gio/gpollableinputstream.h

   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 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, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20
  21 #ifndef __G_POLLABLE_INPUT_STREAM_H__
  22 #define __G_POLLABLE_INPUT_STREAM_H__
  23
  24 #include <gio/gio.h>
  25
  26 G_BEGIN_DECLS
  27
  28 #define G_TYPE_POLLABLE_INPUT_STREAM               (g_pollable_input_stream_get_type ())
  29 #define G_POLLABLE_INPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStream))
  30 #define G_IS_POLLABLE_INPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_INPUT_STREAM))
  31 #define G_POLLABLE_INPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStreamInterface))
  32
  33 /**
  34  * GPollableInputStream:
  35  *
  36  * An interface for a #GInputStream that can be polled for readability.
  37  *
  38  * Since: 2.28
  39  */
  40 typedef struct _GPollableInputStreamInterface GPollableInputStreamInterface;
  41
  42 /**
  43  * GPollableInputStreamInterface:
  44  * @g_iface: The parent interface.
  45  * @can_poll: Checks if the #GPollableInputStream instance is actually pollable
  46  * @is_readable: Checks if the stream is readable
  47  * @create_source: Creates a #GSource to poll the stream
  48  * @read_nonblocking: Does a non-blocking read or returns
  49  *   %G_IO_ERROR_WOULD_BLOCK
  50  *
  51  * The interface for pollable input streams.
  52  *
  53  * The default implementation of @can_poll always returns %TRUE.
  54  *
  55  * The default implementation of @read_nonblocking calls
  56  * g_pollable_input_stream_is_readable(), and then calls
  57  * g_input_stream_read() if it returns %TRUE. This means you only need
  58  * to override it if it is possible that your @is_readable
  59  * implementation may return %TRUE when the stream is not actually
  60  * readable.
  61  *
  62  * Since: 2.28
  63  */
  64 struct _GPollableInputStreamInterface
  65 {
  66   GTypeInterface g_iface;
  67
  68   /* Virtual Table */
  69   gboolean     (*can_poll)         (GPollableInputStream  *stream);
  70
  71   gboolean     (*is_readable)      (GPollableInputStream  *stream);
  72   GSource *    (*create_source)    (GPollableInputStream  *stream,
  73                                     GCancellable          *cancellable);
  74   gssize       (*read_nonblocking) (GPollableInputStream  *stream,
  75                                     void                  *buffer,
  76                                     gsize                  size,
  77                                     GError               **error);
  78 };
  79
  80 GType    g_pollable_input_stream_get_type         (void) G_GNUC_CONST;
  81
  82 gboolean g_pollable_input_stream_can_poll         (GPollableInputStream  *stream);
  83
  84 gboolean g_pollable_input_stream_is_readable      (GPollableInputStream  *stream);
  85 GSource *g_pollable_input_stream_create_source    (GPollableInputStream  *stream,
  86                                                    GCancellable          *cancellable);
  87
  88 gssize   g_pollable_input_stream_read_nonblocking (GPollableInputStream  *stream,
  89                                                    void                  *buffer,
  90                                                    gsize                  size,
  91                                                    GCancellable          *cancellable,
  92                                                    GError               **error);
  93
  94 /* Helper method for stream implementations */
  95 GSource *g_pollable_source_new                    (GObject               *pollable_stream);
  96
  97 G_END_DECLS
  98
  99
 100 #endif /* __G_POLLABLE_INPUT_STREAM_H__ */
 101