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Diffstat (limited to 'contrib/zstd/zbuff.h')
| -rw-r--r-- | contrib/zstd/zbuff.h | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/contrib/zstd/zbuff.h b/contrib/zstd/zbuff.h new file mode 100644 index 000000000..f99e06197 --- /dev/null +++ b/contrib/zstd/zbuff.h @@ -0,0 +1,191 @@ +/** + * 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 */ |