1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2006-2007 Red Hat, Inc.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
18 * Boston, MA 02111-1307, USA.
20 * Author: Alexander Larsson <alexl@redhat.com>
26 #include <gfileoutputstream.h>
27 #include <gseekable.h>
28 #include "gasyncresult.h"
30 #include "gcancellable.h"
36 * SECTION:gfileoutputstream
37 * @short_description: File output streaming operations
39 * @see_also: #GOutputStream, #GDataOutputStream, #GSeekable
41 * GFileOutputStream provides output streams that write their
44 * GFileOutputStream implements #GSeekable, which allows the output
45 * stream to jump to arbitrary positions in the file and to truncate
46 * the file, provided the filesystem of the file supports these
49 * To find the position of a file output stream, use g_seekable_tell().
50 * To find out if a file output stream supports seeking, use
51 * g_seekable_can_seek().To position a file output stream, use
52 * g_seekable_seek(). To find out if a file output stream supports
53 * truncating, use g_seekable_can_truncate(). To truncate a file output
54 * stream, use g_seekable_truncate().
57 static void g_file_output_stream_seekable_iface_init (GSeekableIface
*iface
);
58 static goffset
g_file_output_stream_seekable_tell (GSeekable
*seekable
);
59 static gboolean
g_file_output_stream_seekable_can_seek (GSeekable
*seekable
);
60 static gboolean
g_file_output_stream_seekable_seek (GSeekable
*seekable
,
63 GCancellable
*cancellable
,
65 static gboolean
g_file_output_stream_seekable_can_truncate (GSeekable
*seekable
);
66 static gboolean
g_file_output_stream_seekable_truncate (GSeekable
*seekable
,
68 GCancellable
*cancellable
,
70 static void g_file_output_stream_real_query_info_async (GFileOutputStream
*stream
,
71 const char *attributes
,
73 GCancellable
*cancellable
,
74 GAsyncReadyCallback callback
,
76 static GFileInfo
*g_file_output_stream_real_query_info_finish (GFileOutputStream
*stream
,
80 struct _GFileOutputStreamPrivate
{
81 GAsyncReadyCallback outstanding_callback
;
84 G_DEFINE_TYPE_WITH_CODE (GFileOutputStream
, g_file_output_stream
, G_TYPE_OUTPUT_STREAM
,
85 G_ADD_PRIVATE (GFileOutputStream
)
86 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
87 g_file_output_stream_seekable_iface_init
));
90 g_file_output_stream_class_init (GFileOutputStreamClass
*klass
)
92 klass
->query_info_async
= g_file_output_stream_real_query_info_async
;
93 klass
->query_info_finish
= g_file_output_stream_real_query_info_finish
;
97 g_file_output_stream_seekable_iface_init (GSeekableIface
*iface
)
99 iface
->tell
= g_file_output_stream_seekable_tell
;
100 iface
->can_seek
= g_file_output_stream_seekable_can_seek
;
101 iface
->seek
= g_file_output_stream_seekable_seek
;
102 iface
->can_truncate
= g_file_output_stream_seekable_can_truncate
;
103 iface
->truncate_fn
= g_file_output_stream_seekable_truncate
;
107 g_file_output_stream_init (GFileOutputStream
*stream
)
109 stream
->priv
= g_file_output_stream_get_instance_private (stream
);
113 * g_file_output_stream_query_info:
114 * @stream: a #GFileOutputStream.
115 * @attributes: a file attribute query string.
116 * @cancellable: optional #GCancellable object, %NULL to ignore.
117 * @error: a #GError, %NULL to ignore.
119 * Queries a file output stream for the given @attributes.
120 * This function blocks while querying the stream. For the asynchronous
121 * version of this function, see g_file_output_stream_query_info_async().
122 * While the stream is blocked, the stream will set the pending flag
123 * internally, and any other operations on the stream will fail with
124 * %G_IO_ERROR_PENDING.
126 * Can fail if the stream was already closed (with @error being set to
127 * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
128 * set to %G_IO_ERROR_PENDING), or if querying info is not supported for
129 * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). In
130 * all cases of failure, %NULL will be returned.
132 * If @cancellable is not %NULL, then the operation can be cancelled by
133 * triggering the cancellable object from another thread. If the operation
134 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
137 * Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error.
140 g_file_output_stream_query_info (GFileOutputStream
*stream
,
141 const char *attributes
,
142 GCancellable
*cancellable
,
145 GFileOutputStreamClass
*class;
146 GOutputStream
*output_stream
;
149 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
151 output_stream
= G_OUTPUT_STREAM (stream
);
153 if (!g_output_stream_set_pending (output_stream
, error
))
159 g_cancellable_push_current (cancellable
);
161 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
162 if (class->query_info
)
163 info
= class->query_info (stream
, attributes
, cancellable
, error
);
165 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
166 _("Stream doesn't support query_info"));
169 g_cancellable_pop_current (cancellable
);
171 g_output_stream_clear_pending (output_stream
);
177 async_ready_callback_wrapper (GObject
*source_object
,
181 GFileOutputStream
*stream
= G_FILE_OUTPUT_STREAM (source_object
);
183 g_output_stream_clear_pending (G_OUTPUT_STREAM (stream
));
184 if (stream
->priv
->outstanding_callback
)
185 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
186 g_object_unref (stream
);
190 * g_file_output_stream_query_info_async:
191 * @stream: a #GFileOutputStream.
192 * @attributes: a file attribute query string.
193 * @io_priority: the <link linkend="gio-GIOScheduler">I/O priority</link>
195 * @cancellable: optional #GCancellable object, %NULL to ignore.
196 * @callback: callback to call when the request is satisfied
197 * @user_data: the data to pass to callback function
199 * Asynchronously queries the @stream for a #GFileInfo. When completed,
200 * @callback will be called with a #GAsyncResult which can be used to
201 * finish the operation with g_file_output_stream_query_info_finish().
203 * For the synchronous version of this function, see
204 * g_file_output_stream_query_info().
208 g_file_output_stream_query_info_async (GFileOutputStream
*stream
,
209 const char *attributes
,
211 GCancellable
*cancellable
,
212 GAsyncReadyCallback callback
,
215 GFileOutputStreamClass
*klass
;
216 GOutputStream
*output_stream
;
217 GError
*error
= NULL
;
219 g_return_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
));
221 output_stream
= G_OUTPUT_STREAM (stream
);
223 if (!g_output_stream_set_pending (output_stream
, &error
))
225 g_task_report_error (stream
, callback
, user_data
,
226 g_file_output_stream_query_info_async
,
231 klass
= G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
233 stream
->priv
->outstanding_callback
= callback
;
234 g_object_ref (stream
);
235 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
236 async_ready_callback_wrapper
, user_data
);
240 * g_file_output_stream_query_info_finish:
241 * @stream: a #GFileOutputStream.
242 * @result: a #GAsyncResult.
243 * @error: a #GError, %NULL to ignore.
245 * Finalizes the asynchronous query started
246 * by g_file_output_stream_query_info_async().
248 * Returns: (transfer full): A #GFileInfo for the finished query.
251 g_file_output_stream_query_info_finish (GFileOutputStream
*stream
,
252 GAsyncResult
*result
,
255 GFileOutputStreamClass
*class;
257 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
258 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
260 if (g_async_result_legacy_propagate_error (result
, error
))
262 else if (g_async_result_is_tagged (result
, g_file_output_stream_query_info_async
))
263 return g_task_propagate_pointer (G_TASK (result
), error
);
265 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
266 return class->query_info_finish (stream
, result
, error
);
270 * g_file_output_stream_get_etag:
271 * @stream: a #GFileOutputStream.
273 * Gets the entity tag for the file when it has been written.
274 * This must be called after the stream has been written
275 * and closed, as the etag can change while writing.
277 * Returns: the entity tag for the stream.
280 g_file_output_stream_get_etag (GFileOutputStream
*stream
)
282 GFileOutputStreamClass
*class;
283 GOutputStream
*output_stream
;
286 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
288 output_stream
= G_OUTPUT_STREAM (stream
);
290 if (!g_output_stream_is_closed (output_stream
))
292 g_warning ("stream is not closed yet, can't get etag");
298 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
300 etag
= class->get_etag (stream
);
306 g_file_output_stream_tell (GFileOutputStream
*stream
)
308 GFileOutputStreamClass
*class;
311 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), 0);
313 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
317 offset
= class->tell (stream
);
323 g_file_output_stream_seekable_tell (GSeekable
*seekable
)
325 return g_file_output_stream_tell (G_FILE_OUTPUT_STREAM (seekable
));
329 g_file_output_stream_can_seek (GFileOutputStream
*stream
)
331 GFileOutputStreamClass
*class;
334 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
336 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
343 can_seek
= class->can_seek (stream
);
350 g_file_output_stream_seekable_can_seek (GSeekable
*seekable
)
352 return g_file_output_stream_can_seek (G_FILE_OUTPUT_STREAM (seekable
));
356 g_file_output_stream_seek (GFileOutputStream
*stream
,
359 GCancellable
*cancellable
,
362 GFileOutputStreamClass
*class;
363 GOutputStream
*output_stream
;
366 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
368 output_stream
= G_OUTPUT_STREAM (stream
);
369 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
373 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
374 _("Seek not supported on stream"));
378 if (!g_output_stream_set_pending (output_stream
, error
))
382 g_cancellable_push_current (cancellable
);
384 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
387 g_cancellable_pop_current (cancellable
);
389 g_output_stream_clear_pending (output_stream
);
395 g_file_output_stream_seekable_seek (GSeekable
*seekable
,
398 GCancellable
*cancellable
,
401 return g_file_output_stream_seek (G_FILE_OUTPUT_STREAM (seekable
),
402 offset
, type
, cancellable
, error
);
406 g_file_output_stream_can_truncate (GFileOutputStream
*stream
)
408 GFileOutputStreamClass
*class;
409 gboolean can_truncate
;
411 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
413 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
415 can_truncate
= FALSE
;
416 if (class->truncate_fn
)
419 if (class->can_truncate
)
420 can_truncate
= class->can_truncate (stream
);
427 g_file_output_stream_seekable_can_truncate (GSeekable
*seekable
)
429 return g_file_output_stream_can_truncate (G_FILE_OUTPUT_STREAM (seekable
));
433 g_file_output_stream_truncate (GFileOutputStream
*stream
,
435 GCancellable
*cancellable
,
438 GFileOutputStreamClass
*class;
439 GOutputStream
*output_stream
;
442 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
444 output_stream
= G_OUTPUT_STREAM (stream
);
445 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
447 if (!class->truncate_fn
)
449 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
450 _("Truncate not supported on stream"));
454 if (!g_output_stream_set_pending (output_stream
, error
))
458 g_cancellable_push_current (cancellable
);
460 res
= class->truncate_fn (stream
, size
, cancellable
, error
);
463 g_cancellable_pop_current (cancellable
);
465 g_output_stream_clear_pending (output_stream
);
471 g_file_output_stream_seekable_truncate (GSeekable
*seekable
,
473 GCancellable
*cancellable
,
476 return g_file_output_stream_truncate (G_FILE_OUTPUT_STREAM (seekable
),
477 size
, cancellable
, error
);
479 /********************************************
480 * Default implementation of async ops *
481 ********************************************/
484 query_info_async_thread (GTask
*task
,
485 gpointer source_object
,
487 GCancellable
*cancellable
)
489 GFileOutputStream
*stream
= source_object
;
490 const char *attributes
= task_data
;
491 GFileOutputStreamClass
*class;
492 GError
*error
= NULL
;
493 GFileInfo
*info
= NULL
;
495 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
496 if (class->query_info
)
497 info
= class->query_info (stream
, attributes
, cancellable
, &error
);
499 g_set_error_literal (&error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
500 _("Stream doesn't support query_info"));
503 g_task_return_error (task
, error
);
505 g_task_return_pointer (task
, info
, g_object_unref
);
509 g_file_output_stream_real_query_info_async (GFileOutputStream
*stream
,
510 const char *attributes
,
512 GCancellable
*cancellable
,
513 GAsyncReadyCallback callback
,
518 task
= g_task_new (stream
, cancellable
, callback
, user_data
);
519 g_task_set_task_data (task
, g_strdup (attributes
), g_free
);
520 g_task_set_priority (task
, io_priority
);
522 g_task_run_in_thread (task
, query_info_async_thread
);
523 g_object_unref (task
);
527 g_file_output_stream_real_query_info_finish (GFileOutputStream
*stream
,
531 g_return_val_if_fail (g_task_is_valid (res
, stream
), NULL
);
533 return g_task_propagate_pointer (G_TASK (res
), error
);