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244 lines
12 KiB
C
244 lines
12 KiB
C
/*
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zstd - standard compression library
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Header File for static linking only
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Copyright (C) 2014-2015, Yann Collet.
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the following disclaimer
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in the documentation and/or other materials provided with the
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distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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You can contact the author at :
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- zstd source repository : https://github.com/Cyan4973/zstd
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- ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
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*/
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#ifndef ZSTD_STATIC_H
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#define ZSTD_STATIC_H
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/* The objects defined into this file shall be considered experimental.
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* They are not considered stable, as their prototype may change in the future.
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* You can use them for tests, provide feedback, or if you can endure risks of future changes.
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*/
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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 "zstd.h"
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#include "mem.h"
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/* *************************************
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* Types
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***************************************/
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#define ZSTD_WINDOWLOG_MAX 26
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#define ZSTD_WINDOWLOG_MIN 18
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#define ZSTD_WINDOWLOG_ABSOLUTEMIN 11
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#define ZSTD_CONTENTLOG_MAX (ZSTD_WINDOWLOG_MAX+1)
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#define ZSTD_CONTENTLOG_MIN 4
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#define ZSTD_HASHLOG_MAX 28
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#define ZSTD_HASHLOG_MIN 4
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#define ZSTD_SEARCHLOG_MAX (ZSTD_CONTENTLOG_MAX-1)
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#define ZSTD_SEARCHLOG_MIN 1
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#define ZSTD_SEARCHLENGTH_MAX 7
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#define ZSTD_SEARCHLENGTH_MIN 4
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/** from faster to stronger */
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typedef enum { ZSTD_fast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2, ZSTD_btlazy2, ZSTD_opt, ZSTD_opt_bt } ZSTD_strategy;
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typedef struct
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{
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U64 srcSize; /* optional : tells how much bytes are present in the frame. Use 0 if not known. */
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U32 windowLog; /* largest match distance : larger == more compression, more memory needed during decompression */
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U32 contentLog; /* full search segment : larger == more compression, slower, more memory (useless for fast) */
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U32 hashLog; /* dispatch table : larger == more memory, faster */
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U32 searchLog; /* nb of searches : larger == more compression, slower */
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U32 searchLength; /* size of matches : larger == faster decompression, sometimes less compression */
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ZSTD_strategy strategy;
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} ZSTD_parameters;
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/* *************************************
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* Advanced functions
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***************************************/
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#define ZSTD_MAX_CLEVEL 24
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ZSTDLIB_API unsigned ZSTD_maxCLevel (void);
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/*! ZSTD_getParams
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* @return ZSTD_parameters structure for a selected compression level and srcSize.
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* @srcSizeHint value is optional, select 0 if not known */
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ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, U64 srcSizeHint);
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/*! ZSTD_validateParams
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* correct params value to remain within authorized range */
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ZSTDLIB_API void ZSTD_validateParams(ZSTD_parameters* params);
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/*! ZSTD_compress_advanced
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* Same as ZSTD_compress_usingDict(), with fine-tune control of each compression parameter */
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ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
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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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ZSTD_parameters params);
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/*! ZSTD_compress_usingPreparedDCtx
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* Same as ZSTD_compress_usingDict, but using a reference context preparedCCtx, where dictionary has been loaded.
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* It avoids reloading the dictionary each time.
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* preparedCCtx must have been properly initialized using ZSTD_compressBegin_usingDict() or ZSTD_compressBegin_advanced()
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* Requires 2 contexts : 1 for reference, which will not be modified, and 1 to run the compression operation */
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ZSTDLIB_API size_t ZSTD_compress_usingPreparedCCtx(
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ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx,
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void* dst, size_t dstCapacity,
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const void* src, size_t srcSize);
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/*- Advanced Decompression functions -*/
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/*! ZSTD_decompress_usingPreparedDCtx
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* Same as ZSTD_decompress_usingDict, but using a reference context preparedDCtx, where dictionary has been loaded.
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* It avoids reloading the dictionary each time.
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* preparedDCtx must have been properly initialized using ZSTD_decompressBegin_usingDict().
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* Requires 2 contexts : 1 for reference, which will not be modified, and 1 to run the decompression operation */
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ZSTDLIB_API size_t ZSTD_decompress_usingPreparedDCtx(
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ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx,
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void* dst, size_t dstCapacity,
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const void* src, size_t srcSize);
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/* **************************************
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* Streaming functions (direct mode)
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****************************************/
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ZSTDLIB_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
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ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict,size_t dictSize, int compressionLevel);
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ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict,size_t dictSize, ZSTD_parameters params);
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ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx);
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ZSTDLIB_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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ZSTDLIB_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity);
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/**
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Streaming compression, synchronous mode (bufferless)
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A ZSTD_CCtx object is required to track streaming operations.
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Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage it.
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ZSTD_CCtx object can be re-used multiple times within successive compression operations.
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Start by initializing a context.
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Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression,
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or ZSTD_compressBegin_advanced(), for finer parameter control.
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It's also possible to duplicate a reference context which has been initialized, using ZSTD_copyCCtx()
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Then, consume your input using ZSTD_compressContinue().
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The interface is synchronous, so all input will be consumed and produce a compressed output.
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You must ensure there is enough space in destination buffer to store compressed data under worst case scenario.
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Worst case evaluation is provided by ZSTD_compressBound().
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Finish a frame with ZSTD_compressEnd(), which will write the epilogue.
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Without the epilogue, frames will be considered incomplete by decoder.
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You can then reuse ZSTD_CCtx to compress some new frame.
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*/
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ZSTDLIB_API size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
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ZSTDLIB_API size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
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ZSTDLIB_API void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
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ZSTDLIB_API size_t ZSTD_getFrameParams(ZSTD_parameters* params, const void* src, size_t srcSize);
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ZSTDLIB_API size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
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ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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/**
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Streaming decompression, direct mode (bufferless)
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A ZSTD_DCtx object is required to track streaming operations.
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Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
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A ZSTD_DCtx object can be re-used multiple times.
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First typical operation is to retrieve frame parameters, using ZSTD_getFrameParams().
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This operation is independent, and just needs enough input data to properly decode the frame header.
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Objective is to retrieve *params.windowlog, to know minimum amount of memory required during decoding.
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Result : 0 when successful, it means the ZSTD_parameters structure has been filled.
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>0 : means there is not enough data into src. Provides the expected size to successfully decode header.
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errorCode, which can be tested using ZSTD_isError()
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Start decompression, with ZSTD_decompressBegin() or ZSTD_decompressBegin_usingDict()
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Alternatively, you can copy a prepared context, using ZSTD_copyDCtx()
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Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
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ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
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ZSTD_decompressContinue() requires this exact amount of bytes, or it will fail.
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ZSTD_decompressContinue() needs previous data blocks during decompression, up to (1 << windowlog).
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They should preferably be located contiguously, prior to current block. Alternatively, a round buffer is also possible.
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@result of ZSTD_decompressContinue() 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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A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
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Context can then be reset to start a new decompression.
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*/
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/* **************************************
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* Block functions
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****************************************/
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/*! Block functions produce and decode raw zstd blocks, without frame metadata.
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User will have to save and regenerate necessary information to regenerate data, such as block sizes.
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A few rules to respect :
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- Uncompressed block size must be <= 128 KB
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- Compressing or decompressing requires a context structure
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+ Use ZSTD_createCCtx() and ZSTD_createDCtx()
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- It is necessary to init context before starting
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+ compression : ZSTD_compressBegin()
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+ decompression : ZSTD_decompressBegin()
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+ variants _usingDict() are also allowed
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+ copyCCtx() and copyDCtx() work too
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- When a block is considered not compressible enough, ZSTD_compressBlock() result will be zero.
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In which case, nothing is produced into @dst.
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+ User must test for such outcome and deal directly with uncompressed data
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+ ZSTD_decompressBlock() doesn't accept uncompressed data as input !!
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*/
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size_t ZSTD_compressBlock (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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/* *************************************
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* Error management
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***************************************/
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#include "error_public.h"
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/*! ZSTD_getErrorCode
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transform a function result using `size_t` into a `ZSTD_error_code` enum type
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which can be used to compare directly with enum list within "error_public.h" */
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ZSTD_errorCode ZSTD_getError(size_t code);
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#if defined (__cplusplus)
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}
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#endif
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#endif /* ZSTD_STATIC_H */
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