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 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_getFrameSrcSize() : get the source length of a ZSTD frame 54 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' 55 return : the number of bytes that would be read to decompress this frame 56 or an errorCode if it fails (which can be tested using ZSTDv07_isError()) 57 */ 58 size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t compressedSize); 59 60 /*====== Helper functions ======*/ 61 ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 62 ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from an error code */ 63 64 65 /*-************************************* 66 * Explicit memory management 67 ***************************************/ 68 /** Decompression context */ 69 typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx; 70 ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void); 71 ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */ 72 73 /** ZSTDv07_decompressDCtx() : 74 * Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */ 75 ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 76 77 78 /*-************************ 79 * Simple dictionary API 80 ***************************/ 81 /*! ZSTDv07_decompress_usingDict() : 82 * Decompression using a pre-defined Dictionary content (see dictBuilder). 83 * Dictionary must be identical to the one used during compression. 84 * Note : This function load the dictionary, resulting in a significant startup time */ 85 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx, 86 void* dst, size_t dstCapacity, 87 const void* src, size_t srcSize, 88 const void* dict,size_t dictSize); 89 90 91 /*-************************** 92 * Advanced Dictionary API 93 ****************************/ 94 /*! ZSTDv07_createDDict() : 95 * Create a digested dictionary, ready to start decompression operation without startup delay. 96 * `dict` can be released after creation */ 97 typedef struct ZSTDv07_DDict_s ZSTDv07_DDict; 98 ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize); 99 ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict); 100 101 /*! ZSTDv07_decompress_usingDDict() : 102 * Decompression using a pre-digested Dictionary 103 * Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */ 104 ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx, 105 void* dst, size_t dstCapacity, 106 const void* src, size_t srcSize, 107 const ZSTDv07_DDict* ddict); 108 109 typedef struct { 110 unsigned long long frameContentSize; 111 unsigned windowSize; 112 unsigned dictID; 113 unsigned checksumFlag; 114 } ZSTDv07_frameParams; 115 116 ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */ 117 118 119 120 121 /* ************************************* 122 * Streaming functions 123 ***************************************/ 124 typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx; 125 ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void); 126 ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx); 127 128 ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx); 129 ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize); 130 131 ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx, 132 void* dst, size_t* dstCapacityPtr, 133 const void* src, size_t* srcSizePtr); 134 135 /*-*************************************************************************** 136 * Streaming decompression howto 137 * 138 * A ZBUFFv07_DCtx object is required to track streaming operations. 139 * Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources. 140 * Use ZBUFFv07_decompressInit() to start a new decompression operation, 141 * or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary. 142 * Note that ZBUFFv07_DCtx objects can be re-init multiple times. 143 * 144 * Use ZBUFFv07_decompressContinue() repetitively to consume your input. 145 * *srcSizePtr and *dstCapacityPtr can be any size. 146 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. 147 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. 148 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`. 149 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency), 150 * or 0 when a frame is completely decoded, 151 * or an error code, which can be tested using ZBUFFv07_isError(). 152 * 153 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize() 154 * output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. 155 * input : ZBUFFv07_recommendedDInSize == 128KB + 3; 156 * just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . 157 * *******************************************************************************/ 158 159 160 /* ************************************* 161 * Tool functions 162 ***************************************/ 163 ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode); 164 ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode); 165 166 /** Functions below provide recommended buffer sizes for Compression or Decompression operations. 167 * These sizes are just hints, they tend to offer better latency */ 168 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void); 169 ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void); 170 171 172 /*-************************************* 173 * Constants 174 ***************************************/ 175 #define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */ 176 177 178 #if defined (__cplusplus) 179 } 180 #endif 181 182 #endif /* ZSTDv07_H_235446 */ 183