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 "gsimpleasyncresult.h"
29 #include "gcancellable.h"
30 #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_stream_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 G_DEFINE_TYPE_WITH_CODE (GFileInputStream
, g_file_input_stream
, G_TYPE_INPUT_STREAM
,
77 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE
,
78 g_file_input_stream_seekable_iface_init
))
80 struct _GFileInputStreamPrivate
{
81 GAsyncReadyCallback outstanding_callback
;
85 g_file_input_stream_class_init (GFileInputStreamClass
*klass
)
87 g_type_class_add_private (klass
, sizeof (GFileInputStreamPrivate
));
89 klass
->query_info_async
= g_file_input_stream_real_query_info_async
;
90 klass
->query_info_finish
= g_file_input_stream_real_query_info_finish
;
94 g_file_input_stream_seekable_iface_init (GSeekableIface
*iface
)
96 iface
->tell
= g_file_input_stream_seekable_tell
;
97 iface
->can_seek
= g_file_input_stream_seekable_can_seek
;
98 iface
->seek
= g_file_input_stream_seekable_seek
;
99 iface
->can_truncate
= g_file_input_stream_seekable_can_truncate
;
100 iface
->truncate_fn
= g_file_input_stream_seekable_truncate
;
104 g_file_input_stream_init (GFileInputStream
*stream
)
106 stream
->priv
= G_TYPE_INSTANCE_GET_PRIVATE (stream
,
107 G_TYPE_FILE_INPUT_STREAM
,
108 GFileInputStreamPrivate
);
112 * g_file_input_stream_query_info:
113 * @stream: a #GFileInputStream.
114 * @attributes: a file attribute query string.
115 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
116 * @error: a #GError location to store the error occuring, or %NULL to
119 * Queries a file input stream the given @attributes. This function blocks
120 * while querying the stream. For the asynchronous (non-blocking) version
121 * of this function, see g_file_input_stream_query_info_async(). While the
122 * stream is blocked, the stream will set the pending flag internally, and
123 * any other operations on the stream will fail with %G_IO_ERROR_PENDING.
125 * Returns: (transfer full): a #GFileInfo, or %NULL on error.
128 g_file_input_stream_query_info (GFileInputStream
*stream
,
129 const char *attributes
,
130 GCancellable
*cancellable
,
133 GFileInputStreamClass
*class;
134 GInputStream
*input_stream
;
137 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), NULL
);
139 input_stream
= G_INPUT_STREAM (stream
);
141 if (!g_input_stream_set_pending (input_stream
, error
))
147 g_cancellable_push_current (cancellable
);
149 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
150 if (class->query_info
)
151 info
= class->query_info (stream
, attributes
, cancellable
, error
);
153 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
154 _("Stream doesn't support query_info"));
157 g_cancellable_pop_current (cancellable
);
159 g_input_stream_clear_pending (input_stream
);
165 async_ready_callback_wrapper (GObject
*source_object
,
169 GFileInputStream
*stream
= G_FILE_INPUT_STREAM (source_object
);
171 g_input_stream_clear_pending (G_INPUT_STREAM (stream
));
172 if (stream
->priv
->outstanding_callback
)
173 (*stream
->priv
->outstanding_callback
) (source_object
, res
, user_data
);
174 g_object_unref (stream
);
178 * g_file_input_stream_query_info_async:
179 * @stream: a #GFileInputStream.
180 * @attributes: a file attribute query string.
181 * @io_priority: the <link linkend="io-priority">I/O priority</link>
183 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
184 * @callback: (scope async): callback to call when the request is satisfied
185 * @user_data: (closure): the data to pass to callback function
187 * Queries the stream information asynchronously.
188 * When the operation is finished @callback will be called.
189 * You can then call g_file_input_stream_query_info_finish()
190 * to get the result of the operation.
192 * For the synchronous version of this function,
193 * see g_file_input_stream_query_info().
195 * If @cancellable is not %NULL, then the operation can be cancelled by
196 * triggering the cancellable object from another thread. If the operation
197 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set
201 g_file_input_stream_query_info_async (GFileInputStream
*stream
,
202 const char *attributes
,
204 GCancellable
*cancellable
,
205 GAsyncReadyCallback callback
,
208 GFileInputStreamClass
*klass
;
209 GInputStream
*input_stream
;
210 GError
*error
= NULL
;
212 g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream
));
214 input_stream
= G_INPUT_STREAM (stream
);
216 if (!g_input_stream_set_pending (input_stream
, &error
))
218 g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream
),
225 klass
= G_FILE_INPUT_STREAM_GET_CLASS (stream
);
227 stream
->priv
->outstanding_callback
= callback
;
228 g_object_ref (stream
);
229 klass
->query_info_async (stream
, attributes
, io_priority
, cancellable
,
230 async_ready_callback_wrapper
, user_data
);
234 * g_file_input_stream_query_info_finish:
235 * @stream: a #GFileInputStream.
236 * @result: a #GAsyncResult.
237 * @error: a #GError location to store the error occuring,
238 * or %NULL to ignore.
240 * Finishes an asynchronous info query operation.
242 * Returns: (transfer full): #GFileInfo.
245 g_file_input_stream_query_info_finish (GFileInputStream
*stream
,
246 GAsyncResult
*result
,
249 GSimpleAsyncResult
*simple
;
250 GFileInputStreamClass
*class;
252 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), NULL
);
253 g_return_val_if_fail (G_IS_ASYNC_RESULT (result
), NULL
);
255 if (G_IS_SIMPLE_ASYNC_RESULT (result
))
257 simple
= G_SIMPLE_ASYNC_RESULT (result
);
258 if (g_simple_async_result_propagate_error (simple
, error
))
262 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
263 return class->query_info_finish (stream
, result
, error
);
267 g_file_input_stream_tell (GFileInputStream
*stream
)
269 GFileInputStreamClass
*class;
272 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), 0);
274 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
278 offset
= class->tell (stream
);
284 g_file_input_stream_seekable_tell (GSeekable
*seekable
)
286 return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable
));
290 g_file_input_stream_can_seek (GFileInputStream
*stream
)
292 GFileInputStreamClass
*class;
295 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), FALSE
);
297 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
304 can_seek
= class->can_seek (stream
);
311 g_file_input_stream_seekable_can_seek (GSeekable
*seekable
)
313 return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable
));
317 g_file_input_stream_seek (GFileInputStream
*stream
,
320 GCancellable
*cancellable
,
323 GFileInputStreamClass
*class;
324 GInputStream
*input_stream
;
327 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream
), FALSE
);
329 input_stream
= G_INPUT_STREAM (stream
);
330 class = G_FILE_INPUT_STREAM_GET_CLASS (stream
);
334 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
335 _("Seek not supported on stream"));
339 if (!g_input_stream_set_pending (input_stream
, error
))
343 g_cancellable_push_current (cancellable
);
345 res
= class->seek (stream
, offset
, type
, cancellable
, error
);
348 g_cancellable_pop_current (cancellable
);
350 g_input_stream_clear_pending (input_stream
);
356 g_file_input_stream_seekable_seek (GSeekable
*seekable
,
359 GCancellable
*cancellable
,
362 return g_file_input_stream_seek (G_FILE_INPUT_STREAM (seekable
),
363 offset
, type
, cancellable
, error
);
367 g_file_input_stream_seekable_can_truncate (GSeekable
*seekable
)
373 g_file_input_stream_seekable_truncate (GSeekable
*seekable
,
375 GCancellable
*cancellable
,
378 g_set_error_literal (error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
379 _("Truncate not allowed on input stream"));
383 /********************************************
384 * Default implementation of async ops *
385 ********************************************/
390 } QueryInfoAsyncData
;
393 query_info_data_free (QueryInfoAsyncData
*data
)
396 g_object_unref (data
->info
);
397 g_free (data
->attributes
);
402 query_info_async_thread (GSimpleAsyncResult
*res
,
404 GCancellable
*cancellable
)
406 GFileInputStreamClass
*class;
407 GError
*error
= NULL
;
408 QueryInfoAsyncData
*data
;
411 data
= g_simple_async_result_get_op_res_gpointer (res
);
415 class = G_FILE_INPUT_STREAM_GET_CLASS (object
);
416 if (class->query_info
)
417 info
= class->query_info (G_FILE_INPUT_STREAM (object
), data
->attributes
, cancellable
, &error
);
419 g_set_error_literal (&error
, G_IO_ERROR
, G_IO_ERROR_NOT_SUPPORTED
,
420 _("Stream doesn't support query_info"));
423 g_simple_async_result_take_error (res
, error
);
429 g_file_input_stream_real_query_info_async (GFileInputStream
*stream
,
430 const char *attributes
,
432 GCancellable
*cancellable
,
433 GAsyncReadyCallback callback
,
436 GSimpleAsyncResult
*res
;
437 QueryInfoAsyncData
*data
;
439 data
= g_new0 (QueryInfoAsyncData
, 1);
440 data
->attributes
= g_strdup (attributes
);
442 res
= g_simple_async_result_new (G_OBJECT (stream
), callback
, user_data
, g_file_input_stream_real_query_info_async
);
443 g_simple_async_result_set_op_res_gpointer (res
, data
, (GDestroyNotify
)query_info_data_free
);
445 g_simple_async_result_run_in_thread (res
, query_info_async_thread
, io_priority
, cancellable
);
446 g_object_unref (res
);
450 g_file_input_stream_real_query_info_finish (GFileInputStream
*stream
,
454 GSimpleAsyncResult
*simple
= G_SIMPLE_ASYNC_RESULT (res
);
455 QueryInfoAsyncData
*data
;
457 g_warn_if_fail (g_simple_async_result_get_source_tag (simple
) == g_file_input_stream_real_query_info_async
);
459 data
= g_simple_async_result_get_op_res_gpointer (simple
);
461 return g_object_ref (data
->info
);