1 /* 2 * Copyright (c) 2016-2020, 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 ZSTDv07_H_235446 12 #define ZSTDv07_H_235446 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 * ZSTDv07_DLL_EXPORT : 25 * Enable exporting of functions when building a Windows DLL 26 */ 27 #if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1) 28 # define ZSTDLIBv07_API __declspec(dllexport) 29 #else 30 # define ZSTDLIBv07_API 31 #endif 32 33 34 /* ************************************* 35 * Simple API 36 ***************************************/ 37 /*! ZSTDv07_getDecompressedSize() : 38 * @return : decompressed size if known, 0 otherwise. 39 note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause. 40 note 2 : decompressed size could be wrong or intentionally modified ! 41 always ensure results fit within application's authorized limits */ 42 unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize); 43 44 /*! ZSTDv07_decompress() : 45 `compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail. 46 `dstCapacity` must be equal or larger than originalSize. 47 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), 48 or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */ 49 ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity, 50 const void* src, size_t compressedSize); 51 52 /** 53 ZSTDv07_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.7.x format 54 srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' 55 cSize (output parameter) : the number of bytes that would be read to decompress this frame 56 or an error code if it fails (which can be tested using ZSTDv01_isError()) 57 dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame 58 or ZSTD_CONTENTSIZE_ERROR if an error occurs 59 60 note : assumes `cSize` and `dBound` are _not_ NULL. 61 */ 62 void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize, 63 size_t* cSize, unsigned long long* dBound); 64 65 /*====== Helper functions ======*/ 66 ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 67 ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from an error code */ 68 69 70 /*-************************************* 71 * Explicit memory management 72 ***************************************/ 73 /** Decompression context */ 74 typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx; 75 ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void); 76 ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */ 77 78 /** ZSTDv07_decompressDCtx() : 79 * Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */ 80 ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 81 82 83 /*-************************ 84 * Simple dictionary API 85 ***************************/ 86 /*! ZSTDv07_decompress_usingDict() : 87 * Decompression using a pre-defined Dictionary content (see dictBuilder). 88 * Dictionary must be identical to the one used during compression. 89 * Note : This function load the dictionary, resulting in a significant startup time */ 90 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx, 91 void* dst, size_t dstCapacity, 92 const void* src, size_t srcSize, 93 const void* dict,size_t dictSize); 94 95 96 /*-************************** 97 * Advanced Dictionary API 98 ****************************/ 99 /*! ZSTDv07_createDDict() : 100 * Create a digested dictionary, ready to start decompression operation without startup delay. 101 * `dict` can be released after creation */ 102 typedef struct ZSTDv07_DDict_s ZSTDv07_DDict; 103 ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize); 104 ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict); 105 106 /*! ZSTDv07_decompress_usingDDict() : 107 * Decompression using a pre-digested Dictionary 108 * Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */ 109 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx, 110 void* dst, size_t dstCapacity, 111 const void* src, size_t srcSize, 112 const ZSTDv07_DDict* ddict); 113 114 typedef struct { 115 unsigned long long frameContentSize; 116 unsigned windowSize; 117 unsigned dictID; 118 unsigned checksumFlag; 119 } ZSTDv07_frameParams; 120 121 ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */ 122 123 124 125 126 /* ************************************* 127 * Streaming functions 128 ***************************************/ 129 typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx; 130 ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void); 131 ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx); 132 133 ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx); 134 ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize); 135 136 ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx, 137 void* dst, size_t* dstCapacityPtr, 138 const void* src, size_t* srcSizePtr); 139 140 /*-*************************************************************************** 141 * Streaming decompression howto 142 * 143 * A ZBUFFv07_DCtx object is required to track streaming operations. 144 * Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources. 145 * Use ZBUFFv07_decompressInit() to start a new decompression operation, 146 * or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary. 147 * Note that ZBUFFv07_DCtx objects can be re-init multiple times. 148 * 149 * Use ZBUFFv07_decompressContinue() repetitively to consume your input. 150 * *srcSizePtr and *dstCapacityPtr can be any size. 151 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. 152 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. 153 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`. 154 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency), 155 * or 0 when a frame is completely decoded, 156 * or an error code, which can be tested using ZBUFFv07_isError(). 157 * 158 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize() 159 * output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. 160 * input : ZBUFFv07_recommendedDInSize == 128KB + 3; 161 * just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . 162 * *******************************************************************************/ 163 164 165 /* ************************************* 166 * Tool functions 167 ***************************************/ 168 ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode); 169 ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode); 170 171 /** Functions below provide recommended buffer sizes for Compression or Decompression operations. 172 * These sizes are just hints, they tend to offer better latency */ 173 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void); 174 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void); 175 176 177 /*-************************************* 178 * Constants 179 ***************************************/ 180 #define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */ 181 182 183 #if defined (__cplusplus) 184 } 185 #endif 186 187 #endif /* ZSTDv07_H_235446 */ 188