/src/glib/gio/gpollableoutputstream.c

Source (jump to first uncovered line)
/* GIO - GLib Input, Output and Streaming Library
 *
 * Copyright (C) 2010 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <errno.h>

#include "gpollableoutputstream.h"
#include "gasynchelper.h"
#include "gfiledescriptorbased.h"
#include "glibintl.h"

/**
 * SECTION:gpollableoutputstream
 * @short_description: Interface for pollable output streams
 * @include: gio/gio.h
 * @see_also: #GOutputStream, #GFileDescriptorBased, #GPollableInputStream
 *
 * #GPollableOutputStream is implemented by #GOutputStreams that
 * can be polled for readiness to write. This can be used when
 * interfacing with a non-GIO API that expects
 * UNIX-file-descriptor-style asynchronous I/O rather than GIO-style.
 *
 * Since: 2.28
 */

G_DEFINE_INTERFACE (GPollableOutputStream, g_pollable_output_stream, G_TYPE_OUTPUT_STREAM)

static gboolean g_pollable_output_stream_default_can_poll           (GPollableOutputStream *stream);
static gssize   g_pollable_output_stream_default_write_nonblocking  (GPollableOutputStream  *stream,
                     const void             *buffer,
                     gsize                   count,
                     GError                **error);
static GPollableReturn g_pollable_output_stream_default_writev_nonblocking (GPollableOutputStream  *stream,
                      const GOutputVector    *vectors,
                      gsize                   n_vectors,
                      gsize                  *bytes_written,
                      GError                **error);

static void
g_pollable_output_stream_default_init (GPollableOutputStreamInterface *iface)
{
  iface->can_poll           = g_pollable_output_stream_default_can_poll;
  iface->write_nonblocking  = g_pollable_output_stream_default_write_nonblocking;
  iface->writev_nonblocking = g_pollable_output_stream_default_writev_nonblocking;
}

static gboolean
g_pollable_output_stream_default_can_poll (GPollableOutputStream *stream)
{
  return TRUE;
}

/**
 * g_pollable_output_stream_can_poll:
 * @stream: a #GPollableOutputStream.
 *
 * Checks if @stream is actually pollable. Some classes may implement
 * #GPollableOutputStream but have only certain instances of that
 * class be pollable. If this method returns %FALSE, then the behavior
 * of other #GPollableOutputStream methods is undefined.
 *
 * For any given stream, the value returned by this method is constant;
 * a stream cannot switch from pollable to non-pollable or vice versa.
 *
 * Returns: %TRUE if @stream is pollable, %FALSE if not.
 *
 * Since: 2.28
 */
gboolean
g_pollable_output_stream_can_poll (GPollableOutputStream *stream)
{
  g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), FALSE);

  return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->can_poll (stream);
}

/**
 * g_pollable_output_stream_is_writable:
 * @stream: a #GPollableOutputStream.
 *
 * Checks if @stream can be written.
 *
 * Note that some stream types may not be able to implement this 100%
 * reliably, and it is possible that a call to g_output_stream_write()
 * after this returns %TRUE would still block. To guarantee
 * non-blocking behavior, you should always use
 * g_pollable_output_stream_write_nonblocking(), which will return a
 * %G_IO_ERROR_WOULD_BLOCK error rather than blocking.
 *
 * Returns: %TRUE if @stream is writable, %FALSE if not. If an error
 *   has occurred on @stream, this will result in
 *   g_pollable_output_stream_is_writable() returning %TRUE, and the
 *   next attempt to write will return the error.
 *
 * Since: 2.28
 */
gboolean
g_pollable_output_stream_is_writable (GPollableOutputStream *stream)
{
  g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), FALSE);

  return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->is_writable (stream);
}

/**
 * g_pollable_output_stream_create_source:
 * @stream: a #GPollableOutputStream.
 * @cancellable: (nullable): a #GCancellable, or %NULL
 *
 * Creates a #GSource that triggers when @stream can be written, or
 * @cancellable is triggered or an error occurs. The callback on the
 * source is of the #GPollableSourceFunc type.
 *
 * As with g_pollable_output_stream_is_writable(), it is possible that
 * the stream may not actually be writable even after the source
 * triggers, so you should use g_pollable_output_stream_write_nonblocking()
 * rather than g_output_stream_write() from the callback.
 *
 * Returns: (transfer full): a new #GSource
 *
 * Since: 2.28
 */
GSource *
g_pollable_output_stream_create_source (GPollableOutputStream *stream,
          GCancellable          *cancellable)
{
  g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), NULL);

  return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
    create_source (stream, cancellable);
}

static gssize
g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream  *stream,
                const void             *buffer,
                gsize                   count,
                GError                **error)
{
  if (!g_pollable_output_stream_is_writable (stream))
    {
      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK,
                           g_strerror (EAGAIN));
      return -1;
    }

  return G_OUTPUT_STREAM_GET_CLASS (stream)->
    write_fn (G_OUTPUT_STREAM (stream), buffer, count, NULL, error);
}

static GPollableReturn
g_pollable_output_stream_default_writev_nonblocking (GPollableOutputStream  *stream,
                 const GOutputVector    *vectors,
                 gsize                   n_vectors,
                 gsize                  *bytes_written,
                 GError                **error)
{
  gsize _bytes_written = 0;
  GPollableOutputStreamInterface *iface = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream);
  gsize i;
  GError *err = NULL;

  for (i = 0; i < n_vectors; i++)
    {
      gssize res;

      /* Would we overflow here? In that case simply return and let the caller
       * handle this like a short write */
      if (_bytes_written > G_MAXSIZE - vectors[i].size)
        break;

      res = iface->write_nonblocking (stream, vectors[i].buffer, vectors[i].size, &err);
      if (res == -1)
        {
          if (bytes_written)
            *bytes_written = _bytes_written;

          /* If something was written already we handle this like a short
           * write and assume that the next call would either give the same
           * error again or successfully finish writing without errors or data
           * loss
           */
          if (_bytes_written > 0)
            {
              g_clear_error (&err);
              return G_POLLABLE_RETURN_OK;
            }
          else if (g_error_matches (err, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
            {
              g_clear_error (&err);
              return G_POLLABLE_RETURN_WOULD_BLOCK;
            }
          else
            {
              g_propagate_error (error, err);
              return G_POLLABLE_RETURN_FAILED;
            }
        }

      _bytes_written += res;
      /* if we had a short write break the loop here */
      if ((gsize) res < vectors[i].size)
        break;
    }

  if (bytes_written)
    *bytes_written = _bytes_written;

  return G_POLLABLE_RETURN_OK;
}

/**
 * g_pollable_output_stream_write_nonblocking:
 * @stream: a #GPollableOutputStream
 * @buffer: (array length=count) (element-type guint8): a buffer to write
 *     data from
 * @count: the number of bytes you want to write
 * @cancellable: (nullable): a #GCancellable, or %NULL
 * @error: #GError for error reporting, or %NULL to ignore.
 *
 * Attempts to write up to @count bytes from @buffer to @stream, as
 * with g_output_stream_write(). If @stream is not currently writable,
 * this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can
 * use g_pollable_output_stream_create_source() to create a #GSource
 * that will be triggered when @stream is writable.
 *
 * Note that since this method never blocks, you cannot actually
 * use @cancellable to cancel it. However, it will return an error
 * if @cancellable has already been cancelled when you call, which
 * may happen if you call this method after a source triggers due
 * to having been cancelled.
 *
 * Also note that if %G_IO_ERROR_WOULD_BLOCK is returned some underlying
 * transports like D/TLS require that you re-send the same @buffer and
 * @count in the next write call.
 *
 * Virtual: write_nonblocking
 * Returns: the number of bytes written, or -1 on error (including
 *   %G_IO_ERROR_WOULD_BLOCK).
 */
gssize
g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
              const void             *buffer,
              gsize                   count,
              GCancellable           *cancellable,
              GError                **error)
{
  gssize res;

  g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), -1);
  g_return_val_if_fail (buffer != NULL, 0);

  if (g_cancellable_set_error_if_cancelled (cancellable, error))
    return -1;

  if (count == 0)
    return 0;

  if (((gssize) count) < 0)
    {
      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
       _("Too large count value passed to %s"), G_STRFUNC);
      return -1;
    }

  if (cancellable)
    g_cancellable_push_current (cancellable);

  res = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
    write_nonblocking (stream, buffer, count, error);

  if (cancellable)
    g_cancellable_pop_current (cancellable);

  return res;
}

/**
 * g_pollable_output_stream_writev_nonblocking:
 * @stream: a #GPollableOutputStream
 * @vectors: (array length=n_vectors): the buffer containing the #GOutputVectors to write.
 * @n_vectors: the number of vectors to write
 * @bytes_written: (out) (optional): location to store the number of bytes that were
 *     written to the stream
 * @cancellable: (nullable): a #GCancellable, or %NULL
 * @error: #GError for error reporting, or %NULL to ignore.
 *
 * Attempts to write the bytes contained in the @n_vectors @vectors to @stream,
 * as with g_output_stream_writev(). If @stream is not currently writable,
 * this will immediately return %@G_POLLABLE_RETURN_WOULD_BLOCK, and you can
 * use g_pollable_output_stream_create_source() to create a #GSource
 * that will be triggered when @stream is writable. @error will *not* be
 * set in that case.
 *
 * Note that since this method never blocks, you cannot actually
 * use @cancellable to cancel it. However, it will return an error
 * if @cancellable has already been cancelled when you call, which
 * may happen if you call this method after a source triggers due
 * to having been cancelled.
 *
 * Also note that if %G_POLLABLE_RETURN_WOULD_BLOCK is returned some underlying
 * transports like D/TLS require that you re-send the same @vectors and
 * @n_vectors in the next write call.
 *
 * Virtual: writev_nonblocking
 *
 * Returns: %@G_POLLABLE_RETURN_OK on success, %G_POLLABLE_RETURN_WOULD_BLOCK
 * if the stream is not currently writable (and @error is *not* set), or
 * %G_POLLABLE_RETURN_FAILED if there was an error in which case @error will
 * be set.
 *
 * Since: 2.60
 */
GPollableReturn
g_pollable_output_stream_writev_nonblocking (GPollableOutputStream  *stream,
               const GOutputVector    *vectors,
               gsize                   n_vectors,
               gsize                  *bytes_written,
               GCancellable           *cancellable,
               GError                **error)
{
  GPollableOutputStreamInterface *iface;
  GPollableReturn res;
  gsize _bytes_written = 0;

  if (bytes_written)
    *bytes_written = 0;

  g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), G_POLLABLE_RETURN_FAILED);
  g_return_val_if_fail (vectors != NULL || n_vectors == 0, G_POLLABLE_RETURN_FAILED);
  g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), G_POLLABLE_RETURN_FAILED);
  g_return_val_if_fail (error == NULL || *error == NULL, G_POLLABLE_RETURN_FAILED);

  if (g_cancellable_set_error_if_cancelled (cancellable, error))
    return G_POLLABLE_RETURN_FAILED;

  if (n_vectors == 0)
    return G_POLLABLE_RETURN_OK;

  iface = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream);
  g_return_val_if_fail (iface->writev_nonblocking != NULL, G_POLLABLE_RETURN_FAILED);

  if (cancellable)
    g_cancellable_push_current (cancellable);

  res = iface->
    writev_nonblocking (stream, vectors, n_vectors, &_bytes_written, error);

  if (cancellable)
    g_cancellable_pop_current (cancellable);

  if (res == G_POLLABLE_RETURN_FAILED)
    g_warn_if_fail (error == NULL || (*error != NULL && !g_error_matches (*error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK)));
  else if (res == G_POLLABLE_RETURN_WOULD_BLOCK)
    g_warn_if_fail (error == NULL || *error == NULL);

  /* in case of not-OK nothing must've been written */
  g_warn_if_fail (res == G_POLLABLE_RETURN_OK || _bytes_written == 0);

  if (bytes_written)
    *bytes_written = _bytes_written;

  return res;
}

Coverage Report

Created: 2025-07-01 07:09

Line	Count	Source (jump to first uncovered line)
1		/* GIO - GLib Input, Output and Streaming Library
2		*
3		* Copyright (C) 2010 Red Hat, Inc.
4		*
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.
9		*
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.
14		*
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/>.
17		*/
18
19		#include "config.h"
20
21		#include <errno.h>
22
23		#include "gpollableoutputstream.h"
24		#include "gasynchelper.h"
25		#include "gfiledescriptorbased.h"
26		#include "glibintl.h"
27
28		/**
29		* SECTION:gpollableoutputstream
30		* @short_description: Interface for pollable output streams
31		* @include: gio/gio.h
32		* @see_also: #GOutputStream, #GFileDescriptorBased, #GPollableInputStream
33		*
34		* #GPollableOutputStream is implemented by #GOutputStreams that
35		* can be polled for readiness to write. This can be used when
36		* interfacing with a non-GIO API that expects
37		* UNIX-file-descriptor-style asynchronous I/O rather than GIO-style.
38		*
39		* Since: 2.28
40		*/
41
42		G_DEFINE_INTERFACE (GPollableOutputStream, g_pollable_output_stream, G_TYPE_OUTPUT_STREAM)
43
44		static gboolean g_pollable_output_stream_default_can_poll (GPollableOutputStream *stream);
45		static gssize g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream *stream,
46		const void *buffer,
47		gsize count,
48		GError **error);
49		static GPollableReturn g_pollable_output_stream_default_writev_nonblocking (GPollableOutputStream *stream,
50		const GOutputVector *vectors,
51		gsize n_vectors,
52		gsize *bytes_written,
53		GError **error);
54
55		static void
56		g_pollable_output_stream_default_init (GPollableOutputStreamInterface *iface)
57	0	{
58	0	iface->can_poll = g_pollable_output_stream_default_can_poll;
59	0	iface->write_nonblocking = g_pollable_output_stream_default_write_nonblocking;
60	0	iface->writev_nonblocking = g_pollable_output_stream_default_writev_nonblocking;
61	0	}
62
63		static gboolean
64		g_pollable_output_stream_default_can_poll (GPollableOutputStream *stream)
65	0	{
66	0	return TRUE;
67	0	}
68
69		/**
70		* g_pollable_output_stream_can_poll:
71		* @stream: a #GPollableOutputStream.
72		*
73		* Checks if @stream is actually pollable. Some classes may implement
74		* #GPollableOutputStream but have only certain instances of that
75		* class be pollable. If this method returns %FALSE, then the behavior
76		* of other #GPollableOutputStream methods is undefined.
77		*
78		* For any given stream, the value returned by this method is constant;
79		* a stream cannot switch from pollable to non-pollable or vice versa.
80		*
81		* Returns: %TRUE if @stream is pollable, %FALSE if not.
82		*
83		* Since: 2.28
84		*/
85		gboolean
86		g_pollable_output_stream_can_poll (GPollableOutputStream *stream)
87	0	{
88	0	g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), FALSE);
89
90	0	return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->can_poll (stream);
91	0	}
92
93		/**
94		* g_pollable_output_stream_is_writable:
95		* @stream: a #GPollableOutputStream.
96		*
97		* Checks if @stream can be written.
98		*
99		* Note that some stream types may not be able to implement this 100%
100		* reliably, and it is possible that a call to g_output_stream_write()
101		* after this returns %TRUE would still block. To guarantee
102		* non-blocking behavior, you should always use
103		* g_pollable_output_stream_write_nonblocking(), which will return a
104		* %G_IO_ERROR_WOULD_BLOCK error rather than blocking.
105		*
106		* Returns: %TRUE if @stream is writable, %FALSE if not. If an error
107		* has occurred on @stream, this will result in
108		* g_pollable_output_stream_is_writable() returning %TRUE, and the
109		* next attempt to write will return the error.
110		*
111		* Since: 2.28
112		*/
113		gboolean
114		g_pollable_output_stream_is_writable (GPollableOutputStream *stream)
115	0	{
116	0	g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), FALSE);
117
118	0	return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->is_writable (stream);
119	0	}
120
121		/**
122		* g_pollable_output_stream_create_source:
123		* @stream: a #GPollableOutputStream.
124		* @cancellable: (nullable): a #GCancellable, or %NULL
125		*
126		* Creates a #GSource that triggers when @stream can be written, or
127		* @cancellable is triggered or an error occurs. The callback on the
128		* source is of the #GPollableSourceFunc type.
129		*
130		* As with g_pollable_output_stream_is_writable(), it is possible that
131		* the stream may not actually be writable even after the source
132		* triggers, so you should use g_pollable_output_stream_write_nonblocking()
133		* rather than g_output_stream_write() from the callback.
134		*
135		* Returns: (transfer full): a new #GSource
136		*
137		* Since: 2.28
138		*/
139		GSource *
140		g_pollable_output_stream_create_source (GPollableOutputStream *stream,
141		GCancellable *cancellable)
142	0	{
143	0	g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), NULL);
144
145	0	return G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
146	0	create_source (stream, cancellable);
147	0	}
148
149		static gssize
150		g_pollable_output_stream_default_write_nonblocking (GPollableOutputStream *stream,
151		const void *buffer,
152		gsize count,
153		GError **error)
154	0	{
155	0	if (!g_pollable_output_stream_is_writable (stream))
156	0	{
157	0	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK,
158	0	g_strerror (EAGAIN));
159	0	return -1;
160	0	}
161
162	0	return G_OUTPUT_STREAM_GET_CLASS (stream)->
163	0	write_fn (G_OUTPUT_STREAM (stream), buffer, count, NULL, error);
164	0	}
165
166		static GPollableReturn
167		g_pollable_output_stream_default_writev_nonblocking (GPollableOutputStream *stream,
168		const GOutputVector *vectors,
169		gsize n_vectors,
170		gsize *bytes_written,
171		GError **error)
172	0	{
173	0	gsize _bytes_written = 0;
174	0	GPollableOutputStreamInterface *iface = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream);
175	0	gsize i;
176	0	GError *err = NULL;
177
178	0	for (i = 0; i < n_vectors; i++)
179	0	{
180	0	gssize res;
181
182		/* Would we overflow here? In that case simply return and let the caller
183		* handle this like a short write */
184	0	if (_bytes_written > G_MAXSIZE - vectors[i].size)
185	0	break;
186
187	0	res = iface->write_nonblocking (stream, vectors[i].buffer, vectors[i].size, &err);
188	0	if (res == -1)
189	0	{
190	0	if (bytes_written)
191	0	*bytes_written = _bytes_written;
192
193		/* If something was written already we handle this like a short
194		* write and assume that the next call would either give the same
195		* error again or successfully finish writing without errors or data
196		* loss
197		*/
198	0	if (_bytes_written > 0)
199	0	{
200	0	g_clear_error (&err);
201	0	return G_POLLABLE_RETURN_OK;
202	0	}
203	0	else if (g_error_matches (err, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
204	0	{
205	0	g_clear_error (&err);
206	0	return G_POLLABLE_RETURN_WOULD_BLOCK;
207	0	}
208	0	else
209	0	{
210	0	g_propagate_error (error, err);
211	0	return G_POLLABLE_RETURN_FAILED;
212	0	}
213	0	}
214
215	0	_bytes_written += res;
216		/* if we had a short write break the loop here */
217	0	if ((gsize) res < vectors[i].size)
218	0	break;
219	0	}
220
221	0	if (bytes_written)
222	0	*bytes_written = _bytes_written;
223
224	0	return G_POLLABLE_RETURN_OK;
225	0	}
226
227		/**
228		* g_pollable_output_stream_write_nonblocking:
229		* @stream: a #GPollableOutputStream
230		* @buffer: (array length=count) (element-type guint8): a buffer to write
231		* data from
232		* @count: the number of bytes you want to write
233		* @cancellable: (nullable): a #GCancellable, or %NULL
234		* @error: #GError for error reporting, or %NULL to ignore.
235		*
236		* Attempts to write up to @count bytes from @buffer to @stream, as
237		* with g_output_stream_write(). If @stream is not currently writable,
238		* this will immediately return %G_IO_ERROR_WOULD_BLOCK, and you can
239		* use g_pollable_output_stream_create_source() to create a #GSource
240		* that will be triggered when @stream is writable.
241		*
242		* Note that since this method never blocks, you cannot actually
243		* use @cancellable to cancel it. However, it will return an error
244		* if @cancellable has already been cancelled when you call, which
245		* may happen if you call this method after a source triggers due
246		* to having been cancelled.
247		*
248		* Also note that if %G_IO_ERROR_WOULD_BLOCK is returned some underlying
249		* transports like D/TLS require that you re-send the same @buffer and
250		* @count in the next write call.
251		*
252		* Virtual: write_nonblocking
253		* Returns: the number of bytes written, or -1 on error (including
254		* %G_IO_ERROR_WOULD_BLOCK).
255		*/
256		gssize
257		g_pollable_output_stream_write_nonblocking (GPollableOutputStream *stream,
258		const void *buffer,
259		gsize count,
260		GCancellable *cancellable,
261		GError **error)
262	0	{
263	0	gssize res;
264
265	0	g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), -1);
266	0	g_return_val_if_fail (buffer != NULL, 0);
267
268	0	if (g_cancellable_set_error_if_cancelled (cancellable, error))
269	0	return -1;
270
271	0	if (count == 0)
272	0	return 0;
273
274	0	if (((gssize) count) < 0)
275	0	{
276	0	g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
277	0	_("Too large count value passed to %s"), G_STRFUNC);
278	0	return -1;
279	0	}
280
281	0	if (cancellable)
282	0	g_cancellable_push_current (cancellable);
283
284	0	res = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
285	0	write_nonblocking (stream, buffer, count, error);
286
287	0	if (cancellable)
288	0	g_cancellable_pop_current (cancellable);
289
290	0	return res;
291	0	}
292
293		/**
294		* g_pollable_output_stream_writev_nonblocking:
295		* @stream: a #GPollableOutputStream
296		* @vectors: (array length=n_vectors): the buffer containing the #GOutputVectors to write.
297		* @n_vectors: the number of vectors to write
298		* @bytes_written: (out) (optional): location to store the number of bytes that were
299		* written to the stream
300		* @cancellable: (nullable): a #GCancellable, or %NULL
301		* @error: #GError for error reporting, or %NULL to ignore.
302		*
303		* Attempts to write the bytes contained in the @n_vectors @vectors to @stream,
304		* as with g_output_stream_writev(). If @stream is not currently writable,
305		* this will immediately return %@G_POLLABLE_RETURN_WOULD_BLOCK, and you can
306		* use g_pollable_output_stream_create_source() to create a #GSource
307		* that will be triggered when @stream is writable. @error will not be
308		* set in that case.
309		*
310		* Note that since this method never blocks, you cannot actually
311		* use @cancellable to cancel it. However, it will return an error
312		* if @cancellable has already been cancelled when you call, which
313		* may happen if you call this method after a source triggers due
314		* to having been cancelled.
315		*
316		* Also note that if %G_POLLABLE_RETURN_WOULD_BLOCK is returned some underlying
317		* transports like D/TLS require that you re-send the same @vectors and
318		* @n_vectors in the next write call.
319		*
320		* Virtual: writev_nonblocking
321		*
322		* Returns: %@G_POLLABLE_RETURN_OK on success, %G_POLLABLE_RETURN_WOULD_BLOCK
323		* if the stream is not currently writable (and @error is not set), or
324		* %G_POLLABLE_RETURN_FAILED if there was an error in which case @error will
325		* be set.
326		*
327		* Since: 2.60
328		*/
329		GPollableReturn
330		g_pollable_output_stream_writev_nonblocking (GPollableOutputStream *stream,
331		const GOutputVector *vectors,
332		gsize n_vectors,
333		gsize *bytes_written,
334		GCancellable *cancellable,
335		GError **error)
336	0	{
337	0	GPollableOutputStreamInterface *iface;
338	0	GPollableReturn res;
339	0	gsize _bytes_written = 0;
340
341	0	if (bytes_written)
342	0	*bytes_written = 0;
343
344	0	g_return_val_if_fail (G_IS_POLLABLE_OUTPUT_STREAM (stream), G_POLLABLE_RETURN_FAILED);
345	0	g_return_val_if_fail (vectors != NULL \|\| n_vectors == 0, G_POLLABLE_RETURN_FAILED);
346	0	g_return_val_if_fail (cancellable == NULL \|\| G_IS_CANCELLABLE (cancellable), G_POLLABLE_RETURN_FAILED);
347	0	g_return_val_if_fail (error == NULL \|\| *error == NULL, G_POLLABLE_RETURN_FAILED);
348
349	0	if (g_cancellable_set_error_if_cancelled (cancellable, error))
350	0	return G_POLLABLE_RETURN_FAILED;
351
352	0	if (n_vectors == 0)
353	0	return G_POLLABLE_RETURN_OK;
354
355	0	iface = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream);
356	0	g_return_val_if_fail (iface->writev_nonblocking != NULL, G_POLLABLE_RETURN_FAILED);
357
358	0	if (cancellable)
359	0	g_cancellable_push_current (cancellable);
360
361	0	res = iface->
362	0	writev_nonblocking (stream, vectors, n_vectors, &_bytes_written, error);
363
364	0	if (cancellable)
365	0	g_cancellable_pop_current (cancellable);
366
367	0	if (res == G_POLLABLE_RETURN_FAILED)
368	0	g_warn_if_fail (error == NULL \|\| (error != NULL && !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK)));
369	0	else if (res == G_POLLABLE_RETURN_WOULD_BLOCK)
370	0	g_warn_if_fail (error == NULL \|\| *error == NULL);
371
372		/* in case of not-OK nothing must've been written */
373	0	g_warn_if_fail (res == G_POLLABLE_RETURN_OK \|\| _bytes_written == 0);
374
375	0	if (bytes_written)
376	0	*bytes_written = _bytes_written;
377
378	0	return res;
379	0	}