/* GIO - GLib Input, Output and Streaming Library * * Copyright © 2008 codethink * Copyright © 2009 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General * Public License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * Authors: Ryan Lortie * Alexander Larsson */ #include "config.h" #include #include "glibintl.h" #include "giostream.h" #include #include #include "gioalias.h" G_DEFINE_TYPE (GIOStream, g_io_stream, G_TYPE_OBJECT); /** * SECTION:ginputstream * @short_description: Base class for implementing readwrite streams * @include: gio/gio.h * * GIOStream represents an object that has both read and write streams. * Generally the two streams acts as separate input and output streams, * but they share some common resources and state. For instance, for * seekable streams they may use the same position in both streams. * * To do the actual reading and writing you need to get the substreams * with g_io_stream_get_input_stream() and g_io_stream_get_output_stream(). * * The #GIOStream object owns the input and the output streams, not the other * way around, so keeping the substreams alive will not keep the #GIOStream * object alive. If the #GIOStream object is freed it will be closed, thus * closing the substream, so even if the substreams stay alive they will * always just return a %G_IO_ERROR_CLOSED for all operations. * * To close a stream use g_io_stream_close() which will close the common * stream object and also the individual substreams. You can also close * the substreams themselves. In most cases this only marks the * substream as closed, so further I/O on it fails. However, some streams * may support "half-closed" states where one direction of the stream * is actually shut down. * * Since: 2.22 **/ enum { PROP_0, PROP_INPUT_STREAM, PROP_OUTPUT_STREAM, PROP_CLOSED }; struct _GIOStreamPrivate { guint closed : 1; guint pending : 1; GAsyncReadyCallback outstanding_callback; }; static gboolean g_io_stream_real_close (GIOStream *stream, GCancellable *cancellable, GError **error); static void g_io_stream_real_close_async (GIOStream *stream, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static gboolean g_io_stream_real_close_finish (GIOStream *stream, GAsyncResult *result, GError **error); static void g_io_stream_finalize (GObject *object) { GIOStream *stream; stream = G_IO_STREAM (object); G_OBJECT_CLASS (g_io_stream_parent_class)->finalize (object); } static void g_io_stream_dispose (GObject *object) { GIOStream *stream; stream = G_IO_STREAM (object); if (!stream->priv->closed) g_io_stream_close (stream, NULL, NULL); G_OBJECT_CLASS (g_io_stream_parent_class)->dispose (object); } static void g_io_stream_init (GIOStream *stream) { stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream, G_TYPE_IO_STREAM, GIOStreamPrivate); } static void g_io_stream_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { GIOStream *stream = G_IO_STREAM (object); switch (prop_id) { case PROP_CLOSED: g_value_set_boolean (value, stream->priv->closed); break; case PROP_INPUT_STREAM: g_value_set_object (value, g_io_stream_get_input_stream (stream)); break; case PROP_OUTPUT_STREAM: g_value_set_object (value, g_io_stream_get_output_stream (stream)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); } } static void g_io_stream_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { switch (prop_id) { default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); } } static void g_io_stream_class_init (GIOStreamClass *klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); g_type_class_add_private (klass, sizeof (GIOStreamPrivate)); gobject_class->finalize = g_io_stream_finalize; gobject_class->dispose = g_io_stream_dispose; gobject_class->set_property = g_io_stream_set_property; gobject_class->get_property = g_io_stream_get_property; klass->close_fn = g_io_stream_real_close; klass->close_async = g_io_stream_real_close_async; klass->close_finish = g_io_stream_real_close_finish; g_object_class_install_property (gobject_class, PROP_CLOSED, g_param_spec_boolean ("closed", P_("Closed"), P_("Is the stream closed"), FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_INPUT_STREAM, g_param_spec_object ("input-stream", P_("Input stream"), P_("The GInputStream to read from"), G_TYPE_INPUT_STREAM, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_OUTPUT_STREAM, g_param_spec_object ("output-stream", P_("Output stream"), P_("The GOutputStream to write to"), G_TYPE_OUTPUT_STREAM, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); } /** * g_io_stream_is_closed: * @stream: a #GIOStream. * * Checks if a stream is closed. * * Returns: %TRUE if the stream is closed. * * Since: 2.22 **/ gboolean g_io_stream_is_closed (GIOStream *stream) { g_return_val_if_fail (G_IS_IO_STREAM (stream), TRUE); return stream->priv->closed; } /** * g_io_stream_get_input_stream: * @stream: input #GIOStream. * * Gets the input stream for this object. This is used * for reading. * * Returns: a #GInputStream, owned by the #GIOStream do not free. * * Since: 2.22 **/ GInputStream * g_io_stream_get_input_stream (GIOStream *io_stream) { GIOStreamClass *klass; klass = G_IO_STREAM_GET_CLASS (io_stream); g_assert (klass->get_input_stream != NULL); return klass->get_input_stream (io_stream); } /** * g_io_stream_get_output_stream: * @stream: input #GIOStream. * * Gets the output stream for this object. This is used for * writing. * * Returns: a #GOutputStream, owned by the #GIOStream do not free. * * Since: 2.22 **/ GOutputStream * g_io_stream_get_output_stream (GIOStream *io_stream) { GIOStreamClass *klass; klass = G_IO_STREAM_GET_CLASS (io_stream); g_assert (klass->get_output_stream != NULL); return klass->get_output_stream (io_stream); } /** * g_io_stream_has_pending: * @stream: a #GIOStream. * * Checks if a stream has pending actions. * * Returns: %TRUE if @stream has pending actions. * * Since: 2.22 **/ gboolean g_io_stream_has_pending (GIOStream *stream) { g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE); return stream->priv->pending; } /** * g_io_stream_set_pending: * @stream: a #GIOStream. * @error: a #GError location to store the error occuring, or %NULL to * ignore. * * Sets @stream to have actions pending. If the pending flag is * already set or @stream is closed, it will return %FALSE and set * @error. * * Return value: %TRUE if pending was previously unset and is now set. * * Since: 2.22 **/ gboolean g_io_stream_set_pending (GIOStream *stream, GError **error) { g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE); if (stream->priv->closed) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED, _("Stream is already closed")); return FALSE; } if (stream->priv->pending) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING, /* Translators: This is an error you get if there is * already an operation running against this stream when * you try to start one */ _("Stream has outstanding operation")); return FALSE; } stream->priv->pending = TRUE; return TRUE; } /** * g_io_stream_clear_pending: * @stream: output stream * * Clears the pending flag on @stream. * * Since: 2.22 **/ void g_io_stream_clear_pending (GIOStream *stream) { g_return_if_fail (G_IS_IO_STREAM (stream)); stream->priv->pending = FALSE; } static gboolean g_io_stream_real_close (GIOStream *stream, GCancellable *cancellable, GError **error) { gboolean res; res = g_output_stream_close (g_io_stream_get_output_stream (stream), cancellable, error); /* If this errored out, unset error so that we don't report further errors, but still do the following ops */ if (error != NULL && *error != NULL) error = NULL; res &= g_input_stream_close (g_io_stream_get_input_stream (stream), cancellable, error); return res; } /** * g_io_stream_close: * @stream: A #GIOStream. * @cancellable: optional #GCancellable object, %NULL to ignore. * @error: location to store the error occuring, or %NULL to ignore * * Closes the stream, releasing resources related to it. This will also * closes the individual input and output streams, if they are not already * closed. * * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED. * Closing a stream multiple times will not return an error. * * Closing a stream will automatically flush any outstanding buffers in the * stream. * * Streams will be automatically closed when the last reference * is dropped, but you might want to call this function to make sure * resources are released as early as possible. * * Some streams might keep the backing store of the stream (e.g. a file descriptor) * open after the stream is closed. See the documentation for the individual * stream for details. * * On failure the first error that happened will be reported, but the close * operation will finish as much as possible. A stream that failed to * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it * is important to check and report the error to the user, otherwise * there might be a loss of data as all data might not be written. * * If @cancellable is not NULL, then the operation can be cancelled by * triggering the cancellable object from another thread. If the operation * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. * Cancelling a close will still leave the stream closed, but some streams * can use a faster close that doesn't block to e.g. check errors. * * The default implementation of this method just calls close on the * individual input/output streams. * * Return value: %TRUE on success, %FALSE on failure * * Since: 2.22 **/ gboolean g_io_stream_close (GIOStream *stream, GCancellable *cancellable, GError **error) { GIOStreamClass *class; gboolean res; g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE); class = G_IO_STREAM_GET_CLASS (stream); if (stream->priv->closed) return TRUE; if (!g_io_stream_set_pending (stream, error)) return FALSE; if (cancellable) g_cancellable_push_current (cancellable); res = TRUE; if (class->close_fn) res = class->close_fn (stream, cancellable, error); if (cancellable) g_cancellable_pop_current (cancellable); stream->priv->closed = TRUE; g_io_stream_clear_pending (stream); return res; } static void async_ready_close_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GIOStream *stream = G_IO_STREAM (source_object); stream->priv->closed = TRUE; g_io_stream_clear_pending (stream); if (stream->priv->outstanding_callback) (*stream->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (stream); } /** * g_io_stream_close_async: * @stream: A #GIOStream. * @io_priority: the io priority of the request. * @callback: callback to call when the request is satisfied * @user_data: the data to pass to callback function * @cancellable: optional cancellable object * * Requests an asynchronous close of the stream, releasing resources * related to it. When the operation is finished @callback will be * called. You can then call g_io_stream_close_finish() to get * the result of the operation. * * For behaviour details see g_io_stream_close(). * * The asyncronous methods have a default fallback that uses threads * to implement asynchronicity, so they are optional for inheriting * classes. However, if you override one you must override all. * * Since: 2.22 **/ void g_io_stream_close_async (GIOStream *stream, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GIOStreamClass *class; GSimpleAsyncResult *simple; GError *error = NULL; g_return_if_fail (G_IS_IO_STREAM (stream)); if (stream->priv->closed) { simple = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_io_stream_close_async); g_simple_async_result_complete_in_idle (simple); g_object_unref (simple); return; } if (!g_io_stream_set_pending (stream, &error)) { g_simple_async_report_gerror_in_idle (G_OBJECT (stream), callback, user_data, error); g_error_free (error); return; } class = G_IO_STREAM_GET_CLASS (stream); stream->priv->outstanding_callback = callback; g_object_ref (stream); class->close_async (stream, io_priority, cancellable, async_ready_close_callback_wrapper, user_data); } /** * g_io_stream_close_finish: * @stream: a #GIOStream. * @result: a #GAsyncResult. * @error: a #GError location to store the error occuring, or %NULL to * ignore. * * Closes a stream. * * Returns: %TRUE if stream was successfully closed, %FALSE otherwise. * * Since: 2.22 **/ gboolean g_io_stream_close_finish (GIOStream *stream, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple; GIOStreamClass *class; g_return_val_if_fail (G_IS_IO_STREAM (stream), FALSE); g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE); if (G_IS_SIMPLE_ASYNC_RESULT (result)) { simple = G_SIMPLE_ASYNC_RESULT (result); if (g_simple_async_result_propagate_error (simple, error)) return FALSE; /* Special case already closed */ if (g_simple_async_result_get_source_tag (simple) == g_io_stream_close_async) return TRUE; } class = G_IO_STREAM_GET_CLASS (stream); return class->close_finish (stream, result, error); } static void close_async_thread (GSimpleAsyncResult *res, GObject *object, GCancellable *cancellable) { GIOStreamClass *class; GError *error = NULL; gboolean result; /* Auto handling of cancelation disabled, and ignore cancellation, since we want to close things anyway, although possibly in a quick-n-dirty way. At least we never want to leak open handles */ class = G_IO_STREAM_GET_CLASS (object); result = class->close_fn (G_IO_STREAM (object), cancellable, &error); if (!result) { g_simple_async_result_set_from_error (res, error); g_error_free (error); } } static void g_io_stream_real_close_async (GIOStream *stream, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GSimpleAsyncResult *res; res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_io_stream_real_close_async); g_simple_async_result_set_handle_cancellation (res, FALSE); g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable); g_object_unref (res); } static gboolean g_io_stream_real_close_finish (GIOStream *stream, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result); g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_io_stream_real_close_async); return TRUE; } #define __G_IO_STREAM_C__ #include "gioaliasdef.c"