gio/gpollableoutputstream.h

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2010 Red Hat, Inc.
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-or-later
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #ifndef __G_POLLABLE_OUTPUT_STREAM_H__
  22 #define __G_POLLABLE_OUTPUT_STREAM_H__
  23
  24 #if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
  25 #error "Only <gio/gio.h> can be included directly."
  26 #endif
  27
  28 #include <gio/gio.h>
  29
  30 G_BEGIN_DECLS
  31
  32 #define G_TYPE_POLLABLE_OUTPUT_STREAM               (g_pollable_output_stream_get_type ())
  33 #define G_POLLABLE_OUTPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStream))
  34 #define G_IS_POLLABLE_OUTPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM))
  35 #define G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStreamInterface))
  36
  37 typedef struct _GPollableOutputStreamInterface GPollableOutputStreamInterface;
  38
  39 /**
  40  * GPollableOutputStreamInterface:
  41  * @g_iface: The parent interface.
  42  * @can_poll: Checks if the #GPollableOutputStream instance is actually pollable
  43  * @is_writable: Checks if the stream is writable
  44  * @create_source: Creates a #GSource to poll the stream
  45  * @write_nonblocking: Does a non-blocking write or returns
  46  *   %G_IO_ERROR_WOULD_BLOCK
  47  * @writev_nonblocking: Does a vectored non-blocking write, or returns
  48  *   %G_POLLABLE_RETURN_WOULD_BLOCK
  49  *
  50  * The interface for pollable output streams.
  51  *
  52  * The default implementation of @can_poll always returns %TRUE.
  53  *
  54  * The default implementation of @write_nonblocking calls
  55  * g_pollable_output_stream_is_writable(), and then calls
  56  * g_output_stream_write() if it returns %TRUE. This means you only
  57  * need to override it if it is possible that your @is_writable
  58  * implementation may return %TRUE when the stream is not actually
  59  * writable.
  60  *
  61  * The default implementation of @writev_nonblocking calls
  62  * g_pollable_output_stream_write_nonblocking() for each vector, and converts
  63  * its return value and error (if set) to a #GPollableReturn. You should
  64  * override this where possible to avoid having to allocate a #GError to return
  65  * %G_IO_ERROR_WOULD_BLOCK.
  66  *
  67  * Since: 2.28
  68  */
  69 struct _GPollableOutputStreamInterface
  70 {
  71   GTypeInterface g_iface;
  72
  73   /* Virtual Table */
  74   gboolean     (*can_poll)          (GPollableOutputStream  *stream);
  75
  76   gboolean     (*is_writable)       (GPollableOutputStream  *stream);
  77   GSource *    (*create_source)     (GPollableOutputStream  *stream,
  78                                      GCancellable           *cancellable);
  79   gssize       (*write_nonblocking) (GPollableOutputStream  *stream,
  80                                      const void             *buffer,
  81                                      gsize                   count,
  82                                      GError                **error);
  83   GPollableReturn (*writev_nonblocking) (GPollableOutputStream  *stream,
  84                                          const GOutputVector    *vectors,
  85                                          gsize                   n_vectors,
  86                                          gsize                  *bytes_written,
  87                                          GError                **error);
  88 };
  89
  90 GIO_AVAILABLE_IN_ALL
  91 GType    g_pollable_output_stream_get_type          (void) G_GNUC_CONST;
  92
  93 GIO_AVAILABLE_IN_ALL
  94 gboolean g_pollable_output_stream_can_poll          (GPollableOutputStream  *stream);
  95
  96 GIO_AVAILABLE_IN_ALL
  97 gboolean g_pollable_output_stream_is_writable       (GPollableOutputStream  *stream);
  98 GIO_AVAILABLE_IN_ALL
  99 GSource *g_pollable_output_stream_create_source     (GPollableOutputStream  *stream,
 100                                                      GCancellable           *cancellable);
 101
 102 GIO_AVAILABLE_IN_ALL
 103 gssize   g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
 104                                                      const void             *buffer,
 105                                                      gsize                   count,
 106                                                      GCancellable           *cancellable,
 107                                                      GError                **error);
 108
 109 GIO_AVAILABLE_IN_2_60
 110 GPollableReturn g_pollable_output_stream_writev_nonblocking (GPollableOutputStream  *stream,
 111                                                              const GOutputVector    *vectors,
 112                                                              gsize                   n_vectors,
 113                                                              gsize                  *bytes_written,
 114                                                              GCancellable           *cancellable,
 115                                                              GError                **error);
 116
 117 G_END_DECLS
 118
 119
 120 #endif /* __G_POLLABLE_OUTPUT_STREAM_H__ */