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
|
/*
* QEMU buffered QEMUFile
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu-common.h"
#include "hw/hw.h"
#include "qemu-timer.h"
#include "sysemu.h"
#include "qemu-char.h"
#include "buffered_file.h"
//#define DEBUG_BUFFERED_FILE
typedef struct QEMUFileBuffered
{
BufferedPutFunc *put_buffer;
BufferedPutReadyFunc *put_ready;
BufferedWaitForUnfreezeFunc *wait_for_unfreeze;
BufferedCloseFunc *close;
void *opaque;
QEMUFile *file;
int has_error;
int freeze_output;
size_t bytes_xfer;
size_t xfer_limit;
uint8_t *buffer;
size_t buffer_size;
size_t buffer_capacity;
QEMUTimer *timer;
} QEMUFileBuffered;
#ifdef DEBUG_BUFFERED_FILE
#define dprintf(fmt, ...) \
do { printf("buffered-file: " fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...) \
do { } while (0)
#endif
static void buffered_append(QEMUFileBuffered *s,
const uint8_t *buf, size_t size)
{
if (size > (s->buffer_capacity - s->buffer_size)) {
void *tmp;
dprintf("increasing buffer capacity from %ld by %ld\n",
s->buffer_capacity, size + 1024);
s->buffer_capacity += size + 1024;
tmp = qemu_realloc(s->buffer, s->buffer_capacity);
if (tmp == NULL) {
fprintf(stderr, "qemu file buffer expansion failed\n");
exit(1);
}
s->buffer = tmp;
}
memcpy(s->buffer + s->buffer_size, buf, size);
s->buffer_size += size;
}
static void buffered_flush(QEMUFileBuffered *s)
{
size_t offset = 0;
if (s->has_error) {
dprintf("flush when error, bailing\n");
return;
}
dprintf("flushing %ld byte(s) of data\n", s->buffer_size);
while (offset < s->buffer_size) {
ssize_t ret;
ret = s->put_buffer(s->opaque, s->buffer + offset,
s->buffer_size - offset);
if (ret == -EAGAIN) {
dprintf("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
dprintf("error flushing data, %ld\n", ret);
s->has_error = 1;
break;
} else {
dprintf("flushed %ld byte(s)\n", ret);
offset += ret;
}
}
dprintf("flushed %ld of %ld byte(s)\n", offset, s->buffer_size);
memmove(s->buffer, s->buffer + offset, s->buffer_size - offset);
s->buffer_size -= offset;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
int offset = 0;
ssize_t ret;
dprintf("putting %ld bytes at %Ld\n", size, pos);
if (s->has_error) {
dprintf("flush when error, bailing\n");
return -EINVAL;
}
dprintf("unfreezing output\n");
s->freeze_output = 0;
buffered_flush(s);
while (!s->freeze_output && offset < size) {
if (s->bytes_xfer > s->xfer_limit) {
dprintf("transfer limit exceeded when putting\n");
break;
}
ret = s->put_buffer(s->opaque, buf + offset, size - offset);
if (ret == -EAGAIN) {
dprintf("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
dprintf("error putting\n");
s->has_error = 1;
offset = -EINVAL;
break;
}
dprintf("put %ld byte(s)\n", ret);
offset += ret;
s->bytes_xfer += ret;
}
if (offset >= 0) {
dprintf("buffering %ld bytes\n", size - offset);
buffered_append(s, buf + offset, size - offset);
offset = size;
}
return offset;
}
static int buffered_close(void *opaque)
{
QEMUFileBuffered *s = opaque;
int ret;
dprintf("closing\n");
while (!s->has_error && s->buffer_size) {
buffered_flush(s);
if (s->freeze_output)
s->wait_for_unfreeze(s);
}
ret = s->close(s->opaque);
qemu_del_timer(s->timer);
qemu_free_timer(s->timer);
qemu_free(s->buffer);
qemu_free(s);
return ret;
}
static int buffered_rate_limit(void *opaque)
{
QEMUFileBuffered *s = opaque;
if (s->has_error)
return 0;
if (s->freeze_output)
return 1;
if (s->bytes_xfer > s->xfer_limit)
return 1;
return 0;
}
static void buffered_rate_tick(void *opaque)
{
QEMUFileBuffered *s = opaque;
if (s->has_error)
return;
qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
if (s->freeze_output)
return;
s->bytes_xfer = 0;
buffered_flush(s);
/* Add some checks around this */
s->put_ready(s->opaque);
}
QEMUFile *qemu_fopen_ops_buffered(void *opaque,
size_t bytes_per_sec,
BufferedPutFunc *put_buffer,
BufferedPutReadyFunc *put_ready,
BufferedWaitForUnfreezeFunc *wait_for_unfreeze,
BufferedCloseFunc *close)
{
QEMUFileBuffered *s;
s = qemu_mallocz(sizeof(*s));
if (s == NULL)
return NULL;
s->opaque = opaque;
s->xfer_limit = bytes_per_sec / 10;
s->put_buffer = put_buffer;
s->put_ready = put_ready;
s->wait_for_unfreeze = wait_for_unfreeze;
s->close = close;
s->file = qemu_fopen_ops(s, buffered_put_buffer, NULL,
buffered_close, buffered_rate_limit);
s->timer = qemu_new_timer(rt_clock, buffered_rate_tick, s);
qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
return s->file;
}
|
