1 /* 2 * Copyright (c) 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 ZSTDv05_H 12 #define ZSTDv05_H 13 14 #if defined (__cplusplus) 15 extern "C" { 16 #endif 17 18 /*-************************************* 19 * Dependencies 20 ***************************************/ 21 #include <stddef.h> /* size_t */ 22 #include "../common/mem.h" /* U64, U32 */ 23 24 25 /* ************************************* 26 * Simple functions 27 ***************************************/ 28 /*! ZSTDv05_decompress() : 29 `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail. 30 `dstCapacity` must be large enough, equal or larger than originalSize. 31 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), 32 or an errorCode if it fails (which can be tested using ZSTDv05_isError()) */ 33 size_t ZSTDv05_decompress( void* dst, size_t dstCapacity, 34 const void* src, size_t compressedSize); 35 36 /** 37 ZSTDv05_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.5.x format 38 srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' 39 cSize (output parameter) : the number of bytes that would be read to decompress this frame 40 or an error code if it fails (which can be tested using ZSTDv01_isError()) 41 dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame 42 or ZSTD_CONTENTSIZE_ERROR if an error occurs 43 44 note : assumes `cSize` and `dBound` are _not_ NULL. 45 */ 46 void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize, 47 size_t* cSize, unsigned long long* dBound); 48 49 /* ************************************* 50 * Helper functions 51 ***************************************/ 52 /* Error Management */ 53 unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 54 const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */ 55 56 57 /* ************************************* 58 * Explicit memory management 59 ***************************************/ 60 /** Decompression context */ 61 typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx; 62 ZSTDv05_DCtx* ZSTDv05_createDCtx(void); 63 size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */ 64 65 /** ZSTDv05_decompressDCtx() : 66 * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */ 67 size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 68 69 70 /*-*********************** 71 * Simple Dictionary API 72 *************************/ 73 /*! ZSTDv05_decompress_usingDict() : 74 * Decompression using a pre-defined Dictionary content (see dictBuilder). 75 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted. 76 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */ 77 size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx, 78 void* dst, size_t dstCapacity, 79 const void* src, size_t srcSize, 80 const void* dict,size_t dictSize); 81 82 /*-************************ 83 * Advanced Streaming API 84 ***************************/ 85 typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy; 86 typedef struct { 87 U64 srcSize; 88 U32 windowLog; /* the only useful information to retrieve */ 89 U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy; 90 } ZSTDv05_parameters; 91 size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize); 92 93 size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize); 94 void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx); 95 size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx); 96 size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 97 98 99 /*-*********************** 100 * ZBUFF API 101 *************************/ 102 typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx; 103 ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void); 104 size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx); 105 106 size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx); 107 size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize); 108 109 size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx, 110 void* dst, size_t* dstCapacityPtr, 111 const void* src, size_t* srcSizePtr); 112 113 /*-*************************************************************************** 114 * Streaming decompression 115 * 116 * A ZBUFFv05_DCtx object is required to track streaming operations. 117 * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources. 118 * Use ZBUFFv05_decompressInit() to start a new decompression operation, 119 * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary. 120 * Note that ZBUFFv05_DCtx objects can be reused multiple times. 121 * 122 * Use ZBUFFv05_decompressContinue() repetitively to consume your input. 123 * *srcSizePtr and *dstCapacityPtr can be any size. 124 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. 125 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. 126 * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst. 127 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency) 128 * or 0 when a frame is completely decoded 129 * or an error code, which can be tested using ZBUFFv05_isError(). 130 * 131 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize() 132 * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. 133 * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . 134 * *******************************************************************************/ 135 136 137 /* ************************************* 138 * Tool functions 139 ***************************************/ 140 unsigned ZBUFFv05_isError(size_t errorCode); 141 const char* ZBUFFv05_getErrorName(size_t errorCode); 142 143 /** Functions below provide recommended buffer sizes for Compression or Decompression operations. 144 * These sizes are just hints, and tend to offer better latency */ 145 size_t ZBUFFv05_recommendedDInSize(void); 146 size_t ZBUFFv05_recommendedDOutSize(void); 147 148 149 150 /*-************************************* 151 * Constants 152 ***************************************/ 153 #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */ 154 155 156 157 158 #if defined (__cplusplus) 159 } 160 #endif 161 162 #endif /* ZSTDv0505_H */ 163