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) 15extern "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 */ 42unsigned 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()) */ 49ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity, 50 const void* src, size_t compressedSize); 51 52/** 53ZSTDv07_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*/ 62void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize, 63 size_t* cSize, unsigned long long* dBound); 64 65/*====== Helper functions ======*/ 66ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ 67ZSTDLIBv07_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 */ 74typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx; 75ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void); 76ZSTDLIBv07_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()) */ 80ZSTDLIBv07_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 */ 90ZSTDLIBv07_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 */ 102typedef struct ZSTDv07_DDict_s ZSTDv07_DDict; 103ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize); 104ZSTDLIBv07_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. */ 109ZSTDLIBv07_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 114typedef struct { 115 unsigned long long frameContentSize; 116 unsigned windowSize; 117 unsigned dictID; 118 unsigned checksumFlag; 119} ZSTDv07_frameParams; 120 121ZSTDLIBv07_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***************************************/ 129typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx; 130ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void); 131ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx); 132 133ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx); 134ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize); 135 136ZSTDLIBv07_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***************************************/ 168ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode); 169ZSTDLIBv07_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 */ 173ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void); 174ZSTDLIBv07_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