![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to buffered_file.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Qemu by Fabrice Bellard] / qemu|
Return to buffered_file.c CVS log | Up to [Qemu by Fabrice Bellard] / qemu |
1.1 root 1: /*
2: * QEMU buffered QEMUFile
3: *
4: * Copyright IBM, Corp. 2008
5: *
6: * Authors:
7: * Anthony Liguori <[email protected]>
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 "sysemu.h"
18: #include "qemu-char.h"
19: #include "buffered_file.h"
20:
21: //#define DEBUG_BUFFERED_FILE
22:
23: typedef struct QEMUFileBuffered
24: {
25: BufferedPutFunc *put_buffer;
26: BufferedPutReadyFunc *put_ready;
27: BufferedWaitForUnfreezeFunc *wait_for_unfreeze;
28: BufferedCloseFunc *close;
29: void *opaque;
30: QEMUFile *file;
31: int has_error;
32: int freeze_output;
33: size_t bytes_xfer;
34: size_t xfer_limit;
35: uint8_t *buffer;
36: size_t buffer_size;
37: size_t buffer_capacity;
38: QEMUTimer *timer;
39: } QEMUFileBuffered;
40:
41: #ifdef DEBUG_BUFFERED_FILE
1.1.1.4 root 42: #define DPRINTF(fmt, ...) \
1.1 root 43: do { printf("buffered-file: " fmt, ## __VA_ARGS__); } while (0)
44: #else
1.1.1.4 root 45: #define DPRINTF(fmt, ...) \
1.1 root 46: do { } while (0)
47: #endif
48:
49: static void buffered_append(QEMUFileBuffered *s,
50: const uint8_t *buf, size_t size)
51: {
52: if (size > (s->buffer_capacity - s->buffer_size)) {
53: void *tmp;
54:
1.1.1.4 root 55: DPRINTF("increasing buffer capacity from %zu by %zu\n",
1.1 root 56: s->buffer_capacity, size + 1024);
57:
58: s->buffer_capacity += size + 1024;
59:
60: tmp = qemu_realloc(s->buffer, s->buffer_capacity);
61: if (tmp == NULL) {
62: fprintf(stderr, "qemu file buffer expansion failed\n");
63: exit(1);
64: }
65:
66: s->buffer = tmp;
67: }
68:
69: memcpy(s->buffer + s->buffer_size, buf, size);
70: s->buffer_size += size;
71: }
72:
73: static void buffered_flush(QEMUFileBuffered *s)
74: {
75: size_t offset = 0;
76:
77: if (s->has_error) {
1.1.1.4 root 78: DPRINTF("flush when error, bailing\n");
1.1 root 79: return;
80: }
81:
1.1.1.4 root 82: DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size);
1.1 root 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) {
1.1.1.4 root 90: DPRINTF("backend not ready, freezing\n");
1.1 root 91: s->freeze_output = 1;
92: break;
93: }
94:
95: if (ret <= 0) {
1.1.1.4 root 96: DPRINTF("error flushing data, %zd\n", ret);
1.1 root 97: s->has_error = 1;
98: break;
99: } else {
1.1.1.4 root 100: DPRINTF("flushed %zd byte(s)\n", ret);
1.1 root 101: offset += ret;
102: }
103: }
104:
1.1.1.4 root 105: DPRINTF("flushed %zu of %zu byte(s)\n", offset, s->buffer_size);
1.1 root 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;
114: ssize_t ret;
115:
1.1.1.4 root 116: DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
1.1 root 117:
118: if (s->has_error) {
1.1.1.4 root 119: DPRINTF("flush when error, bailing\n");
1.1 root 120: return -EINVAL;
121: }
122:
1.1.1.4 root 123: DPRINTF("unfreezing output\n");
1.1 root 124: s->freeze_output = 0;
125:
126: buffered_flush(s);
127:
128: while (!s->freeze_output && offset < size) {
129: if (s->bytes_xfer > s->xfer_limit) {
1.1.1.4 root 130: DPRINTF("transfer limit exceeded when putting\n");
1.1 root 131: break;
132: }
133:
134: ret = s->put_buffer(s->opaque, buf + offset, size - offset);
135: if (ret == -EAGAIN) {
1.1.1.4 root 136: DPRINTF("backend not ready, freezing\n");
1.1 root 137: s->freeze_output = 1;
138: break;
139: }
140:
141: if (ret <= 0) {
1.1.1.4 root 142: DPRINTF("error putting\n");
1.1 root 143: s->has_error = 1;
144: offset = -EINVAL;
145: break;
146: }
147:
1.1.1.4 root 148: DPRINTF("put %zd byte(s)\n", ret);
1.1 root 149: offset += ret;
150: s->bytes_xfer += ret;
151: }
152:
153: if (offset >= 0) {
1.1.1.4 root 154: DPRINTF("buffering %d bytes\n", size - offset);
1.1 root 155: buffered_append(s, buf + offset, size - offset);
156: offset = size;
157: }
158:
1.1.1.4 root 159: if (pos == 0 && size == 0) {
160: DPRINTF("file is ready\n");
161: if (s->bytes_xfer <= s->xfer_limit) {
162: DPRINTF("notifying client\n");
163: s->put_ready(s->opaque);
164: }
165: }
166:
1.1 root 167: return offset;
168: }
169:
170: static int buffered_close(void *opaque)
171: {
172: QEMUFileBuffered *s = opaque;
173: int ret;
174:
1.1.1.4 root 175: DPRINTF("closing\n");
1.1 root 176:
177: while (!s->has_error && s->buffer_size) {
178: buffered_flush(s);
179: if (s->freeze_output)
180: s->wait_for_unfreeze(s);
181: }
182:
183: ret = s->close(s->opaque);
184:
185: qemu_del_timer(s->timer);
186: qemu_free_timer(s->timer);
187: qemu_free(s->buffer);
188: qemu_free(s);
189:
190: return ret;
191: }
192:
193: static int buffered_rate_limit(void *opaque)
194: {
195: QEMUFileBuffered *s = opaque;
196:
197: if (s->has_error)
198: return 0;
199:
200: if (s->freeze_output)
201: return 1;
202:
203: if (s->bytes_xfer > s->xfer_limit)
204: return 1;
205:
206: return 0;
207: }
208:
1.1.1.5 ! root 209: static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
1.1.1.2 root 210: {
211: QEMUFileBuffered *s = opaque;
212: if (s->has_error)
213: goto out;
214:
1.1.1.5 ! root 215: if (new_rate > SIZE_MAX) {
! 216: new_rate = SIZE_MAX;
! 217: }
! 218:
1.1.1.2 root 219: s->xfer_limit = new_rate / 10;
220:
221: out:
222: return s->xfer_limit;
223: }
224:
1.1.1.5 ! root 225: static int64_t buffered_get_rate_limit(void *opaque)
1.1.1.3 root 226: {
227: QEMUFileBuffered *s = opaque;
228:
229: return s->xfer_limit;
230: }
231:
1.1 root 232: static void buffered_rate_tick(void *opaque)
233: {
234: QEMUFileBuffered *s = opaque;
235:
1.1.1.4 root 236: if (s->has_error) {
237: buffered_close(s);
1.1 root 238: return;
1.1.1.4 root 239: }
1.1 root 240:
241: qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
242:
243: if (s->freeze_output)
244: return;
245:
246: s->bytes_xfer = 0;
247:
248: buffered_flush(s);
249:
250: /* Add some checks around this */
251: s->put_ready(s->opaque);
252: }
253:
254: QEMUFile *qemu_fopen_ops_buffered(void *opaque,
255: size_t bytes_per_sec,
256: BufferedPutFunc *put_buffer,
257: BufferedPutReadyFunc *put_ready,
258: BufferedWaitForUnfreezeFunc *wait_for_unfreeze,
259: BufferedCloseFunc *close)
260: {
261: QEMUFileBuffered *s;
262:
263: s = qemu_mallocz(sizeof(*s));
264:
265: s->opaque = opaque;
266: s->xfer_limit = bytes_per_sec / 10;
267: s->put_buffer = put_buffer;
268: s->put_ready = put_ready;
269: s->wait_for_unfreeze = wait_for_unfreeze;
270: s->close = close;
271:
272: s->file = qemu_fopen_ops(s, buffered_put_buffer, NULL,
1.1.1.2 root 273: buffered_close, buffered_rate_limit,
1.1.1.3 root 274: buffered_set_rate_limit,
275: buffered_get_rate_limit);
1.1 root 276:
277: s->timer = qemu_new_timer(rt_clock, buffered_rate_tick, s);
278:
279: qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
280:
281: return s->file;
282: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.