mirror of
https://github.com/facebook/zstd.git
synced 2024-12-15 18:00:33 +08:00
171 lines
8.6 KiB
C
171 lines
8.6 KiB
C
/*
|
|
Buffered version of Zstd compression library
|
|
Copyright (C) 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
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above
|
|
copyright notice, this list of conditions and the following disclaimer
|
|
in the documentation and/or other materials provided with the
|
|
distribution.
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
You can contact the author at :
|
|
- zstd source repository : https://github.com/Cyan4973/zstd
|
|
- ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
|
|
*/
|
|
#ifndef ZSTD_BUFFERED_H
|
|
#define ZSTD_BUFFERED_H
|
|
|
|
/* The objects defined into this file should be considered experimental.
|
|
* They are not labelled stable, as their prototype may change in the future.
|
|
* You can use them for tests, provide feedback, or if you can endure risk of future changes.
|
|
*/
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
/* *************************************
|
|
* Includes
|
|
***************************************/
|
|
#include <stddef.h> /* size_t */
|
|
|
|
|
|
/* ***************************************************************
|
|
* Compiler specifics
|
|
*****************************************************************/
|
|
/*!
|
|
* ZSTD_DLL_EXPORT :
|
|
* Enable exporting of functions when building a Windows DLL
|
|
*/
|
|
#if defined(_WIN32) && defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
|
|
# define ZSTDLIB_API __declspec(dllexport)
|
|
#else
|
|
# define ZSTDLIB_API
|
|
#endif
|
|
|
|
|
|
/* *************************************
|
|
* Streaming functions
|
|
***************************************/
|
|
typedef struct ZBUFF_CCtx_s ZBUFF_CCtx;
|
|
ZSTDLIB_API ZBUFF_CCtx* ZBUFF_createCCtx(void);
|
|
ZSTDLIB_API size_t ZBUFF_freeCCtx(ZBUFF_CCtx* cctx);
|
|
|
|
ZSTDLIB_API size_t ZBUFF_compressInit(ZBUFF_CCtx* cctx, int compressionLevel);
|
|
ZSTDLIB_API size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
|
|
|
|
ZSTDLIB_API size_t ZBUFF_compressContinue(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr);
|
|
ZSTDLIB_API size_t ZBUFF_compressFlush(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);
|
|
ZSTDLIB_API size_t ZBUFF_compressEnd(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);
|
|
|
|
/** ************************************************
|
|
* Streaming compression
|
|
*
|
|
* A ZBUFF_CCtx object is required to track streaming operation.
|
|
* Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
|
|
* ZBUFF_CCtx objects can be reused multiple times.
|
|
*
|
|
* Start by initializing ZBUF_CCtx.
|
|
* Use ZBUFF_compressInit() to start a new compression operation.
|
|
* Use ZBUFF_compressInitDictionary() for a compression which requires a dictionary.
|
|
*
|
|
* Use ZBUFF_compressContinue() repetitively to consume input stream.
|
|
* *srcSizePtr and *dstCapacityPtr can be any size.
|
|
* The function will report how many bytes were read or written within *srcSizePtr and *dstCapacityPtr.
|
|
* Note that it may not consume the entire input, in which case it's up to the caller to present again remaining data.
|
|
* The content of @dst will be overwritten (up to *dstCapacityPtr) at each call, so save its content if it matters or change @dst .
|
|
* @return : a hint to preferred nb of bytes to use as input for next function call (it's just a hint, to improve latency)
|
|
* or an error code, which can be tested using ZBUFF_isError().
|
|
*
|
|
* At any moment, it's possible to flush whatever data remains within buffer, using ZBUFF_compressFlush().
|
|
* The nb of bytes written into @dst will be reported into *dstCapacityPtr.
|
|
* Note that the function cannot output more than *dstCapacityPtr,
|
|
* therefore, some content might still be left into internal buffer if *dstCapacityPtr is too small.
|
|
* @return : nb of bytes still present into internal buffer (0 if it's empty)
|
|
* or an error code, which can be tested using ZBUFF_isError().
|
|
*
|
|
* ZBUFF_compressEnd() instructs to finish a frame.
|
|
* It will perform a flush and write frame epilogue.
|
|
* The epilogue is required for decoders to consider a frame completed.
|
|
* Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
|
|
* In which case, call again ZBUFF_compressFlush() to complete the flush.
|
|
* @return : nb of bytes still present into internal buffer (0 if it's empty)
|
|
* or an error code, which can be tested using ZBUFF_isError().
|
|
*
|
|
* Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedCInSize / ZBUFF_recommendedCOutSize
|
|
* input : ZBUFF_recommendedCInSize==128 KB block size is the internal unit, it improves latency to use this value (skipped buffering).
|
|
* output : ZBUFF_recommendedCOutSize==ZSTD_compressBound(128 KB) + 3 + 3 : ensures it's always possible to write/flush/end a full block. Skip some buffering.
|
|
* By using both, it ensures that input will be entirely consumed, and output will always contain the result, reducing intermediate buffering.
|
|
* **************************************************/
|
|
|
|
|
|
typedef struct ZBUFF_DCtx_s ZBUFF_DCtx;
|
|
ZSTDLIB_API ZBUFF_DCtx* ZBUFF_createDCtx(void);
|
|
ZSTDLIB_API size_t ZBUFF_freeDCtx(ZBUFF_DCtx* dctx);
|
|
|
|
ZSTDLIB_API size_t ZBUFF_decompressInit(ZBUFF_DCtx* dctx);
|
|
ZSTDLIB_API size_t ZBUFF_decompressInitDictionary(ZBUFF_DCtx* dctx, const void* dict, size_t dictSize);
|
|
|
|
ZSTDLIB_API size_t ZBUFF_decompressContinue(ZBUFF_DCtx* dctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr);
|
|
|
|
/** ************************************************
|
|
* Streaming decompression
|
|
*
|
|
* A ZBUFF_DCtx object is required to track streaming operation.
|
|
* Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources.
|
|
* Use ZBUFF_decompressInit() to start a new decompression operation,
|
|
* or ZBUFF_decompressInitDictionary() if decompression requires a dictionary.
|
|
* Note that ZBUFF_DCtx objects can be reused multiple times.
|
|
*
|
|
* Use ZBUFF_decompressContinue() repetitively to consume your input.
|
|
* *srcSizePtr and *dstCapacityPtr can be any size.
|
|
* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
|
|
* Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
|
|
* The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst.
|
|
* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency)
|
|
* or 0 when a frame is completely decoded
|
|
* or an error code, which can be tested using ZBUFF_isError().
|
|
*
|
|
* Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize / ZBUFF_recommendedDOutSize
|
|
* output : ZBUFF_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when it's decoded.
|
|
* input : ZBUFF_recommendedDInSize==128Kb+3; just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
|
|
* **************************************************/
|
|
|
|
|
|
/* *************************************
|
|
* Tool functions
|
|
***************************************/
|
|
ZSTDLIB_API unsigned ZBUFF_isError(size_t errorCode);
|
|
ZSTDLIB_API const char* ZBUFF_getErrorName(size_t errorCode);
|
|
|
|
/** The below functions provide recommended buffer sizes for Compression or Decompression operations.
|
|
* These sizes are just hints, and tend to offer better latency */
|
|
ZSTDLIB_API size_t ZBUFF_recommendedCInSize(void);
|
|
ZSTDLIB_API size_t ZBUFF_recommendedCOutSize(void);
|
|
ZSTDLIB_API size_t ZBUFF_recommendedDInSize(void);
|
|
ZSTDLIB_API size_t ZBUFF_recommendedDOutSize(void);
|
|
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* ZSTD_BUFFERED_H */
|