/*
LZ4 auto-framing library
Header File
- Copyright (C) 2011-2014, Yann Collet.
+ Copyright (C) 2011-2015, Yann Collet.
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
Redistribution and use in source and binary forms, with or without
You can contact the author at :
- LZ4 source repository : http://code.google.com/p/lz4/
+ - LZ4 source mirror : https://github.com/Cyan4973/lz4
- LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
*/
/****************************************
Note : experimental API.
- Not yet integrated within lz4 library.
+ Not yet integrated within liblz4
****************************************/
/**************************************
/**************************************
- Error management
-**************************************/
+ * Error management
+ * ************************************/
typedef size_t LZ4F_errorCode_t;
#define LZ4F_LIST_ERRORS(ITEM) \
ITEM(OK_NoError) ITEM(ERROR_GENERIC) \
#define LZ4F_GENERATE_ENUM(ENUM) ENUM,
typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes; /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
-int LZ4F_isError(LZ4F_errorCode_t code); /* Basically : code > -ERROR_maxCode */
-const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /* return enum as string */
+int LZ4F_isError(LZ4F_errorCode_t code); /* Basically : code > -ERROR_maxCode */
+const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /* return error code string; useful for debugging */
/**************************************
- Framing compression functions
-**************************************/
+ * Frame compression types
+ * ************************************/
-typedef enum { LZ4F_default=0, max64KB=4, max256KB=5, max1MB=6, max4MB=7} blockSizeID_t;
+typedef enum { LZ4F_default=0, max64KB=4, max256KB=5, max1MB=6, max4MB=7 } blockSizeID_t;
typedef enum { blockLinked=0, blockIndependent} blockMode_t;
typedef enum { noContentChecksum=0, contentChecksumEnabled } contentChecksum_t;
typedef struct {
LZ4F_frameInfo_t frameInfo;
- unsigned compressionLevel; /* Not yet supported : only fast compression for the time being */
- unsigned autoFlush; /* 1 == always flush; reduce need for tmp buffer */
+ unsigned compressionLevel; /* 0 == default (fast mode); values above 16 count as 16 */
+ unsigned autoFlush; /* 1 == always flush : reduce need for tmp buffer */
unsigned reserved[4];
} LZ4F_preferences_t;
/**********************************
* Advanced compression functions
- * *********************************/
+ * ********************************/
typedef void* LZ4F_compressionContext_t;
/* LZ4F_compressBound() :
* Provides the minimum size of Dst buffer given srcSize to handle worst case situations.
* preferencesPtr is optional : you can provide NULL as argument, all preferences will then be set to default.
+ * Note that different preferences will produce in different results.
*/
size_t LZ4F_compressUpdate(LZ4F_compressionContext_t compressionContext, void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* compressOptionsPtr);
/* Resource management */
-LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_compressionContext_t* LZ4F_decompressionContextPtr, unsigned version);
-LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_compressionContext_t LZ4F_decompressionContext);
+LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_decompressionContext_t* ctxPtr, unsigned version);
+LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_decompressionContext_t ctx);
/* LZ4F_createDecompressionContext() :
* The first thing to do is to create a decompressionContext object, which will be used in all decompression operations.
* This is achieved using LZ4F_createDecompressionContext().
- * The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext object.
+ * The version provided MUST be LZ4F_VERSION. It is intended to track potential version differences between different binaries.
+ * The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext_t object.
* If the result LZ4F_errorCode_t is not OK_NoError, there was an error during context creation.
* Object can release its memory using LZ4F_freeDecompressionContext();
*/
/* Decompression */
-size_t LZ4F_getFrameInfo(LZ4F_decompressionContext_t decompressionContext, LZ4F_frameInfo_t* frameInfoPtr, const void* srcBuffer, size_t* srcSizePtr);
+size_t LZ4F_getFrameInfo(LZ4F_decompressionContext_t ctx,
+ LZ4F_frameInfo_t* frameInfoPtr,
+ const void* srcBuffer, size_t* srcSizePtr);
/* LZ4F_getFrameInfo()
* This function decodes frame header information, such as blockSize.
* It is optional : you could start by calling directly LZ4F_decompress() instead.
* or an error code which can be tested using LZ4F_isError().
*/
-size_t LZ4F_decompress(LZ4F_decompressionContext_t decompressionContext, void* dstBuffer, size_t* dstSizePtr, const void* srcBuffer, size_t* srcSizePtr, const LZ4F_decompressOptions_t* decompressOptionsPtr);
+size_t LZ4F_decompress(LZ4F_decompressionContext_t ctx,
+ void* dstBuffer, size_t* dstSizePtr,
+ const void* srcBuffer, size_t* srcSizePtr,
+ const LZ4F_decompressOptions_t* optionsPtr);
/* LZ4F_decompress()
* Call this function repetitively to regenerate data compressed within srcBuffer.
* The function will attempt to decode *srcSizePtr bytes from srcBuffer, into dstBuffer of maximum size *dstSizePtr.
*
* The function result is an hint of the better srcSize to use for next call to LZ4F_decompress.
* Basically, it's the size of the current (or remaining) compressed block + header of next block.
- * Respecting the hint provides some boost to performance, since it allows less buffer shuffling.
- * Note that this is just a hint, you can always provide any srcSize you want.
+ * Respecting the hint provides some boost to performance, since it does not need intermediate buffers.
+ * This is just a hint, you can always provide any srcSize you want.
* When a frame is fully decoded, the function result will be 0.
* If decompression failed, function result is an error code which can be tested using LZ4F_isError().
*/
projects / platform / upstream / lz4.git / commitdiff