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"
37 * SECTION:gfileoutputstream
38 * @short_description: File output streaming operations
40 * @see_also: #GOutputStream, #GDataOutputStream, #GSeekable
42 * GFileOutputStream provides output streams that write their
45 * GFileOutputStream implements #GSeekable, which allows the output
46 * stream to jump to arbitrary positions in the file and to truncate
47 * the file, provided the filesystem of the file supports these
48 * operations. In addition to the generic g_seekable_ API,
49 * GFileOutputStream has its own API for seeking and positioning.
50 * To find the position of a file output stream, use
51 * g_file_output_stream_tell(). To find out if a file output
52 * stream supports seeking, use g_file_output_stream_can_seek().
53 * To position a file output stream, use g_file_output_stream_seek().
54 * To find out if a file output stream supports truncating, use
55 * g_file_output_stream_can_truncate(). To truncate a file output
56 * stream, use g_file_output_stream_truncate().
59 static void g_file_output_stream_seekable_iface_init (GSeekableIface
*iface
);
60 static goffset
g_file_output_stream_seekable_tell (GSeekable
*seekable
);
61 static gboolean
g_file_output_stream_seekable_can_seek (GSeekable
*seekable
);
62 static gboolean
g_file_output_stream_seekable_seek (GSeekable
*seekable
,
65 GCancellable
*cancellable
,
67 static gboolean
g_file_output_stream_seekable_can_truncate (GSeekable
*seekable
);
68 static gboolean
g_file_output_stream_seekable_truncate (GSeekable
*seekable
,
70 GCancellable
*cancellable
,
72 static void g_file_output_stream_real_query_info_async (GFileOutputStream
*stream
,
73 const char *attributes
,
75 GCancellable
*cancellable
,
76 GAsyncReadyCallback callback
,
78 static GFileInfo
*g_file_output_stream_real_query_info_finish (GFileOutputStream
*stream
,
82 G_DEFINE_TYPE_WITH_CODE (GFileOutputStream
, g_file_output_stream
, G_TYPE_OUTPUT_STREAM
,
83 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
84 g_file_output_stream_seekable_iface_init
));
86 struct _GFileOutputStreamPrivate
{
87 GAsyncReadyCallback outstanding_callback
;
91 g_file_output_stream_class_init (GFileOutputStreamClass
*klass
)
93 g_type_class_add_private (klass
, sizeof (GFileOutputStreamPrivate
));
95 klass
->query_info_async
= g_file_output_stream_real_query_info_async
;
96 klass
->query_info_finish
= g_file_output_stream_real_query_info_finish
;
100 g_file_output_stream_seekable_iface_init (GSeekableIface
*iface
)
102 iface
->tell
= g_file_output_stream_seekable_tell
;
103 iface
->can_seek
= g_file_output_stream_seekable_can_seek
;
104 iface
->seek
= g_file_output_stream_seekable_seek
;
105 iface
->can_truncate
= g_file_output_stream_seekable_can_truncate
;
106 iface
->truncate_fn
= g_file_output_stream_seekable_truncate
;
110 g_file_output_stream_init (GFileOutputStream
*stream
)
112 stream
->priv
= G_TYPE_INSTANCE_GET_PRIVATE (stream
,
113 G_TYPE_FILE_OUTPUT_STREAM
,
114 GFileOutputStreamPrivate
);
118 * g_file_output_stream_query_info:
119 * @stream: a #GFileOutputStream.
120 * @attributes: a file attribute query string.
121 * @cancellable: optional #GCancellable object, %NULL to ignore.
122 * @error: a #GError, %NULL to ignore.
124 * Queries a file output stream for the given @attributes.
125 * This function blocks while querying the stream. For the asynchronous
126 * version of this function, see g_file_output_stream_query_info_async().
127 * While the stream is blocked, the stream will set the pending flag
128 * internally, and any other operations on the stream will fail with
129 * %G_IO_ERROR_PENDING.
131 * Can fail if the stream was already closed (with @error being set to
132 * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
133 * set to %G_IO_ERROR_PENDING), or if querying info is not supported for
134 * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). In
135 * all cases of failure, %NULL will be returned.
137 * If @cancellable is not %NULL, then the operation can be cancelled by
138 * triggering the cancellable object from another thread. If the operation
139 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
142 * Returns: a #GFileInfo for the @stream, or %NULL on error.
145 g_file_output_stream_query_info (GFileOutputStream
*stream
,
146 const char *attributes
,
147 GCancellable
*cancellable
,
150 GFileOutputStreamClass
*class;
151 GOutputStream
*output_stream
;
154 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
156 output_stream
= G_OUTPUT_STREAM (stream
);
158 if (!g_output_stream_set_pending (output_stream
, error
))
164 g_cancellable_push_current (cancellable
);
166 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
167 if (class->query_info
)
168 info
= class->query_info (stream
, attributes
, cancellable
, error
);
170 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
171 _("Stream doesn't support query_info"));
174 g_cancellable_pop_current (cancellable
);
176 g_output_stream_clear_pending (output_stream
);
182 async_ready_callback_wrapper (GObject
*source_object
,
186 GFileOutputStream
*stream
= G_FILE_OUTPUT_STREAM (source_object
);
188 g_output_stream_clear_pending (G_OUTPUT_STREAM (stream
));
189 if (stream
->priv
->outstanding_callback
)
190 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
191 g_object_unref (stream
);
195 * g_file_output_stream_query_info_async:
196 * @stream: a #GFileOutputStream.
197 * @attributes: a file attribute query string.
198 * @io_priority: the <link linkend="gio-GIOScheduler">I/O priority</link>
200 * @cancellable: optional #GCancellable object, %NULL to ignore.
201 * @callback: callback to call when the request is satisfied
202 * @user_data: the data to pass to callback function
204 * Asynchronously queries the @stream for a #GFileInfo. When completed,
205 * @callback will be called with a #GAsyncResult which can be used to
206 * finish the operation with g_file_output_stream_query_info_finish().
208 * For the synchronous version of this function, see
209 * g_file_output_stream_query_info().
213 g_file_output_stream_query_info_async (GFileOutputStream
*stream
,
214 const char *attributes
,
216 GCancellable
*cancellable
,
217 GAsyncReadyCallback callback
,
220 GFileOutputStreamClass
*klass
;
221 GOutputStream
*output_stream
;
222 GError
*error
= NULL
;
224 g_return_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
));
226 output_stream
= G_OUTPUT_STREAM (stream
);
228 if (!g_output_stream_set_pending (output_stream
, &error
))
230 g_simple_async_report_gerror_in_idle (G_OBJECT (stream
),
234 g_error_free (error
);
238 klass
= G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
240 stream
->priv
->outstanding_callback
= callback
;
241 g_object_ref (stream
);
242 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
243 async_ready_callback_wrapper
, user_data
);
247 * g_file_output_stream_query_info_finish:
248 * @stream: a #GFileOutputStream.
249 * @result: a #GAsyncResult.
250 * @error: a #GError, %NULL to ignore.
252 * Finalizes the asynchronous query started
253 * by g_file_output_stream_query_info_async().
255 * Returns: A #GFileInfo for the finished query.
258 g_file_output_stream_query_info_finish (GFileOutputStream
*stream
,
259 GAsyncResult
*result
,
262 GSimpleAsyncResult
*simple
;
263 GFileOutputStreamClass
*class;
265 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
266 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
268 if (G_IS_SIMPLE_ASYNC_RESULT (result
))
270 simple
= G_SIMPLE_ASYNC_RESULT (result
);
271 if (g_simple_async_result_propagate_error (simple
, error
))
275 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
276 return class->query_info_finish (stream
, result
, error
);
280 * g_file_output_stream_get_etag:
281 * @stream: a #GFileOutputStream.
283 * Gets the entity tag for the file when it has been written.
284 * This must be called after the stream has been written
285 * and closed, as the etag can change while writing.
287 * Returns: the entity tag for the stream.
290 g_file_output_stream_get_etag (GFileOutputStream
*stream
)
292 GFileOutputStreamClass
*class;
293 GOutputStream
*output_stream
;
296 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), NULL
);
298 output_stream
= G_OUTPUT_STREAM (stream
);
300 if (!g_output_stream_is_closed (output_stream
))
302 g_warning ("stream is not closed yet, can't get etag");
308 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
310 etag
= class->get_etag (stream
);
316 g_file_output_stream_tell (GFileOutputStream
*stream
)
318 GFileOutputStreamClass
*class;
321 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), 0);
323 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
327 offset
= class->tell (stream
);
333 g_file_output_stream_seekable_tell (GSeekable
*seekable
)
335 return g_file_output_stream_tell (G_FILE_OUTPUT_STREAM (seekable
));
339 g_file_output_stream_can_seek (GFileOutputStream
*stream
)
341 GFileOutputStreamClass
*class;
344 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
346 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
353 can_seek
= class->can_seek (stream
);
360 g_file_output_stream_seekable_can_seek (GSeekable
*seekable
)
362 return g_file_output_stream_can_seek (G_FILE_OUTPUT_STREAM (seekable
));
366 g_file_output_stream_seek (GFileOutputStream
*stream
,
369 GCancellable
*cancellable
,
372 GFileOutputStreamClass
*class;
373 GOutputStream
*output_stream
;
376 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
378 output_stream
= G_OUTPUT_STREAM (stream
);
379 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
383 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
384 _("Seek not supported on stream"));
388 if (!g_output_stream_set_pending (output_stream
, error
))
392 g_cancellable_push_current (cancellable
);
394 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
397 g_cancellable_pop_current (cancellable
);
399 g_output_stream_clear_pending (output_stream
);
405 g_file_output_stream_seekable_seek (GSeekable
*seekable
,
408 GCancellable
*cancellable
,
411 return g_file_output_stream_seek (G_FILE_OUTPUT_STREAM (seekable
),
412 offset
, type
, cancellable
, error
);
416 g_file_output_stream_can_truncate (GFileOutputStream
*stream
)
418 GFileOutputStreamClass
*class;
419 gboolean can_truncate
;
421 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
423 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
425 can_truncate
= FALSE
;
426 if (class->truncate_fn
)
429 if (class->can_truncate
)
430 can_truncate
= class->can_truncate (stream
);
437 g_file_output_stream_seekable_can_truncate (GSeekable
*seekable
)
439 return g_file_output_stream_can_truncate (G_FILE_OUTPUT_STREAM (seekable
));
443 g_file_output_stream_truncate (GFileOutputStream
*stream
,
445 GCancellable
*cancellable
,
448 GFileOutputStreamClass
*class;
449 GOutputStream
*output_stream
;
452 g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream
), FALSE
);
454 output_stream
= G_OUTPUT_STREAM (stream
);
455 class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream
);
457 if (!class->truncate_fn
)
459 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
460 _("Truncate not supported on stream"));
464 if (!g_output_stream_set_pending (output_stream
, error
))
468 g_cancellable_push_current (cancellable
);
470 res
= class->truncate_fn (stream
, size
, cancellable
, error
);
473 g_cancellable_pop_current (cancellable
);
475 g_output_stream_clear_pending (output_stream
);
481 g_file_output_stream_seekable_truncate (GSeekable
*seekable
,
483 GCancellable
*cancellable
,
486 return g_file_output_stream_truncate (G_FILE_OUTPUT_STREAM (seekable
),
487 size
, cancellable
, error
);
489 /********************************************
490 * Default implementation of async ops *
491 ********************************************/
496 } QueryInfoAsyncData
;
499 query_info_data_free (QueryInfoAsyncData
*data
)
502 g_object_unref (data
->info
);
503 g_free (data
->attributes
);
508 query_info_async_thread (GSimpleAsyncResult
*res
,
510 GCancellable
*cancellable
)
512 GFileOutputStreamClass
*class;
513 GError
*error
= NULL
;
514 QueryInfoAsyncData
*data
;
517 data
= g_simple_async_result_get_op_res_gpointer (res
);
521 class = G_FILE_OUTPUT_STREAM_GET_CLASS (object
);
522 if (class->query_info
)
523 info
= class->query_info (G_FILE_OUTPUT_STREAM (object
), data
->attributes
, cancellable
, &error
);
525 g_set_error_literal (&error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
526 _("Stream doesn't support query_info"));
530 g_simple_async_result_set_from_error (res
, error
);
531 g_error_free (error
);
538 g_file_output_stream_real_query_info_async (GFileOutputStream
*stream
,
539 const char *attributes
,
541 GCancellable
*cancellable
,
542 GAsyncReadyCallback callback
,
545 GSimpleAsyncResult
*res
;
546 QueryInfoAsyncData
*data
;
548 data
= g_new0 (QueryInfoAsyncData
, 1);
549 data
->attributes
= g_strdup (attributes
);
551 res
= g_simple_async_result_new (G_OBJECT (stream
), callback
, user_data
, g_file_output_stream_real_query_info_async
);
552 g_simple_async_result_set_op_res_gpointer (res
, data
, (GDestroyNotify
)query_info_data_free
);
554 g_simple_async_result_run_in_thread (res
, query_info_async_thread
, io_priority
, cancellable
);
555 g_object_unref (res
);
559 g_file_output_stream_real_query_info_finish (GFileOutputStream
*stream
,
563 GSimpleAsyncResult
*simple
= G_SIMPLE_ASYNC_RESULT (res
);
564 QueryInfoAsyncData
*data
;
566 g_warn_if_fail (g_simple_async_result_get_source_tag (simple
) == g_file_output_stream_real_query_info_async
);
568 data
= g_simple_async_result_get_op_res_gpointer (simple
);
570 return g_object_ref (data
->info
);
575 #define __G_FILE_OUTPUT_STREAM_C__
576 #include "gioaliasdef.c"