143 lines
6.3 KiB
C
143 lines
6.3 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 both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#ifndef ZSTD_V04_H_91868324769238
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#define ZSTD_V04_H_91868324769238
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#if defined (__cplusplus)
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extern "C" {
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#endif
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/* *************************************
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* Includes
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***************************************/
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#include <stddef.h> /* size_t */
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/* *************************************
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* Simple one-step function
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***************************************/
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/**
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ZSTDv04_decompress() : decompress ZSTD frames compliant with v0.4.x format
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compressedSize : is the exact source size
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maxOriginalSize : is the size of the 'dst' buffer, which must be already allocated.
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It must be equal or larger than originalSize, otherwise decompression will fail.
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return : the number of bytes decompressed into destination buffer (originalSize)
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or an errorCode if it fails (which can be tested using ZSTDv01_isError())
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*/
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size_t ZSTDv04_decompress( void* dst, size_t maxOriginalSize,
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const void* src, size_t compressedSize);
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/**
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ZSTDv04_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.4.x format
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srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
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cSize (output parameter) : the number of bytes that would be read to decompress this frame
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or an error code if it fails (which can be tested using ZSTDv01_isError())
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dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
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or ZSTD_CONTENTSIZE_ERROR if an error occurs
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note : assumes `cSize` and `dBound` are _not_ NULL.
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*/
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void ZSTDv04_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
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size_t* cSize, unsigned long long* dBound);
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/**
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ZSTDv04_isError() : tells if the result of ZSTDv04_decompress() is an error
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*/
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unsigned ZSTDv04_isError(size_t code);
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/* *************************************
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* Advanced functions
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***************************************/
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typedef struct ZSTDv04_Dctx_s ZSTDv04_Dctx;
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ZSTDv04_Dctx* ZSTDv04_createDCtx(void);
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size_t ZSTDv04_freeDCtx(ZSTDv04_Dctx* dctx);
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size_t ZSTDv04_decompressDCtx(ZSTDv04_Dctx* dctx,
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void* dst, size_t maxOriginalSize,
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const void* src, size_t compressedSize);
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/* *************************************
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* Direct Streaming
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***************************************/
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size_t ZSTDv04_resetDCtx(ZSTDv04_Dctx* dctx);
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size_t ZSTDv04_nextSrcSizeToDecompress(ZSTDv04_Dctx* dctx);
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size_t ZSTDv04_decompressContinue(ZSTDv04_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize);
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/**
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Use above functions alternatively.
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ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
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ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
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Result is the number of bytes regenerated within 'dst'.
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It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
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*/
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/* *************************************
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* Buffered Streaming
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***************************************/
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typedef struct ZBUFFv04_DCtx_s ZBUFFv04_DCtx;
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ZBUFFv04_DCtx* ZBUFFv04_createDCtx(void);
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size_t ZBUFFv04_freeDCtx(ZBUFFv04_DCtx* dctx);
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size_t ZBUFFv04_decompressInit(ZBUFFv04_DCtx* dctx);
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size_t ZBUFFv04_decompressWithDictionary(ZBUFFv04_DCtx* dctx, const void* dict, size_t dictSize);
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size_t ZBUFFv04_decompressContinue(ZBUFFv04_DCtx* dctx, void* dst, size_t* maxDstSizePtr, const void* src, size_t* srcSizePtr);
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/** ************************************************
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* Streaming decompression
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*
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* A ZBUFF_DCtx object is required to track streaming operation.
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* Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources.
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* Use ZBUFF_decompressInit() to start a new decompression operation.
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* ZBUFF_DCtx objects can be reused multiple times.
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*
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* Optionally, a reference to a static dictionary can be set, using ZBUFF_decompressWithDictionary()
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* It must be the same content as the one set during compression phase.
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* Dictionary content must remain accessible during the decompression process.
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*
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* Use ZBUFF_decompressContinue() repetitively to consume your input.
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* *srcSizePtr and *maxDstSizePtr can be any size.
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* The function will report how many bytes were read or written by modifying *srcSizePtr and *maxDstSizePtr.
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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 *maxDstSizePtr) 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 improve 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 ZBUFF_isError().
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*
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* Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize / ZBUFF_recommendedDOutSize
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* output : ZBUFF_recommendedDOutSize==128 KB block size is the internal unit, it ensures it's always possible to write a full block when it's decoded.
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* input : ZBUFF_recommendedDInSize==128Kb+3; just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
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* **************************************************/
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unsigned ZBUFFv04_isError(size_t errorCode);
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const char* ZBUFFv04_getErrorName(size_t errorCode);
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/** The below functions provide recommended buffer sizes for Compression or Decompression operations.
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* These sizes are not compulsory, they just tend to offer better latency */
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size_t ZBUFFv04_recommendedDInSize(void);
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size_t ZBUFFv04_recommendedDOutSize(void);
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/* *************************************
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* Prefix - version detection
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***************************************/
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#define ZSTDv04_magicNumber 0xFD2FB524 /* v0.4 */
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#if defined (__cplusplus)
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}
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#endif
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#endif /* ZSTD_V04_H_91868324769238 */
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