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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:
1.1.1.2 root 209: static size_t buffered_set_rate_limit(void *opaque, size_t new_rate)
210: {
211: QEMUFileBuffered *s = opaque;
212:
213: if (s->has_error)
214: goto out;
215:
216: s->xfer_limit = new_rate / 10;
217:
218: out:
219: return s->xfer_limit;
220: }
221:
1.1.1.3 root 222: static size_t buffered_get_rate_limit(void *opaque)
223: {
224: QEMUFileBuffered *s = opaque;
225:
226: return s->xfer_limit;
227: }
228:
1.1 root 229: static void buffered_rate_tick(void *opaque)
230: {
231: QEMUFileBuffered *s = opaque;
232:
1.1.1.4 ! root 233: if (s->has_error) {
! 234: buffered_close(s);
1.1 root 235: return;
1.1.1.4 ! root 236: }
1.1 root 237:
238: qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
239:
240: if (s->freeze_output)
241: return;
242:
243: s->bytes_xfer = 0;
244:
245: buffered_flush(s);
246:
247: /* Add some checks around this */
248: s->put_ready(s->opaque);
249: }
250:
251: QEMUFile *qemu_fopen_ops_buffered(void *opaque,
252: size_t bytes_per_sec,
253: BufferedPutFunc *put_buffer,
254: BufferedPutReadyFunc *put_ready,
255: BufferedWaitForUnfreezeFunc *wait_for_unfreeze,
256: BufferedCloseFunc *close)
257: {
258: QEMUFileBuffered *s;
259:
260: s = qemu_mallocz(sizeof(*s));
261:
262: s->opaque = opaque;
263: s->xfer_limit = bytes_per_sec / 10;
264: s->put_buffer = put_buffer;
265: s->put_ready = put_ready;
266: s->wait_for_unfreeze = wait_for_unfreeze;
267: s->close = close;
268:
269: s->file = qemu_fopen_ops(s, buffered_put_buffer, NULL,
1.1.1.2 root 270: buffered_close, buffered_rate_limit,
1.1.1.3 root 271: buffered_set_rate_limit,
272: buffered_get_rate_limit);
1.1 root 273:
274: s->timer = qemu_new_timer(rt_clock, buffered_rate_tick, s);
275:
276: qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
277:
278: return s->file;
279: }
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