]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * QEMU buffered QEMUFile | |
3 | * | |
4 | * Copyright IBM, Corp. 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <aliguori@us.ibm.com> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include "qemu-common.h" | |
15 | #include "hw/hw.h" | |
16 | #include "qemu-timer.h" | |
17 | #include "qemu-char.h" | |
18 | #include "buffered_file.h" | |
19 | ||
20 | //#define DEBUG_BUFFERED_FILE | |
21 | ||
22 | typedef struct QEMUFileBuffered | |
23 | { | |
24 | BufferedPutFunc *put_buffer; | |
25 | BufferedPutReadyFunc *put_ready; | |
26 | BufferedWaitForUnfreezeFunc *wait_for_unfreeze; | |
27 | BufferedCloseFunc *close; | |
28 | void *opaque; | |
29 | QEMUFile *file; | |
30 | int freeze_output; | |
31 | size_t bytes_xfer; | |
32 | size_t xfer_limit; | |
33 | uint8_t *buffer; | |
34 | size_t buffer_size; | |
35 | size_t buffer_capacity; | |
36 | QEMUTimer *timer; | |
37 | } QEMUFileBuffered; | |
38 | ||
39 | #ifdef DEBUG_BUFFERED_FILE | |
40 | #define DPRINTF(fmt, ...) \ | |
41 | do { printf("buffered-file: " fmt, ## __VA_ARGS__); } while (0) | |
42 | #else | |
43 | #define DPRINTF(fmt, ...) \ | |
44 | do { } while (0) | |
45 | #endif | |
46 | ||
47 | static void buffered_append(QEMUFileBuffered *s, | |
48 | const uint8_t *buf, size_t size) | |
49 | { | |
50 | if (size > (s->buffer_capacity - s->buffer_size)) { | |
51 | void *tmp; | |
52 | ||
53 | DPRINTF("increasing buffer capacity from %zu by %zu\n", | |
54 | s->buffer_capacity, size + 1024); | |
55 | ||
56 | s->buffer_capacity += size + 1024; | |
57 | ||
58 | tmp = g_realloc(s->buffer, s->buffer_capacity); | |
59 | if (tmp == NULL) { | |
60 | fprintf(stderr, "qemu file buffer expansion failed\n"); | |
61 | exit(1); | |
62 | } | |
63 | ||
64 | s->buffer = tmp; | |
65 | } | |
66 | ||
67 | memcpy(s->buffer + s->buffer_size, buf, size); | |
68 | s->buffer_size += size; | |
69 | } | |
70 | ||
71 | static void buffered_flush(QEMUFileBuffered *s) | |
72 | { | |
73 | size_t offset = 0; | |
74 | int error; | |
75 | ||
76 | error = qemu_file_get_error(s->file); | |
77 | if (error != 0) { | |
78 | DPRINTF("flush when error, bailing: %s\n", strerror(-error)); | |
79 | return; | |
80 | } | |
81 | ||
82 | DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size); | |
83 | ||
84 | while (offset < s->buffer_size) { | |
85 | ssize_t ret; | |
86 | ||
87 | ret = s->put_buffer(s->opaque, s->buffer + offset, | |
88 | s->buffer_size - offset); | |
89 | if (ret == -EAGAIN) { | |
90 | DPRINTF("backend not ready, freezing\n"); | |
91 | s->freeze_output = 1; | |
92 | break; | |
93 | } | |
94 | ||
95 | if (ret <= 0) { | |
96 | DPRINTF("error flushing data, %zd\n", ret); | |
97 | qemu_file_set_error(s->file, ret); | |
98 | break; | |
99 | } else { | |
100 | DPRINTF("flushed %zd byte(s)\n", ret); | |
101 | offset += ret; | |
102 | } | |
103 | } | |
104 | ||
105 | DPRINTF("flushed %zu of %zu byte(s)\n", offset, s->buffer_size); | |
106 | memmove(s->buffer, s->buffer + offset, s->buffer_size - offset); | |
107 | s->buffer_size -= offset; | |
108 | } | |
109 | ||
110 | static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size) | |
111 | { | |
112 | QEMUFileBuffered *s = opaque; | |
113 | int offset = 0, error; | |
114 | ssize_t ret; | |
115 | ||
116 | DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos); | |
117 | ||
118 | error = qemu_file_get_error(s->file); | |
119 | if (error) { | |
120 | DPRINTF("flush when error, bailing: %s\n", strerror(-error)); | |
121 | return error; | |
122 | } | |
123 | ||
124 | DPRINTF("unfreezing output\n"); | |
125 | s->freeze_output = 0; | |
126 | ||
127 | buffered_flush(s); | |
128 | ||
129 | while (!s->freeze_output && offset < size) { | |
130 | if (s->bytes_xfer > s->xfer_limit) { | |
131 | DPRINTF("transfer limit exceeded when putting\n"); | |
132 | break; | |
133 | } | |
134 | ||
135 | ret = s->put_buffer(s->opaque, buf + offset, size - offset); | |
136 | if (ret == -EAGAIN) { | |
137 | DPRINTF("backend not ready, freezing\n"); | |
138 | s->freeze_output = 1; | |
139 | break; | |
140 | } | |
141 | ||
142 | if (ret <= 0) { | |
143 | DPRINTF("error putting\n"); | |
144 | qemu_file_set_error(s->file, ret); | |
145 | offset = -EINVAL; | |
146 | break; | |
147 | } | |
148 | ||
149 | DPRINTF("put %zd byte(s)\n", ret); | |
150 | offset += ret; | |
151 | s->bytes_xfer += ret; | |
152 | } | |
153 | ||
154 | if (offset >= 0) { | |
155 | DPRINTF("buffering %d bytes\n", size - offset); | |
156 | buffered_append(s, buf + offset, size - offset); | |
157 | offset = size; | |
158 | } | |
159 | ||
160 | if (pos == 0 && size == 0) { | |
161 | DPRINTF("file is ready\n"); | |
162 | if (s->bytes_xfer <= s->xfer_limit) { | |
163 | DPRINTF("notifying client\n"); | |
164 | s->put_ready(s->opaque); | |
165 | } | |
166 | } | |
167 | ||
168 | return offset; | |
169 | } | |
170 | ||
171 | static int buffered_close(void *opaque) | |
172 | { | |
173 | QEMUFileBuffered *s = opaque; | |
174 | int ret; | |
175 | ||
176 | DPRINTF("closing\n"); | |
177 | ||
178 | while (!qemu_file_get_error(s->file) && s->buffer_size) { | |
179 | buffered_flush(s); | |
180 | if (s->freeze_output) | |
181 | s->wait_for_unfreeze(s->opaque); | |
182 | } | |
183 | ||
184 | ret = s->close(s->opaque); | |
185 | ||
186 | qemu_del_timer(s->timer); | |
187 | qemu_free_timer(s->timer); | |
188 | g_free(s->buffer); | |
189 | g_free(s); | |
190 | ||
191 | return ret; | |
192 | } | |
193 | ||
194 | /* | |
195 | * The meaning of the return values is: | |
196 | * 0: We can continue sending | |
197 | * 1: Time to stop | |
198 | * negative: There has been an error | |
199 | */ | |
200 | static int buffered_rate_limit(void *opaque) | |
201 | { | |
202 | QEMUFileBuffered *s = opaque; | |
203 | int ret; | |
204 | ||
205 | ret = qemu_file_get_error(s->file); | |
206 | if (ret) { | |
207 | return ret; | |
208 | } | |
209 | if (s->freeze_output) | |
210 | return 1; | |
211 | ||
212 | if (s->bytes_xfer > s->xfer_limit) | |
213 | return 1; | |
214 | ||
215 | return 0; | |
216 | } | |
217 | ||
218 | static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate) | |
219 | { | |
220 | QEMUFileBuffered *s = opaque; | |
221 | if (qemu_file_get_error(s->file)) { | |
222 | goto out; | |
223 | } | |
224 | if (new_rate > SIZE_MAX) { | |
225 | new_rate = SIZE_MAX; | |
226 | } | |
227 | ||
228 | s->xfer_limit = new_rate / 10; | |
229 | ||
230 | out: | |
231 | return s->xfer_limit; | |
232 | } | |
233 | ||
234 | static int64_t buffered_get_rate_limit(void *opaque) | |
235 | { | |
236 | QEMUFileBuffered *s = opaque; | |
237 | ||
238 | return s->xfer_limit; | |
239 | } | |
240 | ||
241 | static void buffered_rate_tick(void *opaque) | |
242 | { | |
243 | QEMUFileBuffered *s = opaque; | |
244 | ||
245 | if (qemu_file_get_error(s->file)) { | |
246 | buffered_close(s); | |
247 | return; | |
248 | } | |
249 | ||
250 | qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100); | |
251 | ||
252 | if (s->freeze_output) | |
253 | return; | |
254 | ||
255 | s->bytes_xfer = 0; | |
256 | ||
257 | buffered_flush(s); | |
258 | ||
259 | /* Add some checks around this */ | |
260 | s->put_ready(s->opaque); | |
261 | } | |
262 | ||
263 | QEMUFile *qemu_fopen_ops_buffered(void *opaque, | |
264 | size_t bytes_per_sec, | |
265 | BufferedPutFunc *put_buffer, | |
266 | BufferedPutReadyFunc *put_ready, | |
267 | BufferedWaitForUnfreezeFunc *wait_for_unfreeze, | |
268 | BufferedCloseFunc *close) | |
269 | { | |
270 | QEMUFileBuffered *s; | |
271 | ||
272 | s = g_malloc0(sizeof(*s)); | |
273 | ||
274 | s->opaque = opaque; | |
275 | s->xfer_limit = bytes_per_sec / 10; | |
276 | s->put_buffer = put_buffer; | |
277 | s->put_ready = put_ready; | |
278 | s->wait_for_unfreeze = wait_for_unfreeze; | |
279 | s->close = close; | |
280 | ||
281 | s->file = qemu_fopen_ops(s, buffered_put_buffer, NULL, | |
282 | buffered_close, buffered_rate_limit, | |
283 | buffered_set_rate_limit, | |
284 | buffered_get_rate_limit); | |
285 | ||
286 | s->timer = qemu_new_timer_ms(rt_clock, buffered_rate_tick, s); | |
287 | ||
288 | qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100); | |
289 | ||
290 | return s->file; | |
291 | } |