2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
5 * This source code is licensed under the BSD-style license found in the
6 * LICENSE file in the root directory of this source tree. An additional grant
7 * of patent rights can be found in the PATENTS file in the same directory.
13 #if defined (__cplusplus)
17 /*====== Dependency ======*/
18 #include <stddef.h> /* size_t */
21 /*====== Export for Windows ======*/
23 * ZSTDv06_DLL_EXPORT :
24 * Enable exporting of functions when building a Windows DLL
26 #if defined(_WIN32) && defined(ZSTDv06_DLL_EXPORT) && (ZSTDv06_DLL_EXPORT==1)
27 # define ZSTDLIBv06_API __declspec(dllexport)
29 # define ZSTDLIBv06_API
33 /* *************************************
35 ***************************************/
36 /*! ZSTDv06_decompress() :
37 `compressedSize` : is the _exact_ size of the compressed blob, otherwise decompression will fail.
38 `dstCapacity` must be large enough, equal or larger than originalSize.
39 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
40 or an errorCode if it fails (which can be tested using ZSTDv06_isError()) */
41 ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity,
42 const void* src, size_t compressedSize);
45 ZSTDv06_getFrameSrcSize() : get the source length of a ZSTD frame
46 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
47 return : the number of bytes that would be read to decompress this frame
48 or an errorCode if it fails (which can be tested using ZSTDv06_isError())
50 size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize);
52 /* *************************************
54 ***************************************/
55 ZSTDLIBv06_API size_t ZSTDv06_compressBound(size_t srcSize); /*!< maximum compressed size (worst case scenario) */
57 /* Error Management */
58 ZSTDLIBv06_API unsigned ZSTDv06_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
59 ZSTDLIBv06_API const char* ZSTDv06_getErrorName(size_t code); /*!< provides readable string for an error code */
62 /* *************************************
63 * Explicit memory management
64 ***************************************/
65 /** Decompression context */
66 typedef struct ZSTDv06_DCtx_s ZSTDv06_DCtx;
67 ZSTDLIBv06_API ZSTDv06_DCtx* ZSTDv06_createDCtx(void);
68 ZSTDLIBv06_API size_t ZSTDv06_freeDCtx(ZSTDv06_DCtx* dctx); /*!< @return : errorCode */
70 /** ZSTDv06_decompressDCtx() :
71 * Same as ZSTDv06_decompress(), but requires an already allocated ZSTDv06_DCtx (see ZSTDv06_createDCtx()) */
72 ZSTDLIBv06_API size_t ZSTDv06_decompressDCtx(ZSTDv06_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
75 /*-***********************
77 *************************/
78 /*! ZSTDv06_decompress_usingDict() :
79 * Decompression using a pre-defined Dictionary content (see dictBuilder).
80 * Dictionary must be identical to the one used during compression, otherwise regenerated data will be corrupted.
81 * Note : dict can be NULL, in which case, it's equivalent to ZSTDv06_decompressDCtx() */
82 ZSTDLIBv06_API size_t ZSTDv06_decompress_usingDict(ZSTDv06_DCtx* dctx,
83 void* dst, size_t dstCapacity,
84 const void* src, size_t srcSize,
85 const void* dict,size_t dictSize);
88 /*-************************
89 * Advanced Streaming API
90 ***************************/
91 struct ZSTDv06_frameParams_s { unsigned long long frameContentSize; unsigned windowLog; };
92 typedef struct ZSTDv06_frameParams_s ZSTDv06_frameParams;
94 ZSTDLIBv06_API size_t ZSTDv06_getFrameParams(ZSTDv06_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
95 ZSTDLIBv06_API size_t ZSTDv06_decompressBegin_usingDict(ZSTDv06_DCtx* dctx, const void* dict, size_t dictSize);
96 ZSTDLIBv06_API void ZSTDv06_copyDCtx(ZSTDv06_DCtx* dctx, const ZSTDv06_DCtx* preparedDCtx);
98 ZSTDLIBv06_API size_t ZSTDv06_nextSrcSizeToDecompress(ZSTDv06_DCtx* dctx);
99 ZSTDLIBv06_API size_t ZSTDv06_decompressContinue(ZSTDv06_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
103 /* *************************************
105 ***************************************/
107 typedef struct ZBUFFv06_DCtx_s ZBUFFv06_DCtx;
108 ZSTDLIBv06_API ZBUFFv06_DCtx* ZBUFFv06_createDCtx(void);
109 ZSTDLIBv06_API size_t ZBUFFv06_freeDCtx(ZBUFFv06_DCtx* dctx);
111 ZSTDLIBv06_API size_t ZBUFFv06_decompressInit(ZBUFFv06_DCtx* dctx);
112 ZSTDLIBv06_API size_t ZBUFFv06_decompressInitDictionary(ZBUFFv06_DCtx* dctx, const void* dict, size_t dictSize);
114 ZSTDLIBv06_API size_t ZBUFFv06_decompressContinue(ZBUFFv06_DCtx* dctx,
115 void* dst, size_t* dstCapacityPtr,
116 const void* src, size_t* srcSizePtr);
118 /*-***************************************************************************
119 * Streaming decompression howto
121 * A ZBUFFv06_DCtx object is required to track streaming operations.
122 * Use ZBUFFv06_createDCtx() and ZBUFFv06_freeDCtx() to create/release resources.
123 * Use ZBUFFv06_decompressInit() to start a new decompression operation,
124 * or ZBUFFv06_decompressInitDictionary() if decompression requires a dictionary.
125 * Note that ZBUFFv06_DCtx objects can be re-init multiple times.
127 * Use ZBUFFv06_decompressContinue() repetitively to consume your input.
128 * *srcSizePtr and *dstCapacityPtr can be any size.
129 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
130 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
131 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
132 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
133 * or 0 when a frame is completely decoded,
134 * or an error code, which can be tested using ZBUFFv06_isError().
136 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv06_recommendedDInSize() and ZBUFFv06_recommendedDOutSize()
137 * output : ZBUFFv06_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
138 * input : ZBUFFv06_recommendedDInSize == 128KB + 3;
139 * just follow indications from ZBUFFv06_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
140 * *******************************************************************************/
143 /* *************************************
145 ***************************************/
146 ZSTDLIBv06_API unsigned ZBUFFv06_isError(size_t errorCode);
147 ZSTDLIBv06_API const char* ZBUFFv06_getErrorName(size_t errorCode);
149 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
150 * These sizes are just hints, they tend to offer better latency */
151 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDInSize(void);
152 ZSTDLIBv06_API size_t ZBUFFv06_recommendedDOutSize(void);
155 /*-*************************************
157 ***************************************/
158 #define ZSTDv06_MAGICNUMBER 0xFD2FB526 /* v0.6 */
162 #if defined (__cplusplus)
166 #endif /* ZSTDv06_BUFFERED_H */