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, 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 <gfileiostream.h>
27 #include <gseekable.h>
28 #include "gsimpleasyncresult.h"
29 #include "gasyncresult.h"
30 #include "gcancellable.h"
32 #include "gfileoutputstream.h"
37 * SECTION:gfileiostream
38 * @short_description: File read and write streaming operations
40 * @see_also: #GIOStream, #GFileInputStream, #GFileOutputStream, #GSeekable
42 * GFileIOStream provides io streams that both read and write to the same
45 * GFileIOStream implements #GSeekable, which allows the io
46 * stream to jump to arbitrary positions in the file and to truncate
47 * the file, provided the filesystem of the file supports these
50 * To find the position of a file io stream, use
53 * To find out if a file io stream supports seeking, use g_seekable_can_seek().
54 * To position a file io stream, use g_seekable_seek().
55 * To find out if a file io stream supports truncating, use
56 * g_seekable_can_truncate(). To truncate a file io
57 * stream, use g_seekable_truncate().
59 * The default implementation of all the #GFileIOStream operations
60 * and the implementation of #GSeekable just call into the same operations
61 * on the output stream.
65 static void g_file_io_stream_seekable_iface_init (GSeekableIface *iface);
66 static goffset g_file_io_stream_seekable_tell (GSeekable *seekable);
67 static gboolean g_file_io_stream_seekable_can_seek (GSeekable *seekable);
68 static gboolean g_file_io_stream_seekable_seek (GSeekable *seekable,
71 GCancellable *cancellable,
73 static gboolean g_file_io_stream_seekable_can_truncate (GSeekable *seekable);
74 static gboolean g_file_io_stream_seekable_truncate (GSeekable *seekable,
76 GCancellable *cancellable,
78 static void g_file_io_stream_real_query_info_async (GFileIOStream *stream,
79 const char *attributes,
81 GCancellable *cancellable,
82 GAsyncReadyCallback callback,
84 static GFileInfo *g_file_io_stream_real_query_info_finish (GFileIOStream *stream,
88 G_DEFINE_TYPE_WITH_CODE (GFileIOStream, g_file_io_stream, G_TYPE_IO_STREAM,
89 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
90 g_file_io_stream_seekable_iface_init));
92 struct _GFileIOStreamPrivate {
93 GAsyncReadyCallback outstanding_callback;
97 g_file_io_stream_seekable_iface_init (GSeekableIface *iface)
99 iface->tell = g_file_io_stream_seekable_tell;
100 iface->can_seek = g_file_io_stream_seekable_can_seek;
101 iface->seek = g_file_io_stream_seekable_seek;
102 iface->can_truncate = g_file_io_stream_seekable_can_truncate;
103 iface->truncate_fn = g_file_io_stream_seekable_truncate;
107 g_file_io_stream_init (GFileIOStream *stream)
109 stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
110 G_TYPE_FILE_IO_STREAM,
111 GFileIOStreamPrivate);
115 * g_file_io_stream_query_info:
116 * @stream: a #GFileIOStream.
117 * @attributes: a file attribute query string.
118 * @cancellable: optional #GCancellable object, %NULL to ignore.
119 * @error: a #GError, %NULL to ignore.
121 * Queries a file io stream for the given @attributes.
122 * This function blocks while querying the stream. For the asynchronous
123 * version of this function, see g_file_io_stream_query_info_async().
124 * While the stream is blocked, the stream will set the pending flag
125 * internally, and any other operations on the stream will fail with
126 * %G_IO_ERROR_PENDING.
128 * Can fail if the stream was already closed (with @error being set to
129 * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being
130 * set to %G_IO_ERROR_PENDING), or if querying info is not supported for
131 * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). I
132 * all cases of failure, %NULL will be returned.
134 * If @cancellable is not %NULL, then the operation can be cancelled by
135 * triggering the cancellable object from another thread. If the operation
136 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will
139 * Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error.
144 g_file_io_stream_query_info (GFileIOStream *stream,
145 const char *attributes,
146 GCancellable *cancellable,
149 GFileIOStreamClass *class;
150 GIOStream *io_stream;
153 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL);
155 io_stream = G_IO_STREAM (stream);
157 if (!g_io_stream_set_pending (io_stream, error))
163 g_cancellable_push_current (cancellable);
165 class = G_FILE_IO_STREAM_GET_CLASS (stream);
166 if (class->query_info)
167 info = class->query_info (stream, attributes, cancellable, error);
169 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
170 _("Stream doesn't support query_info"));
173 g_cancellable_pop_current (cancellable);
175 g_io_stream_clear_pending (io_stream);
181 async_ready_callback_wrapper (GObject *source_object,
185 GFileIOStream *stream = G_FILE_IO_STREAM (source_object);
187 g_io_stream_clear_pending (G_IO_STREAM (stream));
188 if (stream->priv->outstanding_callback)
189 (*stream->priv->outstanding_callback) (source_object, res, user_data);
190 g_object_unref (stream);
194 * g_file_io_stream_query_info_async:
195 * @stream: a #GFileIOStream.
196 * @attributes: a file attribute query string.
197 * @io_priority: the <link linkend="gio-GIOScheduler">I/O priority</link>
199 * @cancellable: optional #GCancellable object, %NULL to ignore.
200 * @callback: callback to call when the request is satisfied
201 * @user_data: the data to pass to callback function
203 * Asynchronously queries the @stream for a #GFileInfo. When completed,
204 * @callback will be called with a #GAsyncResult which can be used to
205 * finish the operation with g_file_io_stream_query_info_finish().
207 * For the synchronous version of this function, see
208 * g_file_io_stream_query_info().
213 g_file_io_stream_query_info_async (GFileIOStream *stream,
214 const char *attributes,
216 GCancellable *cancellable,
217 GAsyncReadyCallback callback,
220 GFileIOStreamClass *klass;
221 GIOStream *io_stream;
222 GError *error = NULL;
224 g_return_if_fail (G_IS_FILE_IO_STREAM (stream));
226 io_stream = G_IO_STREAM (stream);
228 if (!g_io_stream_set_pending (io_stream, &error))
230 g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
237 klass = G_FILE_IO_STREAM_GET_CLASS (stream);
239 stream->priv->outstanding_callback = callback;
240 g_object_ref (stream);
241 klass->query_info_async (stream, attributes, io_priority, cancellable,
242 async_ready_callback_wrapper, user_data);
246 * g_file_io_stream_query_info_finish:
247 * @stream: a #GFileIOStream.
248 * @result: a #GAsyncResult.
249 * @error: a #GError, %NULL to ignore.
251 * Finalizes the asynchronous query started
252 * by g_file_io_stream_query_info_async().
254 * Returns: (transfer full): A #GFileInfo for the finished query.
259 g_file_io_stream_query_info_finish (GFileIOStream *stream,
260 GAsyncResult *result,
263 GSimpleAsyncResult *simple;
264 GFileIOStreamClass *class;
266 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL);
267 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
269 if (G_IS_SIMPLE_ASYNC_RESULT (result))
271 simple = G_SIMPLE_ASYNC_RESULT (result);
272 if (g_simple_async_result_propagate_error (simple, error))
276 class = G_FILE_IO_STREAM_GET_CLASS (stream);
277 return class->query_info_finish (stream, result, error);
281 * g_file_io_stream_get_etag:
282 * @stream: a #GFileIOStream.
284 * Gets the entity tag for the file when it has been written.
285 * This must be called after the stream has been written
286 * and closed, as the etag can change while writing.
288 * Returns: the entity tag for the stream.
293 g_file_io_stream_get_etag (GFileIOStream *stream)
295 GFileIOStreamClass *class;
296 GIOStream *io_stream;
299 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL);
301 io_stream = G_IO_STREAM (stream);
303 if (!g_io_stream_is_closed (io_stream))
305 g_warning ("stream is not closed yet, can't get etag");
311 class = G_FILE_IO_STREAM_GET_CLASS (stream);
313 etag = class->get_etag (stream);
319 g_file_io_stream_tell (GFileIOStream *stream)
321 GFileIOStreamClass *class;
324 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), 0);
326 class = G_FILE_IO_STREAM_GET_CLASS (stream);
330 offset = class->tell (stream);
336 g_file_io_stream_seekable_tell (GSeekable *seekable)
338 return g_file_io_stream_tell (G_FILE_IO_STREAM (seekable));
342 g_file_io_stream_can_seek (GFileIOStream *stream)
344 GFileIOStreamClass *class;
347 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE);
349 class = G_FILE_IO_STREAM_GET_CLASS (stream);
356 can_seek = class->can_seek (stream);
363 g_file_io_stream_seekable_can_seek (GSeekable *seekable)
365 return g_file_io_stream_can_seek (G_FILE_IO_STREAM (seekable));
369 g_file_io_stream_seek (GFileIOStream *stream,
372 GCancellable *cancellable,
375 GFileIOStreamClass *class;
376 GIOStream *io_stream;
379 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE);
381 io_stream = G_IO_STREAM (stream);
382 class = G_FILE_IO_STREAM_GET_CLASS (stream);
386 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
387 _("Seek not supported on stream"));
391 if (!g_io_stream_set_pending (io_stream, error))
395 g_cancellable_push_current (cancellable);
397 res = class->seek (stream, offset, type, cancellable, error);
400 g_cancellable_pop_current (cancellable);
402 g_io_stream_clear_pending (io_stream);
408 g_file_io_stream_seekable_seek (GSeekable *seekable,
411 GCancellable *cancellable,
414 return g_file_io_stream_seek (G_FILE_IO_STREAM (seekable),
415 offset, type, cancellable, error);
419 g_file_io_stream_can_truncate (GFileIOStream *stream)
421 GFileIOStreamClass *class;
422 gboolean can_truncate;
424 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE);
426 class = G_FILE_IO_STREAM_GET_CLASS (stream);
428 can_truncate = FALSE;
429 if (class->truncate_fn)
432 if (class->can_truncate)
433 can_truncate = class->can_truncate (stream);
440 g_file_io_stream_seekable_can_truncate (GSeekable *seekable)
442 return g_file_io_stream_can_truncate (G_FILE_IO_STREAM (seekable));
446 g_file_io_stream_truncate (GFileIOStream *stream,
448 GCancellable *cancellable,
451 GFileIOStreamClass *class;
452 GIOStream *io_stream;
455 g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE);
457 io_stream = G_IO_STREAM (stream);
458 class = G_FILE_IO_STREAM_GET_CLASS (stream);
460 if (!class->truncate_fn)
462 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
463 _("Truncate not supported on stream"));
467 if (!g_io_stream_set_pending (io_stream, error))
471 g_cancellable_push_current (cancellable);
473 res = class->truncate_fn (stream, size, cancellable, error);
476 g_cancellable_pop_current (cancellable);
478 g_io_stream_clear_pending (io_stream);
484 g_file_io_stream_seekable_truncate (GSeekable *seekable,
486 GCancellable *cancellable,
489 return g_file_io_stream_truncate (G_FILE_IO_STREAM (seekable),
490 size, cancellable, error);
492 /*****************************************************
493 * Default implementations based on output stream *
494 *****************************************************/
497 g_file_io_stream_real_tell (GFileIOStream *stream)
502 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
503 seekable = G_SEEKABLE (out);
505 return g_seekable_tell (seekable);
509 g_file_io_stream_real_can_seek (GFileIOStream *stream)
514 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
515 seekable = G_SEEKABLE (out);
517 return g_seekable_can_seek (seekable);
521 g_file_io_stream_real_seek (GFileIOStream *stream,
524 GCancellable *cancellable,
530 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
531 seekable = G_SEEKABLE (out);
533 return g_seekable_seek (seekable, offset, type, cancellable, error);
537 g_file_io_stream_real_can_truncate (GFileIOStream *stream)
542 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
543 seekable = G_SEEKABLE (out);
545 return g_seekable_can_truncate (seekable);
549 g_file_io_stream_real_truncate_fn (GFileIOStream *stream,
551 GCancellable *cancellable,
557 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
558 seekable = G_SEEKABLE (out);
560 return g_seekable_truncate (seekable, size, cancellable, error);
564 g_file_io_stream_real_get_etag (GFileIOStream *stream)
567 GFileOutputStream *file_out;
569 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
570 file_out = G_FILE_OUTPUT_STREAM (out);
572 return g_file_output_stream_get_etag (file_out);
576 g_file_io_stream_real_query_info (GFileIOStream *stream,
577 const char *attributes,
578 GCancellable *cancellable,
582 GFileOutputStream *file_out;
584 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
585 file_out = G_FILE_OUTPUT_STREAM (out);
587 return g_file_output_stream_query_info (file_out,
588 attributes, cancellable, error);
593 GAsyncReadyCallback callback;
597 static AsyncOpWrapper *
598 async_op_wrapper_new (gpointer object,
599 GAsyncReadyCallback callback,
602 AsyncOpWrapper *data;
604 data = g_new0 (AsyncOpWrapper, 1);
605 data->object = g_object_ref (object);
606 data->callback = callback;
607 data->user_data = user_data;
613 async_op_wrapper_callback (GObject *source_object,
617 AsyncOpWrapper *data = user_data;
618 data->callback (data->object, res, data->user_data);
619 g_object_unref (data->object);
624 g_file_io_stream_real_query_info_async (GFileIOStream *stream,
625 const char *attributes,
627 GCancellable *cancellable,
628 GAsyncReadyCallback callback,
632 GFileOutputStream *file_out;
633 AsyncOpWrapper *data;
635 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
636 file_out = G_FILE_OUTPUT_STREAM (out);
638 data = async_op_wrapper_new (stream, callback, user_data);
639 g_file_output_stream_query_info_async (file_out,
640 attributes, io_priority,
641 cancellable, async_op_wrapper_callback, data);
645 g_file_io_stream_real_query_info_finish (GFileIOStream *stream,
650 GFileOutputStream *file_out;
652 out = g_io_stream_get_output_stream (G_IO_STREAM (stream));
653 file_out = G_FILE_OUTPUT_STREAM (out);
655 return g_file_output_stream_query_info_finish (file_out, res, error);
659 g_file_io_stream_class_init (GFileIOStreamClass *klass)
661 g_type_class_add_private (klass, sizeof (GFileIOStreamPrivate));
663 klass->tell = g_file_io_stream_real_tell;
664 klass->can_seek = g_file_io_stream_real_can_seek;
665 klass->seek = g_file_io_stream_real_seek;
666 klass->can_truncate = g_file_io_stream_real_can_truncate;
667 klass->truncate_fn = g_file_io_stream_real_truncate_fn;
668 klass->query_info = g_file_io_stream_real_query_info;
669 klass->query_info_async = g_file_io_stream_real_query_info_async;
670 klass->query_info_finish = g_file_io_stream_real_query_info_finish;
671 klass->get_etag = g_file_io_stream_real_get_etag;