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
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* istream.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "compat.h"
#include "sqfs/io.h"
#include "sqfs/error.h"
#include "xfrm/compress.h"
#include "xfrm/wrap.h"
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#define BUFSZ (262144)
typedef struct istream_xfrm_t {
sqfs_istream_t base;
sqfs_istream_t *wrapped;
xfrm_stream_t *xfrm;
size_t buffer_offset;
size_t buffer_used;
sqfs_u8 uncompressed[BUFSZ];
} istream_xfrm_t;
static int precache(sqfs_istream_t *base)
{
istream_xfrm_t *xfrm = (istream_xfrm_t *)base;
int ret;
if (xfrm->buffer_offset > 0 &&
xfrm->buffer_offset < xfrm->buffer_used) {
memmove(xfrm->uncompressed,
xfrm->uncompressed + xfrm->buffer_offset,
xfrm->buffer_used - xfrm->buffer_offset);
}
xfrm->buffer_used -= xfrm->buffer_offset;
xfrm->buffer_offset = 0;
for (;;) {
sqfs_u32 in_off = 0, out_off = xfrm->buffer_used;
int mode = XFRM_STREAM_FLUSH_NONE;
const sqfs_u8 *ptr;
size_t avail;
ret = xfrm->wrapped->get_buffered_data(xfrm->wrapped, &ptr,
&avail, BUFSZ);
if (ret < 0)
return ret;
if (ret > 0)
mode = XFRM_STREAM_FLUSH_FULL;
ret = xfrm->xfrm->process_data(xfrm->xfrm,
ptr, avail,
xfrm->uncompressed + out_off,
BUFSZ - out_off,
&in_off, &out_off, mode);
if (ret == XFRM_STREAM_ERROR)
return SQFS_ERROR_COMPRESSOR;
xfrm->buffer_used = out_off;
xfrm->wrapped->advance_buffer(xfrm->wrapped, in_off);
if (ret == XFRM_STREAM_BUFFER_FULL || out_off >= BUFSZ)
break;
if (mode == XFRM_STREAM_FLUSH_FULL)
break;
}
return 0;
}
static int xfrm_get_buffered_data(sqfs_istream_t *strm, const sqfs_u8 **out,
size_t *size, size_t want)
{
istream_xfrm_t *xfrm = (istream_xfrm_t *)strm;
if (want > BUFSZ)
want = BUFSZ;
if (xfrm->buffer_used == 0 ||
(xfrm->buffer_used - xfrm->buffer_offset) < want) {
int ret = precache(strm);
if (ret)
return ret;
}
*out = xfrm->uncompressed + xfrm->buffer_offset;
*size = xfrm->buffer_used - xfrm->buffer_offset;
return (*size == 0) ? 1 : 0;
}
static void xfrm_advance_buffer(sqfs_istream_t *strm, size_t count)
{
istream_xfrm_t *xfrm = (istream_xfrm_t *)strm;
assert(count <= xfrm->buffer_used);
xfrm->buffer_offset += count;
assert(xfrm->buffer_offset <= xfrm->buffer_used);
}
static const char *xfrm_get_filename(sqfs_istream_t *strm)
{
istream_xfrm_t *xfrm = (istream_xfrm_t *)strm;
return xfrm->wrapped->get_filename(xfrm->wrapped);
}
static void xfrm_destroy(sqfs_object_t *obj)
{
istream_xfrm_t *xfrm = (istream_xfrm_t *)obj;
sqfs_drop(xfrm->xfrm);
sqfs_drop(xfrm->wrapped);
free(xfrm);
}
sqfs_istream_t *istream_xfrm_create(sqfs_istream_t *strm, xfrm_stream_t *xfrm)
{
istream_xfrm_t *stream = calloc(1, sizeof(*stream));
sqfs_istream_t *base = (sqfs_istream_t *)stream;
if (stream == NULL)
goto fail;
sqfs_object_init(stream, xfrm_destroy, NULL);
stream->wrapped = sqfs_grab(strm);
stream->xfrm = sqfs_grab(xfrm);
base->get_buffered_data = xfrm_get_buffered_data;
base->advance_buffer = xfrm_advance_buffer;
base->get_filename = xfrm_get_filename;
return base;
fail:
fprintf(stderr, "%s: error initializing decompressor stream.\n",
strm->get_filename(strm));
return NULL;
}
|
