summaryrefslogtreecommitdiffstats
path: root/lib/lz4frame.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/lz4frame.c')
-rw-r--r--lib/lz4frame.c114
1 files changed, 67 insertions, 47 deletions
diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 3f81ef0..2164470 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -74,7 +74,6 @@ You can contact the author at :
#endif
-
/*-************************************
* Includes
**************************************/
@@ -139,8 +138,8 @@ static U32 LZ4F_readLE32 (const void* src)
{
const BYTE* const srcPtr = (const BYTE*)src;
U32 value32 = srcPtr[0];
- value32 += (srcPtr[1]<<8);
- value32 += (srcPtr[2]<<16);
+ value32 += ((U32)srcPtr[1])<< 8;
+ value32 += ((U32)srcPtr[2])<<16;
value32 += ((U32)srcPtr[3])<<24;
return value32;
}
@@ -204,7 +203,8 @@ static void LZ4F_writeLE64 (void* dst, U64 value64)
static const size_t minFHSize = 7;
static const size_t maxFHSize = LZ4F_HEADER_SIZE_MAX; /* 19 */
-static const size_t BHSize = 4;
+static const size_t BHSize = 4; /* block header : size, and compress flag */
+static const size_t BFSize = 4; /* block footer : checksum (optional) */
/*-************************************
@@ -329,11 +329,10 @@ static size_t LZ4F_compressBound_internal(size_t srcSize,
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);
+ size_t const blockCRCSize = BFSize * prefsPtr->frameInfo.blockChecksumFlag;
+ size_t const frameEnd = BHSize + (prefsPtr->frameInfo.contentChecksumFlag*BFSize);
- return ((blockHeaderSize + blockCRCSize) * nbBlocks) +
+ return ((BHSize + blockCRCSize) * nbBlocks) +
(blockSize * nbFullBlocks) + lastBlockSize + frameEnd;
}
}
@@ -394,15 +393,18 @@ size_t LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx,
if (LZ4F_isError(headerSize)) return headerSize;
dstPtr += headerSize; /* header size */ }
- { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options);
+ 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; }
- { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */
+ 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; }
- return (dstPtr - dstStart);
+ assert(dstEnd >= dstStart);
+ return (size_t)(dstPtr - dstStart);
}
@@ -662,7 +664,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
*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)
+ + ((unsigned)(cctxPtr->prefs.frameInfo.contentSize > 0) << 3)
+ ((cctxPtr->prefs.frameInfo.contentChecksumFlag & _1BIT ) << 2)
+ (cctxPtr->prefs.frameInfo.dictID > 0) );
/* BD Byte */
@@ -679,11 +681,11 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
dstPtr += 4;
}
/* Header CRC Byte */
- *dstPtr = LZ4F_headerChecksum(headerStart, dstPtr - headerStart);
+ *dstPtr = LZ4F_headerChecksum(headerStart, (size_t)(dstPtr - headerStart));
dstPtr++;
cctxPtr->cStage = 1; /* header written, now request input data block */
- return (dstPtr - dstStart);
+ return (size_t)(dstPtr - dstStart);
}
@@ -718,27 +720,31 @@ typedef int (*compressFunc_t)(void* ctx, const char* src, char* dst, int srcSize
/*! LZ4F_makeBlock():
- * compress a single block, add header and checksum
- * assumption : dst buffer capacity is >= srcSize */
-static size_t LZ4F_makeBlock(void* dst, const void* src, size_t srcSize,
+ * compress a single block, add header and optional checksum.
+ * assumption : dst buffer capacity is >= BHSize + srcSize + crcSize
+ */
+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)
+ const LZ4F_CDict* cdict,
+ LZ4F_blockChecksum_t crcFlag)
{
BYTE* const cSizePtr = (BYTE*)dst;
- U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+4),
+ U32 cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize),
(int)(srcSize), (int)(srcSize-1),
level, cdict);
- LZ4F_writeLE32(cSizePtr, cSize);
if (cSize == 0) { /* compression failed */
cSize = (U32)srcSize;
LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG);
- memcpy(cSizePtr+4, src, srcSize);
+ memcpy(cSizePtr+BHSize, src, srcSize);
+ } else {
+ LZ4F_writeLE32(cSizePtr, cSize);
}
if (crcFlag) {
- U32 const crc32 = XXH32(cSizePtr+4, cSize, 0); /* checksum of compressed data */
- LZ4F_writeLE32(cSizePtr+4+cSize, crc32);
+ U32 const crc32 = XXH32(cSizePtr+BHSize, cSize, 0); /* checksum of compressed data */
+ LZ4F_writeLE32(cSizePtr+BHSize+cSize, crc32);
}
- return 4 + cSize + ((U32)crcFlag)*4;
+ return BHSize + cSize + ((U32)crcFlag)*BFSize;
}
@@ -838,9 +844,11 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
memcpy(cctxPtr->tmpIn + cctxPtr->tmpInSize, srcBuffer, sizeToCopy);
srcPtr += sizeToCopy;
- dstPtr += LZ4F_makeBlock(dstPtr, cctxPtr->tmpIn, blockSize,
+ dstPtr += LZ4F_makeBlock(dstPtr,
+ cctxPtr->tmpIn, blockSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
- cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
+ cctxPtr->cdict,
+ cctxPtr->prefs.frameInfo.blockChecksumFlag);
if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize;
cctxPtr->tmpInSize = 0;
@@ -850,18 +858,22 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
while ((size_t)(srcEnd - srcPtr) >= blockSize) {
/* compress full blocks */
lastBlockCompressed = fromSrcBuffer;
- dstPtr += LZ4F_makeBlock(dstPtr, srcPtr, blockSize,
+ dstPtr += LZ4F_makeBlock(dstPtr,
+ srcPtr, blockSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
- cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
+ 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,
+ dstPtr += LZ4F_makeBlock(dstPtr,
+ srcPtr, (size_t)(srcEnd - srcPtr),
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
- cctxPtr->cdict, cctxPtr->prefs.frameInfo.blockChecksumFlag);
+ cctxPtr->cdict,
+ cctxPtr->prefs.frameInfo.blockChecksumFlag);
srcPtr = srcEnd;
}
@@ -887,7 +899,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
/* some input data left, necessarily < blockSize */
if (srcPtr < srcEnd) {
/* fill tmp buffer */
- size_t const sizeToCopy = srcEnd - srcPtr;
+ size_t const sizeToCopy = (size_t)(srcEnd - srcPtr);
memcpy(cctxPtr->tmpIn, srcPtr, sizeToCopy);
cctxPtr->tmpInSize = sizeToCopy;
}
@@ -896,19 +908,21 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
(void)XXH32_update(&(cctxPtr->xxh), srcBuffer, srcSize);
cctxPtr->totalInSize += srcSize;
- return dstPtr - dstStart;
+ return (size_t)(dstPtr - dstStart);
}
/*! LZ4F_flush() :
- * Should you need to create compressed data immediately, without waiting for a block to be filled,
- * you can call LZ4_flush(), which will immediately compress any remaining data stored within compressionContext.
- * The result of the function is the number of bytes written into dstBuffer
- * (it can be zero, this means there was no data left within compressionContext)
+ * 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())
- * The LZ4F_compressOptions_t structure is optional : you can provide NULL as argument.
+ * LZ4F_compressOptions_t* is optional. NULL is a valid argument.
*/
-size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* compressOptionsPtr)
+size_t LZ4F_flush(LZ4F_cctx* cctxPtr,
+ void* dstBuffer, size_t dstCapacity,
+ const LZ4F_compressOptions_t* compressOptionsPtr)
{
BYTE* const dstStart = (BYTE*)dstBuffer;
BYTE* dstPtr = dstStart;
@@ -916,26 +930,32 @@ size_t LZ4F_flush(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapacity, const
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) */
+ 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,
+ 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->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 realDictSize = LZ4F_localSaveDict(cctxPtr);
+ int const realDictSize = LZ4F_localSaveDict(cctxPtr);
cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize;
}
- return dstPtr - dstStart;
+ return (size_t)(dstPtr - dstStart);
}
@@ -981,7 +1001,7 @@ size_t LZ4F_compressEnd(LZ4F_cctx* cctxPtr,
return err0r(LZ4F_ERROR_frameSize_wrong);
}
- return dstPtr - dstStart;
+ return (size_t)(dstPtr - dstStart);
}
@@ -1433,7 +1453,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
/* decode block header */
{ size_t const nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU;
- size_t const crcSize = dctx->frameInfo.blockChecksumFlag * 4;
+ size_t const crcSize = dctx->frameInfo.blockChecksumFlag * BFSize;
if (nextCBlockSize==0) { /* frameEnd signal, no more block */
dctx->dStage = dstage_getSuffix;
break;
@@ -1453,7 +1473,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
dctx->tmpInTarget = nextCBlockSize + crcSize;
dctx->dStage = dstage_getCBlock;
if (dstPtr==dstEnd) {
- nextSrcSizeHint = nextCBlockSize + crcSize + BHSize;
+ nextSrcSizeHint = BHSize + nextCBlockSize + crcSize;
doAnotherStage = 0;
}
break;
generated by cgit v0.12 at 2024-07-18 03:42:41 (GMT)