2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
14 #if defined (__cplusplus)
18 /*====== Dependency ======*/
19 #include <stddef.h> /* size_t */
22 /*====== Export for Windows ======*/
24 * ZSTDv06_DLL_EXPORT :
25 * Enable exporting of functions when building a Windows DLL
27 #if defined(_WIN32) && defined(ZSTDv06_DLL_EXPORT) && (ZSTDv06_DLL_EXPORT==1)
28 # define ZSTDLIBv06_API __declspec(dllexport)
30 # define ZSTDLIBv06_API
34 /* *************************************
36 ***************************************/
37 /*! ZSTDv06_decompress() :
38 `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
39 `dstCapacity` must be large enough, equal or larger than originalSize.
40 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
41 or an errorCode if it fails (which can be tested using ZSTDv06_isError()) */
42 ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity,
43 const void* src, size_t compressedSize);
46 ZSTDv06_getFrameSrcSize() : get the source length of a ZSTD frame
47 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
48 return : the number of bytes that would be read to decompress this frame
49 or an errorCode if it fails (which can be tested using ZSTDv06_isError())
51 size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize);
53 /* *************************************
55 ***************************************/
56 ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */
58 /* Error Management */
59 ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
60 ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */
63 /* *************************************
64 * Explicit memory management
65 ***************************************/
66 /** Decompression context */
67 typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx;
68 ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void);
69 ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */
71 /** ZSTDv06_decompressDCtx() :
72 * Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */
73 ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
76 /*-***********************
78 *************************/
79 /*! ZSTDv06_decompress_usingDict() :
80 * Decompression using a pre-defined Dictionary content (see dictBuilder).
81 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
82 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */
83 ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx,
84 void* dst, size_t dstCapacity,
85 const void* src, size_t srcSize,
86 const void* dict,size_t dictSize);
89 /*-************************
90 * Advanced Streaming API
91 ***************************/
92 struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; };
93 typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams;
95 ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
96 ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize);
97 ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx);
99 ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx);
100 ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
104 /* *************************************
106 ***************************************/
108 typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx;
109 ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void);
110 ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx);
112 ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx);
113 ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize);
115 ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx,
116 void* dst, size_t* dstCapacityPtr,
117 const void* src, size_t* srcSizePtr);
119 /*-***************************************************************************
120 * Streaming decompression howto
122 * A ZBUFFv06_DCtx object is required to track streaming operations.
123 * Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources.
124 * Use ZBUFFv06_decompressInit() to start a new decompression operation,
125 * or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary.
126 * Note that ZBUFFv06_DCtx objects can be re-init multiple times.
128 * Use ZBUFFv06_decompressContinue() repetitively to consume your input.
129 * *srcSizePtr and *dstCapacityPtr can be any size.
130 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
131 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
132 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
133 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
134 * or 0 when a frame is completely decoded,
135 * or an error code, which can be tested using ZBUFFv06_isError().
137 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize()
138 * output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
139 * input : ZBUFFv06_recommendedDInSize == 128KB + 3;
140 * just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
141 * *******************************************************************************/
144 /* *************************************
146 ***************************************/
147 ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode);
148 ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode);
150 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
151 * These sizes are just hints, they tend to offer better latency */
152 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void);
153 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void);
156 /*-*************************************
158 ***************************************/
159 #define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */
163 #if defined (__cplusplus)
167 #endif /* ZSTDv06_BUFFERED_H */