2 * Copyright (c) Yann Collet, Meta Platforms, Inc. and affiliates.
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_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.6.x format
47 srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
48 cSize (output parameter) : the number of bytes that would be read to decompress this frame
49 or an error code if it fails (which can be tested using ZSTDv01_isError())
50 dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
51 or ZSTD_CONTENTSIZE_ERROR if an error occurs
53 note : assumes `cSize` and `dBound` are _not_ NULL.
55 void ZSTDv06_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
56 size_t* cSize, unsigned long long* dBound);
58 /* *************************************
60 ***************************************/
61 ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */
63 /* Error Management */
64 ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
65 ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */
68 /* *************************************
69 * Explicit memory management
70 ***************************************/
71 /** Decompression context */
72 typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx;
73 ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void);
74 ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */
76 /** ZSTDv06_decompressDCtx() :
77 * Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */
78 ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
81 /*-***********************
83 *************************/
84 /*! ZSTDv06_decompress_usingDict() :
85 * Decompression using a pre-defined Dictionary content (see dictBuilder).
86 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
87 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */
88 ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx,
89 void* dst, size_t dstCapacity,
90 const void* src, size_t srcSize,
91 const void* dict,size_t dictSize);
94 /*-************************
95 * Advanced Streaming API
96 ***************************/
97 struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; };
98 typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams;
100 ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
101 ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize);
102 ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx);
104 ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx);
105 ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
109 /* *************************************
111 ***************************************/
113 typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx;
114 ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void);
115 ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx);
117 ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx);
118 ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize);
120 ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx,
121 void* dst, size_t* dstCapacityPtr,
122 const void* src, size_t* srcSizePtr);
124 /*-***************************************************************************
125 * Streaming decompression howto
127 * A ZBUFFv06_DCtx object is required to track streaming operations.
128 * Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources.
129 * Use ZBUFFv06_decompressInit() to start a new decompression operation,
130 * or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary.
131 * Note that ZBUFFv06_DCtx objects can be re-init multiple times.
133 * Use ZBUFFv06_decompressContinue() repetitively to consume your input.
134 * *srcSizePtr and *dstCapacityPtr can be any size.
135 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
136 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
137 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
138 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
139 * or 0 when a frame is completely decoded,
140 * or an error code, which can be tested using ZBUFFv06_isError().
142 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize()
143 * output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
144 * input : ZBUFFv06_recommendedDInSize == 128KB + 3;
145 * just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
146 * *******************************************************************************/
149 /* *************************************
151 ***************************************/
152 ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode);
153 ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode);
155 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
156 * These sizes are just hints, they tend to offer better latency */
157 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void);
158 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void);
161 /*-*************************************
163 ***************************************/
164 #define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */
168 #if defined (__cplusplus)
172 #endif /* ZSTDv06_BUFFERED_H */