1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright © 2008 codethink
4 * Copyright © 2009 Red Hat, Inc.
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.
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.
16 * You should have received a copy of the GNU Lesser General
17 * Public License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
19 * Boston, MA 02111-1307, USA.
21 * Authors: Ryan Lortie <desrt@desrt.ca>
22 * Alexander Larsson <alexl@redhat.com>
29 #include "giostream.h"
30 #include <gio/gsimpleasyncresult.h>
31 #include <gio/gasyncresult.h>
35 G_DEFINE_TYPE (GIOStream, g_io_stream, G_TYPE_OBJECT);
38 * SECTION:ginputstream
39 * @short_description: Base class for implementing readwrite streams
42 * GIOStream represents an object that has both read and write streams.
43 * Generally the two streams acts as separate input and output streams,
44 * but they share some common resources and state. For instance, for
45 * seekable streams they may use the same position in both streams.
47 * To do the actual reading and writing you need to get the substreams
48 * with g_io_stream_get_input_stream() and g_io_stream_get_output_stream().
50 * The #GIOStream object owns the input and the output streams, not the other
51 * way around, so keeping the substreams alive will not keep the #GIOStream
52 * object alive. If the #GIOStream object is freed it will be closed, thus
53 * closing the substream, so even if the substreams stay alive they will
54 * always just return a %G_IO_ERROR_CLOSED for all operations.
56 * To close a stream use g_io_stream_close() which will close the common
57 * stream object and also the individual substreams. You can also close
58 * the substreams themselves. In most cases this only marks the
59 * substream as closed, so further I/O on it fails. However, some streams
60 * may support "half-closed" states where one direction of the stream
61 * is actually shut down.
74 struct _GIOStreamPrivate {
77 GAsyncReadyCallback outstanding_callback;
80 static gboolean g_io_stream_real_close (GIOStream *stream,
81 GCancellable *cancellable,
83 static void g_io_stream_real_close_async (GIOStream *stream,
85 GCancellable *cancellable,
86 GAsyncReadyCallback callback,
88 static gboolean g_io_stream_real_close_finish (GIOStream *stream,
93 g_io_stream_finalize (GObject *object)
97 stream = G_IO_STREAM (object);
99 if (!stream->priv->closed)
100 g_io_stream_close (stream, NULL, NULL);
102 G_OBJECT_CLASS (g_io_stream_parent_class)->finalize (object);
106 g_io_stream_dispose (GObject *object)
110 stream = G_IO_STREAM (object);
112 if (!stream->priv->closed)
113 g_io_stream_close (stream, NULL, NULL);
115 G_OBJECT_CLASS (g_io_stream_parent_class)->dispose (object);
119 g_io_stream_init (GIOStream *stream)
121 stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
127 g_io_stream_get_property (GObject *object,
132 GIOStream *stream = G_IO_STREAM (object);
137 g_value_set_boolean (value, stream->priv->closed);
140 case PROP_INPUT_STREAM:
141 g_value_set_object (value, g_io_stream_get_input_stream (stream));
144 case PROP_OUTPUT_STREAM:
145 g_value_set_object (value, g_io_stream_get_output_stream (stream));
149 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
154 g_io_stream_set_property (GObject *object,
162 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
167 g_io_stream_class_init (GIOStreamClass *klass)
169 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
171 g_type_class_add_private (klass, sizeof (GIOStreamPrivate));
173 gobject_class->finalize = g_io_stream_finalize;
174 gobject_class->dispose = g_io_stream_dispose;
175 gobject_class->set_property = g_io_stream_set_property;
176 gobject_class->get_property = g_io_stream_get_property;
178 klass->close_fn = g_io_stream_real_close;
179 klass->close_async = g_io_stream_real_close_async;
180 klass->close_finish = g_io_stream_real_close_finish;
182 g_object_class_install_property (gobject_class, PROP_CLOSED,
183 g_param_spec_boolean ("closed",
185 P_("Is the stream closed"),
187 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
189 g_object_class_install_property (gobject_class, PROP_INPUT_STREAM,
190 g_param_spec_object ("input-stream",
192 P_("The GInputStream to read from"),
194 G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
195 g_object_class_install_property (gobject_class, PROP_OUTPUT_STREAM,
196 g_param_spec_object ("output-stream",
198 P_("The GOutputStream to write to"),
199 G_TYPE_OUTPUT_STREAM,
200 G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
204 * g_io_stream_is_closed:
205 * @stream: a #GIOStream.
207 * Checks if a stream is closed.
209 * Returns: %TRUE if the stream is closed.
214 g_io_stream_is_closed (GIOStream *stream)
216 g_return_val_if_fail (G_IS_IO_STREAM (stream), TRUE);
218 return stream->priv->closed;
222 * g_io_stream_get_input_stream:
223 * @stream: input #GIOStream.
225 * Gets the input stream for this object. This is used
228 * Returns: a #GInputStream, owned by the #GIOStream do not free.
233 g_io_stream_get_input_stream (GIOStream *io_stream)
235 GIOStreamClass *klass;
237 klass = G_IO_STREAM_GET_CLASS (io_stream);
239 g_assert (klass->get_input_stream != NULL);
241 return klass->get_input_stream (io_stream);
245 * g_io_stream_get_output_stream:
246 * @stream: input #GIOStream.
248 * Gets the output stream for this object. This is used for
251 * Returns: a #GOutputStream, owned by the #GIOStream do not free.
256 g_io_stream_get_output_stream (GIOStream *io_stream)
258 GIOStreamClass *klass;
260 klass = G_IO_STREAM_GET_CLASS (io_stream);
262 g_assert (klass->get_output_stream != NULL);
263 return klass->get_output_stream (io_stream);
267 * g_io_stream_has_pending:
268 * @stream: a #GIOStream.
270 * Checks if a stream has pending actions.
272 * Returns: %TRUE if @stream has pending actions.
277 g_io_stream_has_pending (GIOStream *stream)
279 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
281 return stream->priv->pending;
285 * g_io_stream_set_pending:
286 * @stream: a #GIOStream.
287 * @error: a #GError location to store the error occuring, or %NULL to
290 * Sets @stream to have actions pending. If the pending flag is
291 * already set or @stream is closed, it will return %FALSE and set
294 * Return value: %TRUE if pending was previously unset and is now set.
299 g_io_stream_set_pending (GIOStream *stream,
302 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
304 if (stream->priv->closed)
306 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
307 _("Stream is already closed"));
311 if (stream->priv->pending)
313 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
314 /* Translators: This is an error you get if there is
315 * already an operation running against this stream when
316 * you try to start one */
317 _("Stream has outstanding operation"));
321 stream->priv->pending = TRUE;
326 * g_io_stream_clear_pending:
327 * @stream: output stream
329 * Clears the pending flag on @stream.
334 g_io_stream_clear_pending (GIOStream *stream)
336 g_return_if_fail (G_IS_IO_STREAM (stream));
338 stream->priv->pending = FALSE;
342 g_io_stream_real_close (GIOStream *stream,
343 GCancellable *cancellable,
348 res = g_output_stream_close (g_io_stream_get_output_stream (stream),
351 /* If this errored out, unset error so that we don't report
352 further errors, but still do the following ops */
353 if (error != NULL && *error != NULL)
356 res &= g_input_stream_close (g_io_stream_get_input_stream (stream),
364 * @stream: A #GIOStream.
365 * @cancellable: optional #GCancellable object, %NULL to ignore.
366 * @error: location to store the error occuring, or %NULL to ignore
368 * Closes the stream, releasing resources related to it. This will also
369 * closes the individual input and output streams, if they are not already
372 * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
373 * Closing a stream multiple times will not return an error.
375 * Closing a stream will automatically flush any outstanding buffers in the
378 * Streams will be automatically closed when the last reference
379 * is dropped, but you might want to call this function to make sure
380 * resources are released as early as possible.
382 * Some streams might keep the backing store of the stream (e.g. a file descriptor)
383 * open after the stream is closed. See the documentation for the individual
384 * stream for details.
386 * On failure the first error that happened will be reported, but the close
387 * operation will finish as much as possible. A stream that failed to
388 * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
389 * is important to check and report the error to the user, otherwise
390 * there might be a loss of data as all data might not be written.
392 * If @cancellable is not NULL, then the operation can be cancelled by
393 * triggering the cancellable object from another thread. If the operation
394 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
395 * Cancelling a close will still leave the stream closed, but some streams
396 * can use a faster close that doesn't block to e.g. check errors.
398 * The default implementation of this method just calls close on the
399 * individual input/output streams.
401 * Return value: %TRUE on success, %FALSE on failure
406 g_io_stream_close (GIOStream *stream,
407 GCancellable *cancellable,
410 GIOStreamClass *class;
413 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
415 class = G_IO_STREAM_GET_CLASS (stream);
417 if (stream->priv->closed)
420 if (!g_io_stream_set_pending (stream, error))
424 g_cancellable_push_current (cancellable);
428 res = class->close_fn (stream, cancellable, error);
431 g_cancellable_pop_current (cancellable);
433 stream->priv->closed = TRUE;
434 g_io_stream_clear_pending (stream);
440 async_ready_close_callback_wrapper (GObject *source_object,
444 GIOStream *stream = G_IO_STREAM (source_object);
446 stream->priv->closed = TRUE;
447 g_io_stream_clear_pending (stream);
448 if (stream->priv->outstanding_callback)
449 (*stream->priv->outstanding_callback) (source_object, res, user_data);
450 g_object_unref (stream);
454 * g_io_stream_close_async:
455 * @stream: A #GIOStream.
456 * @io_priority: the io priority of the request.
457 * @callback: callback to call when the request is satisfied
458 * @user_data: the data to pass to callback function
459 * @cancellable: optional cancellable object
461 * Requests an asynchronous close of the stream, releasing resources
462 * related to it. When the operation is finished @callback will be
463 * called. You can then call g_io_stream_close_finish() to get
464 * the result of the operation.
466 * For behaviour details see g_io_stream_close().
468 * The asyncronous methods have a default fallback that uses threads
469 * to implement asynchronicity, so they are optional for inheriting
470 * classes. However, if you override one you must override all.
475 g_io_stream_close_async (GIOStream *stream,
477 GCancellable *cancellable,
478 GAsyncReadyCallback callback,
481 GIOStreamClass *class;
482 GSimpleAsyncResult *simple;
483 GError *error = NULL;
485 g_return_if_fail (G_IS_IO_STREAM (stream));
487 if (stream->priv->closed)
489 simple = g_simple_async_result_new (G_OBJECT (stream),
492 g_io_stream_close_async);
493 g_simple_async_result_complete_in_idle (simple);
494 g_object_unref (simple);
498 if (!g_io_stream_set_pending (stream, &error))
500 g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
504 g_error_free (error);
508 class = G_IO_STREAM_GET_CLASS (stream);
509 stream->priv->outstanding_callback = callback;
510 g_object_ref (stream);
511 class->close_async (stream, io_priority, cancellable,
512 async_ready_close_callback_wrapper, user_data);
516 * g_io_stream_close_finish:
517 * @stream: a #GIOStream.
518 * @result: a #GAsyncResult.
519 * @error: a #GError location to store the error occuring, or %NULL to
524 * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
529 g_io_stream_close_finish (GIOStream *stream,
530 GAsyncResult *result,
533 GSimpleAsyncResult *simple;
534 GIOStreamClass *class;
536 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
537 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
539 if (G_IS_SIMPLE_ASYNC_RESULT (result))
541 simple = G_SIMPLE_ASYNC_RESULT (result);
542 if (g_simple_async_result_propagate_error (simple, error))
545 /* Special case already closed */
546 if (g_simple_async_result_get_source_tag (simple) == g_io_stream_close_async)
550 class = G_IO_STREAM_GET_CLASS (stream);
551 return class->close_finish (stream, result, error);
556 close_async_thread (GSimpleAsyncResult *res,
558 GCancellable *cancellable)
560 GIOStreamClass *class;
561 GError *error = NULL;
564 /* Auto handling of cancelation disabled, and ignore
565 cancellation, since we want to close things anyway, although
566 possibly in a quick-n-dirty way. At least we never want to leak
569 class = G_IO_STREAM_GET_CLASS (object);
570 result = class->close_fn (G_IO_STREAM (object), cancellable, &error);
573 g_simple_async_result_set_from_error (res, error);
574 g_error_free (error);
579 g_io_stream_real_close_async (GIOStream *stream,
581 GCancellable *cancellable,
582 GAsyncReadyCallback callback,
585 GSimpleAsyncResult *res;
587 res = g_simple_async_result_new (G_OBJECT (stream),
590 g_io_stream_real_close_async);
592 g_simple_async_result_set_handle_cancellation (res, FALSE);
594 g_simple_async_result_run_in_thread (res,
598 g_object_unref (res);
602 g_io_stream_real_close_finish (GIOStream *stream,
603 GAsyncResult *result,
606 GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
607 g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
608 g_io_stream_real_close_async);
612 #define __G_IO_STREAM_C__
613 #include "gioaliasdef.c"