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 "gsimpleasyncresult.h"
29 #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 G_DEFINE_TYPE_WITH_CODE (GFileOutputStream
, g_file_output_stream
, G_TYPE_OUTPUT_STREAM
,
81 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
82 g_file_output_stream_seekable_iface_init
));
84 struct _GFileOutputStreamPrivate
{
85 GAsyncReadyCallback outstanding_callback
;
89 g_file_output_stream_class_init (GFileOutputStreamClass
*klass
)
91 g_type_class_add_private (klass
, sizeof (GFileOutputStreamPrivate
));
93 klass
->query_info_async
= g_file_output_stream_real_query_info_async
;
94 klass
->query_info_finish
= g_file_output_stream_real_query_info_finish
;
98 g_file_output_stream_seekable_iface_init (GSeekableIface
*iface
)
100 iface
->tell
= g_file_output_stream_seekable_tell
;
101 iface
->can_seek
= g_file_output_stream_seekable_can_seek
;
102 iface
->seek
= g_file_output_stream_seekable_seek
;
103 iface
->can_truncate
= g_file_output_stream_seekable_can_truncate
;
104 iface
->truncate_fn
= g_file_output_stream_seekable_truncate
;
108 g_file_output_stream_init (GFileOutputStream
*stream
)
110 stream
->priv
= G_TYPE_INSTANCE_GET_PRIVATE (stream
,
111 G_TYPE_FILE_OUTPUT_STREAM
,
112 GFileOutputStreamPrivate
);
116 * g_file_output_stream_query_info:
117 * @stream: a #GFileOutputStream.
118 * @attributes: a file attribute query string.
119 * @cancellable: optional #GCancellable object, %NULL to ignore.
120 * @error: a #GError, %NULL to ignore.
122 * Queries a file output stream for the given @attributes.
123 * This function blocks while querying the stream. For the asynchronous
124 * version of this function, see g_file_output_stream_query_info_async().
125 * While the stream is blocked, the stream will set the pending flag
126 * internally, and any other operations on the stream will fail with
127 * %G_IO_ERROR_PENDING.
129 * Can fail if the stream was already closed (with @error being set to
130 * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
131 * set to %G_IO_ERROR_PENDING), or if querying info is not supported for
132 * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). In
133 * all cases of failure, %NULL will be returned.
135 * If @cancellable is not %NULL, then the operation can be cancelled by
136 * triggering the cancellable object from another thread. If the operation
137 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
140 * Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error.
143 g_file_output_stream_query_info (GFileOutputStream
*stream
,
144 const char *attributes
,
145 GCancellable
*cancellable
,
148 GFileOutputStreamClass
*class;
149 GOutputStream
*output_stream
;
152 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
154 output_stream
= G_OUTPUT_STREAM (stream
);
156 if (!g_output_stream_set_pending (output_stream
, error
))
162 g_cancellable_push_current (cancellable
);
164 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
165 if (class->query_info
)
166 info
= class->query_info (stream
, attributes
, cancellable
, error
);
168 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
169 _("Stream doesn't support query_info"));
172 g_cancellable_pop_current (cancellable
);
174 g_output_stream_clear_pending (output_stream
);
180 async_ready_callback_wrapper (GObject
*source_object
,
184 GFileOutputStream
*stream
= G_FILE_OUTPUT_STREAM (source_object
);
186 g_output_stream_clear_pending (G_OUTPUT_STREAM (stream
));
187 if (stream
->priv
->outstanding_callback
)
188 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
189 g_object_unref (stream
);
193 * g_file_output_stream_query_info_async:
194 * @stream: a #GFileOutputStream.
195 * @attributes: a file attribute query string.
196 * @io_priority: the <link linkend="gio-GIOScheduler">I/O priority</link>
198 * @cancellable: optional #GCancellable object, %NULL to ignore.
199 * @callback: callback to call when the request is satisfied
200 * @user_data: the data to pass to callback function
202 * Asynchronously queries the @stream for a #GFileInfo. When completed,
203 * @callback will be called with a #GAsyncResult which can be used to
204 * finish the operation with g_file_output_stream_query_info_finish().
206 * For the synchronous version of this function, see
207 * g_file_output_stream_query_info().
211 g_file_output_stream_query_info_async (GFileOutputStream
*stream
,
212 const char *attributes
,
214 GCancellable
*cancellable
,
215 GAsyncReadyCallback callback
,
218 GFileOutputStreamClass
*klass
;
219 GOutputStream
*output_stream
;
220 GError
*error
= NULL
;
222 g_return_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
));
224 output_stream
= G_OUTPUT_STREAM (stream
);
226 if (!g_output_stream_set_pending (output_stream
, &error
))
228 g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream
),
235 klass
= G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
237 stream
->priv
->outstanding_callback
= callback
;
238 g_object_ref (stream
);
239 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
240 async_ready_callback_wrapper
, user_data
);
244 * g_file_output_stream_query_info_finish:
245 * @stream: a #GFileOutputStream.
246 * @result: a #GAsyncResult.
247 * @error: a #GError, %NULL to ignore.
249 * Finalizes the asynchronous query started
250 * by g_file_output_stream_query_info_async().
252 * Returns: (transfer full): A #GFileInfo for the finished query.
255 g_file_output_stream_query_info_finish (GFileOutputStream
*stream
,
256 GAsyncResult
*result
,
259 GFileOutputStreamClass
*class;
261 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
262 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
264 if (g_async_result_legacy_propagate_error (result
, error
))
267 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
268 return class->query_info_finish (stream
, result
, error
);
272 * g_file_output_stream_get_etag:
273 * @stream: a #GFileOutputStream.
275 * Gets the entity tag for the file when it has been written.
276 * This must be called after the stream has been written
277 * and closed, as the etag can change while writing.
279 * Returns: the entity tag for the stream.
282 g_file_output_stream_get_etag (GFileOutputStream
*stream
)
284 GFileOutputStreamClass
*class;
285 GOutputStream
*output_stream
;
288 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
290 output_stream
= G_OUTPUT_STREAM (stream
);
292 if (!g_output_stream_is_closed (output_stream
))
294 g_warning ("stream is not closed yet, can't get etag");
300 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
302 etag
= class->get_etag (stream
);
308 g_file_output_stream_tell (GFileOutputStream
*stream
)
310 GFileOutputStreamClass
*class;
313 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), 0);
315 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
319 offset
= class->tell (stream
);
325 g_file_output_stream_seekable_tell (GSeekable
*seekable
)
327 return g_file_output_stream_tell (G_FILE_OUTPUT_STREAM (seekable
));
331 g_file_output_stream_can_seek (GFileOutputStream
*stream
)
333 GFileOutputStreamClass
*class;
336 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
338 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
345 can_seek
= class->can_seek (stream
);
352 g_file_output_stream_seekable_can_seek (GSeekable
*seekable
)
354 return g_file_output_stream_can_seek (G_FILE_OUTPUT_STREAM (seekable
));
358 g_file_output_stream_seek (GFileOutputStream
*stream
,
361 GCancellable
*cancellable
,
364 GFileOutputStreamClass
*class;
365 GOutputStream
*output_stream
;
368 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
370 output_stream
= G_OUTPUT_STREAM (stream
);
371 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
375 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
376 _("Seek not supported on stream"));
380 if (!g_output_stream_set_pending (output_stream
, error
))
384 g_cancellable_push_current (cancellable
);
386 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
389 g_cancellable_pop_current (cancellable
);
391 g_output_stream_clear_pending (output_stream
);
397 g_file_output_stream_seekable_seek (GSeekable
*seekable
,
400 GCancellable
*cancellable
,
403 return g_file_output_stream_seek (G_FILE_OUTPUT_STREAM (seekable
),
404 offset
, type
, cancellable
, error
);
408 g_file_output_stream_can_truncate (GFileOutputStream
*stream
)
410 GFileOutputStreamClass
*class;
411 gboolean can_truncate
;
413 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
415 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
417 can_truncate
= FALSE
;
418 if (class->truncate_fn
)
421 if (class->can_truncate
)
422 can_truncate
= class->can_truncate (stream
);
429 g_file_output_stream_seekable_can_truncate (GSeekable
*seekable
)
431 return g_file_output_stream_can_truncate (G_FILE_OUTPUT_STREAM (seekable
));
435 g_file_output_stream_truncate (GFileOutputStream
*stream
,
437 GCancellable
*cancellable
,
440 GFileOutputStreamClass
*class;
441 GOutputStream
*output_stream
;
444 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
446 output_stream
= G_OUTPUT_STREAM (stream
);
447 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
449 if (!class->truncate_fn
)
451 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
452 _("Truncate not supported on stream"));
456 if (!g_output_stream_set_pending (output_stream
, error
))
460 g_cancellable_push_current (cancellable
);
462 res
= class->truncate_fn (stream
, size
, cancellable
, error
);
465 g_cancellable_pop_current (cancellable
);
467 g_output_stream_clear_pending (output_stream
);
473 g_file_output_stream_seekable_truncate (GSeekable
*seekable
,
475 GCancellable
*cancellable
,
478 return g_file_output_stream_truncate (G_FILE_OUTPUT_STREAM (seekable
),
479 size
, cancellable
, error
);
481 /********************************************
482 * Default implementation of async ops *
483 ********************************************/
488 } QueryInfoAsyncData
;
491 query_info_data_free (QueryInfoAsyncData
*data
)
494 g_object_unref (data
->info
);
495 g_free (data
->attributes
);
500 query_info_async_thread (GSimpleAsyncResult
*res
,
502 GCancellable
*cancellable
)
504 GFileOutputStreamClass
*class;
505 GError
*error
= NULL
;
506 QueryInfoAsyncData
*data
;
509 data
= g_simple_async_result_get_op_res_gpointer (res
);
513 class = G_FILE_OUTPUT_STREAM_GET_CLASS (object
);
514 if (class->query_info
)
515 info
= class->query_info (G_FILE_OUTPUT_STREAM (object
), data
->attributes
, cancellable
, &error
);
517 g_set_error_literal (&error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
518 _("Stream doesn't support query_info"));
521 g_simple_async_result_take_error (res
, error
);
527 g_file_output_stream_real_query_info_async (GFileOutputStream
*stream
,
528 const char *attributes
,
530 GCancellable
*cancellable
,
531 GAsyncReadyCallback callback
,
534 GSimpleAsyncResult
*res
;
535 QueryInfoAsyncData
*data
;
537 data
= g_new0 (QueryInfoAsyncData
, 1);
538 data
->attributes
= g_strdup (attributes
);
540 res
= g_simple_async_result_new (G_OBJECT (stream
), callback
, user_data
, g_file_output_stream_real_query_info_async
);
541 g_simple_async_result_set_op_res_gpointer (res
, data
, (GDestroyNotify
)query_info_data_free
);
543 g_simple_async_result_run_in_thread (res
, query_info_async_thread
, io_priority
, cancellable
);
544 g_object_unref (res
);
548 g_file_output_stream_real_query_info_finish (GFileOutputStream
*stream
,
552 GSimpleAsyncResult
*simple
= G_SIMPLE_ASYNC_RESULT (res
);
553 QueryInfoAsyncData
*data
;
555 g_warn_if_fail (g_simple_async_result_get_source_tag (simple
) == g_file_output_stream_real_query_info_async
);
557 if (g_simple_async_result_propagate_error (simple
, error
))
560 data
= g_simple_async_result_get_op_res_gpointer (simple
);
562 return g_object_ref (data
->info
);