1/* 2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 * You may select, at your option, one of the above-listed licenses. 9 */ 10 11#ifndef ZSTDv06_H 12#define ZSTDv06_H 13 14#if defined (__cplusplus) 15extern "C" { 16#endif 17 18/*====== Dependency ======*/ 19#include <stddef.h> /* size_t */ 20 21 22/*====== Export for Windows ======*/ 23/*! 24* ZSTDv06_DLL_EXPORT : 25* Enable exporting of functions when building a Windows DLL 26*/ 27#if defined(_WIN32) && defined(ZSTDv06_DLL_EXPORT) && (ZSTDv06_DLL_EXPORT==1) 28# define ZSTDLIBv06_API __declspec(dllexport) 29#else 30# define ZSTDLIBv06_API 31#endif 32 33 34/* ************************************* 35* Simple functions 36***************************************/ 37/*! ZSTDv06_decompress() : 38 `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail. 39 `dstCapacity` must be large enough, equal or larger than originalSize. 40 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), 41 or an errorCode if it fails (which can be tested using ZSTDv06_isError()) */ 42ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity, 43 const void* src, size_t compressedSize); 44 45/** 46ZSTDv06_getFrameSrcSize() : get the source length of a ZSTD frame 47 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' 48 return : the number of bytes that would be read to decompress this frame 49 or an errorCode if it fails (which can be tested using ZSTDv06_isError()) 50*/ 51size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize); 52 53/* ************************************* 54* Helper functions 55***************************************/ 56ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */ 57 58/* Error Management */ 59ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 60ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */ 61 62 63/* ************************************* 64* Explicit memory management 65***************************************/ 66/** Decompression context */ 67typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx; 68ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void); 69ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */ 70 71/** ZSTDv06_decompressDCtx() : 72* Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */ 73ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 74 75 76/*-*********************** 77* Dictionary API 78*************************/ 79/*! ZSTDv06_decompress_usingDict() : 80* Decompression using a pre-defined Dictionary content (see dictBuilder). 81* Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted. 82* Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */ 83ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx, 84 void* dst, size_t dstCapacity, 85 const void* src, size_t srcSize, 86 const void* dict,size_t dictSize); 87 88 89/*-************************ 90* Advanced Streaming API 91***************************/ 92struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; }; 93typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams; 94 95ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */ 96ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize); 97ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx); 98 99ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx); 100ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 101 102 103 104/* ************************************* 105* ZBUFF API 106***************************************/ 107 108typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx; 109ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void); 110ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx); 111 112ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx); 113ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize); 114 115ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx, 116 void* dst, size_t* dstCapacityPtr, 117 const void* src, size_t* srcSizePtr); 118 119/*-*************************************************************************** 120* Streaming decompression howto 121* 122* A ZBUFFv06_DCtx object is required to track streaming operations. 123* Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources. 124* Use ZBUFFv06_decompressInit() to start a new decompression operation, 125* or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary. 126* Note that ZBUFFv06_DCtx objects can be re-init multiple times. 127* 128* Use ZBUFFv06_decompressContinue() repetitively to consume your input. 129* *srcSizePtr and *dstCapacityPtr can be any size. 130* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. 131* Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. 132* The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`. 133* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency), 134* or 0 when a frame is completely decoded, 135* or an error code, which can be tested using ZBUFFv06_isError(). 136* 137* Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize() 138* output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. 139* input : ZBUFFv06_recommendedDInSize == 128KB + 3; 140* just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . 141* *******************************************************************************/ 142 143 144/* ************************************* 145* Tool functions 146***************************************/ 147ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode); 148ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode); 149 150/** Functions below provide recommended buffer sizes for Compression or Decompression operations. 151* These sizes are just hints, they tend to offer better latency */ 152ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void); 153ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void); 154 155 156/*-************************************* 157* Constants 158***************************************/ 159#define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */ 160 161 162 163#if defined (__cplusplus) 164} 165#endif 166 167#endif /* ZSTDv06_BUFFERED_H */ 168