() :
-* Initialize a BIT_DStream_t.
-* `bitD` : a pointer to an already allocated BIT_DStream_t structure.
-* `srcBuffer` must point at the beginning of a bitStream.
-* `srcSize` must be the exact size of the bitStream.
-* @return : size of stream (== srcSize) or an errorCode if a problem is detected
+/*! BIT_initDStream() :
+* Initialize a BIT_DStream_t.
+* `bitD` : a pointer to an already allocated BIT_DStream_t structure.
+* `srcBuffer` must point at the beginning of a bitStream.
+* `srcSize` must be the exact size of the bitStream, in bytes.
+* @return : size of stream (== srcSize) or an errorCode if a problem is detected
*/
MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
{
return srcSize;
}
-/*!BIT_lookBits() :
- * Provides next n bits from local register.
- * local register is not modified (bits are still present for next read/look).
- * On 32-bits, maxNbBits==24.
- * On 64-bits, maxNbBits==56.
- * @return : value extracted
+/*! BIT_lookBits() :
+ * Provides next n bits from local register.
+ * local register is not modified (bits are still present for next read/look).
+ * On 32-bits, maxNbBits==24.
+ * On 64-bits, maxNbBits==56.
+ * @return : value extracted
*/
MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
{
return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
}
-/*! BIT_lookBitsFast*() :
+/*! BIT_lookBitsFast() :
* unsafe version; only works only if nbBits >= 1 */
MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
{
bitD->bitsConsumed += nbBits;
}
-/*!BIT_readBits() :
- * Read next n bits from local register.
- * pay attention to not read more than nbBits contained into local register.
- * @return : extracted value.
+/*! BIT_readBits() :
+ * Read next n bits from local register.
+ * pay attention to not read more than nbBits contained into local register.
+ * @return : extracted value.
*/
MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
{
return value;
}
-/*!BIT_readBitsFast() :
-* unsafe version; only works only if nbBits >= 1 */
+/*! BIT_readBitsFast() :
+* unsafe version; only works only if nbBits >= 1 */
MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
{
size_t value = BIT_lookBitsFast(bitD, nbBits);
return value;
}
+/*! BIT_reloadDStream() :
+* Refill `BIT_DStream_t` from src buffer previously defined (see BIT_initDStream() ).
+* This function is safe, it guarantees it will not read beyond src buffer.
+* @return : status of `BIT_DStream_t` internal register.
+ if status == unfinished, internal register is filled with >= (sizeof(size_t)*8 - 7) bits */
MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
{
if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8)) /* should never happen */
if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
return BIT_DStream_completed;
}
- {
- U32 nbBytes = bitD->bitsConsumed >> 3;
+ { U32 nbBytes = bitD->bitsConsumed >> 3;
BIT_DStream_status result = BIT_DStream_unfinished;
if (bitD->ptr - nbBytes < bitD->start) {
nbBytes = (U32)(bitD->ptr - bitD->start); /* ptr > start */
}
/*! BIT_endOfDStream() :
-* @return Tells if DStream has reached its exact end
+* @return Tells if DStream has exactly reached its end (all bits consumed).
*/
MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
{
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 : http://www.zstd.net
*/
/* ***************************************************************
#endif
-/*-*************************************
-* Local types
-***************************************/
-typedef struct
-{
- blockType_t blockType;
- U32 origSize;
-} blockProperties_t;
-
-
/*_*******************************************************
* Memory operations
**********************************************************/
/** ZSTD_decodeFrameHeader() :
* `srcSize` must be the size provided by ZSTD_frameHeaderSize().
-* @return : 0, or an error code, which can be tested using ZSTD_isError() */
+* @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* zc, const void* src, size_t srcSize)
{
size_t result = ZSTD_getFrameParams(&(zc->fParams), src, srcSize);
}
+typedef struct
+{
+ blockType_t blockType;
+ U32 origSize;
+} blockProperties_t;
+
+/*! ZSTD_getcBlockSize() :
+* Provides the size of compressed block from block header `src` */
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
{
const BYTE* const in = (const BYTE* const)src;
- BYTE headerFlags;
- U32 cSize;
+ size_t cSize;
- if (srcSize < 3)
- return ERROR(srcSize_wrong);
+ if (srcSize < ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
- headerFlags = *in;
+ bpPtr->blockType = (blockType_t)((*in) >> 6);
cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
-
- bpPtr->blockType = (blockType_t)(headerFlags >> 6);
bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
if (bpPtr->blockType == bt_end) return 0;
}
-static size_t ZSTD_copyRawBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
- if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
+ if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall);
memcpy(dst, src, srcSize);
return srcSize;
}
} seqState_t;
-
static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls)
{
const BYTE* dumps = seqState->dumps;
if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
/* MatchLength */
- {
- size_t matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
+ { size_t matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
if (matchLength == MaxML) {
const U32 add = *dumps++;
if (add < 255) matchLength += add;
match += oend_8 - op;
op = oend_8;
}
- while (op < oMatchEnd)
- *op++ = *match++;
+ while (op < oMatchEnd) *op++ = *match++;
} else {
ZSTD_wildcopy(op, match, sequence.matchLength-8); /* works even if matchLength < 8 */
}
}
/* last literal segment */
- {
- size_t lastLLSize = litEnd - litPtr;
+ { size_t const lastLLSize = litEnd - litPtr;
if (litPtr > litEnd) return ERROR(corruption_detected); /* too many literals already used */
if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
memcpy(op, litPtr, lastLLSize);
/*! ZSTD_decompress_continueDCtx() :
* `dctx` must have been properly initialized */
static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
- void* dst, size_t maxDstSize,
+ void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
const BYTE* ip = (const BYTE*)src;
const BYTE* iend = ip + srcSize;
BYTE* const ostart = (BYTE* const)dst;
BYTE* op = ostart;
- BYTE* const oend = ostart + maxDstSize;
+ BYTE* const oend = ostart + dstCapacity;
size_t remainingSize = srcSize;
blockProperties_t blockProperties;
- /* Frame Header */
- {
- size_t frameHeaderSize, errorCode;
- if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+ /* check */
+ if (srcSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
- {
- const U32 magicNumber = MEM_readLE32(src);
- if (ZSTD_isLegacy(magicNumber))
- return ZSTD_decompressLegacy(dst, maxDstSize, src, srcSize, magicNumber);
- }
+ { const U32 magicNumber = MEM_readLE32(src);
+ if (ZSTD_isLegacy(magicNumber))
+ return ZSTD_decompressLegacy(dst, dstCapacity, src, srcSize, magicNumber);
+ }
#endif
- frameHeaderSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_min);
+
+ /* Frame Header */
+ { size_t const frameHeaderSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_min);
if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
if (srcSize < frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
- errorCode = ZSTD_decodeFrameHeader(dctx, src, frameHeaderSize);
- if (ZSTD_isError(errorCode)) return errorCode;
+ if (ZSTD_decodeFrameHeader(dctx, src, frameHeaderSize)) return ERROR(corruption_detected);
ip += frameHeaderSize; remainingSize -= frameHeaderSize;
}
/* Loop on each block */
- while (1)
- {
+ while (1) {
size_t decodedSize=0;
size_t cBlockSize = ZSTD_getcBlockSize(ip, iend-ip, &blockProperties);
if (ZSTD_isError(cBlockSize)) return cBlockSize;
size_t ZSTD_decompress_usingPreparedDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* refDCtx,
- void* dst, size_t maxDstSize,
+ void* dst, size_t dstCapacity,
const void* src, size_t srcSize)
{
ZSTD_copyDCtx(dctx, refDCtx);
ZSTD_checkContinuity(dctx, dst);
- return ZSTD_decompressFrame(dctx, dst, maxDstSize, src, srcSize);
+ return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
}
size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
- void* dst, size_t maxDstSize,
+ void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const void* dict, size_t dictSize)
{
ZSTD_decompressBegin_usingDict(dctx, dict, dictSize);
ZSTD_LOG_BLOCK("%p: ZSTD_decompressBegin_usingDict searchLength=%d\n", dctx->base, dctx->params.searchLength);
ZSTD_checkContinuity(dctx, dst);
- return ZSTD_decompressFrame(dctx, dst, maxDstSize, src, srcSize);
+ return ZSTD_decompressFrame(dctx, dst, dstCapacity, src, srcSize);
}
-size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
- return ZSTD_decompress_usingDict(dctx, dst, maxDstSize, src, srcSize, NULL, 0);
+ return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0);
}
-size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
+size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE==1)
size_t regenSize;
ZSTD_DCtx* dctx = ZSTD_createDCtx();
if (dctx==NULL) return ERROR(memory_allocation);
- regenSize = ZSTD_decompressDCtx(dctx, dst, maxDstSize, src, srcSize);
+ regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
ZSTD_freeDCtx(dctx);
return regenSize;
#else
ZSTD_DCtx dctx;
- return ZSTD_decompressDCtx(&dctx, dst, maxDstSize, src, srcSize);
+ return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
#endif
}
projects / thirdparty / zstd.git / commitdiff
