summaryrefslogtreecommitdiffstats
path: root/lib/lz4frame.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/lz4frame.c')
-rw-r--r--lib/lz4frame.c121
1 files changed, 102 insertions, 19 deletions
diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index a0275ca..80e244b 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -220,6 +220,9 @@ static const size_t BFSize = LZ4F_BLOCK_CHECKSUM_SIZE; /* block footer : checks
/*-************************************
* Structures and local types
**************************************/
+
+typedef enum { LZ4B_COMPRESSED, LZ4B_UNCOMPRESSED} LZ4F_blockCompression_t;
+
typedef struct LZ4F_cctx_s
{
LZ4F_preferences_t prefs;
@@ -236,6 +239,7 @@ typedef struct LZ4F_cctx_s
void* lz4CtxPtr;
U16 lz4CtxAlloc; /* sized for: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
U16 lz4CtxState; /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
+ LZ4F_blockCompression_t blockCompression;
} LZ4F_cctx_t;
@@ -757,14 +761,27 @@ 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)
+ LZ4F_blockChecksum_t crcFlag,
+ LZ4F_blockCompression_t blockCompression)
{
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);
+ U32 cSize;
+ if (compress != NULL) {
+ cSize = (U32)compress(lz4ctx, (const char*)src, (char*)(cSizePtr+BHSize),
+ (int)(srcSize), (int)(srcSize-1),
+ level, cdict);
+ } else {
+ cSize = (U32)srcSize;
+ /* force no compression if compress callback is null */
+ blockCompression = LZ4B_UNCOMPRESSED;
+ }
+
+ if (cSize == 0) { /* compression failed */
+ DEBUGLOG(5, "LZ4F_makeBlock: compression failed, creating a raw block (size %u)", (U32)srcSize);
+ blockCompression = LZ4B_UNCOMPRESSED;
+ }
+
+ if (blockCompression == LZ4B_UNCOMPRESSED) {
cSize = (U32)srcSize;
LZ4F_writeLE32(cSizePtr, cSize | LZ4F_BLOCKUNCOMPRESSED_FLAG);
memcpy(cSizePtr+BHSize, src, srcSize);
@@ -836,21 +853,25 @@ typedef enum { notDone, fromTmpBuffer, fromSrcBuffer } LZ4F_lastBlockStatus;
static const LZ4F_compressOptions_t k_cOptionsNull = { 0, { 0, 0, 0 } };
-/*! LZ4F_compressUpdate() :
+
+ /*! LZ4F_compressUpdateImpl() :
* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
* When successful, the function always entirely consumes @srcBuffer.
* src data is either buffered or compressed into @dstBuffer.
- * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ * If the block compression does not match the compression of the previous block, the old data is flushed
+ * and operations continue with the new compression mode.
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr) when block compression is turned on.
* @compressOptionsPtr is optional : provide NULL to mean "default".
* @return : 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())
* After an error, the state is left in a UB state, and must be re-initialized.
*/
-size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
- void* dstBuffer, size_t dstCapacity,
+static size_t LZ4F_compressUpdateImpl(LZ4F_cctx* cctxPtr,
+ void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
- const LZ4F_compressOptions_t* compressOptionsPtr)
-{
+ const LZ4F_compressOptions_t* compressOptionsPtr,
+ LZ4F_blockCompression_t blockCompression)
+ {
size_t const blockSize = cctxPtr->maxBlockSize;
const BYTE* srcPtr = (const BYTE*)srcBuffer;
const BYTE* const srcEnd = srcPtr + srcSize;
@@ -858,12 +879,23 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
BYTE* dstPtr = dstStart;
LZ4F_lastBlockStatus lastBlockCompressed = notDone;
compressFunc_t const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
-
+ size_t bytesWritten;
DEBUGLOG(4, "LZ4F_compressUpdate (srcSize=%zu)", srcSize);
RETURN_ERROR_IF(cctxPtr->cStage != 1, compressionState_uninitialized); /* state must be initialized and waiting for next block */
if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize))
RETURN_ERROR(dstMaxSize_tooSmall);
+
+ if (blockCompression == LZ4B_UNCOMPRESSED && dstCapacity < srcSize)
+ RETURN_ERROR(dstMaxSize_tooSmall);
+
+ /* flush currently written block, to continue with new block compression */
+ if (cctxPtr->blockCompression != blockCompression) {
+ bytesWritten = LZ4F_flush(cctxPtr, dstBuffer, dstCapacity, compressOptionsPtr);
+ dstPtr += bytesWritten;
+ cctxPtr->blockCompression = blockCompression;
+ }
+
if (compressOptionsPtr == NULL) compressOptionsPtr = &k_cOptionsNull;
/* complete tmp buffer */
@@ -886,8 +918,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
cctxPtr->tmpIn, blockSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
cctxPtr->cdict,
- cctxPtr->prefs.frameInfo.blockChecksumFlag);
-
+ cctxPtr->prefs.frameInfo.blockChecksumFlag, blockCompression);
if (cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) cctxPtr->tmpIn += blockSize;
cctxPtr->tmpInSize = 0;
} }
@@ -899,7 +930,8 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
srcPtr, blockSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
cctxPtr->cdict,
- cctxPtr->prefs.frameInfo.blockChecksumFlag);
+ cctxPtr->prefs.frameInfo.blockChecksumFlag,
+ blockCompression);
srcPtr += blockSize;
}
@@ -910,12 +942,15 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
srcPtr, (size_t)(srcEnd - srcPtr),
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
cctxPtr->cdict,
- cctxPtr->prefs.frameInfo.blockChecksumFlag);
- srcPtr = srcEnd;
+ cctxPtr->prefs.frameInfo.blockChecksumFlag,
+ blockCompression);
+ srcPtr = srcEnd;
}
/* preserve dictionary within @tmpBuff whenever necessary */
if ((cctxPtr->prefs.frameInfo.blockMode==LZ4F_blockLinked) && (lastBlockCompressed==fromSrcBuffer)) {
+ /* linked blocks are only supported in compressed mode, see LZ4F_uncompressedUpdate */
+ assert(blockCompression == LZ4B_COMPRESSED);
if (compressOptionsPtr->stableSrc) {
cctxPtr->tmpIn = cctxPtr->tmpBuff; /* src is stable : dictionary remains in src across invocations */
} else {
@@ -951,6 +986,53 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
return (size_t)(dstPtr - dstStart);
}
+/*! LZ4F_compressUpdate() :
+ * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ * When successful, the function always entirely consumes @srcBuffer.
+ * src data is either buffered or compressed into @dstBuffer.
+ * If previously an uncompressed block was written, buffered data is flushed
+ * before appending compressed data is continued.
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ * @compressOptionsPtr is optional : provide NULL to mean "default".
+ * @return : 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())
+ * After an error, the state is left in a UB state, and must be re-initialized.
+ */
+size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
+ void* dstBuffer, size_t dstCapacity,
+ const void* srcBuffer, size_t srcSize,
+ const LZ4F_compressOptions_t* compressOptionsPtr)
+{
+ return LZ4F_compressUpdateImpl(cctxPtr,
+ dstBuffer, dstCapacity,
+ srcBuffer, srcSize,
+ compressOptionsPtr, LZ4B_COMPRESSED);
+}
+
+/*! LZ4F_compressUpdate() :
+ * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ * When successful, the function always entirely consumes @srcBuffer.
+ * src data is either buffered or compressed into @dstBuffer.
+ * If previously an uncompressed block was written, buffered data is flushed
+ * before appending compressed data is continued.
+ * This is only supported when LZ4F_blockIndependent is used
+ * @dstCapacity MUST be >= LZ4F_compressBound(srcSize, preferencesPtr).
+ * @compressOptionsPtr is optional : provide NULL to mean "default".
+ * @return : 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())
+ * After an error, the state is left in a UB state, and must be re-initialized.
+ */
+size_t LZ4F_uncompressedUpdate(LZ4F_cctx* cctxPtr,
+ void* dstBuffer, size_t dstCapacity,
+ const void* srcBuffer, size_t srcSize,
+ const LZ4F_compressOptions_t* compressOptionsPtr) {
+ RETURN_ERROR_IF(cctxPtr->prefs.frameInfo.blockMode != LZ4F_blockIndependent, blockMode_invalid);
+ return LZ4F_compressUpdateImpl(cctxPtr,
+ dstBuffer, dstCapacity,
+ srcBuffer, srcSize,
+ compressOptionsPtr, LZ4B_UNCOMPRESSED);
+}
+
/*! LZ4F_flush() :
* When compressed data must be sent immediately, without waiting for a block to be filled,
@@ -981,7 +1063,8 @@ size_t LZ4F_flush(LZ4F_cctx* cctxPtr,
cctxPtr->tmpIn, cctxPtr->tmpInSize,
compress, cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel,
cctxPtr->cdict,
- cctxPtr->prefs.frameInfo.blockChecksumFlag);
+ cctxPtr->prefs.frameInfo.blockChecksumFlag,
+ cctxPtr->blockCompression);
assert(((void)"flush overflows dstBuffer!", (size_t)(dstPtr - dstStart) <= dstCapacity));
if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked)
generated by cgit v0.12 at 2024-11-17 18:14:05 (GMT)