183 lines
8.1 KiB
C
183 lines
8.1 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 ZSTDv07_H_235446
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#define ZSTDv07_H_235446
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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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* ZSTDv07_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(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1)
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# define ZSTDLIBv07_API __declspec(dllexport)
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#else
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# define ZSTDLIBv07_API
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#endif
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/* *************************************
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* Simple API
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***************************************/
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/*! ZSTDv07_getDecompressedSize() :
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* @return : decompressed size if known, 0 otherwise.
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note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause.
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note 2 : decompressed size could be wrong or intentionally modified !
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always ensure results fit within application's authorized limits */
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unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize);
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/*! ZSTDv07_decompress() :
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`compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail.
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`dstCapacity` must be 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 ZSTDv07_isError()) */
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ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity,
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const void* src, size_t compressedSize);
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/**
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ZSTDv07_getFrameSrcSize() : get the source length of a ZSTD frame
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compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
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return : the number of bytes that would be read to decompress this frame
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or an errorCode if it fails (which can be tested using ZSTDv07_isError())
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*/
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size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t compressedSize);
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/*====== Helper functions ======*/
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ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
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ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from 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 ZSTDv07_DCtx_s ZSTDv07_DCtx;
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ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void);
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ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */
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/** ZSTDv07_decompressDCtx() :
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* Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */
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ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
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/*-************************
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* Simple dictionary API
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***************************/
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/*! ZSTDv07_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.
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* Note : This function load the dictionary, resulting in a significant startup time */
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ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_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 Dictionary API
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****************************/
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/*! ZSTDv07_createDDict() :
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* Create a digested dictionary, ready to start decompression operation without startup delay.
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* `dict` can be released after creation */
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typedef struct ZSTDv07_DDict_s ZSTDv07_DDict;
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ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize);
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ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict);
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/*! ZSTDv07_decompress_usingDDict() :
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* Decompression using a pre-digested Dictionary
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* Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */
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ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_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 ZSTDv07_DDict* ddict);
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typedef struct {
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unsigned long long frameContentSize;
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unsigned windowSize;
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unsigned dictID;
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unsigned checksumFlag;
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} ZSTDv07_frameParams;
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ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
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/* *************************************
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* Streaming functions
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***************************************/
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typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx;
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ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void);
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ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx);
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ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx);
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ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize);
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ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_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 ZBUFFv07_DCtx object is required to track streaming operations.
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* Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
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* Use ZBUFFv07_decompressInit() to start a new decompression operation,
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* or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
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* Note that ZBUFFv07_DCtx objects can be re-init multiple times.
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*
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* Use ZBUFFv07_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 ZBUFFv07_isError().
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*
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* Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
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* output : ZBUFFv07_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 : ZBUFFv07_recommendedDInSize == 128KB + 3;
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* just follow indications from ZBUFFv07_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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ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode);
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ZSTDLIBv07_API const char* ZBUFFv07_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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ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void);
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ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void);
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/*-*************************************
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* Constants
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***************************************/
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#define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */
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#if defined (__cplusplus)
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}
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#endif
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#endif /* ZSTDv07_H_235446 */
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