diff options
Diffstat (limited to 'lib/lz4.h')
| -rw-r--r-- | lib/lz4.h | 77 |
1 files changed, 38 insertions, 39 deletions
@@ -70,11 +70,11 @@ int LZ4_versionNumber (void); * Simple Functions **************************************/ -int LZ4_compress_safe (const char* source, char* dest, int sourceSize, int maxDestSize); +int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize); int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize); /* -LZ4_compress_safe() : +LZ4_compress_default() : Compresses 'sourceSize' bytes from buffer 'source' into already allocated 'dest' buffer of size 'maxDestSize'. Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize). @@ -86,7 +86,7 @@ LZ4_compress_safe() : sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE maxDestSize : full or partial size of buffer 'dest' (which must be already allocated) return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize) - or 0 if compression fails + or 0 if compression fails LZ4_decompress_safe() : compressedSize : is obviously the source size @@ -95,7 +95,7 @@ LZ4_decompress_safe() : If the destination buffer is not large enough, decoding will stop and output an error code (<0). If the source stream is detected malformed, the function will stop decoding and return a negative result. This function is protected against buffer overflow exploits, including malicious data packets. - It never writes outside of output buffer, nor reads outside of input buffer. + It never writes outside output buffer, nor reads outside input buffer. */ @@ -108,36 +108,35 @@ LZ4_decompress_safe() : /* LZ4_compressBound() : Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) - This function is primarily useful for memory allocation purposes (output buffer size). + This function is primarily useful for memory allocation purposes (destination buffer size). Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). - - inputSize : max supported value is LZ4_MAX_INPUT_SIZE - return : maximum output size in a "worst case" scenario - or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE) + Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize) + inputSize : max supported value is LZ4_MAX_INPUT_SIZE + return : maximum output size in a "worst case" scenario + or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE) */ int LZ4_compressBound(int inputSize); /* -LZ4_compress_safe_extState() : - Same compression function, just using an externally allocated memory space to store compression state. - Use LZ4_sizeofState() to know how much memory must be allocated, - and then, provide it as 'void* state' to compression functions. - Note that 'state' ptr must be aligned on 4-bytes boundaries. +LZ4_compress_fast() : + Same as LZ4_compress_default(), but allows to select an "acceleration" factor. + The larger the acceleration value, the faster the algorithm, but also the lesser the compression. + It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. + An acceleration value of "0" means "use Default value" (see lz4.c) + An acceleration value of "1" is the same as regular LZ4_compress_default() */ -int LZ4_sizeofState(void); -int LZ4_compress_safe_extState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); +int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration); + /* -LZ4_compress_fast() : - Same as LZ4_compress_safe(), but allows to select an "acceleration" factor. - The larger the acceleration value, the faster the algorithm, but also the lesser the compression. - It's a trade-off. It can be fine tuned, with each successive value providing an additional +2/3% to speed. - An acceleration value of "0" means "use Default value", which is typically 17 (see lz4.c source code). - An acceleration value of "1" is the same as regular LZ4_compress_safe() - Note : this function is "safe", even if its name does not explicitly contain the word. It's just faster and compress less. +LZ4_compress_fast_extState() : + Same compression function, just using an externally allocated memory space to store compression state. + Use LZ4_sizeofState() to know how much memory must be allocated, + and allocate it on 8-bytes boundaries (using malloc() typically). + Then, provide it as 'void* state' to compression function. */ -int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, unsigned acceleration); -int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, unsigned acceleration); +int LZ4_sizeofState(void); +int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration); /* @@ -186,7 +185,7 @@ typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t; * LZ4_resetStream * Use this function to init an allocated LZ4_stream_t structure */ -void LZ4_resetStream (LZ4_stream_t* LZ4_streamPtr); +void LZ4_resetStream (LZ4_stream_t* streamPtr); /* * LZ4_createStream will allocate and initialize an LZ4_stream_t structure @@ -195,7 +194,7 @@ void LZ4_resetStream (LZ4_stream_t* LZ4_streamPtr); * They are more future proof, in case of a change of LZ4_stream_t size. */ LZ4_stream_t* LZ4_createStream(void); -int LZ4_freeStream (LZ4_stream_t* LZ4_streamPtr); +int LZ4_freeStream (LZ4_stream_t* streamPtr); /* * LZ4_loadDict @@ -204,27 +203,27 @@ int LZ4_freeStream (LZ4_stream_t* LZ4_streamPtr); * Loading a size of 0 is allowed. * Return : dictionary size, in bytes (necessarily <= 64 KB) */ -int LZ4_loadDict (LZ4_stream_t* LZ4_streamPtr, const char* dictionary, int dictSize); +int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); /* - * LZ4_compress_safe_continue - * Compress data block 'source', using data from previous blocks to improve compression ratio. + * 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 ! - * dest buffer must be already allocated. - * if maxOutpuSize >= (inputSize), compression is guaranteed to succeed. - * if not, and if target size objective cannot be met, compression stops, and function returns a zero. + * 'dst' buffer must be already allocated. + * If maxDstSize >= 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. */ -int LZ4_compress_safe_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize); +int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration); /* * LZ4_saveDict * If previously compressed data block is not guaranteed to remain available at its 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 again LZ4_compress_continue() + * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue() * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error */ -int LZ4_saveDict (LZ4_stream_t* LZ4_streamPtr, char* safeBuffer, int dictSize); +int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize); /************************************************ @@ -310,7 +309,7 @@ int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalS # pragma message("WARNING: You need to implement LZ4_DEPRECATED for this compiler") # define LZ4_DEPRECATED(message) # endif -#endif // LZ4_DEPRECATE_WARNING_DEFBLOCK +#endif /* LZ4_DEPRECATE_WARNING_DEFBLOCK */ /* Obsolete compression functions */ /* These functions are planned to start generate warnings by r131 approximately */ @@ -338,8 +337,8 @@ LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state); /* Obsolete streaming decoding functions */ -LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* source, char* dest, int compressedSize, int maxOutputSize); -LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* source, char* dest, int originalSize); +LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize); +LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize); #if defined (__cplusplus) |