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, see <http://www.gnu.org/licenses/>.
18 * Author: Alexander Larsson <alexl@redhat.com>
24 #include <gfileinputstream.h>
25 #include <gseekable.h>
26 #include "gcancellable.h"
27 #include "gasyncresult.h"
34 * SECTION:gfileinputstream
35 * @short_description: File input streaming operations
37 * @see_also: #GInputStream, #GDataInputStream, #GSeekable
39 * GFileInputStream provides input streams that take their
40 * content from a file.
42 * GFileInputStream implements #GSeekable, which allows the input
43 * stream to jump to arbitrary positions in the file, provided the
44 * filesystem of the file allows it. To find the position of a file
45 * input stream, use g_seekable_tell(). To find out if a file input
46 * stream supports seeking, use g_seekable_can_seek().
47 * To position a file input stream, use g_seekable_seek().
50 static void g_file_input_stream_seekable_iface_init (GSeekableIface *iface);
51 static goffset g_file_input_stream_seekable_tell (GSeekable *seekable);
52 static gboolean g_file_input_stream_seekable_can_seek (GSeekable *seekable);
53 static gboolean g_file_input_stream_seekable_seek (GSeekable *seekable,
56 GCancellable *cancellable,
58 static gboolean g_file_input_stream_seekable_can_truncate (GSeekable *seekable);
59 static gboolean g_file_input_stream_seekable_truncate (GSeekable *seekable,
61 GCancellable *cancellable,
63 static void g_file_input_stream_real_query_info_async (GFileInputStream *stream,
64 const char *attributes,
66 GCancellable *cancellable,
67 GAsyncReadyCallback callback,
69 static GFileInfo *g_file_input_stream_real_query_info_finish (GFileInputStream *stream,
74 struct _GFileInputStreamPrivate {
75 GAsyncReadyCallback outstanding_callback;
78 G_DEFINE_TYPE_WITH_CODE (GFileInputStream, g_file_input_stream, G_TYPE_INPUT_STREAM,
79 G_ADD_PRIVATE (GFileInputStream)
80 G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
81 g_file_input_stream_seekable_iface_init))
84 g_file_input_stream_class_init (GFileInputStreamClass *klass)
86 klass->query_info_async = g_file_input_stream_real_query_info_async;
87 klass->query_info_finish = g_file_input_stream_real_query_info_finish;
91 g_file_input_stream_seekable_iface_init (GSeekableIface *iface)
93 iface->tell = g_file_input_stream_seekable_tell;
94 iface->can_seek = g_file_input_stream_seekable_can_seek;
95 iface->seek = g_file_input_stream_seekable_seek;
96 iface->can_truncate = g_file_input_stream_seekable_can_truncate;
97 iface->truncate_fn = g_file_input_stream_seekable_truncate;
101 g_file_input_stream_init (GFileInputStream *stream)
103 stream->priv = g_file_input_stream_get_instance_private (stream);
107 * g_file_input_stream_query_info:
108 * @stream: a #GFileInputStream.
109 * @attributes: a file attribute query string.
110 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
111 * @error: a #GError location to store the error occurring, or %NULL to
114 * Queries a file input stream the given @attributes. This function blocks
115 * while querying the stream. For the asynchronous (non-blocking) version
116 * of this function, see g_file_input_stream_query_info_async(). While the
117 * stream is blocked, the stream will set the pending flag internally, and
118 * any other operations on the stream will fail with %G_IO_ERROR_PENDING.
120 * Returns: (transfer full): a #GFileInfo, or %NULL on error.
123 g_file_input_stream_query_info (GFileInputStream *stream,
124 const char *attributes,
125 GCancellable *cancellable,
128 GFileInputStreamClass *class;
129 GInputStream *input_stream;
132 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), NULL);
134 input_stream = G_INPUT_STREAM (stream);
136 if (!g_input_stream_set_pending (input_stream, error))
142 g_cancellable_push_current (cancellable);
144 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
145 if (class->query_info)
146 info = class->query_info (stream, attributes, cancellable, error);
148 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
149 _("Stream doesn't support query_info"));
152 g_cancellable_pop_current (cancellable);
154 g_input_stream_clear_pending (input_stream);
160 async_ready_callback_wrapper (GObject *source_object,
164 GFileInputStream *stream = G_FILE_INPUT_STREAM (source_object);
166 g_input_stream_clear_pending (G_INPUT_STREAM (stream));
167 if (stream->priv->outstanding_callback)
168 (*stream->priv->outstanding_callback) (source_object, res, user_data);
169 g_object_unref (stream);
173 * g_file_input_stream_query_info_async:
174 * @stream: a #GFileInputStream.
175 * @attributes: a file attribute query string.
176 * @io_priority: the <link linkend="io-priority">I/O priority</link>
178 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
179 * @callback: (scope async): callback to call when the request is satisfied
180 * @user_data: (closure): the data to pass to callback function
182 * Queries the stream information asynchronously.
183 * When the operation is finished @callback will be called.
184 * You can then call g_file_input_stream_query_info_finish()
185 * to get the result of the operation.
187 * For the synchronous version of this function,
188 * see g_file_input_stream_query_info().
190 * If @cancellable is not %NULL, then the operation can be cancelled by
191 * triggering the cancellable object from another thread. If the operation
192 * was cancelled, the error %G_IO_ERROR_CANCELLED will be set
196 g_file_input_stream_query_info_async (GFileInputStream *stream,
197 const char *attributes,
199 GCancellable *cancellable,
200 GAsyncReadyCallback callback,
203 GFileInputStreamClass *klass;
204 GInputStream *input_stream;
205 GError *error = NULL;
207 g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream));
209 input_stream = G_INPUT_STREAM (stream);
211 if (!g_input_stream_set_pending (input_stream, &error))
213 g_task_report_error (stream, callback, user_data,
214 g_file_input_stream_query_info_async,
219 klass = G_FILE_INPUT_STREAM_GET_CLASS (stream);
221 stream->priv->outstanding_callback = callback;
222 g_object_ref (stream);
223 klass->query_info_async (stream, attributes, io_priority, cancellable,
224 async_ready_callback_wrapper, user_data);
228 * g_file_input_stream_query_info_finish:
229 * @stream: a #GFileInputStream.
230 * @result: a #GAsyncResult.
231 * @error: a #GError location to store the error occurring,
232 * or %NULL to ignore.
234 * Finishes an asynchronous info query operation.
236 * Returns: (transfer full): #GFileInfo.
239 g_file_input_stream_query_info_finish (GFileInputStream *stream,
240 GAsyncResult *result,
243 GFileInputStreamClass *class;
245 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), NULL);
246 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
248 if (g_async_result_legacy_propagate_error (result, error))
250 else if (g_async_result_is_tagged (result, g_file_input_stream_query_info_async))
251 return g_task_propagate_pointer (G_TASK (result), error);
253 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
254 return class->query_info_finish (stream, result, error);
258 g_file_input_stream_tell (GFileInputStream *stream)
260 GFileInputStreamClass *class;
263 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), 0);
265 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
269 offset = class->tell (stream);
275 g_file_input_stream_seekable_tell (GSeekable *seekable)
277 return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable));
281 g_file_input_stream_can_seek (GFileInputStream *stream)
283 GFileInputStreamClass *class;
286 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE);
288 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
295 can_seek = class->can_seek (stream);
302 g_file_input_stream_seekable_can_seek (GSeekable *seekable)
304 return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable));
308 g_file_input_stream_seek (GFileInputStream *stream,
311 GCancellable *cancellable,
314 GFileInputStreamClass *class;
315 GInputStream *input_stream;
318 g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE);
320 input_stream = G_INPUT_STREAM (stream);
321 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
325 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
326 _("Seek not supported on stream"));
330 if (!g_input_stream_set_pending (input_stream, error))
334 g_cancellable_push_current (cancellable);
336 res = class->seek (stream, offset, type, cancellable, error);
339 g_cancellable_pop_current (cancellable);
341 g_input_stream_clear_pending (input_stream);
347 g_file_input_stream_seekable_seek (GSeekable *seekable,
350 GCancellable *cancellable,
353 return g_file_input_stream_seek (G_FILE_INPUT_STREAM (seekable),
354 offset, type, cancellable, error);
358 g_file_input_stream_seekable_can_truncate (GSeekable *seekable)
364 g_file_input_stream_seekable_truncate (GSeekable *seekable,
366 GCancellable *cancellable,
369 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
370 _("Truncate not allowed on input stream"));
374 /********************************************
375 * Default implementation of async ops *
376 ********************************************/
379 query_info_async_thread (GTask *task,
380 gpointer source_object,
382 GCancellable *cancellable)
384 GFileInputStream *stream = source_object;
385 const char *attributes = task_data;
386 GFileInputStreamClass *class;
387 GError *error = NULL;
388 GFileInfo *info = NULL;
390 class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
391 if (class->query_info)
392 info = class->query_info (stream, attributes, cancellable, &error);
394 g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
395 _("Stream doesn't support query_info"));
398 g_task_return_error (task, error);
400 g_task_return_pointer (task, info, g_object_unref);
404 g_file_input_stream_real_query_info_async (GFileInputStream *stream,
405 const char *attributes,
407 GCancellable *cancellable,
408 GAsyncReadyCallback callback,
413 task = g_task_new (stream, cancellable, callback, user_data);
414 g_task_set_task_data (task, g_strdup (attributes), g_free);
415 g_task_set_priority (task, io_priority);
417 g_task_run_in_thread (task, query_info_async_thread);
418 g_object_unref (task);
422 g_file_input_stream_real_query_info_finish (GFileInputStream *stream,
426 g_return_val_if_fail (g_task_is_valid (res, stream), NULL);
428 return g_task_propagate_pointer (G_TASK (res), error);