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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 "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
1.1.1.4 root 40: #define DPRINTF(fmt, ...) \
1.1 root 41: do { printf("buffered-file: " fmt, ## __VA_ARGS__); } while (0)
42: #else
1.1.1.4 root 43: #define DPRINTF(fmt, ...) \
1.1 root 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:
1.1.1.4 root 53: DPRINTF("increasing buffer capacity from %zu by %zu\n",
1.1 root 54: s->buffer_capacity, size + 1024);
55:
56: s->buffer_capacity += size + 1024;
57:
1.1.1.7 ! root 58: tmp = g_realloc(s->buffer, s->buffer_capacity);
1.1 root 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;
1.1.1.7 ! root 74: int error;
1.1 root 75:
1.1.1.7 ! root 76: error = qemu_file_get_error(s->file);
! 77: if (error != 0) {
! 78: DPRINTF("flush when error, bailing: %s\n", strerror(-error));
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);
1.1.1.7 ! root 97: qemu_file_set_error(s->file, ret);
1.1 root 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;
1.1.1.7 ! root 113: int offset = 0, error;
1.1 root 114: ssize_t ret;
115:
1.1.1.4 root 116: DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
1.1 root 117:
1.1.1.7 ! root 118: error = qemu_file_get_error(s->file);
! 119: if (error) {
! 120: DPRINTF("flush when error, bailing: %s\n", strerror(-error));
! 121: return error;
1.1 root 122: }
123:
1.1.1.4 root 124: DPRINTF("unfreezing output\n");
1.1 root 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) {
1.1.1.4 root 131: DPRINTF("transfer limit exceeded when putting\n");
1.1 root 132: break;
133: }
134:
135: ret = s->put_buffer(s->opaque, buf + offset, size - offset);
136: if (ret == -EAGAIN) {
1.1.1.4 root 137: DPRINTF("backend not ready, freezing\n");
1.1 root 138: s->freeze_output = 1;
139: break;
140: }
141:
142: if (ret <= 0) {
1.1.1.4 root 143: DPRINTF("error putting\n");
1.1.1.7 ! root 144: qemu_file_set_error(s->file, ret);
1.1 root 145: offset = -EINVAL;
146: break;
147: }
148:
1.1.1.4 root 149: DPRINTF("put %zd byte(s)\n", ret);
1.1 root 150: offset += ret;
151: s->bytes_xfer += ret;
152: }
153:
154: if (offset >= 0) {
1.1.1.4 root 155: DPRINTF("buffering %d bytes\n", size - offset);
1.1 root 156: buffered_append(s, buf + offset, size - offset);
157: offset = size;
158: }
159:
1.1.1.4 root 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:
1.1 root 168: return offset;
169: }
170:
171: static int buffered_close(void *opaque)
172: {
173: QEMUFileBuffered *s = opaque;
174: int ret;
175:
1.1.1.4 root 176: DPRINTF("closing\n");
1.1 root 177:
1.1.1.7 ! root 178: while (!qemu_file_get_error(s->file) && s->buffer_size) {
1.1 root 179: buffered_flush(s);
180: if (s->freeze_output)
1.1.1.7 ! root 181: s->wait_for_unfreeze(s->opaque);
1.1 root 182: }
183:
184: ret = s->close(s->opaque);
185:
186: qemu_del_timer(s->timer);
187: qemu_free_timer(s->timer);
1.1.1.7 ! root 188: g_free(s->buffer);
! 189: g_free(s);
1.1 root 190:
191: return ret;
192: }
193:
1.1.1.7 ! root 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: */
1.1 root 200: static int buffered_rate_limit(void *opaque)
201: {
202: QEMUFileBuffered *s = opaque;
1.1.1.7 ! root 203: int ret;
1.1 root 204:
1.1.1.7 ! root 205: ret = qemu_file_get_error(s->file);
! 206: if (ret) {
! 207: return ret;
! 208: }
1.1 root 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:
1.1.1.5 root 218: static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
1.1.1.2 root 219: {
220: QEMUFileBuffered *s = opaque;
1.1.1.7 ! root 221: if (qemu_file_get_error(s->file)) {
1.1.1.2 root 222: goto out;
1.1.1.7 ! root 223: }
1.1.1.5 root 224: if (new_rate > SIZE_MAX) {
225: new_rate = SIZE_MAX;
226: }
227:
1.1.1.2 root 228: s->xfer_limit = new_rate / 10;
229:
230: out:
231: return s->xfer_limit;
232: }
233:
1.1.1.5 root 234: static int64_t buffered_get_rate_limit(void *opaque)
1.1.1.3 root 235: {
236: QEMUFileBuffered *s = opaque;
237:
238: return s->xfer_limit;
239: }
240:
1.1 root 241: static void buffered_rate_tick(void *opaque)
242: {
243: QEMUFileBuffered *s = opaque;
244:
1.1.1.7 ! root 245: if (qemu_file_get_error(s->file)) {
1.1.1.4 root 246: buffered_close(s);
1.1 root 247: return;
1.1.1.4 root 248: }
1.1 root 249:
1.1.1.6 root 250: qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100);
1.1 root 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:
1.1.1.7 ! root 272: s = g_malloc0(sizeof(*s));
1.1 root 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,
1.1.1.2 root 282: buffered_close, buffered_rate_limit,
1.1.1.3 root 283: buffered_set_rate_limit,
284: buffered_get_rate_limit);
1.1 root 285:
1.1.1.6 root 286: s->timer = qemu_new_timer_ms(rt_clock, buffered_rate_tick, s);
1.1 root 287:
1.1.1.6 root 288: qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100);
1.1 root 289:
290: return s->file;
291: }
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