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 <gfileinputstream.h>
27 #include <gseekable.h>
28 #include "gcancellable.h"
29 #include "gasyncresult.h"
36 * SECTION:gfileinputstream
37 * @short_description: File input streaming operations
39 * @see_also: #GInputStream, #GDataInputStream, #GSeekable
41 * GFileInputStream provides input streams that take their
42 * content from a file.
44 * GFileInputStream implements #GSeekable, which allows the input
45 * stream to jump to arbitrary positions in the file, provided the
46 * filesystem of the file allows it. To find the position of a file
47 * input stream, use g_seekable_tell(). To find out if a file input
48 * stream supports seeking, use g_seekable_can_seek().
49 * To position a file input stream, use g_seekable_seek().
52 static void g_file_input_stream_seekable_iface_init (GSeekableIface
*iface
);
53 static goffset
g_file_input_stream_seekable_tell (GSeekable
*seekable
);
54 static gboolean
g_file_input_stream_seekable_can_seek (GSeekable
*seekable
);
55 static gboolean
g_file_input_stream_seekable_seek (GSeekable
*seekable
,
58 GCancellable
*cancellable
,
60 static gboolean
g_file_input_stream_seekable_can_truncate (GSeekable
*seekable
);
61 static gboolean
g_file_input_stream_seekable_truncate (GSeekable
*seekable
,
63 GCancellable
*cancellable
,
65 static void g_file_input_stream_real_query_info_async (GFileInputStream
*stream
,
66 const char *attributes
,
68 GCancellable
*cancellable
,
69 GAsyncReadyCallback callback
,
71 static GFileInfo
*g_file_input_stream_real_query_info_finish (GFileInputStream
*stream
,
76 struct _GFileInputStreamPrivate
{
77 GAsyncReadyCallback outstanding_callback
;
80 G_DEFINE_TYPE_WITH_CODE (GFileInputStream
, g_file_input_stream
, G_TYPE_INPUT_STREAM
,
81 G_ADD_PRIVATE (GFileInputStream
)
82 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
83 g_file_input_stream_seekable_iface_init
))
86 g_file_input_stream_class_init (GFileInputStreamClass
*klass
)
88 klass
->query_info_async
= g_file_input_stream_real_query_info_async
;
89 klass
->query_info_finish
= g_file_input_stream_real_query_info_finish
;
93 g_file_input_stream_seekable_iface_init (GSeekableIface
*iface
)
95 iface
->tell
= g_file_input_stream_seekable_tell
;
96 iface
->can_seek
= g_file_input_stream_seekable_can_seek
;
97 iface
->seek
= g_file_input_stream_seekable_seek
;
98 iface
->can_truncate
= g_file_input_stream_seekable_can_truncate
;
99 iface
->truncate_fn
= g_file_input_stream_seekable_truncate
;
103 g_file_input_stream_init (GFileInputStream
*stream
)
105 stream
->priv
= g_file_input_stream_get_instance_private (stream
);
109 * g_file_input_stream_query_info:
110 * @stream: a #GFileInputStream.
111 * @attributes: a file attribute query string.
112 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
113 * @error: a #GError location to store the error occurring, or %NULL to
116 * Queries a file input stream the given @attributes. This function blocks
117 * while querying the stream. For the asynchronous (non-blocking) version
118 * of this function, see g_file_input_stream_query_info_async(). While the
119 * stream is blocked, the stream will set the pending flag internally, and
120 * any other operations on the stream will fail with %G_IO_ERROR_PENDING.
122 * Returns: (transfer full): a #GFileInfo, or %NULL on error.
125 g_file_input_stream_query_info (GFileInputStream
*stream
,
126 const char *attributes
,
127 GCancellable
*cancellable
,
130 GFileInputStreamClass
*class;
131 GInputStream
*input_stream
;
134 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), NULL
);
136 input_stream
= G_INPUT_STREAM (stream
);
138 if (!g_input_stream_set_pending (input_stream
, error
))
144 g_cancellable_push_current (cancellable
);
146 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
147 if (class->query_info
)
148 info
= class->query_info (stream
, attributes
, cancellable
, error
);
150 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
151 _("Stream doesn't support query_info"));
154 g_cancellable_pop_current (cancellable
);
156 g_input_stream_clear_pending (input_stream
);
162 async_ready_callback_wrapper (GObject
*source_object
,
166 GFileInputStream
*stream
= G_FILE_INPUT_STREAM (source_object
);
168 g_input_stream_clear_pending (G_INPUT_STREAM (stream
));
169 if (stream
->priv
->outstanding_callback
)
170 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
171 g_object_unref (stream
);
175 * g_file_input_stream_query_info_async:
176 * @stream: a #GFileInputStream.
177 * @attributes: a file attribute query string.
178 * @io_priority: the <link linkend="io-priority">I/O priority</link>
180 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
181 * @callback: (scope async): callback to call when the request is satisfied
182 * @user_data: (closure): the data to pass to callback function
184 * Queries the stream information asynchronously.
185 * When the operation is finished @callback will be called.
186 * You can then call g_file_input_stream_query_info_finish()
187 * to get the result of the operation.
189 * For the synchronous version of this function,
190 * see g_file_input_stream_query_info().
192 * If @cancellable is not %NULL, then the operation can be cancelled by
193 * triggering the cancellable object from another thread. If the operation
194 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set
198 g_file_input_stream_query_info_async (GFileInputStream
*stream
,
199 const char *attributes
,
201 GCancellable
*cancellable
,
202 GAsyncReadyCallback callback
,
205 GFileInputStreamClass
*klass
;
206 GInputStream
*input_stream
;
207 GError
*error
= NULL
;
209 g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream
));
211 input_stream
= G_INPUT_STREAM (stream
);
213 if (!g_input_stream_set_pending (input_stream
, &error
))
215 g_task_report_error (stream
, callback
, user_data
,
216 g_file_input_stream_query_info_async
,
221 klass
= G_FILE_INPUT_STREAM_GET_CLASS (stream
);
223 stream
->priv
->outstanding_callback
= callback
;
224 g_object_ref (stream
);
225 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
226 async_ready_callback_wrapper
, user_data
);
230 * g_file_input_stream_query_info_finish:
231 * @stream: a #GFileInputStream.
232 * @result: a #GAsyncResult.
233 * @error: a #GError location to store the error occurring,
234 * or %NULL to ignore.
236 * Finishes an asynchronous info query operation.
238 * Returns: (transfer full): #GFileInfo.
241 g_file_input_stream_query_info_finish (GFileInputStream
*stream
,
242 GAsyncResult
*result
,
245 GFileInputStreamClass
*class;
247 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), NULL
);
248 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
250 if (g_async_result_legacy_propagate_error (result
, error
))
252 else if (g_async_result_is_tagged (result
, g_file_input_stream_query_info_async
))
253 return g_task_propagate_pointer (G_TASK (result
), error
);
255 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
256 return class->query_info_finish (stream
, result
, error
);
260 g_file_input_stream_tell (GFileInputStream
*stream
)
262 GFileInputStreamClass
*class;
265 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), 0);
267 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
271 offset
= class->tell (stream
);
277 g_file_input_stream_seekable_tell (GSeekable
*seekable
)
279 return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable
));
283 g_file_input_stream_can_seek (GFileInputStream
*stream
)
285 GFileInputStreamClass
*class;
288 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), FALSE
);
290 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
297 can_seek
= class->can_seek (stream
);
304 g_file_input_stream_seekable_can_seek (GSeekable
*seekable
)
306 return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable
));
310 g_file_input_stream_seek (GFileInputStream
*stream
,
313 GCancellable
*cancellable
,
316 GFileInputStreamClass
*class;
317 GInputStream
*input_stream
;
320 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), FALSE
);
322 input_stream
= G_INPUT_STREAM (stream
);
323 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
327 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
328 _("Seek not supported on stream"));
332 if (!g_input_stream_set_pending (input_stream
, error
))
336 g_cancellable_push_current (cancellable
);
338 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
341 g_cancellable_pop_current (cancellable
);
343 g_input_stream_clear_pending (input_stream
);
349 g_file_input_stream_seekable_seek (GSeekable
*seekable
,
352 GCancellable
*cancellable
,
355 return g_file_input_stream_seek (G_FILE_INPUT_STREAM (seekable
),
356 offset
, type
, cancellable
, error
);
360 g_file_input_stream_seekable_can_truncate (GSeekable
*seekable
)
366 g_file_input_stream_seekable_truncate (GSeekable
*seekable
,
368 GCancellable
*cancellable
,
371 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
372 _("Truncate not allowed on input stream"));
376 /********************************************
377 * Default implementation of async ops *
378 ********************************************/
381 query_info_async_thread (GTask
*task
,
382 gpointer source_object
,
384 GCancellable
*cancellable
)
386 GFileInputStream
*stream
= source_object
;
387 const char *attributes
= task_data
;
388 GFileInputStreamClass
*class;
389 GError
*error
= NULL
;
390 GFileInfo
*info
= NULL
;
392 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
393 if (class->query_info
)
394 info
= class->query_info (stream
, attributes
, cancellable
, &error
);
396 g_set_error_literal (&error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
397 _("Stream doesn't support query_info"));
400 g_task_return_error (task
, error
);
402 g_task_return_pointer (task
, info
, g_object_unref
);
406 g_file_input_stream_real_query_info_async (GFileInputStream
*stream
,
407 const char *attributes
,
409 GCancellable
*cancellable
,
410 GAsyncReadyCallback callback
,
415 task
= g_task_new (stream
, cancellable
, callback
, user_data
);
416 g_task_set_task_data (task
, g_strdup (attributes
), g_free
);
417 g_task_set_priority (task
, io_priority
);
419 g_task_run_in_thread (task
, query_info_async_thread
);
420 g_object_unref (task
);
424 g_file_input_stream_real_query_info_finish (GFileInputStream
*stream
,
428 g_return_val_if_fail (g_task_is_valid (res
, stream
), NULL
);
430 return g_task_propagate_pointer (G_TASK (res
), error
);