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) 15 extern "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()) */ 42 ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity, 43 const void* src, size_t compressedSize); 44 45 /** 46 ZSTDv06_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 */ 51 size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize); 52 53 /* ************************************* 54 * Helper functions 55 ***************************************/ 56 ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */ 57 58 /* Error Management */ 59 ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 60 ZSTDLIBv06_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 */ 67 typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx; 68 ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void); 69 ZSTDLIBv06_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()) */ 73 ZSTDLIBv06_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() */ 83 ZSTDLIBv06_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 ***************************/ 92 struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; }; 93 typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams; 94 95 ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */ 96 ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize); 97 ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx); 98 99 ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx); 100 ZSTDLIBv06_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 ***************************************/ 107 108 typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx; 109 ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void); 110 ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx); 111 112 ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx); 113 ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize); 114 115 ZSTDLIBv06_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 ***************************************/ 147 ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode); 148 ZSTDLIBv06_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 */ 152 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void); 153 ZSTDLIBv06_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