Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200925a' into...
[qemu.git] / io / channel-buffer.c
1 /*
2 * QEMU I/O channels memory buffer driver
3 *
4 * Copyright (c) 2015 Red Hat, Inc.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21 #include "qemu/osdep.h"
22 #include "io/channel-buffer.h"
23 #include "io/channel-watch.h"
24 #include "qemu/module.h"
25 #include "qemu/sockets.h"
26 #include "trace.h"
27
28 QIOChannelBuffer *
29 qio_channel_buffer_new(size_t capacity)
30 {
31 QIOChannelBuffer *ioc;
32
33 ioc = QIO_CHANNEL_BUFFER(object_new(TYPE_QIO_CHANNEL_BUFFER));
34
35 if (capacity) {
36 ioc->data = g_new0(uint8_t, capacity);
37 ioc->capacity = capacity;
38 }
39
40 return ioc;
41 }
42
43
44 static void qio_channel_buffer_finalize(Object *obj)
45 {
46 QIOChannelBuffer *ioc = QIO_CHANNEL_BUFFER(obj);
47 g_free(ioc->data);
48 ioc->capacity = ioc->usage = ioc->offset = 0;
49 }
50
51
52 static ssize_t qio_channel_buffer_readv(QIOChannel *ioc,
53 const struct iovec *iov,
54 size_t niov,
55 int **fds,
56 size_t *nfds,
57 Error **errp)
58 {
59 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
60 ssize_t ret = 0;
61 size_t i;
62
63 for (i = 0; i < niov; i++) {
64 size_t want = iov[i].iov_len;
65 if (bioc->offset >= bioc->usage) {
66 break;
67 }
68 if ((bioc->offset + want) > bioc->usage) {
69 want = bioc->usage - bioc->offset;
70 }
71 memcpy(iov[i].iov_base, bioc->data + bioc->offset, want);
72 ret += want;
73 bioc->offset += want;
74 }
75
76 return ret;
77 }
78
79 static ssize_t qio_channel_buffer_writev(QIOChannel *ioc,
80 const struct iovec *iov,
81 size_t niov,
82 int *fds,
83 size_t nfds,
84 Error **errp)
85 {
86 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
87 ssize_t ret = 0;
88 size_t i;
89 size_t towrite = 0;
90
91 for (i = 0; i < niov; i++) {
92 towrite += iov[i].iov_len;
93 }
94
95 if ((bioc->offset + towrite) > bioc->capacity) {
96 bioc->capacity = bioc->offset + towrite;
97 bioc->data = g_realloc(bioc->data, bioc->capacity);
98 }
99
100 if (bioc->offset > bioc->usage) {
101 memset(bioc->data, 0, bioc->offset - bioc->usage);
102 bioc->usage = bioc->offset;
103 }
104
105 for (i = 0; i < niov; i++) {
106 memcpy(bioc->data + bioc->usage,
107 iov[i].iov_base,
108 iov[i].iov_len);
109 bioc->usage += iov[i].iov_len;
110 bioc->offset += iov[i].iov_len;
111 ret += iov[i].iov_len;
112 }
113
114 return ret;
115 }
116
117 static int qio_channel_buffer_set_blocking(QIOChannel *ioc G_GNUC_UNUSED,
118 bool enabled G_GNUC_UNUSED,
119 Error **errp G_GNUC_UNUSED)
120 {
121 return 0;
122 }
123
124
125 static off_t qio_channel_buffer_seek(QIOChannel *ioc,
126 off_t offset,
127 int whence,
128 Error **errp)
129 {
130 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
131
132 bioc->offset = offset;
133
134 return offset;
135 }
136
137
138 static int qio_channel_buffer_close(QIOChannel *ioc,
139 Error **errp)
140 {
141 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
142
143 g_free(bioc->data);
144 bioc->data = NULL;
145 bioc->capacity = bioc->usage = bioc->offset = 0;
146
147 return 0;
148 }
149
150
151 typedef struct QIOChannelBufferSource QIOChannelBufferSource;
152 struct QIOChannelBufferSource {
153 GSource parent;
154 QIOChannelBuffer *bioc;
155 GIOCondition condition;
156 };
157
158 static gboolean
159 qio_channel_buffer_source_prepare(GSource *source,
160 gint *timeout)
161 {
162 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
163
164 *timeout = -1;
165
166 return (G_IO_IN | G_IO_OUT) & bsource->condition;
167 }
168
169 static gboolean
170 qio_channel_buffer_source_check(GSource *source)
171 {
172 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
173
174 return (G_IO_IN | G_IO_OUT) & bsource->condition;
175 }
176
177 static gboolean
178 qio_channel_buffer_source_dispatch(GSource *source,
179 GSourceFunc callback,
180 gpointer user_data)
181 {
182 QIOChannelFunc func = (QIOChannelFunc)callback;
183 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
184
185 return (*func)(QIO_CHANNEL(bsource->bioc),
186 ((G_IO_IN | G_IO_OUT) & bsource->condition),
187 user_data);
188 }
189
190 static void
191 qio_channel_buffer_source_finalize(GSource *source)
192 {
193 QIOChannelBufferSource *ssource = (QIOChannelBufferSource *)source;
194
195 object_unref(OBJECT(ssource->bioc));
196 }
197
198 GSourceFuncs qio_channel_buffer_source_funcs = {
199 qio_channel_buffer_source_prepare,
200 qio_channel_buffer_source_check,
201 qio_channel_buffer_source_dispatch,
202 qio_channel_buffer_source_finalize
203 };
204
205 static GSource *qio_channel_buffer_create_watch(QIOChannel *ioc,
206 GIOCondition condition)
207 {
208 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
209 QIOChannelBufferSource *ssource;
210 GSource *source;
211
212 source = g_source_new(&qio_channel_buffer_source_funcs,
213 sizeof(QIOChannelBufferSource));
214 ssource = (QIOChannelBufferSource *)source;
215
216 ssource->bioc = bioc;
217 object_ref(OBJECT(bioc));
218
219 ssource->condition = condition;
220
221 return source;
222 }
223
224
225 static void qio_channel_buffer_class_init(ObjectClass *klass,
226 void *class_data G_GNUC_UNUSED)
227 {
228 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
229
230 ioc_klass->io_writev = qio_channel_buffer_writev;
231 ioc_klass->io_readv = qio_channel_buffer_readv;
232 ioc_klass->io_set_blocking = qio_channel_buffer_set_blocking;
233 ioc_klass->io_seek = qio_channel_buffer_seek;
234 ioc_klass->io_close = qio_channel_buffer_close;
235 ioc_klass->io_create_watch = qio_channel_buffer_create_watch;
236 }
237
238 static const TypeInfo qio_channel_buffer_info = {
239 .parent = TYPE_QIO_CHANNEL,
240 .name = TYPE_QIO_CHANNEL_BUFFER,
241 .instance_size = sizeof(QIOChannelBuffer),
242 .instance_finalize = qio_channel_buffer_finalize,
243 .class_init = qio_channel_buffer_class_init,
244 };
245
246 static void qio_channel_buffer_register_types(void)
247 {
248 type_register_static(&qio_channel_buffer_info);
249 }
250
251 type_init(qio_channel_buffer_register_types);