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
|
///////////////////////////////////////////////////////////////////////////////
//
/// \file block_encoder.c
/// \brief Encodes .xz Blocks
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "block_encoder.h"
#include "filter_encoder.h"
#include "check.h"
typedef struct {
/// The filters in the chain; initialized with lzma_raw_decoder_init().
lzma_next_coder next;
/// Encoding options; we also write Unpadded Size, Compressed Size,
/// and Uncompressed Size back to this structure when the encoding
/// has been finished.
lzma_block *block;
enum {
SEQ_CODE,
SEQ_PADDING,
SEQ_CHECK,
} sequence;
/// Compressed Size calculated while encoding
lzma_vli compressed_size;
/// Uncompressed Size calculated while encoding
lzma_vli uncompressed_size;
/// Position in the Check field
size_t pos;
/// Check of the uncompressed data
lzma_check_state check;
} lzma_block_coder;
static lzma_ret
block_encode(void *coder_ptr, const lzma_allocator *allocator,
const uint8_t *restrict in, size_t *restrict in_pos,
size_t in_size, uint8_t *restrict out,
size_t *restrict out_pos, size_t out_size, lzma_action action)
{
lzma_block_coder *coder = coder_ptr;
// Check that our amount of input stays in proper limits.
if (LZMA_VLI_MAX - coder->uncompressed_size < in_size - *in_pos)
return LZMA_DATA_ERROR;
switch (coder->sequence) {
case SEQ_CODE: {
const size_t in_start = *in_pos;
const size_t out_start = *out_pos;
const lzma_ret ret = coder->next.code(coder->next.coder,
allocator, in, in_pos, in_size,
out, out_pos, out_size, action);
const size_t in_used = *in_pos - in_start;
const size_t out_used = *out_pos - out_start;
if (COMPRESSED_SIZE_MAX - coder->compressed_size < out_used)
return LZMA_DATA_ERROR;
coder->compressed_size += out_used;
// No need to check for overflow because we have already
// checked it at the beginning of this function.
coder->uncompressed_size += in_used;
lzma_check_update(&coder->check, coder->block->check,
in + in_start, in_used);
if (ret != LZMA_STREAM_END || action == LZMA_SYNC_FLUSH)
return ret;
assert(*in_pos == in_size);
assert(action == LZMA_FINISH);
// Copy the values into coder->block. The caller
// may use this information to construct Index.
coder->block->compressed_size = coder->compressed_size;
coder->block->uncompressed_size = coder->uncompressed_size;
coder->sequence = SEQ_PADDING;
}
// Fall through
case SEQ_PADDING:
// Pad Compressed Data to a multiple of four bytes. We can
// use coder->compressed_size for this since we don't need
// it for anything else anymore.
while (coder->compressed_size & 3) {
if (*out_pos >= out_size)
return LZMA_OK;
out[*out_pos] = 0x00;
++*out_pos;
++coder->compressed_size;
}
if (coder->block->check == LZMA_CHECK_NONE)
return LZMA_STREAM_END;
lzma_check_finish(&coder->check, coder->block->check);
coder->sequence = SEQ_CHECK;
// Fall through
case SEQ_CHECK: {
const size_t check_size = lzma_check_size(coder->block->check);
lzma_bufcpy(coder->check.buffer.u8, &coder->pos, check_size,
out, out_pos, out_size);
if (coder->pos < check_size)
return LZMA_OK;
memcpy(coder->block->raw_check, coder->check.buffer.u8,
check_size);
return LZMA_STREAM_END;
}
}
return LZMA_PROG_ERROR;
}
static void
block_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
{
lzma_block_coder *coder = coder_ptr;
lzma_next_end(&coder->next, allocator);
lzma_free(coder, allocator);
return;
}
static lzma_ret
block_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
const lzma_filter *filters lzma_attribute((__unused__)),
const lzma_filter *reversed_filters)
{
lzma_block_coder *coder = coder_ptr;
if (coder->sequence != SEQ_CODE)
return LZMA_PROG_ERROR;
return lzma_next_filter_update(
&coder->next, allocator, reversed_filters);
}
extern lzma_ret
lzma_block_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
lzma_block *block)
{
lzma_next_coder_init(&lzma_block_encoder_init, next, allocator);
if (block == NULL)
return LZMA_PROG_ERROR;
// The contents of the structure may depend on the version so
// check the version first.
if (block->version > 1)
return LZMA_OPTIONS_ERROR;
// If the Check ID is not supported, we cannot calculate the check and
// thus not create a proper Block.
if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
return LZMA_PROG_ERROR;
if (!lzma_check_is_supported(block->check))
return LZMA_UNSUPPORTED_CHECK;
// Allocate and initialize *next->coder if needed.
lzma_block_coder *coder = next->coder;
if (coder == NULL) {
coder = lzma_alloc(sizeof(lzma_block_coder), allocator);
if (coder == NULL)
return LZMA_MEM_ERROR;
next->coder = coder;
next->code = &block_encode;
next->end = &block_encoder_end;
next->update = &block_encoder_update;
coder->next = LZMA_NEXT_CODER_INIT;
}
// Basic initializations
coder->sequence = SEQ_CODE;
coder->block = block;
coder->compressed_size = 0;
coder->uncompressed_size = 0;
coder->pos = 0;
// Initialize the check
lzma_check_init(&coder->check, block->check);
// Initialize the requested filters.
return lzma_raw_encoder_init(&coder->next, allocator, block->filters);
}
extern LZMA_API(lzma_ret)
lzma_block_encoder(lzma_stream *strm, lzma_block *block)
{
lzma_next_strm_init(lzma_block_encoder_init, strm, block);
strm->internal->supported_actions[LZMA_RUN] = true;
strm->internal->supported_actions[LZMA_FINISH] = true;
return LZMA_OK;
}
|
