1 /* GIO - GLib Input, IO 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, see <http://www.gnu.org/licenses/>.
18 * Author: Alexander Larsson <alexl@redhat.com>
24 #include <gfileiostream.h>
25 #include <gseekable.h>
26 #include "gasyncresult.h"
28 #include "gcancellable.h"
30 #include "gfileoutputstream.h"
35 * SECTION:gfileiostream
36 * @short_description: File read and write streaming operations
38 * @see_also: #GIOStream, #GFileInputStream, #GFileOutputStream, #GSeekable
40 * GFileIOStream provides io streams that both read and write to the same
43 * GFileIOStream implements #GSeekable, which allows the io
44 * stream to jump to arbitrary positions in the file and to truncate
45 * the file, provided the filesystem of the file supports these
48 * To find the position of a file io stream, use
51 * To find out if a file io stream supports seeking, use g_seekable_can_seek().
52 * To position a file io stream, use g_seekable_seek().
53 * To find out if a file io stream supports truncating, use
54 * g_seekable_can_truncate(). To truncate a file io
55 * stream, use g_seekable_truncate().
57 * The default implementation of all the #GFileIOStream operations
58 * and the implementation of #GSeekable just call into the same operations
59 * on the output stream.
63 static void g_file_io_stream_seekable_iface_init (GSeekableIface
*iface
);
64 static goffset
g_file_io_stream_seekable_tell (GSeekable
*seekable
);
65 static gboolean
g_file_io_stream_seekable_can_seek (GSeekable
*seekable
);
66 static gboolean
g_file_io_stream_seekable_seek (GSeekable
*seekable
,
69 GCancellable
*cancellable
,
71 static gboolean
g_file_io_stream_seekable_can_truncate (GSeekable
*seekable
);
72 static gboolean
g_file_io_stream_seekable_truncate (GSeekable
*seekable
,
74 GCancellable
*cancellable
,
76 static void g_file_io_stream_real_query_info_async (GFileIOStream
*stream
,
77 const char *attributes
,
79 GCancellable
*cancellable
,
80 GAsyncReadyCallback callback
,
82 static GFileInfo
*g_file_io_stream_real_query_info_finish (GFileIOStream
*stream
,
86 struct _GFileIOStreamPrivate
{
87 GAsyncReadyCallback outstanding_callback
;
90 G_DEFINE_TYPE_WITH_CODE (GFileIOStream
, g_file_io_stream
, G_TYPE_IO_STREAM
,
91 G_ADD_PRIVATE (GFileIOStream
)
92 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
93 g_file_io_stream_seekable_iface_init
))
96 g_file_io_stream_seekable_iface_init (GSeekableIface
*iface
)
98 iface
->tell
= g_file_io_stream_seekable_tell
;
99 iface
->can_seek
= g_file_io_stream_seekable_can_seek
;
100 iface
->seek
= g_file_io_stream_seekable_seek
;
101 iface
->can_truncate
= g_file_io_stream_seekable_can_truncate
;
102 iface
->truncate_fn
= g_file_io_stream_seekable_truncate
;
106 g_file_io_stream_init (GFileIOStream
*stream
)
108 stream
->priv
= g_file_io_stream_get_instance_private (stream
);
112 * g_file_io_stream_query_info:
113 * @stream: a #GFileIOStream.
114 * @attributes: a file attribute query string.
115 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
116 * @error: a #GError, %NULL to ignore.
118 * Queries a file io stream for the given @attributes.
119 * This function blocks while querying the stream. For the asynchronous
120 * version of this function, see g_file_io_stream_query_info_async().
121 * While the stream is blocked, the stream will set the pending flag
122 * internally, and any other operations on the stream will fail with
123 * %G_IO_ERROR_PENDING.
125 * Can fail if the stream was already closed (with @error being set to
126 * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
127 * set to %G_IO_ERROR_PENDING), or if querying info is not supported for
128 * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). I
129 * all cases of failure, %NULL will be returned.
131 * If @cancellable is not %NULL, then the operation can be cancelled by
132 * triggering the cancellable object from another thread. If the operation
133 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
136 * Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error.
141 g_file_io_stream_query_info (GFileIOStream
*stream
,
142 const char *attributes
,
143 GCancellable
*cancellable
,
146 GFileIOStreamClass
*class;
147 GIOStream
*io_stream
;
150 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), NULL
);
152 io_stream
= G_IO_STREAM (stream
);
154 if (!g_io_stream_set_pending (io_stream
, error
))
160 g_cancellable_push_current (cancellable
);
162 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
163 if (class->query_info
)
164 info
= class->query_info (stream
, attributes
, cancellable
, error
);
166 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
167 _("Stream doesn’t support query_info"));
170 g_cancellable_pop_current (cancellable
);
172 g_io_stream_clear_pending (io_stream
);
178 async_ready_callback_wrapper (GObject
*source_object
,
182 GFileIOStream
*stream
= G_FILE_IO_STREAM (source_object
);
184 g_io_stream_clear_pending (G_IO_STREAM (stream
));
185 if (stream
->priv
->outstanding_callback
)
186 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
187 g_object_unref (stream
);
191 * g_file_io_stream_query_info_async:
192 * @stream: a #GFileIOStream.
193 * @attributes: a file attribute query string.
194 * @io_priority: the [I/O priority][gio-GIOScheduler] of the request
195 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
196 * @callback: (scope async): callback to call when the request is satisfied
197 * @user_data: (closure): 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_io_stream_query_info_finish().
203 * For the synchronous version of this function, see
204 * g_file_io_stream_query_info().
209 g_file_io_stream_query_info_async (GFileIOStream
*stream
,
210 const char *attributes
,
212 GCancellable
*cancellable
,
213 GAsyncReadyCallback callback
,
216 GFileIOStreamClass
*klass
;
217 GIOStream
*io_stream
;
218 GError
*error
= NULL
;
220 g_return_if_fail (G_IS_FILE_IO_STREAM (stream
));
222 io_stream
= G_IO_STREAM (stream
);
224 if (!g_io_stream_set_pending (io_stream
, &error
))
226 g_task_report_error (stream
, callback
, user_data
,
227 g_file_io_stream_query_info_async
,
232 klass
= G_FILE_IO_STREAM_GET_CLASS (stream
);
234 stream
->priv
->outstanding_callback
= callback
;
235 g_object_ref (stream
);
236 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
237 async_ready_callback_wrapper
, user_data
);
241 * g_file_io_stream_query_info_finish:
242 * @stream: a #GFileIOStream.
243 * @result: a #GAsyncResult.
244 * @error: a #GError, %NULL to ignore.
246 * Finalizes the asynchronous query started
247 * by g_file_io_stream_query_info_async().
249 * Returns: (transfer full): A #GFileInfo for the finished query.
254 g_file_io_stream_query_info_finish (GFileIOStream
*stream
,
255 GAsyncResult
*result
,
258 GFileIOStreamClass
*class;
260 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), NULL
);
261 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
263 if (g_async_result_legacy_propagate_error (result
, error
))
265 else if (g_async_result_is_tagged (result
, g_file_io_stream_query_info_async
))
266 return g_task_propagate_pointer (G_TASK (result
), error
);
268 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
269 return class->query_info_finish (stream
, result
, error
);
273 * g_file_io_stream_get_etag:
274 * @stream: a #GFileIOStream.
276 * Gets the entity tag for the file when it has been written.
277 * This must be called after the stream has been written
278 * and closed, as the etag can change while writing.
280 * Returns: the entity tag for the stream.
285 g_file_io_stream_get_etag (GFileIOStream
*stream
)
287 GFileIOStreamClass
*class;
288 GIOStream
*io_stream
;
291 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), NULL
);
293 io_stream
= G_IO_STREAM (stream
);
295 if (!g_io_stream_is_closed (io_stream
))
297 g_warning ("stream is not closed yet, can't get etag");
303 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
305 etag
= class->get_etag (stream
);
311 g_file_io_stream_tell (GFileIOStream
*stream
)
313 GFileIOStreamClass
*class;
316 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), 0);
318 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
322 offset
= class->tell (stream
);
328 g_file_io_stream_seekable_tell (GSeekable
*seekable
)
330 return g_file_io_stream_tell (G_FILE_IO_STREAM (seekable
));
334 g_file_io_stream_can_seek (GFileIOStream
*stream
)
336 GFileIOStreamClass
*class;
339 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), FALSE
);
341 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
348 can_seek
= class->can_seek (stream
);
355 g_file_io_stream_seekable_can_seek (GSeekable
*seekable
)
357 return g_file_io_stream_can_seek (G_FILE_IO_STREAM (seekable
));
361 g_file_io_stream_seek (GFileIOStream
*stream
,
364 GCancellable
*cancellable
,
367 GFileIOStreamClass
*class;
368 GIOStream
*io_stream
;
371 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), FALSE
);
373 io_stream
= G_IO_STREAM (stream
);
374 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
378 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
379 _("Seek not supported on stream"));
383 if (!g_io_stream_set_pending (io_stream
, error
))
387 g_cancellable_push_current (cancellable
);
389 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
392 g_cancellable_pop_current (cancellable
);
394 g_io_stream_clear_pending (io_stream
);
400 g_file_io_stream_seekable_seek (GSeekable
*seekable
,
403 GCancellable
*cancellable
,
406 return g_file_io_stream_seek (G_FILE_IO_STREAM (seekable
),
407 offset
, type
, cancellable
, error
);
411 g_file_io_stream_can_truncate (GFileIOStream
*stream
)
413 GFileIOStreamClass
*class;
414 gboolean can_truncate
;
416 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), FALSE
);
418 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
420 can_truncate
= FALSE
;
421 if (class->truncate_fn
)
424 if (class->can_truncate
)
425 can_truncate
= class->can_truncate (stream
);
432 g_file_io_stream_seekable_can_truncate (GSeekable
*seekable
)
434 return g_file_io_stream_can_truncate (G_FILE_IO_STREAM (seekable
));
438 g_file_io_stream_truncate (GFileIOStream
*stream
,
440 GCancellable
*cancellable
,
443 GFileIOStreamClass
*class;
444 GIOStream
*io_stream
;
447 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream
), FALSE
);
449 io_stream
= G_IO_STREAM (stream
);
450 class = G_FILE_IO_STREAM_GET_CLASS (stream
);
452 if (!class->truncate_fn
)
454 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
455 _("Truncate not supported on stream"));
459 if (!g_io_stream_set_pending (io_stream
, error
))
463 g_cancellable_push_current (cancellable
);
465 res
= class->truncate_fn (stream
, size
, cancellable
, error
);
468 g_cancellable_pop_current (cancellable
);
470 g_io_stream_clear_pending (io_stream
);
476 g_file_io_stream_seekable_truncate (GSeekable
*seekable
,
478 GCancellable
*cancellable
,
481 return g_file_io_stream_truncate (G_FILE_IO_STREAM (seekable
),
482 size
, cancellable
, error
);
484 /*****************************************************
485 * Default implementations based on output stream *
486 *****************************************************/
489 g_file_io_stream_real_tell (GFileIOStream
*stream
)
494 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
495 seekable
= G_SEEKABLE (out
);
497 return g_seekable_tell (seekable
);
501 g_file_io_stream_real_can_seek (GFileIOStream
*stream
)
506 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
507 seekable
= G_SEEKABLE (out
);
509 return g_seekable_can_seek (seekable
);
513 g_file_io_stream_real_seek (GFileIOStream
*stream
,
516 GCancellable
*cancellable
,
522 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
523 seekable
= G_SEEKABLE (out
);
525 return g_seekable_seek (seekable
, offset
, type
, cancellable
, error
);
529 g_file_io_stream_real_can_truncate (GFileIOStream
*stream
)
534 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
535 seekable
= G_SEEKABLE (out
);
537 return g_seekable_can_truncate (seekable
);
541 g_file_io_stream_real_truncate_fn (GFileIOStream
*stream
,
543 GCancellable
*cancellable
,
549 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
550 seekable
= G_SEEKABLE (out
);
552 return g_seekable_truncate (seekable
, size
, cancellable
, error
);
556 g_file_io_stream_real_get_etag (GFileIOStream
*stream
)
559 GFileOutputStream
*file_out
;
561 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
562 file_out
= G_FILE_OUTPUT_STREAM (out
);
564 return g_file_output_stream_get_etag (file_out
);
568 g_file_io_stream_real_query_info (GFileIOStream
*stream
,
569 const char *attributes
,
570 GCancellable
*cancellable
,
574 GFileOutputStream
*file_out
;
576 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
577 file_out
= G_FILE_OUTPUT_STREAM (out
);
579 return g_file_output_stream_query_info (file_out
,
580 attributes
, cancellable
, error
);
585 GAsyncReadyCallback callback
;
589 static AsyncOpWrapper
*
590 async_op_wrapper_new (gpointer object
,
591 GAsyncReadyCallback callback
,
594 AsyncOpWrapper
*data
;
596 data
= g_new0 (AsyncOpWrapper
, 1);
597 data
->object
= g_object_ref (object
);
598 data
->callback
= callback
;
599 data
->user_data
= user_data
;
605 async_op_wrapper_callback (GObject
*source_object
,
609 AsyncOpWrapper
*data
= user_data
;
610 data
->callback (data
->object
, res
, data
->user_data
);
611 g_object_unref (data
->object
);
616 g_file_io_stream_real_query_info_async (GFileIOStream
*stream
,
617 const char *attributes
,
619 GCancellable
*cancellable
,
620 GAsyncReadyCallback callback
,
624 GFileOutputStream
*file_out
;
625 AsyncOpWrapper
*data
;
627 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
628 file_out
= G_FILE_OUTPUT_STREAM (out
);
630 data
= async_op_wrapper_new (stream
, callback
, user_data
);
631 g_file_output_stream_query_info_async (file_out
,
632 attributes
, io_priority
,
633 cancellable
, async_op_wrapper_callback
, data
);
637 g_file_io_stream_real_query_info_finish (GFileIOStream
*stream
,
642 GFileOutputStream
*file_out
;
644 out
= g_io_stream_get_output_stream (G_IO_STREAM (stream
));
645 file_out
= G_FILE_OUTPUT_STREAM (out
);
647 return g_file_output_stream_query_info_finish (file_out
, res
, error
);
651 g_file_io_stream_class_init (GFileIOStreamClass
*klass
)
653 klass
->tell
= g_file_io_stream_real_tell
;
654 klass
->can_seek
= g_file_io_stream_real_can_seek
;
655 klass
->seek
= g_file_io_stream_real_seek
;
656 klass
->can_truncate
= g_file_io_stream_real_can_truncate
;
657 klass
->truncate_fn
= g_file_io_stream_real_truncate_fn
;
658 klass
->query_info
= g_file_io_stream_real_query_info
;
659 klass
->query_info_async
= g_file_io_stream_real_query_info_async
;
660 klass
->query_info_finish
= g_file_io_stream_real_query_info_finish
;
661 klass
->get_etag
= g_file_io_stream_real_get_etag
;