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 2.1 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 * See the documentation for #GIOStream for details of thread safety of
48 * All of these functions have async variants too.
51 struct _GInputStreamPrivate {
54 GAsyncReadyCallback outstanding_callback;
57 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GInputStream, g_input_stream, G_TYPE_OBJECT)
59 static gssize g_input_stream_real_skip (GInputStream *stream,
61 GCancellable *cancellable,
63 static void g_input_stream_real_read_async (GInputStream *stream,
67 GCancellable *cancellable,
68 GAsyncReadyCallback callback,
70 static gssize g_input_stream_real_read_finish (GInputStream *stream,
73 static void g_input_stream_real_skip_async (GInputStream *stream,
76 GCancellable *cancellable,
77 GAsyncReadyCallback callback,
79 static gssize g_input_stream_real_skip_finish (GInputStream *stream,
82 static void g_input_stream_real_close_async (GInputStream *stream,
84 GCancellable *cancellable,
85 GAsyncReadyCallback callback,
87 static gboolean g_input_stream_real_close_finish (GInputStream *stream,
92 g_input_stream_dispose (GObject *object)
96 stream = G_INPUT_STREAM (object);
98 if (!stream->priv->closed)
99 g_input_stream_close (stream, NULL, NULL);
101 G_OBJECT_CLASS (g_input_stream_parent_class)->dispose (object);
106 g_input_stream_class_init (GInputStreamClass *klass)
108 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
110 gobject_class->dispose = g_input_stream_dispose;
112 klass->skip = g_input_stream_real_skip;
113 klass->read_async = g_input_stream_real_read_async;
114 klass->read_finish = g_input_stream_real_read_finish;
115 klass->skip_async = g_input_stream_real_skip_async;
116 klass->skip_finish = g_input_stream_real_skip_finish;
117 klass->close_async = g_input_stream_real_close_async;
118 klass->close_finish = g_input_stream_real_close_finish;
122 g_input_stream_init (GInputStream *stream)
124 stream->priv = g_input_stream_get_instance_private (stream);
128 * g_input_stream_read:
129 * @stream: a #GInputStream.
130 * @buffer: (array length=count) (element-type guint8) (out caller-allocates):
131 * a buffer to read data into (which should be at least count bytes long).
132 * @count: the number of bytes that will be read from the stream
133 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
134 * @error: location to store the error occurring, or %NULL to ignore
136 * Tries to read @count bytes from the stream into the buffer starting at
137 * @buffer. Will block during this read.
139 * If count is zero returns zero and does nothing. A value of @count
140 * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
142 * On success, the number of bytes read into the buffer is returned.
143 * It is not an error if this is not the same as the requested size, as it
144 * can happen e.g. near the end of a file. Zero is returned on end of file
145 * (or if @count is zero), but never otherwise.
147 * The returned @buffer is not a nul-terminated string, it can contain nul bytes
148 * at any position, and this function doesn't nul-terminate the @buffer.
150 * If @cancellable is not %NULL, then the operation can be cancelled by
151 * triggering the cancellable object from another thread. If the operation
152 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
153 * operation was partially finished when the operation was cancelled the
154 * partial result will be returned, without an error.
156 * On error -1 is returned and @error is set accordingly.
158 * Returns: Number of bytes read, or -1 on error, or 0 on end of file.
161 g_input_stream_read (GInputStream *stream,
164 GCancellable *cancellable,
167 GInputStreamClass *class;
170 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
171 g_return_val_if_fail (buffer != NULL, 0);
176 if (((gssize) count) < 0)
178 g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
179 _("Too large count value passed to %s"), G_STRFUNC);
183 class = G_INPUT_STREAM_GET_CLASS (stream);
185 if (class->read_fn == NULL)
187 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
188 _("Input stream doesn’t implement read"));
192 if (!g_input_stream_set_pending (stream, error))
196 g_cancellable_push_current (cancellable);
198 res = class->read_fn (stream, buffer, count, cancellable, error);
201 g_cancellable_pop_current (cancellable);
203 g_input_stream_clear_pending (stream);
209 * g_input_stream_read_all:
210 * @stream: a #GInputStream.
211 * @buffer: (array length=count) (element-type guint8) (out caller-allocates):
212 * a buffer to read data into (which should be at least count bytes long).
213 * @count: the number of bytes that will be read from the stream
214 * @bytes_read: (out): location to store the number of bytes that was read from the stream
215 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
216 * @error: location to store the error occurring, or %NULL to ignore
218 * Tries to read @count bytes from the stream into the buffer starting at
219 * @buffer. Will block during this read.
221 * This function is similar to g_input_stream_read(), except it tries to
222 * read as many bytes as requested, only stopping on an error or end of stream.
224 * On a successful read of @count bytes, or if we reached the end of the
225 * stream, %TRUE is returned, and @bytes_read is set to the number of bytes
228 * If there is an error during the operation %FALSE is returned and @error
229 * is set to indicate the error status.
231 * As a special exception to the normal conventions for functions that
232 * use #GError, if this function returns %FALSE (and sets @error) then
233 * @bytes_read will be set to the number of bytes that were successfully
234 * read before the error was encountered. This functionality is only
235 * available from C. If you need it from another language then you must
236 * write your own loop around g_input_stream_read().
238 * Returns: %TRUE on success, %FALSE if there was an error
241 g_input_stream_read_all (GInputStream *stream,
245 GCancellable *cancellable,
251 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
252 g_return_val_if_fail (buffer != NULL, FALSE);
255 while (_bytes_read < count)
257 res = g_input_stream_read (stream, (char *)buffer + _bytes_read, count - _bytes_read,
262 *bytes_read = _bytes_read;
273 *bytes_read = _bytes_read;
278 * g_input_stream_read_bytes:
279 * @stream: a #GInputStream.
280 * @count: maximum number of bytes that will be read from the stream. Common
281 * values include 4096 and 8192.
282 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
283 * @error: location to store the error occurring, or %NULL to ignore
285 * Like g_input_stream_read(), this tries to read @count bytes from
286 * the stream in a blocking fashion. However, rather than reading into
287 * a user-supplied buffer, this will create a new #GBytes containing
288 * the data that was read. This may be easier to use from language
291 * If count is zero, returns a zero-length #GBytes and does nothing. A
292 * value of @count larger than %G_MAXSSIZE will cause a
293 * %G_IO_ERROR_INVALID_ARGUMENT error.
295 * On success, a new #GBytes is returned. It is not an error if the
296 * size of this object is not the same as the requested size, as it
297 * can happen e.g. near the end of a file. A zero-length #GBytes is
298 * returned on end of file (or if @count is zero), but never
301 * If @cancellable is not %NULL, then the operation can be cancelled by
302 * triggering the cancellable object from another thread. If the operation
303 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
304 * operation was partially finished when the operation was cancelled the
305 * partial result will be returned, without an error.
307 * On error %NULL is returned and @error is set accordingly.
309 * Returns: (transfer full): a new #GBytes, or %NULL on error
314 g_input_stream_read_bytes (GInputStream *stream,
316 GCancellable *cancellable,
322 buf = g_malloc (count);
323 nread = g_input_stream_read (stream, buf, count, cancellable, error);
332 return g_bytes_new_static ("", 0);
335 return g_bytes_new_take (buf, nread);
339 * g_input_stream_skip:
340 * @stream: a #GInputStream.
341 * @count: the number of bytes that will be skipped from the stream
342 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
343 * @error: location to store the error occurring, or %NULL to ignore
345 * Tries to skip @count bytes from the stream. Will block during the operation.
347 * This is identical to g_input_stream_read(), from a behaviour standpoint,
348 * but the bytes that are skipped are not returned to the user. Some
349 * streams have an implementation that is more efficient than reading the data.
351 * This function is optional for inherited classes, as the default implementation
352 * emulates it using read.
354 * If @cancellable is not %NULL, then the operation can be cancelled by
355 * triggering the cancellable object from another thread. If the operation
356 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
357 * operation was partially finished when the operation was cancelled the
358 * partial result will be returned, without an error.
360 * Returns: Number of bytes skipped, or -1 on error
363 g_input_stream_skip (GInputStream *stream,
365 GCancellable *cancellable,
368 GInputStreamClass *class;
371 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
376 if (((gssize) count) < 0)
378 g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
379 _("Too large count value passed to %s"), G_STRFUNC);
383 class = G_INPUT_STREAM_GET_CLASS (stream);
385 if (!g_input_stream_set_pending (stream, error))
389 g_cancellable_push_current (cancellable);
391 res = class->skip (stream, count, cancellable, error);
394 g_cancellable_pop_current (cancellable);
396 g_input_stream_clear_pending (stream);
402 g_input_stream_real_skip (GInputStream *stream,
404 GCancellable *cancellable,
407 GInputStreamClass *class;
408 gssize ret, read_bytes;
412 if (G_IS_SEEKABLE (stream) && g_seekable_can_seek (G_SEEKABLE (stream)))
414 if (g_seekable_seek (G_SEEKABLE (stream),
422 /* If not seekable, or seek failed, fall back to reading data: */
424 class = G_INPUT_STREAM_GET_CLASS (stream);
431 ret = class->read_fn (stream, buffer, MIN (sizeof (buffer), count),
432 cancellable, &my_error);
435 if (read_bytes > 0 &&
436 my_error->domain == G_IO_ERROR &&
437 my_error->code == G_IO_ERROR_CANCELLED)
439 g_error_free (my_error);
443 g_propagate_error (error, my_error);
450 if (ret == 0 || count == 0)
456 * g_input_stream_close:
457 * @stream: A #GInputStream.
458 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
459 * @error: location to store the error occurring, or %NULL to ignore
461 * Closes the stream, releasing resources related to it.
463 * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
464 * Closing a stream multiple times will not return an error.
466 * Streams will be automatically closed when the last reference
467 * is dropped, but you might want to call this function to make sure
468 * resources are released as early as possible.
470 * Some streams might keep the backing store of the stream (e.g. a file descriptor)
471 * open after the stream is closed. See the documentation for the individual
472 * stream for details.
474 * On failure the first error that happened will be reported, but the close
475 * operation will finish as much as possible. A stream that failed to
476 * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
477 * is important to check and report the error to the user.
479 * If @cancellable is not %NULL, then the operation can be cancelled by
480 * triggering the cancellable object from another thread. If the operation
481 * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
482 * Cancelling a close will still leave the stream closed, but some streams
483 * can use a faster close that doesn't block to e.g. check errors.
485 * Returns: %TRUE on success, %FALSE on failure
488 g_input_stream_close (GInputStream *stream,
489 GCancellable *cancellable,
492 GInputStreamClass *class;
495 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
497 class = G_INPUT_STREAM_GET_CLASS (stream);
499 if (stream->priv->closed)
504 if (!g_input_stream_set_pending (stream, error))
508 g_cancellable_push_current (cancellable);
511 res = class->close_fn (stream, cancellable, error);
514 g_cancellable_pop_current (cancellable);
516 g_input_stream_clear_pending (stream);
518 stream->priv->closed = TRUE;
524 async_ready_callback_wrapper (GObject *source_object,
528 GInputStream *stream = G_INPUT_STREAM (source_object);
530 g_input_stream_clear_pending (stream);
531 if (stream->priv->outstanding_callback)
532 (*stream->priv->outstanding_callback) (source_object, res, user_data);
533 g_object_unref (stream);
537 async_ready_close_callback_wrapper (GObject *source_object,
541 GInputStream *stream = G_INPUT_STREAM (source_object);
543 g_input_stream_clear_pending (stream);
544 stream->priv->closed = TRUE;
545 if (stream->priv->outstanding_callback)
546 (*stream->priv->outstanding_callback) (source_object, res, user_data);
547 g_object_unref (stream);
551 * g_input_stream_read_async:
552 * @stream: A #GInputStream.
553 * @buffer: (array length=count) (element-type guint8) (out caller-allocates):
554 * a buffer to read data into (which should be at least count bytes long).
555 * @count: the number of bytes that will be read from the stream
556 * @io_priority: the [I/O priority][io-priority]
558 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
559 * @callback: (scope async): callback to call when the request is satisfied
560 * @user_data: (closure): the data to pass to callback function
562 * Request an asynchronous read of @count bytes from the stream into the buffer
563 * starting at @buffer. When the operation is finished @callback will be called.
564 * You can then call g_input_stream_read_finish() to get the result of the
567 * During an async request no other sync and async calls are allowed on @stream, and will
568 * result in %G_IO_ERROR_PENDING errors.
570 * A value of @count larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
572 * On success, the number of bytes read into the buffer will be passed to the
573 * callback. It is not an error if this is not the same as the requested size, as it
574 * can happen e.g. near the end of a file, but generally we try to read
575 * as many bytes as requested. Zero is returned on end of file
576 * (or if @count is zero), but never otherwise.
578 * Any outstanding i/o request with higher priority (lower numerical value) will
579 * be executed before an outstanding request with lower priority. Default
580 * priority is %G_PRIORITY_DEFAULT.
582 * The asynchronous methods have a default fallback that uses threads to implement
583 * asynchronicity, so they are optional for inheriting classes. However, if you
584 * override one you must override all.
587 g_input_stream_read_async (GInputStream *stream,
591 GCancellable *cancellable,
592 GAsyncReadyCallback callback,
595 GInputStreamClass *class;
596 GError *error = NULL;
598 g_return_if_fail (G_IS_INPUT_STREAM (stream));
599 g_return_if_fail (buffer != NULL);
605 task = g_task_new (stream, cancellable, callback, user_data);
606 g_task_set_source_tag (task, g_input_stream_read_async);
607 g_task_return_int (task, 0);
608 g_object_unref (task);
612 if (((gssize) count) < 0)
614 g_task_report_new_error (stream, callback, user_data,
615 g_input_stream_read_async,
616 G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
617 _("Too large count value passed to %s"),
622 if (!g_input_stream_set_pending (stream, &error))
624 g_task_report_error (stream, callback, user_data,
625 g_input_stream_read_async,
630 class = G_INPUT_STREAM_GET_CLASS (stream);
631 stream->priv->outstanding_callback = callback;
632 g_object_ref (stream);
633 class->read_async (stream, buffer, count, io_priority, cancellable,
634 async_ready_callback_wrapper, user_data);
638 * g_input_stream_read_finish:
639 * @stream: a #GInputStream.
640 * @result: a #GAsyncResult.
641 * @error: a #GError location to store the error occurring, or %NULL to
644 * Finishes an asynchronous stream read operation.
646 * Returns: number of bytes read in, or -1 on error, or 0 on end of file.
649 g_input_stream_read_finish (GInputStream *stream,
650 GAsyncResult *result,
653 GInputStreamClass *class;
655 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
656 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
658 if (g_async_result_legacy_propagate_error (result, error))
660 else if (g_async_result_is_tagged (result, g_input_stream_read_async))
661 return g_task_propagate_int (G_TASK (result), error);
663 class = G_INPUT_STREAM_GET_CLASS (stream);
664 return class->read_finish (stream, result, error);
675 free_async_read_all (gpointer data)
677 g_slice_free (AsyncReadAll, data);
681 read_all_callback (GObject *stream,
682 GAsyncResult *result,
685 GTask *task = user_data;
686 AsyncReadAll *data = g_task_get_task_data (task);
687 gboolean got_eof = FALSE;
691 GError *error = NULL;
694 nread = g_input_stream_read_finish (G_INPUT_STREAM (stream), result, &error);
698 g_task_return_error (task, error);
699 g_object_unref (task);
703 g_assert_cmpint (nread, <=, data->to_read);
704 data->to_read -= nread;
705 data->bytes_read += nread;
706 got_eof = (nread == 0);
709 if (got_eof || data->to_read == 0)
711 g_task_return_boolean (task, TRUE);
712 g_object_unref (task);
716 g_input_stream_read_async (G_INPUT_STREAM (stream),
717 data->buffer + data->bytes_read,
719 g_task_get_priority (task),
720 g_task_get_cancellable (task),
721 read_all_callback, task);
726 read_all_async_thread (GTask *task,
727 gpointer source_object,
729 GCancellable *cancellable)
731 GInputStream *stream = source_object;
732 AsyncReadAll *data = task_data;
733 GError *error = NULL;
735 if (g_input_stream_read_all (stream, data->buffer, data->to_read, &data->bytes_read,
736 g_task_get_cancellable (task), &error))
737 g_task_return_boolean (task, TRUE);
739 g_task_return_error (task, error);
743 * g_input_stream_read_all_async:
744 * @stream: A #GInputStream
745 * @buffer: (array length=count) (element-type guint8) (out caller-allocates):
746 * a buffer to read data into (which should be at least count bytes long)
747 * @count: the number of bytes that will be read from the stream
748 * @io_priority: the [I/O priority][io-priority] of the request
749 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore
750 * @callback: (scope async): callback to call when the request is satisfied
751 * @user_data: (closure): the data to pass to callback function
753 * Request an asynchronous read of @count bytes from the stream into the
754 * buffer starting at @buffer.
756 * This is the asynchronous equivalent of g_input_stream_read_all().
758 * Call g_input_stream_read_all_finish() to collect the result.
760 * Any outstanding I/O request with higher priority (lower numerical
761 * value) will be executed before an outstanding request with lower
762 * priority. Default priority is %G_PRIORITY_DEFAULT.
767 g_input_stream_read_all_async (GInputStream *stream,
771 GCancellable *cancellable,
772 GAsyncReadyCallback callback,
778 g_return_if_fail (G_IS_INPUT_STREAM (stream));
779 g_return_if_fail (buffer != NULL || count == 0);
781 task = g_task_new (stream, cancellable, callback, user_data);
782 data = g_slice_new0 (AsyncReadAll);
783 data->buffer = buffer;
784 data->to_read = count;
786 g_task_set_source_tag (task, g_input_stream_read_all_async);
787 g_task_set_task_data (task, data, free_async_read_all);
788 g_task_set_priority (task, io_priority);
790 /* If async reads are going to be handled via the threadpool anyway
791 * then we may as well do it with a single dispatch instead of
792 * bouncing in and out.
794 if (g_input_stream_async_read_is_via_threads (stream))
796 g_task_run_in_thread (task, read_all_async_thread);
797 g_object_unref (task);
800 read_all_callback (G_OBJECT (stream), NULL, task);
804 * g_input_stream_read_all_finish:
805 * @stream: a #GInputStream
806 * @result: a #GAsyncResult
807 * @bytes_read: (out): location to store the number of bytes that was read from the stream
808 * @error: a #GError location to store the error occurring, or %NULL to ignore
810 * Finishes an asynchronous stream read operation started with
811 * g_input_stream_read_all_async().
813 * As a special exception to the normal conventions for functions that
814 * use #GError, if this function returns %FALSE (and sets @error) then
815 * @bytes_read will be set to the number of bytes that were successfully
816 * read before the error was encountered. This functionality is only
817 * available from C. If you need it from another language then you must
818 * write your own loop around g_input_stream_read_async().
820 * Returns: %TRUE on success, %FALSE if there was an error
825 g_input_stream_read_all_finish (GInputStream *stream,
826 GAsyncResult *result,
832 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
833 g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
835 task = G_TASK (result);
839 AsyncReadAll *data = g_task_get_task_data (task);
841 *bytes_read = data->bytes_read;
844 return g_task_propagate_boolean (task, error);
848 read_bytes_callback (GObject *stream,
849 GAsyncResult *result,
852 GTask *task = user_data;
853 guchar *buf = g_task_get_task_data (task);
854 GError *error = NULL;
856 GBytes *bytes = NULL;
858 nread = g_input_stream_read_finish (G_INPUT_STREAM (stream),
863 g_task_return_error (task, error);
868 bytes = g_bytes_new_static ("", 0);
871 bytes = g_bytes_new_take (buf, nread);
874 g_task_return_pointer (task, bytes, (GDestroyNotify)g_bytes_unref);
876 g_object_unref (task);
880 * g_input_stream_read_bytes_async:
881 * @stream: A #GInputStream.
882 * @count: the number of bytes that will be read from the stream
883 * @io_priority: the [I/O priority][io-priority] of the request
884 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
885 * @callback: (scope async): callback to call when the request is satisfied
886 * @user_data: (closure): the data to pass to callback function
888 * Request an asynchronous read of @count bytes from the stream into a
889 * new #GBytes. When the operation is finished @callback will be
890 * called. You can then call g_input_stream_read_bytes_finish() to get the
891 * result of the operation.
893 * During an async request no other sync and async calls are allowed
894 * on @stream, and will result in %G_IO_ERROR_PENDING errors.
896 * A value of @count larger than %G_MAXSSIZE will cause a
897 * %G_IO_ERROR_INVALID_ARGUMENT error.
899 * On success, the new #GBytes will be passed to the callback. It is
900 * not an error if this is smaller than the requested size, as it can
901 * happen e.g. near the end of a file, but generally we try to read as
902 * many bytes as requested. Zero is returned on end of file (or if
903 * @count is zero), but never otherwise.
905 * Any outstanding I/O request with higher priority (lower numerical
906 * value) will be executed before an outstanding request with lower
907 * priority. Default priority is %G_PRIORITY_DEFAULT.
912 g_input_stream_read_bytes_async (GInputStream *stream,
915 GCancellable *cancellable,
916 GAsyncReadyCallback callback,
922 task = g_task_new (stream, cancellable, callback, user_data);
923 g_task_set_source_tag (task, g_input_stream_read_bytes_async);
925 buf = g_malloc (count);
926 g_task_set_task_data (task, buf, NULL);
928 g_input_stream_read_async (stream, buf, count,
929 io_priority, cancellable,
930 read_bytes_callback, task);
934 * g_input_stream_read_bytes_finish:
935 * @stream: a #GInputStream.
936 * @result: a #GAsyncResult.
937 * @error: a #GError location to store the error occurring, or %NULL to
940 * Finishes an asynchronous stream read-into-#GBytes operation.
942 * Returns: (transfer full): the newly-allocated #GBytes, or %NULL on error
947 g_input_stream_read_bytes_finish (GInputStream *stream,
948 GAsyncResult *result,
951 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), NULL);
952 g_return_val_if_fail (g_task_is_valid (result, stream), NULL);
954 return g_task_propagate_pointer (G_TASK (result), error);
958 * g_input_stream_skip_async:
959 * @stream: A #GInputStream.
960 * @count: the number of bytes that will be skipped from the stream
961 * @io_priority: the [I/O priority][io-priority] of the request
962 * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
963 * @callback: (scope async): callback to call when the request is satisfied
964 * @user_data: (closure): the data to pass to callback function
966 * Request an asynchronous skip of @count bytes from the stream.
967 * When the operation is finished @callback will be called.
968 * You can then call g_input_stream_skip_finish() to get the result
971 * During an async request no other sync and async calls are allowed,
972 * and will result in %G_IO_ERROR_PENDING errors.
974 * A value of @count larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
976 * On success, the number of bytes skipped will be passed to the callback.
977 * It is not an error if this is not the same as the requested size, as it
978 * can happen e.g. near the end of a file, but generally we try to skip
979 * as many bytes as requested. Zero is returned on end of file
980 * (or if @count is zero), but never otherwise.
982 * Any outstanding i/o request with higher priority (lower numerical value)
983 * will be executed before an outstanding request with lower priority.
984 * Default priority is %G_PRIORITY_DEFAULT.
986 * The asynchronous methods have a default fallback that uses threads to
987 * implement asynchronicity, so they are optional for inheriting classes.
988 * However, if you override one, you must override all.
991 g_input_stream_skip_async (GInputStream *stream,
994 GCancellable *cancellable,
995 GAsyncReadyCallback callback,
998 GInputStreamClass *class;
999 GError *error = NULL;
1001 g_return_if_fail (G_IS_INPUT_STREAM (stream));
1007 task = g_task_new (stream, cancellable, callback, user_data);
1008 g_task_set_source_tag (task, g_input_stream_skip_async);
1009 g_task_return_int (task, 0);
1010 g_object_unref (task);
1014 if (((gssize) count) < 0)
1016 g_task_report_new_error (stream, callback, user_data,
1017 g_input_stream_skip_async,
1018 G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
1019 _("Too large count value passed to %s"),
1024 if (!g_input_stream_set_pending (stream, &error))
1026 g_task_report_error (stream, callback, user_data,
1027 g_input_stream_skip_async,
1032 class = G_INPUT_STREAM_GET_CLASS (stream);
1033 stream->priv->outstanding_callback = callback;
1034 g_object_ref (stream);
1035 class->skip_async (stream, count, io_priority, cancellable,
1036 async_ready_callback_wrapper, user_data);
1040 * g_input_stream_skip_finish:
1041 * @stream: a #GInputStream.
1042 * @result: a #GAsyncResult.
1043 * @error: a #GError location to store the error occurring, or %NULL to
1046 * Finishes a stream skip operation.
1048 * Returns: the size of the bytes skipped, or `-1` on error.
1051 g_input_stream_skip_finish (GInputStream *stream,
1052 GAsyncResult *result,
1055 GInputStreamClass *class;
1057 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), -1);
1058 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
1060 if (g_async_result_legacy_propagate_error (result, error))
1062 else if (g_async_result_is_tagged (result, g_input_stream_skip_async))
1063 return g_task_propagate_int (G_TASK (result), error);
1065 class = G_INPUT_STREAM_GET_CLASS (stream);
1066 return class->skip_finish (stream, result, error);
1070 * g_input_stream_close_async:
1071 * @stream: A #GInputStream.
1072 * @io_priority: the [I/O priority][io-priority] of the request
1073 * @cancellable: (nullable): optional cancellable object
1074 * @callback: (scope async): callback to call when the request is satisfied
1075 * @user_data: (closure): the data to pass to callback function
1077 * Requests an asynchronous closes of the stream, releasing resources related to it.
1078 * When the operation is finished @callback will be called.
1079 * You can then call g_input_stream_close_finish() to get the result of the
1082 * For behaviour details see g_input_stream_close().
1084 * The asynchronous methods have a default fallback that uses threads to implement
1085 * asynchronicity, so they are optional for inheriting classes. However, if you
1086 * override one you must override all.
1089 g_input_stream_close_async (GInputStream *stream,
1091 GCancellable *cancellable,
1092 GAsyncReadyCallback callback,
1095 GInputStreamClass *class;
1096 GError *error = NULL;
1098 g_return_if_fail (G_IS_INPUT_STREAM (stream));
1100 if (stream->priv->closed)
1104 task = g_task_new (stream, cancellable, callback, user_data);
1105 g_task_set_source_tag (task, g_input_stream_close_async);
1106 g_task_return_boolean (task, TRUE);
1107 g_object_unref (task);
1111 if (!g_input_stream_set_pending (stream, &error))
1113 g_task_report_error (stream, callback, user_data,
1114 g_input_stream_close_async,
1119 class = G_INPUT_STREAM_GET_CLASS (stream);
1120 stream->priv->outstanding_callback = callback;
1121 g_object_ref (stream);
1122 class->close_async (stream, io_priority, cancellable,
1123 async_ready_close_callback_wrapper, user_data);
1127 * g_input_stream_close_finish:
1128 * @stream: a #GInputStream.
1129 * @result: a #GAsyncResult.
1130 * @error: a #GError location to store the error occurring, or %NULL to
1133 * Finishes closing a stream asynchronously, started from g_input_stream_close_async().
1135 * Returns: %TRUE if the stream was closed successfully.
1138 g_input_stream_close_finish (GInputStream *stream,
1139 GAsyncResult *result,
1142 GInputStreamClass *class;
1144 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1145 g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1147 if (g_async_result_legacy_propagate_error (result, error))
1149 else if (g_async_result_is_tagged (result, g_input_stream_close_async))
1150 return g_task_propagate_boolean (G_TASK (result), error);
1152 class = G_INPUT_STREAM_GET_CLASS (stream);
1153 return class->close_finish (stream, result, error);
1157 * g_input_stream_is_closed:
1158 * @stream: input stream.
1160 * Checks if an input stream is closed.
1162 * Returns: %TRUE if the stream is closed.
1165 g_input_stream_is_closed (GInputStream *stream)
1167 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), TRUE);
1169 return stream->priv->closed;
1173 * g_input_stream_has_pending:
1174 * @stream: input stream.
1176 * Checks if an input stream has pending actions.
1178 * Returns: %TRUE if @stream has pending actions.
1181 g_input_stream_has_pending (GInputStream *stream)
1183 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), TRUE);
1185 return stream->priv->pending;
1189 * g_input_stream_set_pending:
1190 * @stream: input stream
1191 * @error: a #GError location to store the error occurring, or %NULL to
1194 * Sets @stream to have actions pending. If the pending flag is
1195 * already set or @stream is closed, it will return %FALSE and set
1198 * Returns: %TRUE if pending was previously unset and is now set.
1201 g_input_stream_set_pending (GInputStream *stream, GError **error)
1203 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1205 if (stream->priv->closed)
1207 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1208 _("Stream is already closed"));
1212 if (stream->priv->pending)
1214 g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1215 /* Translators: This is an error you get if there is already an
1216 * operation running against this stream when you try to start
1218 _("Stream has outstanding operation"));
1222 stream->priv->pending = TRUE;
1227 * g_input_stream_clear_pending:
1228 * @stream: input stream
1230 * Clears the pending flag on @stream.
1233 g_input_stream_clear_pending (GInputStream *stream)
1235 g_return_if_fail (G_IS_INPUT_STREAM (stream));
1237 stream->priv->pending = FALSE;
1241 * g_input_stream_async_read_is_via_threads:
1242 * @stream: input stream
1244 * Checks if an input stream's read_async function uses threads.
1246 * Returns: %TRUE if @stream's read_async function uses threads.
1249 g_input_stream_async_read_is_via_threads (GInputStream *stream)
1251 GInputStreamClass *class;
1253 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1255 class = G_INPUT_STREAM_GET_CLASS (stream);
1257 return (class->read_async == g_input_stream_real_read_async &&
1258 !(G_IS_POLLABLE_INPUT_STREAM (stream) &&
1259 g_pollable_input_stream_can_poll (G_POLLABLE_INPUT_STREAM (stream))));
1263 * g_input_stream_async_close_is_via_threads:
1264 * @stream: input stream
1266 * Checks if an input stream's close_async function uses threads.
1268 * Returns: %TRUE if @stream's close_async function uses threads.
1271 g_input_stream_async_close_is_via_threads (GInputStream *stream)
1273 GInputStreamClass *class;
1275 g_return_val_if_fail (G_IS_INPUT_STREAM (stream), FALSE);
1277 class = G_INPUT_STREAM_GET_CLASS (stream);
1279 return class->close_async == g_input_stream_real_close_async;
1282 /********************************************
1283 * Default implementation of async ops *
1284 ********************************************/
1292 free_read_data (ReadData *op)
1294 g_slice_free (ReadData, op);
1298 read_async_thread (GTask *task,
1299 gpointer source_object,
1301 GCancellable *cancellable)
1303 GInputStream *stream = source_object;
1304 ReadData *op = task_data;
1305 GInputStreamClass *class;
1306 GError *error = NULL;
1309 class = G_INPUT_STREAM_GET_CLASS (stream);
1311 nread = class->read_fn (stream,
1312 op->buffer, op->count,
1313 g_task_get_cancellable (task),
1316 g_task_return_error (task, error);
1318 g_task_return_int (task, nread);
1321 static void read_async_pollable (GPollableInputStream *stream,
1325 read_async_pollable_ready (GPollableInputStream *stream,
1328 GTask *task = user_data;
1330 read_async_pollable (stream, task);
1335 read_async_pollable (GPollableInputStream *stream,
1338 ReadData *op = g_task_get_task_data (task);
1339 GError *error = NULL;
1342 if (g_task_return_error_if_cancelled (task))
1345 nread = G_POLLABLE_INPUT_STREAM_GET_INTERFACE (stream)->
1346 read_nonblocking (stream, op->buffer, op->count, &error);
1348 if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1352 g_error_free (error);
1354 source = g_pollable_input_stream_create_source (stream,
1355 g_task_get_cancellable (task));
1356 g_task_attach_source (task, source,
1357 (GSourceFunc) read_async_pollable_ready);
1358 g_source_unref (source);
1363 g_task_return_error (task, error);
1365 g_task_return_int (task, nread);
1366 /* g_input_stream_real_read_async() unrefs task */
1371 g_input_stream_real_read_async (GInputStream *stream,
1375 GCancellable *cancellable,
1376 GAsyncReadyCallback callback,
1382 op = g_slice_new0 (ReadData);
1383 task = g_task_new (stream, cancellable, callback, user_data);
1384 g_task_set_source_tag (task, g_input_stream_real_read_async);
1385 g_task_set_task_data (task, op, (GDestroyNotify) free_read_data);
1386 g_task_set_priority (task, io_priority);
1387 op->buffer = buffer;
1390 if (!g_input_stream_async_read_is_via_threads (stream))
1391 read_async_pollable (G_POLLABLE_INPUT_STREAM (stream), task);
1393 g_task_run_in_thread (task, read_async_thread);
1394 g_object_unref (task);
1398 g_input_stream_real_read_finish (GInputStream *stream,
1399 GAsyncResult *result,
1402 g_return_val_if_fail (g_task_is_valid (result, stream), -1);
1404 return g_task_propagate_int (G_TASK (result), error);
1409 skip_async_thread (GTask *task,
1410 gpointer source_object,
1412 GCancellable *cancellable)
1414 GInputStream *stream = source_object;
1415 gsize count = GPOINTER_TO_SIZE (task_data);
1416 GInputStreamClass *class;
1417 GError *error = NULL;
1420 class = G_INPUT_STREAM_GET_CLASS (stream);
1421 ret = class->skip (stream, count,
1422 g_task_get_cancellable (task),
1425 g_task_return_error (task, error);
1427 g_task_return_int (task, ret);
1433 gsize count_skipped;
1434 } SkipFallbackAsyncData;
1437 skip_callback_wrapper (GObject *source_object,
1441 GInputStreamClass *class;
1442 GTask *task = user_data;
1443 SkipFallbackAsyncData *data = g_task_get_task_data (task);
1444 GError *error = NULL;
1447 ret = g_input_stream_read_finish (G_INPUT_STREAM (source_object), res, &error);
1452 data->count_skipped += ret;
1454 if (data->count > 0)
1456 class = G_INPUT_STREAM_GET_CLASS (source_object);
1457 class->read_async (G_INPUT_STREAM (source_object),
1458 data->buffer, MIN (8192, data->count),
1459 g_task_get_priority (task),
1460 g_task_get_cancellable (task),
1461 skip_callback_wrapper, task);
1467 g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) &&
1468 data->count_skipped)
1470 /* No error, return partial read */
1471 g_clear_error (&error);
1475 g_task_return_error (task, error);
1477 g_task_return_int (task, data->count_skipped);
1478 g_object_unref (task);
1482 g_input_stream_real_skip_async (GInputStream *stream,
1485 GCancellable *cancellable,
1486 GAsyncReadyCallback callback,
1489 GInputStreamClass *class;
1490 SkipFallbackAsyncData *data;
1493 class = G_INPUT_STREAM_GET_CLASS (stream);
1495 task = g_task_new (stream, cancellable, callback, user_data);
1496 g_task_set_source_tag (task, g_input_stream_real_skip_async);
1497 g_task_set_priority (task, io_priority);
1499 if (g_input_stream_async_read_is_via_threads (stream))
1501 /* Read is thread-using async fallback.
1502 * Make skip use threads too, so that we can use a possible sync skip
1503 * implementation. */
1504 g_task_set_task_data (task, GSIZE_TO_POINTER (count), NULL);
1506 g_task_run_in_thread (task, skip_async_thread);
1507 g_object_unref (task);
1511 /* TODO: Skip fallback uses too much memory, should do multiple read calls */
1513 /* There is a custom async read function, lets use that. */
1514 data = g_new (SkipFallbackAsyncData, 1);
1515 data->count = count;
1516 data->count_skipped = 0;
1517 g_task_set_task_data (task, data, g_free);
1518 g_task_set_check_cancellable (task, FALSE);
1519 class->read_async (stream, data->buffer, MIN (8192, count), io_priority, cancellable,
1520 skip_callback_wrapper, task);
1526 g_input_stream_real_skip_finish (GInputStream *stream,
1527 GAsyncResult *result,
1530 g_return_val_if_fail (g_task_is_valid (result, stream), -1);
1532 return g_task_propagate_int (G_TASK (result), error);
1536 close_async_thread (GTask *task,
1537 gpointer source_object,
1539 GCancellable *cancellable)
1541 GInputStream *stream = source_object;
1542 GInputStreamClass *class;
1543 GError *error = NULL;
1546 class = G_INPUT_STREAM_GET_CLASS (stream);
1547 if (class->close_fn)
1549 result = class->close_fn (stream,
1550 g_task_get_cancellable (task),
1554 g_task_return_error (task, error);
1559 g_task_return_boolean (task, TRUE);
1563 g_input_stream_real_close_async (GInputStream *stream,
1565 GCancellable *cancellable,
1566 GAsyncReadyCallback callback,
1571 task = g_task_new (stream, cancellable, callback, user_data);
1572 g_task_set_source_tag (task, g_input_stream_real_close_async);
1573 g_task_set_check_cancellable (task, FALSE);
1574 g_task_set_priority (task, io_priority);
1576 g_task_run_in_thread (task, close_async_thread);
1577 g_object_unref (task);
1581 g_input_stream_real_close_finish (GInputStream *stream,
1582 GAsyncResult *result,
1585 g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1587 return g_task_propagate_boolean (G_TASK (result), error);