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10c490cdfe
See https://developer.gnome.org/hig/stable/typography.html https://bugzilla.gnome.org/show_bug.cgi?id=772221
533 lines
16 KiB
C
533 lines
16 KiB
C
/* GIO - GLib Input, Output and Streaming Library
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*
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* Copyright (C) 2006-2007 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General
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* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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* Author: Alexander Larsson <alexl@redhat.com>
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*/
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#include "config.h"
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#include <glib.h>
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#include <gfileoutputstream.h>
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#include <gseekable.h>
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#include "gasyncresult.h"
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#include "gtask.h"
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#include "gcancellable.h"
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#include "gioerror.h"
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#include "glibintl.h"
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/**
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* SECTION:gfileoutputstream
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* @short_description: File output streaming operations
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* @include: gio/gio.h
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* @see_also: #GOutputStream, #GDataOutputStream, #GSeekable
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*
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* GFileOutputStream provides output streams that write their
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* content to a file.
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*
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* GFileOutputStream implements #GSeekable, which allows the output
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* stream to jump to arbitrary positions in the file and to truncate
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* the file, provided the filesystem of the file supports these
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* operations.
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*
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* To find the position of a file output stream, use g_seekable_tell().
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* To find out if a file output stream supports seeking, use
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* g_seekable_can_seek().To position a file output stream, use
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* g_seekable_seek(). To find out if a file output stream supports
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* truncating, use g_seekable_can_truncate(). To truncate a file output
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* stream, use g_seekable_truncate().
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**/
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static void g_file_output_stream_seekable_iface_init (GSeekableIface *iface);
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static goffset g_file_output_stream_seekable_tell (GSeekable *seekable);
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static gboolean g_file_output_stream_seekable_can_seek (GSeekable *seekable);
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static gboolean g_file_output_stream_seekable_seek (GSeekable *seekable,
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goffset offset,
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GSeekType type,
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GCancellable *cancellable,
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GError **error);
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static gboolean g_file_output_stream_seekable_can_truncate (GSeekable *seekable);
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static gboolean g_file_output_stream_seekable_truncate (GSeekable *seekable,
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goffset offset,
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GCancellable *cancellable,
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GError **error);
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static void g_file_output_stream_real_query_info_async (GFileOutputStream *stream,
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const char *attributes,
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int io_priority,
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GCancellable *cancellable,
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GAsyncReadyCallback callback,
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gpointer user_data);
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static GFileInfo *g_file_output_stream_real_query_info_finish (GFileOutputStream *stream,
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GAsyncResult *result,
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GError **error);
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struct _GFileOutputStreamPrivate {
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GAsyncReadyCallback outstanding_callback;
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};
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G_DEFINE_TYPE_WITH_CODE (GFileOutputStream, g_file_output_stream, G_TYPE_OUTPUT_STREAM,
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G_ADD_PRIVATE (GFileOutputStream)
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G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
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g_file_output_stream_seekable_iface_init));
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static void
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g_file_output_stream_class_init (GFileOutputStreamClass *klass)
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{
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klass->query_info_async = g_file_output_stream_real_query_info_async;
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klass->query_info_finish = g_file_output_stream_real_query_info_finish;
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}
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static void
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g_file_output_stream_seekable_iface_init (GSeekableIface *iface)
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{
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iface->tell = g_file_output_stream_seekable_tell;
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iface->can_seek = g_file_output_stream_seekable_can_seek;
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iface->seek = g_file_output_stream_seekable_seek;
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iface->can_truncate = g_file_output_stream_seekable_can_truncate;
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iface->truncate_fn = g_file_output_stream_seekable_truncate;
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}
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static void
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g_file_output_stream_init (GFileOutputStream *stream)
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{
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stream->priv = g_file_output_stream_get_instance_private (stream);
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}
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/**
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* g_file_output_stream_query_info:
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* @stream: a #GFileOutputStream.
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* @attributes: a file attribute query string.
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* @cancellable: optional #GCancellable object, %NULL to ignore.
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* @error: a #GError, %NULL to ignore.
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*
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* Queries a file output stream for the given @attributes.
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* This function blocks while querying the stream. For the asynchronous
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* version of this function, see g_file_output_stream_query_info_async().
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* While the stream is blocked, the stream will set the pending flag
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* internally, and any other operations on the stream will fail with
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* %G_IO_ERROR_PENDING.
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*
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* Can fail if the stream was already closed (with @error being set to
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* %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
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* set to %G_IO_ERROR_PENDING), or if querying info is not supported for
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* the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). In
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* all cases of failure, %NULL will be returned.
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*
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* If @cancellable is not %NULL, then the operation can be cancelled by
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* triggering the cancellable object from another thread. If the operation
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* was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
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* be returned.
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*
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* Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error.
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**/
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GFileInfo *
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g_file_output_stream_query_info (GFileOutputStream *stream,
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const char *attributes,
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GCancellable *cancellable,
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GError **error)
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{
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GFileOutputStreamClass *class;
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GOutputStream *output_stream;
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GFileInfo *info;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL);
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output_stream = G_OUTPUT_STREAM (stream);
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if (!g_output_stream_set_pending (output_stream, error))
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return NULL;
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info = NULL;
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if (cancellable)
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g_cancellable_push_current (cancellable);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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if (class->query_info)
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info = class->query_info (stream, attributes, cancellable, error);
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else
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g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
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_("Stream doesn’t support query_info"));
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if (cancellable)
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g_cancellable_pop_current (cancellable);
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g_output_stream_clear_pending (output_stream);
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return info;
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}
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static void
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async_ready_callback_wrapper (GObject *source_object,
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GAsyncResult *res,
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gpointer user_data)
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{
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GFileOutputStream *stream = G_FILE_OUTPUT_STREAM (source_object);
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g_output_stream_clear_pending (G_OUTPUT_STREAM (stream));
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if (stream->priv->outstanding_callback)
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(*stream->priv->outstanding_callback) (source_object, res, user_data);
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g_object_unref (stream);
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}
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/**
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* g_file_output_stream_query_info_async:
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* @stream: a #GFileOutputStream.
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* @attributes: a file attribute query string.
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* @io_priority: the [I/O priority][gio-GIOScheduler] of the request
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* @cancellable: optional #GCancellable object, %NULL to ignore.
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* @callback: callback to call when the request is satisfied
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* @user_data: the data to pass to callback function
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*
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* Asynchronously queries the @stream for a #GFileInfo. When completed,
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* @callback will be called with a #GAsyncResult which can be used to
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* finish the operation with g_file_output_stream_query_info_finish().
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*
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* For the synchronous version of this function, see
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* g_file_output_stream_query_info().
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*
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**/
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void
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g_file_output_stream_query_info_async (GFileOutputStream *stream,
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const char *attributes,
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int io_priority,
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GCancellable *cancellable,
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GAsyncReadyCallback callback,
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gpointer user_data)
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{
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GFileOutputStreamClass *klass;
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GOutputStream *output_stream;
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GError *error = NULL;
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g_return_if_fail (G_IS_FILE_OUTPUT_STREAM (stream));
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output_stream = G_OUTPUT_STREAM (stream);
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if (!g_output_stream_set_pending (output_stream, &error))
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{
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g_task_report_error (stream, callback, user_data,
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g_file_output_stream_query_info_async,
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error);
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return;
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}
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klass = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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stream->priv->outstanding_callback = callback;
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g_object_ref (stream);
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klass->query_info_async (stream, attributes, io_priority, cancellable,
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async_ready_callback_wrapper, user_data);
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}
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/**
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* g_file_output_stream_query_info_finish:
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* @stream: a #GFileOutputStream.
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* @result: a #GAsyncResult.
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* @error: a #GError, %NULL to ignore.
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*
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* Finalizes the asynchronous query started
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* by g_file_output_stream_query_info_async().
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*
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* Returns: (transfer full): A #GFileInfo for the finished query.
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**/
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GFileInfo *
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g_file_output_stream_query_info_finish (GFileOutputStream *stream,
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GAsyncResult *result,
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GError **error)
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{
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GFileOutputStreamClass *class;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL);
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g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
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if (g_async_result_legacy_propagate_error (result, error))
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return NULL;
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else if (g_async_result_is_tagged (result, g_file_output_stream_query_info_async))
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return g_task_propagate_pointer (G_TASK (result), error);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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return class->query_info_finish (stream, result, error);
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}
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/**
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* g_file_output_stream_get_etag:
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* @stream: a #GFileOutputStream.
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*
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* Gets the entity tag for the file when it has been written.
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* This must be called after the stream has been written
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* and closed, as the etag can change while writing.
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*
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* Returns: the entity tag for the stream.
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**/
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char *
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g_file_output_stream_get_etag (GFileOutputStream *stream)
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{
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GFileOutputStreamClass *class;
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GOutputStream *output_stream;
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char *etag;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL);
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output_stream = G_OUTPUT_STREAM (stream);
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if (!g_output_stream_is_closed (output_stream))
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{
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g_warning ("stream is not closed yet, can't get etag");
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return NULL;
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}
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etag = NULL;
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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if (class->get_etag)
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etag = class->get_etag (stream);
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return etag;
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}
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static goffset
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g_file_output_stream_tell (GFileOutputStream *stream)
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{
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GFileOutputStreamClass *class;
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goffset offset;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), 0);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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offset = 0;
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if (class->tell)
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offset = class->tell (stream);
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return offset;
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}
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static goffset
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g_file_output_stream_seekable_tell (GSeekable *seekable)
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{
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return g_file_output_stream_tell (G_FILE_OUTPUT_STREAM (seekable));
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}
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static gboolean
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g_file_output_stream_can_seek (GFileOutputStream *stream)
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{
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GFileOutputStreamClass *class;
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gboolean can_seek;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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can_seek = FALSE;
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if (class->seek)
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{
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can_seek = TRUE;
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if (class->can_seek)
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can_seek = class->can_seek (stream);
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}
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return can_seek;
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}
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static gboolean
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g_file_output_stream_seekable_can_seek (GSeekable *seekable)
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{
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return g_file_output_stream_can_seek (G_FILE_OUTPUT_STREAM (seekable));
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}
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static gboolean
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g_file_output_stream_seek (GFileOutputStream *stream,
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goffset offset,
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GSeekType type,
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GCancellable *cancellable,
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GError **error)
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{
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GFileOutputStreamClass *class;
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GOutputStream *output_stream;
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gboolean res;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE);
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output_stream = G_OUTPUT_STREAM (stream);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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if (!class->seek)
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{
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g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
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_("Seek not supported on stream"));
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return FALSE;
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}
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if (!g_output_stream_set_pending (output_stream, error))
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return FALSE;
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if (cancellable)
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g_cancellable_push_current (cancellable);
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res = class->seek (stream, offset, type, cancellable, error);
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if (cancellable)
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g_cancellable_pop_current (cancellable);
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g_output_stream_clear_pending (output_stream);
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return res;
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}
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static gboolean
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g_file_output_stream_seekable_seek (GSeekable *seekable,
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goffset offset,
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GSeekType type,
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GCancellable *cancellable,
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GError **error)
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{
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return g_file_output_stream_seek (G_FILE_OUTPUT_STREAM (seekable),
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offset, type, cancellable, error);
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}
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static gboolean
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g_file_output_stream_can_truncate (GFileOutputStream *stream)
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{
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GFileOutputStreamClass *class;
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gboolean can_truncate;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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can_truncate = FALSE;
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if (class->truncate_fn)
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{
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can_truncate = TRUE;
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if (class->can_truncate)
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can_truncate = class->can_truncate (stream);
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}
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return can_truncate;
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}
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static gboolean
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g_file_output_stream_seekable_can_truncate (GSeekable *seekable)
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{
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return g_file_output_stream_can_truncate (G_FILE_OUTPUT_STREAM (seekable));
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}
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static gboolean
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g_file_output_stream_truncate (GFileOutputStream *stream,
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goffset size,
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GCancellable *cancellable,
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GError **error)
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{
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GFileOutputStreamClass *class;
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GOutputStream *output_stream;
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gboolean res;
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g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE);
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output_stream = G_OUTPUT_STREAM (stream);
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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if (!class->truncate_fn)
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{
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g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
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_("Truncate not supported on stream"));
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return FALSE;
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}
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if (!g_output_stream_set_pending (output_stream, error))
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return FALSE;
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if (cancellable)
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g_cancellable_push_current (cancellable);
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res = class->truncate_fn (stream, size, cancellable, error);
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if (cancellable)
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g_cancellable_pop_current (cancellable);
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g_output_stream_clear_pending (output_stream);
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return res;
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}
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static gboolean
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g_file_output_stream_seekable_truncate (GSeekable *seekable,
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goffset size,
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GCancellable *cancellable,
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GError **error)
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{
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return g_file_output_stream_truncate (G_FILE_OUTPUT_STREAM (seekable),
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size, cancellable, error);
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}
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/********************************************
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* Default implementation of async ops *
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********************************************/
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static void
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query_info_async_thread (GTask *task,
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gpointer source_object,
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gpointer task_data,
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GCancellable *cancellable)
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{
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GFileOutputStream *stream = source_object;
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const char *attributes = task_data;
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GFileOutputStreamClass *class;
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GError *error = NULL;
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GFileInfo *info = NULL;
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class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream);
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if (class->query_info)
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info = class->query_info (stream, attributes, cancellable, &error);
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else
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g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
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_("Stream doesn’t support query_info"));
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if (info == NULL)
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g_task_return_error (task, error);
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else
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g_task_return_pointer (task, info, g_object_unref);
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}
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static void
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g_file_output_stream_real_query_info_async (GFileOutputStream *stream,
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const char *attributes,
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int io_priority,
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||
GCancellable *cancellable,
|
||
GAsyncReadyCallback callback,
|
||
gpointer user_data)
|
||
{
|
||
GTask *task;
|
||
|
||
task = g_task_new (stream, cancellable, callback, user_data);
|
||
g_task_set_source_tag (task, g_file_output_stream_real_query_info_async);
|
||
g_task_set_task_data (task, g_strdup (attributes), g_free);
|
||
g_task_set_priority (task, io_priority);
|
||
|
||
g_task_run_in_thread (task, query_info_async_thread);
|
||
g_object_unref (task);
|
||
}
|
||
|
||
static GFileInfo *
|
||
g_file_output_stream_real_query_info_finish (GFileOutputStream *stream,
|
||
GAsyncResult *res,
|
||
GError **error)
|
||
{
|
||
g_return_val_if_fail (g_task_is_valid (res, stream), NULL);
|
||
|
||
return g_task_propagate_pointer (G_TASK (res), error);
|
||
}
|