1 /* GIO - GLib Input, Output and Streaming Library
2 *
3 * Copyright (C) 2010 Red Hat, Inc.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #include "config.h"
20
21 #include <errno.h>
22
23 #include "gpollableinputstream.h"
24 #include "gasynchelper.h"
25 #include "glibintl.h"
26
27 /**
28 * SECTION:gpollableutils
29 * @short_description: Utilities for pollable streams
30 * @include: gio/gio.h
31 *
32 * Utility functions for #GPollableInputStream and
33 * #GPollableOutputStream implementations.
34 */
35
36 typedef struct {
37 GSource source;
38
39 GObject *stream;
40 } GPollableSource;
41
42 static gboolean
pollable_source_dispatch(GSource * source,GSourceFunc callback,gpointer user_data)43 pollable_source_dispatch (GSource *source,
44 GSourceFunc callback,
45 gpointer user_data)
46 {
47 GPollableSourceFunc func = (GPollableSourceFunc)callback;
48 GPollableSource *pollable_source = (GPollableSource *)source;
49
50 return (*func) (pollable_source->stream, user_data);
51 }
52
53 static void
pollable_source_finalize(GSource * source)54 pollable_source_finalize (GSource *source)
55 {
56 GPollableSource *pollable_source = (GPollableSource *)source;
57
58 g_object_unref (pollable_source->stream);
59 }
60
61 static gboolean
pollable_source_closure_callback(GObject * stream,gpointer data)62 pollable_source_closure_callback (GObject *stream,
63 gpointer data)
64 {
65 GClosure *closure = data;
66
67 GValue param = G_VALUE_INIT;
68 GValue result_value = G_VALUE_INIT;
69 gboolean result;
70
71 g_value_init (&result_value, G_TYPE_BOOLEAN);
72
73 g_value_init (¶m, G_TYPE_OBJECT);
74 g_value_set_object (¶m, stream);
75
76 g_closure_invoke (closure, &result_value, 1, ¶m, NULL);
77
78 result = g_value_get_boolean (&result_value);
79 g_value_unset (&result_value);
80 g_value_unset (¶m);
81
82 return result;
83 }
84
85 static GSourceFuncs pollable_source_funcs =
86 {
87 NULL,
88 NULL,
89 pollable_source_dispatch,
90 pollable_source_finalize,
91 (GSourceFunc)pollable_source_closure_callback,
92 };
93
94 /**
95 * g_pollable_source_new:
96 * @pollable_stream: the stream associated with the new source
97 *
98 * Utility method for #GPollableInputStream and #GPollableOutputStream
99 * implementations. Creates a new #GSource that expects a callback of
100 * type #GPollableSourceFunc. The new source does not actually do
101 * anything on its own; use g_source_add_child_source() to add other
102 * sources to it to cause it to trigger.
103 *
104 * Returns: (transfer full): the new #GSource.
105 *
106 * Since: 2.28
107 */
108 GSource *
g_pollable_source_new(GObject * pollable_stream)109 g_pollable_source_new (GObject *pollable_stream)
110 {
111 GSource *source;
112 GPollableSource *pollable_source;
113
114 g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (pollable_stream) ||
115 G_IS_POLLABLE_OUTPUT_STREAM (pollable_stream), NULL);
116
117 source = g_source_new (&pollable_source_funcs, sizeof (GPollableSource));
118 g_source_set_name (source, "GPollableSource");
119 pollable_source = (GPollableSource *)source;
120 pollable_source->stream = g_object_ref (pollable_stream);
121
122 return source;
123 }
124
125 /**
126 * g_pollable_source_new_full:
127 * @pollable_stream: (type GObject): the stream associated with the
128 * new source
129 * @child_source: (nullable): optional child source to attach
130 * @cancellable: (nullable): optional #GCancellable to attach
131 *
132 * Utility method for #GPollableInputStream and #GPollableOutputStream
133 * implementations. Creates a new #GSource, as with
134 * g_pollable_source_new(), but also attaching @child_source (with a
135 * dummy callback), and @cancellable, if they are non-%NULL.
136 *
137 * Returns: (transfer full): the new #GSource.
138 *
139 * Since: 2.34
140 */
141 GSource *
g_pollable_source_new_full(gpointer pollable_stream,GSource * child_source,GCancellable * cancellable)142 g_pollable_source_new_full (gpointer pollable_stream,
143 GSource *child_source,
144 GCancellable *cancellable)
145 {
146 GSource *source;
147
148 g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (pollable_stream) ||
149 G_IS_POLLABLE_OUTPUT_STREAM (pollable_stream), NULL);
150
151 source = g_pollable_source_new (pollable_stream);
152 if (child_source)
153 {
154 g_source_set_dummy_callback (child_source);
155 g_source_add_child_source (source, child_source);
156 }
157 if (cancellable)
158 {
159 GSource *cancellable_source = g_cancellable_source_new (cancellable);
160
161 g_source_set_dummy_callback (cancellable_source);
162 g_source_add_child_source (source, cancellable_source);
163 g_source_unref (cancellable_source);
164 }
165
166 return source;
167 }
168
169 /**
170 * g_pollable_stream_read:
171 * @stream: a #GInputStream
172 * @buffer: (array length=count) (element-type guint8): a buffer to
173 * read data into
174 * @count: the number of bytes to read
175 * @blocking: whether to do blocking I/O
176 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
177 * @error: location to store the error occurring, or %NULL to ignore
178 *
179 * Tries to read from @stream, as with g_input_stream_read() (if
180 * @blocking is %TRUE) or g_pollable_input_stream_read_nonblocking()
181 * (if @blocking is %FALSE). This can be used to more easily share
182 * code between blocking and non-blocking implementations of a method.
183 *
184 * If @blocking is %FALSE, then @stream must be a
185 * #GPollableInputStream for which g_pollable_input_stream_can_poll()
186 * returns %TRUE, or else the behavior is undefined. If @blocking is
187 * %TRUE, then @stream does not need to be a #GPollableInputStream.
188 *
189 * Returns: the number of bytes read, or -1 on error.
190 *
191 * Since: 2.34
192 */
193 gssize
g_pollable_stream_read(GInputStream * stream,void * buffer,gsize count,gboolean blocking,GCancellable * cancellable,GError ** error)194 g_pollable_stream_read (GInputStream *stream,
195 void *buffer,
196 gsize count,
197 gboolean blocking,
198 GCancellable *cancellable,
199 GError **error)
200 {
201 if (blocking)
202 {
203 return g_input_stream_read (stream,
204 buffer, count,
205 cancellable, error);
206 }
207 else
208 {
209 return g_pollable_input_stream_read_nonblocking (G_POLLABLE_INPUT_STREAM (stream),
210 buffer, count,
211 cancellable, error);
212 }
213 }
214
215 /**
216 * g_pollable_stream_write:
217 * @stream: a #GOutputStream.
218 * @buffer: (array length=count) (element-type guint8): the buffer
219 * containing the data to write.
220 * @count: the number of bytes to write
221 * @blocking: whether to do blocking I/O
222 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
223 * @error: location to store the error occurring, or %NULL to ignore
224 *
225 * Tries to write to @stream, as with g_output_stream_write() (if
226 * @blocking is %TRUE) or g_pollable_output_stream_write_nonblocking()
227 * (if @blocking is %FALSE). This can be used to more easily share
228 * code between blocking and non-blocking implementations of a method.
229 *
230 * If @blocking is %FALSE, then @stream must be a
231 * #GPollableOutputStream for which
232 * g_pollable_output_stream_can_poll() returns %TRUE or else the
233 * behavior is undefined. If @blocking is %TRUE, then @stream does not
234 * need to be a #GPollableOutputStream.
235 *
236 * Returns: the number of bytes written, or -1 on error.
237 *
238 * Since: 2.34
239 */
240 gssize
g_pollable_stream_write(GOutputStream * stream,const void * buffer,gsize count,gboolean blocking,GCancellable * cancellable,GError ** error)241 g_pollable_stream_write (GOutputStream *stream,
242 const void *buffer,
243 gsize count,
244 gboolean blocking,
245 GCancellable *cancellable,
246 GError **error)
247 {
248 if (blocking)
249 {
250 return g_output_stream_write (stream,
251 buffer, count,
252 cancellable, error);
253 }
254 else
255 {
256 return g_pollable_output_stream_write_nonblocking (G_POLLABLE_OUTPUT_STREAM (stream),
257 buffer, count,
258 cancellable, error);
259 }
260 }
261
262 /**
263 * g_pollable_stream_write_all:
264 * @stream: a #GOutputStream.
265 * @buffer: (array length=count) (element-type guint8): the buffer
266 * containing the data to write.
267 * @count: the number of bytes to write
268 * @blocking: whether to do blocking I/O
269 * @bytes_written: (out): location to store the number of bytes that was
270 * written to the stream
271 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
272 * @error: location to store the error occurring, or %NULL to ignore
273 *
274 * Tries to write @count bytes to @stream, as with
275 * g_output_stream_write_all(), but using g_pollable_stream_write()
276 * rather than g_output_stream_write().
277 *
278 * On a successful write of @count bytes, %TRUE is returned, and
279 * @bytes_written is set to @count.
280 *
281 * If there is an error during the operation (including
282 * %G_IO_ERROR_WOULD_BLOCK in the non-blocking case), %FALSE is
283 * returned and @error is set to indicate the error status,
284 * @bytes_written is updated to contain the number of bytes written
285 * into the stream before the error occurred.
286 *
287 * As with g_pollable_stream_write(), if @blocking is %FALSE, then
288 * @stream must be a #GPollableOutputStream for which
289 * g_pollable_output_stream_can_poll() returns %TRUE or else the
290 * behavior is undefined. If @blocking is %TRUE, then @stream does not
291 * need to be a #GPollableOutputStream.
292 *
293 * Returns: %TRUE on success, %FALSE if there was an error
294 *
295 * Since: 2.34
296 */
297 gboolean
g_pollable_stream_write_all(GOutputStream * stream,const void * buffer,gsize count,gboolean blocking,gsize * bytes_written,GCancellable * cancellable,GError ** error)298 g_pollable_stream_write_all (GOutputStream *stream,
299 const void *buffer,
300 gsize count,
301 gboolean blocking,
302 gsize *bytes_written,
303 GCancellable *cancellable,
304 GError **error)
305 {
306 gsize _bytes_written;
307 gssize res;
308
309 _bytes_written = 0;
310 while (_bytes_written < count)
311 {
312 res = g_pollable_stream_write (stream,
313 (char *)buffer + _bytes_written,
314 count - _bytes_written,
315 blocking,
316 cancellable, error);
317 if (res == -1)
318 {
319 if (bytes_written)
320 *bytes_written = _bytes_written;
321 return FALSE;
322 }
323
324 if (res == 0)
325 g_warning ("Write returned zero without error");
326
327 _bytes_written += res;
328 }
329
330 if (bytes_written)
331 *bytes_written = _bytes_written;
332
333 return TRUE;
334 }
335