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https://gitlab.gnome.org/GNOME/glib.git
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f99be75ff9
The docs mentions a separate seekable API for the various file streams which don't actually exists. Change this to refer to the generic GSeekable calls.
474 lines
15 KiB
C
474 lines
15 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, write to the
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* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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* Boston, MA 02111-1307, USA.
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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 <gfileinputstream.h>
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#include <gseekable.h>
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#include "gsimpleasyncresult.h"
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#include "gcancellable.h"
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#include "gasyncresult.h"
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#include "gioerror.h"
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#include "glibintl.h"
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#include "gioalias.h"
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/**
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* SECTION:gfileinputstream
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* @short_description: File input streaming operations
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* @include: gio/gio.h
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* @see_also: #GInputStream, #GDataInputStream, #GSeekable
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*
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* GFileInputStream provides input streams that take their
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* content from a file.
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*
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* GFileInputStream implements #GSeekable, which allows the input
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* stream to jump to arbitrary positions in the file, provided the
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* filesystem of the file allows it. To find the position of a file
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* input stream, use g_seekable_tell(). To find out if a file input
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* stream supports seeking, use g_seekable_stream_can_seek().
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* To position a file input stream, use g_seekable_seek().
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**/
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static void g_file_input_stream_seekable_iface_init (GSeekableIface *iface);
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static goffset g_file_input_stream_seekable_tell (GSeekable *seekable);
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static gboolean g_file_input_stream_seekable_can_seek (GSeekable *seekable);
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static gboolean g_file_input_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_input_stream_seekable_can_truncate (GSeekable *seekable);
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static gboolean g_file_input_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_input_stream_real_query_info_async (GFileInputStream *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_input_stream_real_query_info_finish (GFileInputStream *stream,
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GAsyncResult *result,
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GError **error);
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G_DEFINE_TYPE_WITH_CODE (GFileInputStream, g_file_input_stream, G_TYPE_INPUT_STREAM,
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G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
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g_file_input_stream_seekable_iface_init))
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struct _GFileInputStreamPrivate {
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GAsyncReadyCallback outstanding_callback;
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};
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static void
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g_file_input_stream_class_init (GFileInputStreamClass *klass)
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{
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g_type_class_add_private (klass, sizeof (GFileInputStreamPrivate));
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klass->query_info_async = g_file_input_stream_real_query_info_async;
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klass->query_info_finish = g_file_input_stream_real_query_info_finish;
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}
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static void
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g_file_input_stream_seekable_iface_init (GSeekableIface *iface)
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{
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iface->tell = g_file_input_stream_seekable_tell;
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iface->can_seek = g_file_input_stream_seekable_can_seek;
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iface->seek = g_file_input_stream_seekable_seek;
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iface->can_truncate = g_file_input_stream_seekable_can_truncate;
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iface->truncate_fn = g_file_input_stream_seekable_truncate;
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}
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static void
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g_file_input_stream_init (GFileInputStream *stream)
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{
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stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
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G_TYPE_FILE_INPUT_STREAM,
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GFileInputStreamPrivate);
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}
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/**
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* g_file_input_stream_query_info:
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* @stream: a #GFileInputStream.
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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 location to store the error occuring, or %NULL to
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* ignore.
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*
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* Queries a file input stream the given @attributes. This function blocks
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* while querying the stream. For the asynchronous (non-blocking) version
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* of this function, see g_file_input_stream_query_info_async(). While the
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* stream is blocked, the stream will set the pending flag internally, and
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* any other operations on the stream will fail with %G_IO_ERROR_PENDING.
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*
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* Returns: a #GFileInfo, or %NULL on error.
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**/
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GFileInfo *
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g_file_input_stream_query_info (GFileInputStream *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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GFileInputStreamClass *class;
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GInputStream *input_stream;
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GFileInfo *info;
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g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), NULL);
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input_stream = G_INPUT_STREAM (stream);
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if (!g_input_stream_set_pending (input_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_INPUT_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_input_stream_clear_pending (input_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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GFileInputStream *stream = G_FILE_INPUT_STREAM (source_object);
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g_input_stream_clear_pending (G_INPUT_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_input_stream_query_info_async:
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* @stream: a #GFileInputStream.
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* @attributes: a file attribute query string.
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* @io_priority: the <link linkend="io-priority">I/O priority</link>
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* 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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* Queries the stream information asynchronously.
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* When the operation is finished @callback will be called.
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* You can then call g_file_input_stream_query_info_finish()
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* to get the result of the operation.
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*
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* For the synchronous version of this function,
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* see g_file_input_stream_query_info().
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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
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*
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**/
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void
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g_file_input_stream_query_info_async (GFileInputStream *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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GFileInputStreamClass *klass;
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GInputStream *input_stream;
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GError *error = NULL;
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g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream));
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input_stream = G_INPUT_STREAM (stream);
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if (!g_input_stream_set_pending (input_stream, &error))
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{
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g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
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callback,
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user_data,
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error);
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g_error_free (error);
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return;
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}
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klass = G_FILE_INPUT_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_input_stream_query_info_finish:
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* @stream: a #GFileInputStream.
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* @result: a #GAsyncResult.
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* @error: a #GError location to store the error occuring,
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* or %NULL to ignore.
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*
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* Finishes an asynchronous info query operation.
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*
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* Returns: #GFileInfo.
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**/
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GFileInfo *
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g_file_input_stream_query_info_finish (GFileInputStream *stream,
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GAsyncResult *result,
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GError **error)
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{
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GSimpleAsyncResult *simple;
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GFileInputStreamClass *class;
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g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), NULL);
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g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
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if (G_IS_SIMPLE_ASYNC_RESULT (result))
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{
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simple = G_SIMPLE_ASYNC_RESULT (result);
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if (g_simple_async_result_propagate_error (simple, error))
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return NULL;
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}
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class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
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return class->query_info_finish (stream, result, error);
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}
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static goffset
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g_file_input_stream_tell (GFileInputStream *stream)
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{
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GFileInputStreamClass *class;
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goffset offset;
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g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), 0);
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class = G_FILE_INPUT_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_input_stream_seekable_tell (GSeekable *seekable)
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{
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return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable));
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}
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static gboolean
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g_file_input_stream_can_seek (GFileInputStream *stream)
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{
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GFileInputStreamClass *class;
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gboolean can_seek;
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g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE);
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class = G_FILE_INPUT_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_input_stream_seekable_can_seek (GSeekable *seekable)
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{
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return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable));
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}
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static gboolean
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g_file_input_stream_seek (GFileInputStream *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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GFileInputStreamClass *class;
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GInputStream *input_stream;
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gboolean res;
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g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE);
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input_stream = G_INPUT_STREAM (stream);
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class = G_FILE_INPUT_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_input_stream_set_pending (input_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_input_stream_clear_pending (input_stream);
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return res;
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}
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static gboolean
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g_file_input_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_input_stream_seek (G_FILE_INPUT_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_input_stream_seekable_can_truncate (GSeekable *seekable)
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{
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return FALSE;
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}
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static gboolean
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g_file_input_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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{
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g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
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_("Truncate not allowed on input stream"));
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return FALSE;
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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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typedef struct {
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char *attributes;
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GFileInfo *info;
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} QueryInfoAsyncData;
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static void
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query_info_data_free (QueryInfoAsyncData *data)
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{
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if (data->info)
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g_object_unref (data->info);
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g_free (data->attributes);
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g_free (data);
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}
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static void
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query_info_async_thread (GSimpleAsyncResult *res,
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GObject *object,
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GCancellable *cancellable)
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{
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GFileInputStreamClass *class;
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GError *error = NULL;
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QueryInfoAsyncData *data;
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GFileInfo *info;
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data = g_simple_async_result_get_op_res_gpointer (res);
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info = NULL;
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class = G_FILE_INPUT_STREAM_GET_CLASS (object);
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if (class->query_info)
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info = class->query_info (G_FILE_INPUT_STREAM (object), data->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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{
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g_simple_async_result_set_from_error (res, error);
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g_error_free (error);
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}
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else
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data->info = info;
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}
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static void
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g_file_input_stream_real_query_info_async (GFileInputStream *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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GSimpleAsyncResult *res;
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QueryInfoAsyncData *data;
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data = g_new0 (QueryInfoAsyncData, 1);
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data->attributes = g_strdup (attributes);
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res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_file_input_stream_real_query_info_async);
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g_simple_async_result_set_op_res_gpointer (res, data, (GDestroyNotify)query_info_data_free);
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g_simple_async_result_run_in_thread (res, query_info_async_thread, io_priority, cancellable);
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g_object_unref (res);
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}
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static GFileInfo *
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g_file_input_stream_real_query_info_finish (GFileInputStream *stream,
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GAsyncResult *res,
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GError **error)
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{
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GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (res);
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QueryInfoAsyncData *data;
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g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_file_input_stream_real_query_info_async);
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data = g_simple_async_result_get_op_res_gpointer (simple);
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if (data->info)
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return g_object_ref (data->info);
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return NULL;
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}
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#define __G_FILE_INPUT_STREAM_C__
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#include "gioaliasdef.c"
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