/* * Copyright (c) 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 ZSTDv05_H #define ZSTDv05_H #if defined (__cplusplus) extern "C" { #endif /*-************************************* * Dependencies ***************************************/ #include /* size_t */ #include "../common/mem.h" /* U64, U32 */ /* ************************************* * Simple functions ***************************************/ /*! ZSTDv05_decompress() : `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail. `dstCapacity` must be large enough, 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 ZSTDv05_isError()) */ size_t ZSTDv05_decompress( void* dst, size_t dstCapacity, const void* src, size_t compressedSize); /** ZSTDv05_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.5.x format srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src' cSize (output parameter) : the number of bytes that would be read to decompress this frame or an error code if it fails (which can be tested using ZSTDv01_isError()) dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame or ZSTD_CONTENTSIZE_ERROR if an error occurs note : assumes `cSize` and `dBound` are _not_ NULL. */ void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound); /* ************************************* * Helper functions ***************************************/ /* Error Management */ unsigned ZSTDv05_isError(size_t code); /*!< tells if a `size_t` function result is an error code */ const char* ZSTDv05_getErrorName(size_t code); /*!< provides readable string for an error code */ /* ************************************* * Explicit memory management ***************************************/ /** Decompression context */ typedef struct ZSTDv05_DCtx_s ZSTDv05_DCtx; ZSTDv05_DCtx* ZSTDv05_createDCtx(void); size_t ZSTDv05_freeDCtx(ZSTDv05_DCtx* dctx); /*!< @return : errorCode */ /** ZSTDv05_decompressDCtx() : * Same as ZSTDv05_decompress(), but requires an already allocated ZSTDv05_DCtx (see ZSTDv05_createDCtx()) */ size_t ZSTDv05_decompressDCtx(ZSTDv05_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); /*-*********************** * Simple Dictionary API *************************/ /*! ZSTDv05_decompress_usingDict() : * Decompression using a pre-defined Dictionary content (see dictBuilder). * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted. * Note : dict can be NULL, in which case, it's equivalent to ZSTDv05_decompressDCtx() */ size_t ZSTDv05_decompress_usingDict(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, const void* dict,size_t dictSize); /*-************************ * Advanced Streaming API ***************************/ typedef enum { ZSTDv05_fast, ZSTDv05_greedy, ZSTDv05_lazy, ZSTDv05_lazy2, ZSTDv05_btlazy2, ZSTDv05_opt, ZSTDv05_btopt } ZSTDv05_strategy; typedef struct { U64 srcSize; U32 windowLog; /* the only useful information to retrieve */ U32 contentLog; U32 hashLog; U32 searchLog; U32 searchLength; U32 targetLength; ZSTDv05_strategy strategy; } ZSTDv05_parameters; size_t ZSTDv05_getFrameParams(ZSTDv05_parameters* params, const void* src, size_t srcSize); size_t ZSTDv05_decompressBegin_usingDict(ZSTDv05_DCtx* dctx, const void* dict, size_t dictSize); void ZSTDv05_copyDCtx(ZSTDv05_DCtx* dstDCtx, const ZSTDv05_DCtx* srcDCtx); size_t ZSTDv05_nextSrcSizeToDecompress(ZSTDv05_DCtx* dctx); size_t ZSTDv05_decompressContinue(ZSTDv05_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize); /*-*********************** * ZBUFF API *************************/ typedef struct ZBUFFv05_DCtx_s ZBUFFv05_DCtx; ZBUFFv05_DCtx* ZBUFFv05_createDCtx(void); size_t ZBUFFv05_freeDCtx(ZBUFFv05_DCtx* dctx); size_t ZBUFFv05_decompressInit(ZBUFFv05_DCtx* dctx); size_t ZBUFFv05_decompressInitDictionary(ZBUFFv05_DCtx* dctx, const void* dict, size_t dictSize); size_t ZBUFFv05_decompressContinue(ZBUFFv05_DCtx* dctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr); /*-*************************************************************************** * Streaming decompression * * A ZBUFFv05_DCtx object is required to track streaming operations. * Use ZBUFFv05_createDCtx() and ZBUFFv05_freeDCtx() to create/release resources. * Use ZBUFFv05_decompressInit() to start a new decompression operation, * or ZBUFFv05_decompressInitDictionary() if decompression requires a dictionary. * Note that ZBUFFv05_DCtx objects can be reused multiple times. * * Use ZBUFFv05_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 ZBUFFv05_isError(). * * Hint : recommended buffer sizes (not compulsory) : ZBUFFv05_recommendedDInSize() / ZBUFFv05_recommendedDOutSize() * output : ZBUFFv05_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded. * input : ZBUFFv05_recommendedDInSize==128Kb+3; just follow indications from ZBUFFv05_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 . * *******************************************************************************/ /* ************************************* * Tool functions ***************************************/ unsigned ZBUFFv05_isError(size_t errorCode); const char* ZBUFFv05_getErrorName(size_t errorCode); /** Functions below provide recommended buffer sizes for Compression or Decompression operations. * These sizes are just hints, and tend to offer better latency */ size_t ZBUFFv05_recommendedDInSize(void); size_t ZBUFFv05_recommendedDOutSize(void); /*-************************************* * Constants ***************************************/ #define ZSTDv05_MAGICNUMBER 0xFD2FB525 /* v0.5 */ #if defined (__cplusplus) } #endif #endif /* ZSTDv0505_H */