diff options
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | lib/lz4.h | 14 | ||||
| -rw-r--r-- | lib/lz4frame.c | 12 | ||||
| -rw-r--r-- | lib/lz4frame.h | 2 | ||||
| -rw-r--r-- | tests/frametest.c | 12 |
5 files changed, 26 insertions, 15 deletions
@@ -2,6 +2,7 @@ v1.7.6 cli : fix : do not modify /dev/null permissions, reported by @Maokaman1 cli : added GNU separator -- specifying that all following arguments are files API : added LZ4_compress_HC_destSize(), by Oleg (@remittor) +API : lz4frame : negative compression levels trigger fast acceleration API : fix : expose obsolete decoding functions, reported by Chen Yufei build : dragonFlyBSD, OpenBSD, NetBSD supported build : LZ4_MEMORY_USAGE can be modified at compile time, through external define @@ -256,19 +256,19 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in /*! LZ4_compress_fast_continue() : * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio. - * Important : Previous data blocks are assumed to still be present and unmodified ! + * Important : Previous data blocks are assumed to remain present and unmodified ! * 'dst' buffer must be already allocated. - * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. + * If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster. * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero. + * After an error, the stream status is invalid, and it can only be reset or freed. */ -LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration); +LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); /*! LZ4_saveDict() : - * If previously compressed data block is not guaranteed to remain available at its memory location, + * If previously compressed data block is not guaranteed to remain available at its current memory location, * save it into a safer place (char* safeBuffer). - * Note : you don't need to call LZ4_loadDict() afterwards, - * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue(). - * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error. + * Note : it's not necessary to call LZ4_loadDict() after LZ4_saveDict(), dictionary is immediately usable. + * @return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error. */ LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize); diff --git a/lib/lz4frame.c b/lib/lz4frame.c index fc0c7b5..356be8a 100644 --- a/lib/lz4frame.c +++ b/lib/lz4frame.c @@ -517,14 +517,14 @@ static size_t LZ4F_compressBlock(void* dst, const void* src, size_t srcSize, com static int LZ4F_localLZ4_compress_limitedOutput_withState(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level) { - (void) level; - return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, 1); + int const acceleration = (level < -1) ? -level : 1; + return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, acceleration); } static int LZ4F_localLZ4_compress_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level) { - (void) level; - return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, 1); + int const acceleration = (level < -1) ? -level : 1; + return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration); } static int LZ4F_localLZ4_compressHC_limitedOutput_continue(void* ctx, const char* src, char* dst, int srcSize, int dstSize, int level) @@ -619,7 +619,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci if (compressOptionsPtr->stableSrc) { cctxPtr->tmpIn = cctxPtr->tmpBuff; } else { - int realDictSize = LZ4F_localSaveDict(cctxPtr); + int const realDictSize = LZ4F_localSaveDict(cctxPtr); if (realDictSize==0) return err0r(LZ4F_ERROR_GENERIC); cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; } @@ -629,7 +629,7 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr, void* dstBuffer, size_t dstCapaci if ((cctxPtr->tmpIn + blockSize) > (cctxPtr->tmpBuff + cctxPtr->maxBufferSize) /* necessarily LZ4F_blockLinked && lastBlockCompressed==fromTmpBuffer */ && !(cctxPtr->prefs.autoFlush)) { - int realDictSize = LZ4F_localSaveDict(cctxPtr); + int const realDictSize = LZ4F_localSaveDict(cctxPtr); cctxPtr->tmpIn = cctxPtr->tmpBuff + realDictSize; } diff --git a/lib/lz4frame.h b/lib/lz4frame.h index 76b4e69..1b3e498 100644 --- a/lib/lz4frame.h +++ b/lib/lz4frame.h @@ -167,7 +167,7 @@ typedef struct { * All reserved fields must be set to zero. */ typedef struct { LZ4F_frameInfo_t frameInfo; - int compressionLevel; /* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 count as 0 */ + int compressionLevel; /* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */ unsigned autoFlush; /* 1 == always flush (reduce usage of tmp buffer) */ unsigned reserved[4]; /* must be zero for forward compatibility */ } LZ4F_preferences_t; diff --git a/tests/frametest.c b/tests/frametest.c index ae8416b..a4c548e 100644 --- a/tests/frametest.c +++ b/tests/frametest.c @@ -218,6 +218,16 @@ int basicTests(U32 seed, double compressibility) /* test one-pass frame compression */ testSize = COMPRESSIBLE_NOISE_LENGTH; + + DISPLAYLEVEL(3, "LZ4F_compressFrame, using fast level -3 : "); + { LZ4F_preferences_t fastCompressPrefs; + memset(&fastCompressPrefs, 0, sizeof(fastCompressPrefs)); + fastCompressPrefs.compressionLevel = -3; + cSize = LZ4F_compressFrame(compressedBuffer, LZ4F_compressFrameBound(testSize, NULL), CNBuffer, testSize, &fastCompressPrefs); + if (LZ4F_isError(cSize)) goto _output_error; + DISPLAYLEVEL(3, "Compressed %u bytes into a %u bytes frame \n", (U32)testSize, (U32)cSize); + } + DISPLAYLEVEL(3, "LZ4F_compressFrame, using default preferences : "); cSize = LZ4F_compressFrame(compressedBuffer, LZ4F_compressFrameBound(testSize, NULL), CNBuffer, testSize, NULL); if (LZ4F_isError(cSize)) goto _output_error; @@ -618,7 +628,7 @@ int fuzzerTests(U32 seed, unsigned nbTests, unsigned startTest, double compressi prefs.frameInfo.contentChecksumFlag = (LZ4F_contentChecksum_t)(FUZ_rand(&randState) & 1); prefs.frameInfo.contentSize = ((FUZ_rand(&randState) & 0xF) == 1) ? srcSize : 0; prefs.autoFlush = neverFlush ? 0 : (FUZ_rand(&randState) & 7) == 2; - prefs.compressionLevel = FUZ_rand(&randState) % 5; + prefs.compressionLevel = -5 + (int)(FUZ_rand(&randState) % 11); if ((FUZ_rand(&randState) & 0xF) == 1) prefsPtr = NULL; DISPLAYUPDATE(2, "\r%5u ", testNb); |