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.
11 #ifndef ZSTDv07_H_235446
12 #define ZSTDv07_H_235446
14 #if defined (__cplusplus)
18 /*====== Dependency ======*/
19 #include <stddef.h> /* size_t */
22 /*====== Export for Windows ======*/
24 * ZSTDv07_DLL_EXPORT :
25 * Enable exporting of functions when building a Windows DLL
27 #if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1)
28 # define ZSTDLIBv07_API __declspec(dllexport)
30 # define ZSTDLIBv07_API
34 /* *************************************
36 ***************************************/
37 /*! ZSTDv07_getDecompressedSize() :
38 * @return : decompressed size if known, 0 otherwise.
39 note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause.
40 note 2 : decompressed size could be wrong or intentionally modified !
41 always ensure results fit within application's authorized limits */
42 unsigned long long ZSTDv07_getDecompressedSize(const void* src
, size_t srcSize
);
44 /*! ZSTDv07_decompress() :
45 `compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail.
46 `dstCapacity` must be equal or larger than originalSize.
47 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
48 or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */
49 ZSTDLIBv07_API
size_t ZSTDv07_decompress( void* dst
, size_t dstCapacity
,
50 const void* src
, size_t compressedSize
);
53 ZSTDv07_getFrameSrcSize() : get the source length of a ZSTD frame
54 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
55 return : the number of bytes that would be read to decompress this frame
56 or an errorCode if it fails (which can be tested using ZSTDv07_isError())
58 size_t ZSTDv07_findFrameCompressedSize(const void* src
, size_t compressedSize
);
60 /*====== Helper functions ======*/
61 ZSTDLIBv07_API
unsigned ZSTDv07_isError(size_t code
); /*!< tells if a `size_t` function result is an error code */
62 ZSTDLIBv07_API
const char* ZSTDv07_getErrorName(size_t code
); /*!< provides readable string from an error code */
65 /*-*************************************
66 * Explicit memory management
67 ***************************************/
68 /** Decompression context */
69 typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx
;
70 ZSTDLIBv07_API ZSTDv07_DCtx
* ZSTDv07_createDCtx(void);
71 ZSTDLIBv07_API
size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx
* dctx
); /*!< @return : errorCode */
73 /** ZSTDv07_decompressDCtx() :
74 * Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */
75 ZSTDLIBv07_API
size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx
* ctx
, void* dst
, size_t dstCapacity
, const void* src
, size_t srcSize
);
78 /*-************************
79 * Simple dictionary API
80 ***************************/
81 /*! ZSTDv07_decompress_usingDict() :
82 * Decompression using a pre-defined Dictionary content (see dictBuilder).
83 * Dictionary must be identical to the one used during compression.
84 * Note : This function load the dictionary, resulting in a significant startup time */
85 ZSTDLIBv07_API
size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx
* dctx
,
86 void* dst
, size_t dstCapacity
,
87 const void* src
, size_t srcSize
,
88 const void* dict
,size_t dictSize
);
91 /*-**************************
92 * Advanced Dictionary API
93 ****************************/
94 /*! ZSTDv07_createDDict() :
95 * Create a digested dictionary, ready to start decompression operation without startup delay.
96 * `dict` can be released after creation */
97 typedef struct ZSTDv07_DDict_s ZSTDv07_DDict
;
98 ZSTDLIBv07_API ZSTDv07_DDict
* ZSTDv07_createDDict(const void* dict
, size_t dictSize
);
99 ZSTDLIBv07_API
size_t ZSTDv07_freeDDict(ZSTDv07_DDict
* ddict
);
101 /*! ZSTDv07_decompress_usingDDict() :
102 * Decompression using a pre-digested Dictionary
103 * Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */
104 ZSTDLIBv07_API
size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx
* dctx
,
105 void* dst
, size_t dstCapacity
,
106 const void* src
, size_t srcSize
,
107 const ZSTDv07_DDict
* ddict
);
110 unsigned long long frameContentSize
;
113 unsigned checksumFlag
;
114 } ZSTDv07_frameParams
;
116 ZSTDLIBv07_API
size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams
* fparamsPtr
, const void* src
, size_t srcSize
); /**< doesn't consume input */
121 /* *************************************
122 * Streaming functions
123 ***************************************/
124 typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx
;
125 ZSTDLIBv07_API ZBUFFv07_DCtx
* ZBUFFv07_createDCtx(void);
126 ZSTDLIBv07_API
size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx
* dctx
);
128 ZSTDLIBv07_API
size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx
* dctx
);
129 ZSTDLIBv07_API
size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx
* dctx
, const void* dict
, size_t dictSize
);
131 ZSTDLIBv07_API
size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx
* dctx
,
132 void* dst
, size_t* dstCapacityPtr
,
133 const void* src
, size_t* srcSizePtr
);
135 /*-***************************************************************************
136 * Streaming decompression howto
138 * A ZBUFFv07_DCtx object is required to track streaming operations.
139 * Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
140 * Use ZBUFFv07_decompressInit() to start a new decompression operation,
141 * or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
142 * Note that ZBUFFv07_DCtx objects can be re-init multiple times.
144 * Use ZBUFFv07_decompressContinue() repetitively to consume your input.
145 * *srcSizePtr and *dstCapacityPtr can be any size.
146 * The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
147 * Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
148 * The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
149 * @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
150 * or 0 when a frame is completely decoded,
151 * or an error code, which can be tested using ZBUFFv07_isError().
153 * Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
154 * output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
155 * input : ZBUFFv07_recommendedDInSize == 128KB + 3;
156 * just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
157 * *******************************************************************************/
160 /* *************************************
162 ***************************************/
163 ZSTDLIBv07_API
unsigned ZBUFFv07_isError(size_t errorCode
);
164 ZSTDLIBv07_API
const char* ZBUFFv07_getErrorName(size_t errorCode
);
166 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
167 * These sizes are just hints, they tend to offer better latency */
168 ZSTDLIBv07_API
size_t ZBUFFv07_recommendedDInSize(void);
169 ZSTDLIBv07_API
size_t ZBUFFv07_recommendedDOutSize(void);
172 /*-*************************************
174 ***************************************/
175 #define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */
178 #if defined (__cplusplus)
182 #endif /* ZSTDv07_H_235446 */