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>
25 #include "ginputstream.h"
26 #include "gioprivate.h"
27 #include "gseekable.h"
28 #include "gcancellable.h"
29 #include "gasyncresult.h"
31 #include "gpollableinputstream.h"
34 * SECTION:ginputstream
35 * @short_description: Base class for implementing streaming input
38 * #GInputStream has functions to read from a stream (g_input_stream_read()),
39 * to close a stream (g_input_stream_close()) and to skip some content
40 * (g_input_stream_skip()).
42 * To copy the content of an input stream to an output stream without
43 * manually handling the reads and writes, use g_output_stream_splice().
45 * All of these functions have async variants too.
48 struct _GInputStreamPrivate {
51 GAsyncReadyCallback outstanding_callback;
54 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GInputStream, g_input_stream, G_TYPE_OBJECT)
56 static gssize g_input_stream_real_skip (GInputStream *stream,
58 GCancellable *cancellable,
60 static void g_input_stream_real_read_async (GInputStream *stream,
64 GCancellable *cancellable,
65 GAsyncReadyCallback callback,
67 static gssize g_input_stream_real_read_finish (GInputStream *stream,
70 static void g_input_stream_real_skip_async (GInputStream *stream,
73 GCancellable *cancellable,
74 GAsyncReadyCallback callback,
76 static gssize g_input_stream_real_skip_finish (GInputStream *stream,
79 static void g_input_stream_real_close_async (GInputStream *stream,
81 GCancellable *cancellable,
82 GAsyncReadyCallback callback,
84 static gboolean g_input_stream_real_close_finish (GInputStream *stream,
89 g_input_stream_dispose (GObject *object)
93 stream = G_INPUT_STREAM (object);
95 if (!stream->priv->closed)
96 g_input_stream_close (stream, NULL, NULL);
98 G_OBJECT_CLASS (g_input_stream_parent_class)->dispose (object);
103 g_input_stream_class_init (GInputStreamClass *klass)
105 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
107 gobject_class->dispose = g_input_stream_dispose;
109 klass->skip = g_input_stream_real_skip;
110 klass->read_async = g_input_stream_real_read_async;
111 klass->read_finish = g_input_stream_real_read_finish;
112 klass->skip_async = g_input_stream_real_skip_async;
113 klass->skip_finish = g_input_stream_real_skip_finish;
114 klass->close_async = g_input_stream_real_close_async;
115 klass->close_finish = g_input_stream_real_close_finish;
119 g_input_stream_init (GInputStream *stream)
121 stream->priv = g_input_stream_get_instance_private (stream);
125 * g_input_stream_read:
126 * @stream: a #GInputStream.
127 * @buffer: (array length=count) (element-type guint8): a buffer to
128 * read data into (which should be at least count bytes long).
129 * @count: the number of bytes that will be read from the stream
130 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
131 * @error: location to store the error occurring, or %NULL to ignore
133 * Tries to read @count bytes from the stream into the buffer starting at
134 * @buffer. Will block during this read.
136 * If count is zero returns zero and does nothing. A value of @count
137 * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
139 * On success, the number of bytes read into the buffer is returned.
140 * It is not an error if this is not the same as the requested size, as it
141 * can happen e.g. near the end of a file. Zero is returned on end of file
142 * (or if @count is zero), but never otherwise.
144 * The returned @buffer is not a nul-terminated string, it can contain nul bytes
145 * at any position, and this function doesn't nul-terminate the @buffer.
147 * If @cancellable is not %NULL, then the operation can be cancelled by
148 * triggering the cancellable object from another thread. If the operation
149 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
150 * operation was partially finished when the operation was cancelled the
151 * partial result will be returned, without an error.
153 * On error -1 is returned and @error is set accordingly.
155 * Returns: Number of bytes read, or -1 on error, or 0 on end of file.
158 g_input_stream_read (GInputStream *stream,
161 GCancellable *cancellable,
164 GInputStreamClass *class;
167 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
168 g_return_val_if_fail (buffer != NULL, 0);
173 if (((gssize) count) < 0)
175 g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
176 _("Too large count value passed to %s"), G_STRFUNC);
180 class = G_INPUT_STREAM_GET_CLASS (stream);
182 if (class->read_fn == NULL)
184 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
185 _("Input stream doesn't implement read"));
189 if (!g_input_stream_set_pending (stream, error))
193 g_cancellable_push_current (cancellable);
195 res = class->read_fn (stream, buffer, count, cancellable, error);
198 g_cancellable_pop_current (cancellable);
200 g_input_stream_clear_pending (stream);
206 * g_input_stream_read_all:
207 * @stream: a #GInputStream.
208 * @buffer: (array length=count) (element-type guint8): a buffer to
209 * read data into (which should be at least count bytes long).
210 * @count: the number of bytes that will be read from the stream
211 * @bytes_read: (out): location to store the number of bytes that was read from the stream
212 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
213 * @error: location to store the error occurring, or %NULL to ignore
215 * Tries to read @count bytes from the stream into the buffer starting at
216 * @buffer. Will block during this read.
218 * This function is similar to g_input_stream_read(), except it tries to
219 * read as many bytes as requested, only stopping on an error or end of stream.
221 * On a successful read of @count bytes, or if we reached the end of the
222 * stream, %TRUE is returned, and @bytes_read is set to the number of bytes
225 * If there is an error during the operation %FALSE is returned and @error
226 * is set to indicate the error status, @bytes_read is updated to contain
227 * the number of bytes read into @buffer before the error occurred.
229 * Returns: %TRUE on success, %FALSE if there was an error
232 g_input_stream_read_all (GInputStream *stream,
236 GCancellable *cancellable,
242 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
243 g_return_val_if_fail (buffer != NULL, FALSE);
246 while (_bytes_read < count)
248 res = g_input_stream_read (stream, (char *)buffer + _bytes_read, count - _bytes_read,
253 *bytes_read = _bytes_read;
264 *bytes_read = _bytes_read;
269 * g_input_stream_read_bytes:
270 * @stream: a #GInputStream.
271 * @count: maximum number of bytes that will be read from the stream. Common
272 * values include 4096 and 8192.
273 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
274 * @error: location to store the error occurring, or %NULL to ignore
276 * Like g_input_stream_read(), this tries to read @count bytes from
277 * the stream in a blocking fashion. However, rather than reading into
278 * a user-supplied buffer, this will create a new #GBytes containing
279 * the data that was read. This may be easier to use from language
282 * If count is zero, returns a zero-length #GBytes and does nothing. A
283 * value of @count larger than %G_MAXSSIZE will cause a
284 * %G_IO_ERROR_INVALID_ARGUMENT error.
286 * On success, a new #GBytes is returned. It is not an error if the
287 * size of this object is not the same as the requested size, as it
288 * can happen e.g. near the end of a file. A zero-length #GBytes is
289 * returned on end of file (or if @count is zero), but never
292 * If @cancellable is not %NULL, then the operation can be cancelled by
293 * triggering the cancellable object from another thread. If the operation
294 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
295 * operation was partially finished when the operation was cancelled the
296 * partial result will be returned, without an error.
298 * On error %NULL is returned and @error is set accordingly.
300 * Returns: a new #GBytes, or %NULL on error
305 g_input_stream_read_bytes (GInputStream *stream,
307 GCancellable *cancellable,
313 buf = g_malloc (count);
314 nread = g_input_stream_read (stream, buf, count, cancellable, error);
323 return g_bytes_new_static ("", 0);
326 return g_bytes_new_take (buf, nread);
330 * g_input_stream_skip:
331 * @stream: a #GInputStream.
332 * @count: the number of bytes that will be skipped from the stream
333 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
334 * @error: location to store the error occurring, or %NULL to ignore
336 * Tries to skip @count bytes from the stream. Will block during the operation.
338 * This is identical to g_input_stream_read(), from a behaviour standpoint,
339 * but the bytes that are skipped are not returned to the user. Some
340 * streams have an implementation that is more efficient than reading the data.
342 * This function is optional for inherited classes, as the default implementation
343 * emulates it using read.
345 * If @cancellable is not %NULL, then the operation can be cancelled by
346 * triggering the cancellable object from another thread. If the operation
347 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
348 * operation was partially finished when the operation was cancelled the
349 * partial result will be returned, without an error.
351 * Returns: Number of bytes skipped, or -1 on error
354 g_input_stream_skip (GInputStream *stream,
356 GCancellable *cancellable,
359 GInputStreamClass *class;
362 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
367 if (((gssize) count) < 0)
369 g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
370 _("Too large count value passed to %s"), G_STRFUNC);
374 class = G_INPUT_STREAM_GET_CLASS (stream);
376 if (!g_input_stream_set_pending (stream, error))
380 g_cancellable_push_current (cancellable);
382 res = class->skip (stream, count, cancellable, error);
385 g_cancellable_pop_current (cancellable);
387 g_input_stream_clear_pending (stream);
393 g_input_stream_real_skip (GInputStream *stream,
395 GCancellable *cancellable,
398 GInputStreamClass *class;
399 gssize ret, read_bytes;
403 if (G_IS_SEEKABLE (stream) && g_seekable_can_seek (G_SEEKABLE (stream)))
405 if (g_seekable_seek (G_SEEKABLE (stream),
413 /* If not seekable, or seek failed, fall back to reading data: */
415 class = G_INPUT_STREAM_GET_CLASS (stream);
422 ret = class->read_fn (stream, buffer, MIN (sizeof (buffer), count),
423 cancellable, &my_error);
426 if (read_bytes > 0 &&
427 my_error->domain == G_IO_ERROR &&
428 my_error->code == G_IO_ERROR_CANCELLED)
430 g_error_free (my_error);
434 g_propagate_error (error, my_error);
441 if (ret == 0 || count == 0)
447 * g_input_stream_close:
448 * @stream: A #GInputStream.
449 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
450 * @error: location to store the error occurring, or %NULL to ignore
452 * Closes the stream, releasing resources related to it.
454 * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
455 * Closing a stream multiple times will not return an error.
457 * Streams will be automatically closed when the last reference
458 * is dropped, but you might want to call this function to make sure
459 * resources are released as early as possible.
461 * Some streams might keep the backing store of the stream (e.g. a file descriptor)
462 * open after the stream is closed. See the documentation for the individual
463 * stream for details.
465 * On failure the first error that happened will be reported, but the close
466 * operation will finish as much as possible. A stream that failed to
467 * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
468 * is important to check and report the error to the user.
470 * If @cancellable is not %NULL, then the operation can be cancelled by
471 * triggering the cancellable object from another thread. If the operation
472 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
473 * Cancelling a close will still leave the stream closed, but some streams
474 * can use a faster close that doesn't block to e.g. check errors.
476 * Returns: %TRUE on success, %FALSE on failure
479 g_input_stream_close (GInputStream *stream,
480 GCancellable *cancellable,
483 GInputStreamClass *class;
486 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
488 class = G_INPUT_STREAM_GET_CLASS (stream);
490 if (stream->priv->closed)
495 if (!g_input_stream_set_pending (stream, error))
499 g_cancellable_push_current (cancellable);
502 res = class->close_fn (stream, cancellable, error);
505 g_cancellable_pop_current (cancellable);
507 g_input_stream_clear_pending (stream);
509 stream->priv->closed = TRUE;
515 async_ready_callback_wrapper (GObject *source_object,
519 GInputStream *stream = G_INPUT_STREAM (source_object);
521 g_input_stream_clear_pending (stream);
522 if (stream->priv->outstanding_callback)
523 (*stream->priv->outstanding_callback) (source_object, res, user_data);
524 g_object_unref (stream);
528 async_ready_close_callback_wrapper (GObject *source_object,
532 GInputStream *stream = G_INPUT_STREAM (source_object);
534 g_input_stream_clear_pending (stream);
535 stream->priv->closed = TRUE;
536 if (stream->priv->outstanding_callback)
537 (*stream->priv->outstanding_callback) (source_object, res, user_data);
538 g_object_unref (stream);
542 * g_input_stream_read_async:
543 * @stream: A #GInputStream.
544 * @buffer: (array length=count) (element-type guint8): a buffer to
545 * read data into (which should be at least count bytes long).
546 * @count: the number of bytes that will be read from the stream
547 * @io_priority: the [I/O priority][io-priority]
549 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
550 * @callback: (scope async): callback to call when the request is satisfied
551 * @user_data: (closure): the data to pass to callback function
553 * Request an asynchronous read of @count bytes from the stream into the buffer
554 * starting at @buffer. When the operation is finished @callback will be called.
555 * You can then call g_input_stream_read_finish() to get the result of the
558 * During an async request no other sync and async calls are allowed on @stream, and will
559 * result in %G_IO_ERROR_PENDING errors.
561 * A value of @count larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
563 * On success, the number of bytes read into the buffer will be passed to the
564 * callback. It is not an error if this is not the same as the requested size, as it
565 * can happen e.g. near the end of a file, but generally we try to read
566 * as many bytes as requested. Zero is returned on end of file
567 * (or if @count is zero), but never otherwise.
569 * Any outstanding i/o request with higher priority (lower numerical value) will
570 * be executed before an outstanding request with lower priority. Default
571 * priority is %G_PRIORITY_DEFAULT.
573 * The asyncronous methods have a default fallback that uses threads to implement
574 * asynchronicity, so they are optional for inheriting classes. However, if you
575 * override one you must override all.
578 g_input_stream_read_async (GInputStream *stream,
582 GCancellable *cancellable,
583 GAsyncReadyCallback callback,
586 GInputStreamClass *class;
587 GError *error = NULL;
589 g_return_if_fail (G_IS_INPUT_STREAM (stream));
590 g_return_if_fail (buffer != NULL);
596 task = g_task_new (stream, cancellable, callback, user_data);
597 g_task_set_source_tag (task, g_input_stream_read_async);
598 g_task_return_int (task, 0);
599 g_object_unref (task);
603 if (((gssize) count) < 0)
605 g_task_report_new_error (stream, callback, user_data,
606 g_input_stream_read_async,
607 G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
608 _("Too large count value passed to %s"),
613 if (!g_input_stream_set_pending (stream, &error))
615 g_task_report_error (stream, callback, user_data,
616 g_input_stream_read_async,
621 class = G_INPUT_STREAM_GET_CLASS (stream);
622 stream->priv->outstanding_callback = callback;
623 g_object_ref (stream);
624 class->read_async (stream, buffer, count, io_priority, cancellable,
625 async_ready_callback_wrapper, user_data);
629 * g_input_stream_read_finish:
630 * @stream: a #GInputStream.
631 * @result: a #GAsyncResult.
632 * @error: a #GError location to store the error occurring, or %NULL to
635 * Finishes an asynchronous stream read operation.
637 * Returns: number of bytes read in, or -1 on error, or 0 on end of file.
640 g_input_stream_read_finish (GInputStream *stream,
641 GAsyncResult *result,
644 GInputStreamClass *class;
646 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
647 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
649 if (g_async_result_legacy_propagate_error (result, error))
651 else if (g_async_result_is_tagged (result, g_input_stream_read_async))
652 return g_task_propagate_int (G_TASK (result), error);
654 class = G_INPUT_STREAM_GET_CLASS (stream);
655 return class->read_finish (stream, result, error);
666 free_async_read_all (gpointer data)
668 g_slice_free (AsyncReadAll, data);
672 read_all_callback (GObject *stream,
673 GAsyncResult *result,
676 GTask *task = user_data;
677 AsyncReadAll *data = g_task_get_task_data (task);
678 gboolean got_eof = FALSE;
682 GError *error = NULL;
685 nread = g_input_stream_read_finish (G_INPUT_STREAM (stream), result, &error);
689 g_task_return_error (task, error);
690 g_object_unref (task);
694 g_assert_cmpint (nread, <=, data->to_read);
695 data->to_read -= nread;
696 data->bytes_read += nread;
697 got_eof = (nread == 0);
700 if (got_eof || data->to_read == 0)
702 g_task_return_boolean (task, TRUE);
703 g_object_unref (task);
707 g_input_stream_read_async (G_INPUT_STREAM (stream),
708 data->buffer + data->bytes_read,
710 g_task_get_priority (task),
711 g_task_get_cancellable (task),
712 read_all_callback, task);
717 read_all_async_thread (GTask *task,
718 gpointer source_object,
720 GCancellable *cancellable)
722 GInputStream *stream = source_object;
723 AsyncReadAll *data = task_data;
724 GError *error = NULL;
726 if (g_input_stream_read_all (stream, data->buffer, data->to_read, &data->bytes_read,
727 g_task_get_cancellable (task), &error))
728 g_task_return_boolean (task, TRUE);
730 g_task_return_error (task, error);
734 * g_input_stream_read_all_async:
735 * @stream: A #GInputStream
736 * @buffer: (array length=count) (element-type guint8): a buffer to
737 * read data into (which should be at least count bytes long)
738 * @count: the number of bytes that will be read from the stream
739 * @io_priority: the [I/O priority][io-priority] of the request
740 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore
741 * @callback: (scope async): callback to call when the request is satisfied
742 * @user_data: (closure): the data to pass to callback function
744 * Request an asynchronous read of @count bytes from the stream into the
745 * buffer starting at @buffer.
747 * This is the asynchronous equivalent of g_input_stream_read_all().
749 * Call g_input_stream_read_all_finish() to collect the result.
751 * Any outstanding I/O request with higher priority (lower numerical
752 * value) will be executed before an outstanding request with lower
753 * priority. Default priority is %G_PRIORITY_DEFAULT.
758 g_input_stream_read_all_async (GInputStream *stream,
762 GCancellable *cancellable,
763 GAsyncReadyCallback callback,
769 g_return_if_fail (G_IS_INPUT_STREAM (stream));
770 g_return_if_fail (buffer != NULL || count == 0);
772 task = g_task_new (stream, cancellable, callback, user_data);
773 data = g_slice_new0 (AsyncReadAll);
774 data->buffer = buffer;
775 data->to_read = count;
777 g_task_set_task_data (task, data, free_async_read_all);
778 g_task_set_priority (task, io_priority);
780 /* If async reads are going to be handled via the threadpool anyway
781 * then we may as well do it with a single dispatch instead of
782 * bouncing in and out.
784 if (g_input_stream_async_read_is_via_threads (stream))
786 g_task_run_in_thread (task, read_all_async_thread);
787 g_object_unref (task);
790 read_all_callback (G_OBJECT (stream), NULL, task);
794 * g_input_stream_read_all_finish:
795 * @stream: a #GInputStream
796 * @result: a #GAsyncResult
797 * @bytes_read: (out): location to store the number of bytes that was read from the stream
798 * @error: a #GError location to store the error occurring, or %NULL to ignore
800 * Finishes an asynchronous stream read operation started with
801 * g_input_stream_read_all_async().
803 * As a special exception to the normal conventions for functions that
804 * use #GError, if this function returns %FALSE (and sets @error) then
805 * @bytes_read will be set to the number of bytes that were successfully
806 * read before the error was encountered. This functionality is only
807 * available from C. If you need it from another language then you must
808 * write your own loop around g_input_stream_read_async().
810 * Returns: %TRUE on success, %FALSE if there was an error
815 g_input_stream_read_all_finish (GInputStream *stream,
816 GAsyncResult *result,
822 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
823 g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
825 task = G_TASK (result);
829 AsyncReadAll *data = g_task_get_task_data (task);
831 *bytes_read = data->bytes_read;
834 return g_task_propagate_boolean (task, error);
838 read_bytes_callback (GObject *stream,
839 GAsyncResult *result,
842 GTask *task = user_data;
843 guchar *buf = g_task_get_task_data (task);
844 GError *error = NULL;
846 GBytes *bytes = NULL;
848 nread = g_input_stream_read_finish (G_INPUT_STREAM (stream),
853 g_task_return_error (task, error);
858 bytes = g_bytes_new_static ("", 0);
861 bytes = g_bytes_new_take (buf, nread);
864 g_task_return_pointer (task, bytes, (GDestroyNotify)g_bytes_unref);
866 g_object_unref (task);
870 * g_input_stream_read_bytes_async:
871 * @stream: A #GInputStream.
872 * @count: the number of bytes that will be read from the stream
873 * @io_priority: the [I/O priority][io-priority] of the request
874 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
875 * @callback: (scope async): callback to call when the request is satisfied
876 * @user_data: (closure): the data to pass to callback function
878 * Request an asynchronous read of @count bytes from the stream into a
879 * new #GBytes. When the operation is finished @callback will be
880 * called. You can then call g_input_stream_read_bytes_finish() to get the
881 * result of the operation.
883 * During an async request no other sync and async calls are allowed
884 * on @stream, and will result in %G_IO_ERROR_PENDING errors.
886 * A value of @count larger than %G_MAXSSIZE will cause a
887 * %G_IO_ERROR_INVALID_ARGUMENT error.
889 * On success, the new #GBytes will be passed to the callback. It is
890 * not an error if this is smaller than the requested size, as it can
891 * happen e.g. near the end of a file, but generally we try to read as
892 * many bytes as requested. Zero is returned on end of file (or if
893 * @count is zero), but never otherwise.
895 * Any outstanding I/O request with higher priority (lower numerical
896 * value) will be executed before an outstanding request with lower
897 * priority. Default priority is %G_PRIORITY_DEFAULT.
902 g_input_stream_read_bytes_async (GInputStream *stream,
905 GCancellable *cancellable,
906 GAsyncReadyCallback callback,
912 task = g_task_new (stream, cancellable, callback, user_data);
913 buf = g_malloc (count);
914 g_task_set_task_data (task, buf, NULL);
916 g_input_stream_read_async (stream, buf, count,
917 io_priority, cancellable,
918 read_bytes_callback, task);
922 * g_input_stream_read_bytes_finish:
923 * @stream: a #GInputStream.
924 * @result: a #GAsyncResult.
925 * @error: a #GError location to store the error occurring, or %NULL to
928 * Finishes an asynchronous stream read-into-#GBytes operation.
930 * Returns: the newly-allocated #GBytes, or %NULL on error
935 g_input_stream_read_bytes_finish (GInputStream *stream,
936 GAsyncResult *result,
939 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), NULL);
940 g_return_val_if_fail (g_task_is_valid (result, stream), NULL);
942 return g_task_propagate_pointer (G_TASK (result), error);
946 * g_input_stream_skip_async:
947 * @stream: A #GInputStream.
948 * @count: the number of bytes that will be skipped from the stream
949 * @io_priority: the [I/O priority][io-priority] of the request
950 * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
951 * @callback: (scope async): callback to call when the request is satisfied
952 * @user_data: (closure): the data to pass to callback function
954 * Request an asynchronous skip of @count bytes from the stream.
955 * When the operation is finished @callback will be called.
956 * You can then call g_input_stream_skip_finish() to get the result
959 * During an async request no other sync and async calls are allowed,
960 * and will result in %G_IO_ERROR_PENDING errors.
962 * A value of @count larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
964 * On success, the number of bytes skipped will be passed to the callback.
965 * It is not an error if this is not the same as the requested size, as it
966 * can happen e.g. near the end of a file, but generally we try to skip
967 * as many bytes as requested. Zero is returned on end of file
968 * (or if @count is zero), but never otherwise.
970 * Any outstanding i/o request with higher priority (lower numerical value)
971 * will be executed before an outstanding request with lower priority.
972 * Default priority is %G_PRIORITY_DEFAULT.
974 * The asynchronous methods have a default fallback that uses threads to
975 * implement asynchronicity, so they are optional for inheriting classes.
976 * However, if you override one, you must override all.
979 g_input_stream_skip_async (GInputStream *stream,
982 GCancellable *cancellable,
983 GAsyncReadyCallback callback,
986 GInputStreamClass *class;
987 GError *error = NULL;
989 g_return_if_fail (G_IS_INPUT_STREAM (stream));
995 task = g_task_new (stream, cancellable, callback, user_data);
996 g_task_set_source_tag (task, g_input_stream_skip_async);
997 g_task_return_int (task, 0);
998 g_object_unref (task);
1002 if (((gssize) count) < 0)
1004 g_task_report_new_error (stream, callback, user_data,
1005 g_input_stream_skip_async,
1006 G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
1007 _("Too large count value passed to %s"),
1012 if (!g_input_stream_set_pending (stream, &error))
1014 g_task_report_error (stream, callback, user_data,
1015 g_input_stream_skip_async,
1020 class = G_INPUT_STREAM_GET_CLASS (stream);
1021 stream->priv->outstanding_callback = callback;
1022 g_object_ref (stream);
1023 class->skip_async (stream, count, io_priority, cancellable,
1024 async_ready_callback_wrapper, user_data);
1028 * g_input_stream_skip_finish:
1029 * @stream: a #GInputStream.
1030 * @result: a #GAsyncResult.
1031 * @error: a #GError location to store the error occurring, or %NULL to
1034 * Finishes a stream skip operation.
1036 * Returns: the size of the bytes skipped, or %-1 on error.
1039 g_input_stream_skip_finish (GInputStream *stream,
1040 GAsyncResult *result,
1043 GInputStreamClass *class;
1045 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
1046 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
1048 if (g_async_result_legacy_propagate_error (result, error))
1050 else if (g_async_result_is_tagged (result, g_input_stream_skip_async))
1051 return g_task_propagate_int (G_TASK (result), error);
1053 class = G_INPUT_STREAM_GET_CLASS (stream);
1054 return class->skip_finish (stream, result, error);
1058 * g_input_stream_close_async:
1059 * @stream: A #GInputStream.
1060 * @io_priority: the [I/O priority][io-priority] of the request
1061 * @cancellable: (allow-none): optional cancellable object
1062 * @callback: (scope async): callback to call when the request is satisfied
1063 * @user_data: (closure): the data to pass to callback function
1065 * Requests an asynchronous closes of the stream, releasing resources related to it.
1066 * When the operation is finished @callback will be called.
1067 * You can then call g_input_stream_close_finish() to get the result of the
1070 * For behaviour details see g_input_stream_close().
1072 * The asyncronous methods have a default fallback that uses threads to implement
1073 * asynchronicity, so they are optional for inheriting classes. However, if you
1074 * override one you must override all.
1077 g_input_stream_close_async (GInputStream *stream,
1079 GCancellable *cancellable,
1080 GAsyncReadyCallback callback,
1083 GInputStreamClass *class;
1084 GError *error = NULL;
1086 g_return_if_fail (G_IS_INPUT_STREAM (stream));
1088 if (stream->priv->closed)
1092 task = g_task_new (stream, cancellable, callback, user_data);
1093 g_task_set_source_tag (task, g_input_stream_close_async);
1094 g_task_return_boolean (task, TRUE);
1095 g_object_unref (task);
1099 if (!g_input_stream_set_pending (stream, &error))
1101 g_task_report_error (stream, callback, user_data,
1102 g_input_stream_close_async,
1107 class = G_INPUT_STREAM_GET_CLASS (stream);
1108 stream->priv->outstanding_callback = callback;
1109 g_object_ref (stream);
1110 class->close_async (stream, io_priority, cancellable,
1111 async_ready_close_callback_wrapper, user_data);
1115 * g_input_stream_close_finish:
1116 * @stream: a #GInputStream.
1117 * @result: a #GAsyncResult.
1118 * @error: a #GError location to store the error occurring, or %NULL to
1121 * Finishes closing a stream asynchronously, started from g_input_stream_close_async().
1123 * Returns: %TRUE if the stream was closed successfully.
1126 g_input_stream_close_finish (GInputStream *stream,
1127 GAsyncResult *result,
1130 GInputStreamClass *class;
1132 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1133 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1135 if (g_async_result_legacy_propagate_error (result, error))
1137 else if (g_async_result_is_tagged (result, g_input_stream_close_async))
1138 return g_task_propagate_boolean (G_TASK (result), error);
1140 class = G_INPUT_STREAM_GET_CLASS (stream);
1141 return class->close_finish (stream, result, error);
1145 * g_input_stream_is_closed:
1146 * @stream: input stream.
1148 * Checks if an input stream is closed.
1150 * Returns: %TRUE if the stream is closed.
1153 g_input_stream_is_closed (GInputStream *stream)
1155 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), TRUE);
1157 return stream->priv->closed;
1161 * g_input_stream_has_pending:
1162 * @stream: input stream.
1164 * Checks if an input stream has pending actions.
1166 * Returns: %TRUE if @stream has pending actions.
1169 g_input_stream_has_pending (GInputStream *stream)
1171 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), TRUE);
1173 return stream->priv->pending;
1177 * g_input_stream_set_pending:
1178 * @stream: input stream
1179 * @error: a #GError location to store the error occurring, or %NULL to
1182 * Sets @stream to have actions pending. If the pending flag is
1183 * already set or @stream is closed, it will return %FALSE and set
1186 * Returns: %TRUE if pending was previously unset and is now set.
1189 g_input_stream_set_pending (GInputStream *stream, GError **error)
1191 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1193 if (stream->priv->closed)
1195 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1196 _("Stream is already closed"));
1200 if (stream->priv->pending)
1202 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1203 /* Translators: This is an error you get if there is already an
1204 * operation running against this stream when you try to start
1206 _("Stream has outstanding operation"));
1210 stream->priv->pending = TRUE;
1215 * g_input_stream_clear_pending:
1216 * @stream: input stream
1218 * Clears the pending flag on @stream.
1221 g_input_stream_clear_pending (GInputStream *stream)
1223 g_return_if_fail (G_IS_INPUT_STREAM (stream));
1225 stream->priv->pending = FALSE;
1229 * g_input_stream_async_read_is_via_threads:
1230 * @stream: input stream
1232 * Checks if an input stream's read_async function uses threads.
1234 * Returns: %TRUE if @stream's read_async function uses threads.
1237 g_input_stream_async_read_is_via_threads (GInputStream *stream)
1239 GInputStreamClass *class;
1241 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1243 class = G_INPUT_STREAM_GET_CLASS (stream);
1245 return (class->read_async == g_input_stream_real_read_async &&
1246 !(G_IS_POLLABLE_INPUT_STREAM (stream) &&
1247 g_pollable_input_stream_can_poll (G_POLLABLE_INPUT_STREAM (stream))));
1250 /********************************************
1251 * Default implementation of async ops *
1252 ********************************************/
1260 free_read_data (ReadData *op)
1262 g_slice_free (ReadData, op);
1266 read_async_thread (GTask *task,
1267 gpointer source_object,
1269 GCancellable *cancellable)
1271 GInputStream *stream = source_object;
1272 ReadData *op = task_data;
1273 GInputStreamClass *class;
1274 GError *error = NULL;
1277 class = G_INPUT_STREAM_GET_CLASS (stream);
1279 nread = class->read_fn (stream,
1280 op->buffer, op->count,
1281 g_task_get_cancellable (task),
1284 g_task_return_error (task, error);
1286 g_task_return_int (task, nread);
1289 static void read_async_pollable (GPollableInputStream *stream,
1293 read_async_pollable_ready (GPollableInputStream *stream,
1296 GTask *task = user_data;
1298 read_async_pollable (stream, task);
1303 read_async_pollable (GPollableInputStream *stream,
1306 ReadData *op = g_task_get_task_data (task);
1307 GError *error = NULL;
1310 if (g_task_return_error_if_cancelled (task))
1313 nread = G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
1314 read_nonblocking (stream, op->buffer, op->count, &error);
1316 if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1320 g_error_free (error);
1322 source = g_pollable_input_stream_create_source (stream,
1323 g_task_get_cancellable (task));
1324 g_task_attach_source (task, source,
1325 (GSourceFunc) read_async_pollable_ready);
1326 g_source_unref (source);
1331 g_task_return_error (task, error);
1333 g_task_return_int (task, nread);
1334 /* g_input_stream_real_read_async() unrefs task */
1339 g_input_stream_real_read_async (GInputStream *stream,
1343 GCancellable *cancellable,
1344 GAsyncReadyCallback callback,
1350 op = g_slice_new0 (ReadData);
1351 task = g_task_new (stream, cancellable, callback, user_data);
1352 g_task_set_task_data (task, op, (GDestroyNotify) free_read_data);
1353 g_task_set_priority (task, io_priority);
1354 op->buffer = buffer;
1357 if (!g_input_stream_async_read_is_via_threads (stream))
1358 read_async_pollable (G_POLLABLE_INPUT_STREAM (stream), task);
1360 g_task_run_in_thread (task, read_async_thread);
1361 g_object_unref (task);
1365 g_input_stream_real_read_finish (GInputStream *stream,
1366 GAsyncResult *result,
1369 g_return_val_if_fail (g_task_is_valid (result, stream), -1);
1371 return g_task_propagate_int (G_TASK (result), error);
1376 skip_async_thread (GTask *task,
1377 gpointer source_object,
1379 GCancellable *cancellable)
1381 GInputStream *stream = source_object;
1382 gsize count = GPOINTER_TO_SIZE (task_data);
1383 GInputStreamClass *class;
1384 GError *error = NULL;
1387 class = G_INPUT_STREAM_GET_CLASS (stream);
1388 ret = class->skip (stream, count,
1389 g_task_get_cancellable (task),
1392 g_task_return_error (task, error);
1394 g_task_return_int (task, ret);
1400 gsize count_skipped;
1401 } SkipFallbackAsyncData;
1404 skip_callback_wrapper (GObject *source_object,
1408 GInputStreamClass *class;
1409 GTask *task = user_data;
1410 SkipFallbackAsyncData *data = g_task_get_task_data (task);
1411 GError *error = NULL;
1414 ret = g_input_stream_read_finish (G_INPUT_STREAM (source_object), res, &error);
1419 data->count_skipped += ret;
1421 if (data->count > 0)
1423 class = G_INPUT_STREAM_GET_CLASS (source_object);
1424 class->read_async (G_INPUT_STREAM (source_object),
1425 data->buffer, MIN (8192, data->count),
1426 g_task_get_priority (task),
1427 g_task_get_cancellable (task),
1428 skip_callback_wrapper, task);
1434 g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) &&
1435 data->count_skipped)
1437 /* No error, return partial read */
1438 g_clear_error (&error);
1442 g_task_return_error (task, error);
1444 g_task_return_int (task, data->count_skipped);
1445 g_object_unref (task);
1449 g_input_stream_real_skip_async (GInputStream *stream,
1452 GCancellable *cancellable,
1453 GAsyncReadyCallback callback,
1456 GInputStreamClass *class;
1457 SkipFallbackAsyncData *data;
1460 class = G_INPUT_STREAM_GET_CLASS (stream);
1462 task = g_task_new (stream, cancellable, callback, user_data);
1463 g_task_set_priority (task, io_priority);
1465 if (g_input_stream_async_read_is_via_threads (stream))
1467 /* Read is thread-using async fallback.
1468 * Make skip use threads too, so that we can use a possible sync skip
1469 * implementation. */
1470 g_task_set_task_data (task, GSIZE_TO_POINTER (count), NULL);
1472 g_task_run_in_thread (task, skip_async_thread);
1473 g_object_unref (task);
1477 /* TODO: Skip fallback uses too much memory, should do multiple read calls */
1479 /* There is a custom async read function, lets use that. */
1480 data = g_new (SkipFallbackAsyncData, 1);
1481 data->count = count;
1482 data->count_skipped = 0;
1483 g_task_set_task_data (task, data, g_free);
1484 g_task_set_check_cancellable (task, FALSE);
1485 class->read_async (stream, data->buffer, MIN (8192, count), io_priority, cancellable,
1486 skip_callback_wrapper, task);
1492 g_input_stream_real_skip_finish (GInputStream *stream,
1493 GAsyncResult *result,
1496 g_return_val_if_fail (g_task_is_valid (result, stream), -1);
1498 return g_task_propagate_int (G_TASK (result), error);
1502 close_async_thread (GTask *task,
1503 gpointer source_object,
1505 GCancellable *cancellable)
1507 GInputStream *stream = source_object;
1508 GInputStreamClass *class;
1509 GError *error = NULL;
1512 class = G_INPUT_STREAM_GET_CLASS (stream);
1513 if (class->close_fn)
1515 result = class->close_fn (stream,
1516 g_task_get_cancellable (task),
1520 g_task_return_error (task, error);
1525 g_task_return_boolean (task, TRUE);
1529 g_input_stream_real_close_async (GInputStream *stream,
1531 GCancellable *cancellable,
1532 GAsyncReadyCallback callback,
1537 task = g_task_new (stream, cancellable, callback, user_data);
1538 g_task_set_check_cancellable (task, FALSE);
1539 g_task_set_priority (task, io_priority);
1541 g_task_run_in_thread (task, close_async_thread);
1542 g_object_unref (task);
1546 g_input_stream_real_close_finish (GInputStream *stream,
1547 GAsyncResult *result,
1550 g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1552 return g_task_propagate_boolean (G_TASK (result), error);