ClickHouse/contrib/libzstd/include/zstd/common/zbuff.h
2016-10-25 10:14:12 +03:00

192 lines
9.4 KiB
C++

/**
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
/* ***************************************************************
* NOTES/WARNINGS
*****************************************************************/
/* The streaming API defined here will soon be deprecated by the
* new one in 'zstd.h'; consider migrating towards newer streaming
* API. See 'lib/README.md'.
*****************************************************************/
#ifndef ZSTD_BUFFERED_H_23987
#define ZSTD_BUFFERED_H_23987
#if defined (__cplusplus)
extern "C" {
#endif
/* *************************************
* Dependencies
***************************************/
#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
***************************************/
/* This is the easier "buffered" streaming API,
* using an internal buffer to lift all restrictions on user-provided buffers
* which can be any size, any place, for both input and output.
* ZBUFF and ZSTD are 100% interoperable,
* frames created by one can be decoded by the other one */
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 - howto
*
* 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, use this value to reduce intermediate stages (better latency)
* 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 howto
*
* A ZBUFF_DCtx object is required to track streaming operations.
* 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 re-init 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 : 0 when a frame is completely decoded and fully flushed,
* 1 when there is still some data left within internal buffer to flush,
* >1 when more data is expected, with value being a suggested next input size (it's just a hint, which helps latency),
* or an error code, which can be tested using ZBUFF_isError().
*
* Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize() and 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 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);
/** Functions below provide recommended buffer sizes for Compression or Decompression operations.
* These sizes are just hints, they 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);
#ifdef ZBUFF_STATIC_LINKING_ONLY
/* ====================================================================================
* The definitions in this section are considered experimental.
* They should never be used in association with a dynamic library, as they may change in the future.
* They are provided for advanced usages.
* Use them only in association with static linking.
* ==================================================================================== */
/*--- Dependency ---*/
#define ZSTD_STATIC_LINKING_ONLY /* ZSTD_parameters, ZSTD_customMem */
#include "zstd.h"
/*--- Custom memory allocator ---*/
/*! ZBUFF_createCCtx_advanced() :
* Create a ZBUFF compression context using external alloc and free functions */
ZSTDLIB_API ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem);
/*! ZBUFF_createDCtx_advanced() :
* Create a ZBUFF decompression context using external alloc and free functions */
ZSTDLIB_API ZBUFF_DCtx* ZBUFF_createDCtx_advanced(ZSTD_customMem customMem);
/*--- Advanced Streaming Initialization ---*/
ZSTDLIB_API size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
const void* dict, size_t dictSize,
ZSTD_parameters params, unsigned long long pledgedSrcSize);
#endif /* ZBUFF_STATIC_LINKING_ONLY */
#if defined (__cplusplus)
}
#endif
#endif /* ZSTD_BUFFERED_H_23987 */