mirror of
https://github.com/facebook/zstd.git
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160 lines
7.0 KiB
C
160 lines
7.0 KiB
C
/**
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* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*/
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#ifndef ZSTDv06_H
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#define ZSTDv06_H
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/*====== Dependency ======*/
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#include <stddef.h> /* size_t */
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/*====== Export for Windows ======*/
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/*!
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* ZSTDv06_DLL_EXPORT :
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* Enable exporting of functions when building a Windows DLL
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*/
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#if defined(_WIN32) && defined(ZSTDv06_DLL_EXPORT) && (ZSTDv06_DLL_EXPORT==1)
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# define ZSTDLIBv06_API __declspec(dllexport)
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#else
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# define ZSTDLIBv06_API
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#endif
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/* *************************************
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* Simple functions
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***************************************/
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/*! ZSTDv06_decompress() :
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`compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
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`dstCapacity` must be large enough, equal or larger than originalSize.
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@return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
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or an errorCode if it fails (which can be tested using ZSTDv06_isError()) */
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ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity,
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const void* src, size_t compressedSize);
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/* *************************************
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* Helper functions
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***************************************/
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ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */
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/* Error Management */
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ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
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ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */
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/* *************************************
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* Explicit memory management
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***************************************/
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/** Decompression context */
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typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx;
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ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void);
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ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */
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/** ZSTDv06_decompressDCtx() :
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* Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */
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ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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/*-***********************
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* Dictionary API
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*************************/
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/*! ZSTDv06_decompress_usingDict() :
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* Decompression using a pre-defined Dictionary content (see dictBuilder).
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* Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
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* Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */
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ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx,
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void* dst, size_t dstCapacity,
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const void* src, size_t srcSize,
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const void* dict,size_t dictSize);
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/*-************************
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* Advanced Streaming API
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***************************/
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struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; };
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typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams;
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ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
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ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize);
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ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx);
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ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx);
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ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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/* *************************************
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* ZBUFF API
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***************************************/
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typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx;
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ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void);
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ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx);
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ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx);
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ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize);
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ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx,
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void* dst, size_t* dstCapacityPtr,
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const void* src, size_t* srcSizePtr);
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/*-***************************************************************************
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* Streaming decompression howto
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*
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* A ZBUFFv06_DCtx object is required to track streaming operations.
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* Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources.
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* Use ZBUFFv06_decompressInit() to start a new decompression operation,
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* or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary.
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* Note that ZBUFFv06_DCtx objects can be re-init multiple times.
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*
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* Use ZBUFFv06_decompressContinue() repetitively to consume your input.
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* *srcSizePtr and *dstCapacityPtr can be any size.
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* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
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* Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
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* The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
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* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
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* or 0 when a frame is completely decoded,
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* or an error code, which can be tested using ZBUFFv06_isError().
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*
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* Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize()
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* output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
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* input : ZBUFFv06_recommendedDInSize == 128KB + 3;
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* just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
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* *******************************************************************************/
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/* *************************************
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* Tool functions
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***************************************/
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ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode);
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ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode);
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/** Functions below provide recommended buffer sizes for Compression or Decompression operations.
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* These sizes are just hints, they tend to offer better latency */
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ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void);
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ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void);
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/*-*************************************
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* Constants
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***************************************/
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#define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */
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#if defined (__cplusplus)
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}
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#endif
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#endif /* ZSTDv06_BUFFERED_H */
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