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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
|
/**
* \file lzma/stream_flags.h
* \brief .xz Stream Header and Stream Footer encoder and decoder
* \note Never include this file directly. Use <lzma.h> instead.
*/
/*
* Author: Lasse Collin
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef LZMA_H_INTERNAL
# error Never include this file directly. Use <lzma.h> instead.
#endif
/**
* \brief Size of Stream Header and Stream Footer
*
* Stream Header and Stream Footer have the same size and they are not
* going to change even if a newer version of the .xz file format is
* developed in future.
*/
#define LZMA_STREAM_HEADER_SIZE 12
/**
* \brief Options for encoding/decoding Stream Header and Stream Footer
*/
typedef struct {
/**
* \brief Stream Flags format version
*
* To prevent API and ABI breakages if new features are needed in
* Stream Header or Stream Footer, a version number is used to
* indicate which members in this structure are in use. For now,
* version must always be zero. With non-zero version, the
* lzma_stream_header_encode() and lzma_stream_footer_encode()
* will return LZMA_OPTIONS_ERROR.
*
* lzma_stream_header_decode() and lzma_stream_footer_decode()
* will always set this to the lowest value that supports all the
* features indicated by the Stream Flags field. The application
* must check that the version number set by the decoding functions
* is supported by the application. Otherwise it is possible that
* the application will decode the Stream incorrectly.
*/
uint32_t version;
/**
* \brief Backward Size
*
* Backward Size must be a multiple of four bytes. In this Stream
* format version, Backward Size is the size of the Index field.
*
* Backward Size isn't actually part of the Stream Flags field, but
* it is convenient to include in this structure anyway. Backward
* Size is present only in the Stream Footer. There is no need to
* initialize backward_size when encoding Stream Header.
*
* lzma_stream_header_decode() always sets backward_size to
* LZMA_VLI_UNKNOWN so that it is convenient to use
* lzma_stream_flags_compare() when both Stream Header and Stream
* Footer have been decoded.
*/
lzma_vli backward_size;
/**
* \brief Minimum value for lzma_stream_flags.backward_size
*/
# define LZMA_BACKWARD_SIZE_MIN 4
/**
* \brief Maximum value for lzma_stream_flags.backward_size
*/
# define LZMA_BACKWARD_SIZE_MAX (LZMA_VLI_C(1) << 34)
/**
* \brief Check ID
*
* This indicates the type of the integrity check calculated from
* uncompressed data.
*/
lzma_check check;
/*
* Reserved space to allow possible future extensions without
* breaking the ABI. You should not touch these, because the
* names of these variables may change.
*
* (We will never be able to use all of these since Stream Flags
* is just two bytes plus Backward Size of four bytes. But it's
* nice to have the proper types when they are needed.)
*/
/** \private Reserved member. */
lzma_reserved_enum reserved_enum1;
/** \private Reserved member. */
lzma_reserved_enum reserved_enum2;
/** \private Reserved member. */
lzma_reserved_enum reserved_enum3;
/** \private Reserved member. */
lzma_reserved_enum reserved_enum4;
/** \private Reserved member. */
lzma_bool reserved_bool1;
/** \private Reserved member. */
lzma_bool reserved_bool2;
/** \private Reserved member. */
lzma_bool reserved_bool3;
/** \private Reserved member. */
lzma_bool reserved_bool4;
/** \private Reserved member. */
lzma_bool reserved_bool5;
/** \private Reserved member. */
lzma_bool reserved_bool6;
/** \private Reserved member. */
lzma_bool reserved_bool7;
/** \private Reserved member. */
lzma_bool reserved_bool8;
/** \private Reserved member. */
uint32_t reserved_int1;
/** \private Reserved member. */
uint32_t reserved_int2;
} lzma_stream_flags;
/**
* \brief Encode Stream Header
*
* \param options Stream Header options to be encoded.
* options->backward_size is ignored and doesn't
* need to be initialized.
* \param[out] out Beginning of the output buffer of
* LZMA_STREAM_HEADER_SIZE bytes.
*
* \return Possible lzma_ret values:
* - LZMA_OK: Encoding was successful.
* - LZMA_OPTIONS_ERROR: options->version is not supported by
* this liblzma version.
* - LZMA_PROG_ERROR: Invalid options.
*/
extern LZMA_API(lzma_ret) lzma_stream_header_encode(
const lzma_stream_flags *options, uint8_t *out)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Encode Stream Footer
*
* \param options Stream Footer options to be encoded.
* \param[out] out Beginning of the output buffer of
* LZMA_STREAM_HEADER_SIZE bytes.
*
* \return Possible lzma_ret values:
* - LZMA_OK: Encoding was successful.
* - LZMA_OPTIONS_ERROR: options->version is not supported by
* this liblzma version.
* - LZMA_PROG_ERROR: Invalid options.
*/
extern LZMA_API(lzma_ret) lzma_stream_footer_encode(
const lzma_stream_flags *options, uint8_t *out)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Decode Stream Header
*
* options->backward_size is always set to LZMA_VLI_UNKNOWN. This is to
* help comparing Stream Flags from Stream Header and Stream Footer with
* lzma_stream_flags_compare().
*
* \note When decoding .xz files that contain multiple Streams, it may
* make sense to print "file format not recognized" only if
* decoding of the Stream Header of the \a first Stream gives
* LZMA_FORMAT_ERROR. If non-first Stream Header gives
* LZMA_FORMAT_ERROR, the message used for LZMA_DATA_ERROR is
* probably more appropriate.
* For example, the Stream decoder in liblzma uses
* LZMA_DATA_ERROR if LZMA_FORMAT_ERROR is returned by
* lzma_stream_header_decode() when decoding non-first Stream.
*
* \param[out] options Target for the decoded Stream Header options.
* \param in Beginning of the input buffer of
* LZMA_STREAM_HEADER_SIZE bytes.
*
*
* \return Possible lzma_ret values:
* - LZMA_OK: Decoding was successful.
* - LZMA_FORMAT_ERROR: Magic bytes don't match, thus the given
* buffer cannot be Stream Header.
* - LZMA_DATA_ERROR: CRC32 doesn't match, thus the header
* is corrupt.
* - LZMA_OPTIONS_ERROR: Unsupported options are present
* in the header.
*/
extern LZMA_API(lzma_ret) lzma_stream_header_decode(
lzma_stream_flags *options, const uint8_t *in)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Decode Stream Footer
*
* \note If Stream Header was already decoded successfully, but
* decoding Stream Footer returns LZMA_FORMAT_ERROR, the
* application should probably report some other error message
* than "file format not recognized". The file likely
* is corrupt (possibly truncated). The Stream decoder in liblzma
* uses LZMA_DATA_ERROR in this situation.
*
* \param[out] options Target for the decoded Stream Footer options.
* \param in Beginning of the input buffer of
* LZMA_STREAM_HEADER_SIZE bytes.
*
* \return Possible lzma_ret values:
* - LZMA_OK: Decoding was successful.
* - LZMA_FORMAT_ERROR: Magic bytes don't match, thus the given
* buffer cannot be Stream Footer.
* - LZMA_DATA_ERROR: CRC32 doesn't match, thus the Stream Footer
* is corrupt.
* - LZMA_OPTIONS_ERROR: Unsupported options are present
* in Stream Footer.
*/
extern LZMA_API(lzma_ret) lzma_stream_footer_decode(
lzma_stream_flags *options, const uint8_t *in)
lzma_nothrow lzma_attr_warn_unused_result;
/**
* \brief Compare two lzma_stream_flags structures
*
* backward_size values are compared only if both are not
* LZMA_VLI_UNKNOWN.
*
* \param a Pointer to lzma_stream_flags structure
* \param b Pointer to lzma_stream_flags structure
*
* \return Possible lzma_ret values:
* - LZMA_OK: Both are equal. If either had backward_size set
* to LZMA_VLI_UNKNOWN, backward_size values were not
* compared or validated.
* - LZMA_DATA_ERROR: The structures differ.
* - LZMA_OPTIONS_ERROR: version in either structure is greater
* than the maximum supported version (currently zero).
* - LZMA_PROG_ERROR: Invalid value, e.g. invalid check or
* backward_size.
*/
extern LZMA_API(lzma_ret) lzma_stream_flags_compare(
const lzma_stream_flags *a, const lzma_stream_flags *b)
lzma_nothrow lzma_attr_pure;
|
