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 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 "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_getFrameSrcSize() : get the source length of a ZSTD frame 38 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' 39 return : the number of bytes that would be read to decompress this frame 40 or an errorCode if it fails (which can be tested using ZSTDv05_isError()) 41 */ 42 size_t ZSTDv05_findFrameCompressedSize(const void* src, size_t compressedSize); 43 44 /* ************************************* 45 * Helper functions 46 ***************************************/ 47 /* Error Management */ 48 unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 49 const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */ 50 51 52 /* ************************************* 53 * Explicit memory management 54 ***************************************/ 55 /** Decompression context */ 56 typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx; 57 ZSTDv05_DCtx* ZSTDv05_createDCtx(void); 58 size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */ 59 60 /** ZSTDv05_decompressDCtx() : 61 * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */ 62 size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 63 64 65 /*-*********************** 66 * Simple Dictionary API 67 *************************/ 68 /*! ZSTDv05_decompress_usingDict() : 69 * Decompression using a pre-defined Dictionary content (see dictBuilder). 70 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted. 71 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */ 72 size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx, 73 void* dst, size_t dstCapacity, 74 const void* src, size_t srcSize, 75 const void* dict,size_t dictSize); 76 77 /*-************************ 78 * Advanced Streaming API 79 ***************************/ 80 typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy; 81 typedef struct { 82 U64 srcSize; 83 U32 windowLog; /* the only useful information to retrieve */ 84 U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy; 85 } ZSTDv05_parameters; 86 size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize); 87 88 size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize); 89 void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx); 90 size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx); 91 size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); 92 93 94 /*-*********************** 95 * ZBUFF API 96 *************************/ 97 typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx; 98 ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void); 99 size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx); 100 101 size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx); 102 size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize); 103 104 size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx, 105 void* dst, size_t* dstCapacityPtr, 106 const void* src, size_t* srcSizePtr); 107 108 /*-*************************************************************************** 109 * Streaming decompression 110 * 111 * A ZBUFFv05_DCtx object is required to track streaming operations. 112 * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources. 113 * Use ZBUFFv05_decompressInit() to start a new decompression operation, 114 * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary. 115 * Note that ZBUFFv05_DCtx objects can be reused multiple times. 116 * 117 * Use ZBUFFv05_decompressContinue() repetitively to consume your input. 118 * *srcSizePtr and *dstCapacityPtr can be any size. 119 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. 120 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. 121 * The content of @dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change @dst. 122 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency) 123 * or 0 when a frame is completely decoded 124 * or an error code, which can be tested using ZBUFFv05_isError(). 125 * 126 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize() 127 * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. 128 * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . 129 * *******************************************************************************/ 130 131 132 /* ************************************* 133 * Tool functions 134 ***************************************/ 135 unsigned ZBUFFv05_isError(size_t errorCode); 136 const char* ZBUFFv05_getErrorName(size_t errorCode); 137 138 /** Functions below provide recommended buffer sizes for Compression or Decompression operations. 139 * These sizes are just hints, and tend to offer better latency */ 140 size_t ZBUFFv05_recommendedDInSize(void); 141 size_t ZBUFFv05_recommendedDOutSize(void); 142 143 144 145 /*-************************************* 146 * Constants 147 ***************************************/ 148 #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */ 149 150 151 152 153 #if defined (__cplusplus) 154 } 155 #endif 156 157 #endif /* ZSTDv0505_H */ 158