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 * To close a stream use g_io_stream_close() which will close the common
51 * stream object and also the individual substreams. You can also close
52 * the substreams themselves. In most cases this only marks the
53 * substream as closed, so further I/O on it fails. However, some streams
54 * may support "half-closed" states where one direction of the stream
55 * is actually shut down.
68 struct _GIOStreamPrivate {
71 GAsyncReadyCallback outstanding_callback;
74 static gboolean g_io_stream_real_close (GIOStream *stream,
75 GCancellable *cancellable,
77 static void g_io_stream_real_close_async (GIOStream *stream,
79 GCancellable *cancellable,
80 GAsyncReadyCallback callback,
82 static gboolean g_io_stream_real_close_finish (GIOStream *stream,
87 g_io_stream_finalize (GObject *object)
91 stream = G_IO_STREAM (object);
93 if (!stream->priv->closed)
94 g_io_stream_close (stream, NULL, NULL);
96 G_OBJECT_CLASS (g_io_stream_parent_class)->finalize (object);
100 g_io_stream_dispose (GObject *object)
104 stream = G_IO_STREAM (object);
106 if (!stream->priv->closed)
107 g_io_stream_close (stream, NULL, NULL);
109 G_OBJECT_CLASS (g_io_stream_parent_class)->dispose (object);
113 g_io_stream_init (GIOStream *stream)
115 stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
121 g_io_stream_get_property (GObject *object,
126 GIOStream *stream = G_IO_STREAM (object);
131 g_value_set_boolean (value, stream->priv->closed);
134 case PROP_INPUT_STREAM:
135 g_value_set_object (value, g_io_stream_get_input_stream (stream));
138 case PROP_OUTPUT_STREAM:
139 g_value_set_object (value, g_io_stream_get_output_stream (stream));
143 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
148 g_io_stream_set_property (GObject *object,
156 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
161 g_io_stream_class_init (GIOStreamClass *klass)
163 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
165 g_type_class_add_private (klass, sizeof (GIOStreamPrivate));
167 gobject_class->finalize = g_io_stream_finalize;
168 gobject_class->dispose = g_io_stream_dispose;
169 gobject_class->set_property = g_io_stream_set_property;
170 gobject_class->get_property = g_io_stream_get_property;
172 klass->close_fn = g_io_stream_real_close;
173 klass->close_async = g_io_stream_real_close_async;
174 klass->close_finish = g_io_stream_real_close_finish;
176 g_object_class_install_property (gobject_class, PROP_CLOSED,
177 g_param_spec_boolean ("closed",
179 P_("Is the stream closed"),
181 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
183 g_object_class_install_property (gobject_class, PROP_INPUT_STREAM,
184 g_param_spec_object ("input-stream",
186 P_("The GInputStream to read from"),
188 G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
189 g_object_class_install_property (gobject_class, PROP_OUTPUT_STREAM,
190 g_param_spec_object ("output-stream",
192 P_("The GOutputStream to write to"),
193 G_TYPE_OUTPUT_STREAM,
194 G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
198 * g_io_stream_is_closed:
199 * @stream: a #GIOStream.
201 * Checks if a stream is closed.
203 * Returns: %TRUE if the stream is closed.
208 g_io_stream_is_closed (GIOStream *stream)
210 g_return_val_if_fail (G_IS_IO_STREAM (stream), TRUE);
212 return stream->priv->closed;
216 * g_io_stream_get_input_stream:
217 * @stream: input #GIOStream.
219 * Gets the input stream for this object. This is used
222 * Returns: a #GInputStream, owned by the #GIOStream do not free.
227 g_io_stream_get_input_stream (GIOStream *io_stream)
229 GIOStreamClass *klass;
231 klass = G_IO_STREAM_GET_CLASS (io_stream);
233 g_assert (klass->get_input_stream != NULL);
235 return klass->get_input_stream (io_stream);
239 * g_io_stream_get_output_stream:
240 * @stream: input #GIOStream.
242 * Gets the output stream for this object. This is used for
245 * Returns: a #GOutputStream, owned by the #GIOStream do not free.
250 g_io_stream_get_output_stream (GIOStream *io_stream)
252 GIOStreamClass *klass;
254 klass = G_IO_STREAM_GET_CLASS (io_stream);
256 g_assert (klass->get_output_stream != NULL);
257 return klass->get_output_stream (io_stream);
261 * g_io_stream_has_pending:
262 * @stream: a #GIOStream.
264 * Checks if a stream has pending actions.
266 * Returns: %TRUE if @stream has pending actions.
271 g_io_stream_has_pending (GIOStream *stream)
273 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
275 return stream->priv->pending;
279 * g_io_stream_set_pending:
280 * @stream: a #GIOStream.
281 * @error: a #GError location to store the error occuring, or %NULL to
284 * Sets @stream to have actions pending. If the pending flag is
285 * already set or @stream is closed, it will return %FALSE and set
288 * Return value: %TRUE if pending was previously unset and is now set.
293 g_io_stream_set_pending (GIOStream *stream,
296 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
298 if (stream->priv->closed)
300 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
301 _("Stream is already closed"));
305 if (stream->priv->pending)
307 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
308 /* Translators: This is an error you get if there is
309 * already an operation running against this stream when
310 * you try to start one */
311 _("Stream has outstanding operation"));
315 stream->priv->pending = TRUE;
320 * g_io_stream_clear_pending:
321 * @stream: output stream
323 * Clears the pending flag on @stream.
328 g_io_stream_clear_pending (GIOStream *stream)
330 g_return_if_fail (G_IS_IO_STREAM (stream));
332 stream->priv->pending = FALSE;
336 g_io_stream_real_close (GIOStream *stream,
337 GCancellable *cancellable,
342 res = g_output_stream_close (g_io_stream_get_output_stream (stream),
345 /* If this errored out, unset error so that we don't report
346 further errors, but still do the following ops */
347 if (error != NULL && *error != NULL)
350 res &= g_input_stream_close (g_io_stream_get_input_stream (stream),
358 * @stream: A #GIOStream.
359 * @cancellable: optional #GCancellable object, %NULL to ignore.
360 * @error: location to store the error occuring, or %NULL to ignore
362 * Closes the stream, releasing resources related to it. This will also
363 * closes the individual input and output streams, if they are not already
366 * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
367 * Closing a stream multiple times will not return an error.
369 * Closing a stream will automatically flush any outstanding buffers in the
372 * Streams will be automatically closed when the last reference
373 * is dropped, but you might want to call this function to make sure
374 * resources are released as early as possible.
376 * Some streams might keep the backing store of the stream (e.g. a file descriptor)
377 * open after the stream is closed. See the documentation for the individual
378 * stream for details.
380 * On failure the first error that happened will be reported, but the close
381 * operation will finish as much as possible. A stream that failed to
382 * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
383 * is important to check and report the error to the user, otherwise
384 * there might be a loss of data as all data might not be written.
386 * If @cancellable is not NULL, then the operation can be cancelled by
387 * triggering the cancellable object from another thread. If the operation
388 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
389 * Cancelling a close will still leave the stream closed, but some streams
390 * can use a faster close that doesn't block to e.g. check errors.
392 * The default implementation of this method just calls close on the
393 * individual input/output streams.
395 * Return value: %TRUE on success, %FALSE on failure
400 g_io_stream_close (GIOStream *stream,
401 GCancellable *cancellable,
404 GIOStreamClass *class;
407 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
409 class = G_IO_STREAM_GET_CLASS (stream);
411 if (stream->priv->closed)
414 if (!g_io_stream_set_pending (stream, error))
418 g_cancellable_push_current (cancellable);
422 res = class->close_fn (stream, cancellable, error);
425 g_cancellable_pop_current (cancellable);
427 stream->priv->closed = TRUE;
428 g_io_stream_clear_pending (stream);
434 async_ready_close_callback_wrapper (GObject *source_object,
438 GIOStream *stream = G_IO_STREAM (source_object);
440 stream->priv->closed = TRUE;
441 g_io_stream_clear_pending (stream);
442 if (stream->priv->outstanding_callback)
443 (*stream->priv->outstanding_callback) (source_object, res, user_data);
444 g_object_unref (stream);
448 * g_io_stream_close_async:
449 * @stream: A #GIOStream.
450 * @io_priority: the io priority of the request.
451 * @callback: callback to call when the request is satisfied
452 * @user_data: the data to pass to callback function
453 * @cancellable: optional cancellable object
455 * Requests an asynchronous close of the stream, releasing resources
456 * related to it. When the operation is finished @callback will be
457 * called. You can then call g_io_stream_close_finish() to get
458 * the result of the operation.
460 * For behaviour details see g_io_stream_close().
462 * The asyncronous methods have a default fallback that uses threads
463 * to implement asynchronicity, so they are optional for inheriting
464 * classes. However, if you override one you must override all.
469 g_io_stream_close_async (GIOStream *stream,
471 GCancellable *cancellable,
472 GAsyncReadyCallback callback,
475 GIOStreamClass *class;
476 GSimpleAsyncResult *simple;
477 GError *error = NULL;
479 g_return_if_fail (G_IS_IO_STREAM (stream));
481 if (stream->priv->closed)
483 simple = g_simple_async_result_new (G_OBJECT (stream),
486 g_io_stream_close_async);
487 g_simple_async_result_complete_in_idle (simple);
488 g_object_unref (simple);
492 if (!g_io_stream_set_pending (stream, &error))
494 g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
498 g_error_free (error);
502 class = G_IO_STREAM_GET_CLASS (stream);
503 stream->priv->outstanding_callback = callback;
504 g_object_ref (stream);
505 class->close_async (stream, io_priority, cancellable,
506 async_ready_close_callback_wrapper, user_data);
510 * g_io_stream_close_finish:
511 * @stream: a #GIOStream.
512 * @result: a #GAsyncResult.
513 * @error: a #GError location to store the error occuring, or %NULL to
518 * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
523 g_io_stream_close_finish (GIOStream *stream,
524 GAsyncResult *result,
527 GSimpleAsyncResult *simple;
528 GIOStreamClass *class;
530 g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE);
531 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
533 if (G_IS_SIMPLE_ASYNC_RESULT (result))
535 simple = G_SIMPLE_ASYNC_RESULT (result);
536 if (g_simple_async_result_propagate_error (simple, error))
539 /* Special case already closed */
540 if (g_simple_async_result_get_source_tag (simple) == g_io_stream_close_async)
544 class = G_IO_STREAM_GET_CLASS (stream);
545 return class->close_finish (stream, result, error);
550 close_async_thread (GSimpleAsyncResult *res,
552 GCancellable *cancellable)
554 GIOStreamClass *class;
555 GError *error = NULL;
558 /* Auto handling of cancelation disabled, and ignore
559 cancellation, since we want to close things anyway, although
560 possibly in a quick-n-dirty way. At least we never want to leak
563 class = G_IO_STREAM_GET_CLASS (object);
564 result = class->close_fn (G_IO_STREAM (object), cancellable, &error);
567 g_simple_async_result_set_from_error (res, error);
568 g_error_free (error);
573 g_io_stream_real_close_async (GIOStream *stream,
575 GCancellable *cancellable,
576 GAsyncReadyCallback callback,
579 GSimpleAsyncResult *res;
581 res = g_simple_async_result_new (G_OBJECT (stream),
584 g_io_stream_real_close_async);
586 g_simple_async_result_set_handle_cancellation (res, FALSE);
588 g_simple_async_result_run_in_thread (res,
592 g_object_unref (res);
596 g_io_stream_real_close_finish (GIOStream *stream,
597 GAsyncResult *result,
600 GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
601 g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
602 g_io_stream_real_close_async);
606 #define __G_IO_STREAM_C__
607 #include "gioaliasdef.c"