/* * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ #ifndef ZSTDv07_H_235446 #define ZSTDv07_H_235446 #if defined (__cplusplus) extern "C" { #endif /*====== Dependency ======*/ #include /* size_t */ /*====== Export for Windows ======*/ /*! * ZSTDv07_DLL_EXPORT : * Enable exporting of functions when building a Windows DLL */ #if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1) # define ZSTDLIBv07_API __declspec(dllexport) #else # define ZSTDLIBv07_API #endif /* ************************************* * Simple API ***************************************/ /*! ZSTDv07_getDecompressedSize() : * @return : decompressed size if known, 0 otherwise. note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause. note 2 : decompressed size could be wrong or intentionally modified ! always ensure results fit within application's authorized limits */ unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize); /*! ZSTDv07_decompress() : `compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail. `dstCapacity` must be equal or larger than originalSize. @return : the number of bytes decompressed into `dst` (<= `dstCapacity`), or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */ ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity, const void* src, size_t compressedSize); /** ZSTDv07_getFrameSrcSize() : get the source length of a ZSTD frame compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' return : the number of bytes that would be read to decompress this frame or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */ size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t compressedSize); /*====== Helper functions ======*/ ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from an error code */ /*-************************************* * Explicit memory management ***************************************/ /** Decompression context */ typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx; ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void); ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */ /** ZSTDv07_decompressDCtx() : * Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */ ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); /*-************************ * Simple dictionary API ***************************/ /*! ZSTDv07_decompress_usingDict() : * Decompression using a pre-defined Dictionary content (see dictBuilder). * Dictionary must be identical to the one used during compression. * Note : This function load the dictionary, resulting in a significant startup time */ ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, const void* dict,size_t dictSize); /*-************************** * Advanced Dictionary API ****************************/ /*! ZSTDv07_createDDict() : * Create a digested dictionary, ready to start decompression operation without startup delay. * `dict` can be released after creation */ typedef struct ZSTDv07_DDict_s ZSTDv07_DDict; ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize); ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict); /*! ZSTDv07_decompress_usingDDict() : * Decompression using a pre-digested Dictionary * Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */ ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, const ZSTDv07_DDict* ddict); typedef struct { unsigned long long frameContentSize; unsigned windowSize; unsigned dictID; unsigned checksumFlag; } ZSTDv07_frameParams; ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */ /* ************************************* * Streaming functions ***************************************/ typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx; ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void); ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx); ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx); ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize); ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr); /*-*************************************************************************** * Streaming decompression howto * * A ZBUFFv07_DCtx object is required to track streaming operations. * Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources. * Use ZBUFFv07_decompressInit() to start a new decompression operation, * or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary. * Note that ZBUFFv07_DCtx objects can be re-init multiple times. * * Use ZBUFFv07_decompressContinue() repetitively to consume your input. * *srcSizePtr and *dstCapacityPtr can be any size. * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr. * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again. * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`. * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency), * or 0 when a frame is completely decoded, * or an error code, which can be tested using ZBUFFv07_isError(). * * Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize() * output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. * input : ZBUFFv07_recommendedDInSize == 128KB + 3; * just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . * *******************************************************************************/ /* ************************************* * Tool functions ***************************************/ ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode); ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode); /** Functions below provide recommended buffer sizes for Compression or Decompression operations. * These sizes are just hints, they tend to offer better latency */ ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void); ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void); /*-************************************* * Constants ***************************************/ #define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */ #if defined (__cplusplus) } #endif #endif /* ZSTDv07_H_235446 */