forked from DataDog/zstd
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathzstd_v07.h
187 lines (151 loc) · 8.51 KB
/
zstd_v07.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/*
* Copyright (c) Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#ifndef ZSTDv07_H_235446
#define ZSTDv07_H_235446
#if defined (__cplusplus)
extern "C" {
#endif
/*====== Dependency ======*/
#include <stddef.h> /* size_t */
/*====== Export for Windows ======*/
/*!
* ZSTDv07_DLL_EXPORT :
* Enable exporting of functions when building a Windows DLL
*/
#if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1)
# define ZSTDLIBv07_API __declspec(dllexport)
#else
# define ZSTDLIBv07_API
#endif
/* *************************************
* Simple API
***************************************/
/*! ZSTDv07_getDecompressedSize() :
* @return : decompressed size if known, 0 otherwise.
note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause.
note 2 : decompressed size could be wrong or intentionally modified !
always ensure results fit within application's authorized limits */
unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize);
/*! ZSTDv07_decompress() :
`compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail.
`dstCapacity` must be equal or larger than originalSize.
@return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */
ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity,
const void* src, size_t compressedSize);
/**
ZSTDv07_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.7.x format
srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
cSize (output parameter) : the number of bytes that would be read to decompress this frame
or an error code if it fails (which can be tested using ZSTDv01_isError())
dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
or ZSTD_CONTENTSIZE_ERROR if an error occurs
note : assumes `cSize` and `dBound` are _not_ NULL.
*/
void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
size_t* cSize, unsigned long long* dBound);
/*====== Helper functions ======*/
ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from an error code */
/*-*************************************
* Explicit memory management
***************************************/
/** Decompression context */
typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx;
ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void);
ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */
/** ZSTDv07_decompressDCtx() :
* Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */
ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
/*-************************
* Simple dictionary API
***************************/
/*! ZSTDv07_decompress_usingDict() :
* Decompression using a pre-defined Dictionary content (see dictBuilder).
* Dictionary must be identical to the one used during compression.
* Note : This function load the dictionary, resulting in a significant startup time */
ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const void* dict,size_t dictSize);
/*-**************************
* Advanced Dictionary API
****************************/
/*! ZSTDv07_createDDict() :
* Create a digested dictionary, ready to start decompression operation without startup delay.
* `dict` can be released after creation */
typedef struct ZSTDv07_DDict_s ZSTDv07_DDict;
ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize);
ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict);
/*! ZSTDv07_decompress_usingDDict() :
* Decompression using a pre-digested Dictionary
* Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */
ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const ZSTDv07_DDict* ddict);
typedef struct {
unsigned long long frameContentSize;
unsigned windowSize;
unsigned dictID;
unsigned checksumFlag;
} ZSTDv07_frameParams;
ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
/* *************************************
* Streaming functions
***************************************/
typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx;
ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void);
ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx);
ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx);
ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize);
ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx,
void* dst, size_t* dstCapacityPtr,
const void* src, size_t* srcSizePtr);
/*-***************************************************************************
* Streaming decompression howto
*
* A ZBUFFv07_DCtx object is required to track streaming operations.
* Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
* Use ZBUFFv07_decompressInit() to start a new decompression operation,
* or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
* Note that ZBUFFv07_DCtx objects can be re-init multiple times.
*
* Use ZBUFFv07_decompressContinue() repetitively to consume your input.
* *srcSizePtr and *dstCapacityPtr can be any size.
* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
* Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
* The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
* or 0 when a frame is completely decoded,
* or an error code, which can be tested using ZBUFFv07_isError().
*
* Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
* output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
* input : ZBUFFv07_recommendedDInSize == 128KB + 3;
* just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
* *******************************************************************************/
/* *************************************
* Tool functions
***************************************/
ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode);
ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode);
/** Functions below provide recommended buffer sizes for Compression or Decompression operations.
* These sizes are just hints, they tend to offer better latency */
ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void);
ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void);
/*-*************************************
* Constants
***************************************/
#define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */
#if defined (__cplusplus)
}
#endif
#endif /* ZSTDv07_H_235446 */