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_INPUT_STREAM_H__
      22  #define __G_POLLABLE_INPUT_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_INPUT_STREAM               (g_pollable_input_stream_get_type ())
      33  #define G_POLLABLE_INPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStream))
      34  #define G_IS_POLLABLE_INPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_INPUT_STREAM))
      35  #define G_POLLABLE_INPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStreamInterface))
      36  
      37  typedef struct _GPollableInputStreamInterface GPollableInputStreamInterface;
      38  
      39  /**
      40   * GPollableInputStreamInterface:
      41   * @g_iface: The parent interface.
      42   * @can_poll: Checks if the #GPollableInputStream instance is actually pollable
      43   * @is_readable: Checks if the stream is readable
      44   * @create_source: Creates a #GSource to poll the stream
      45   * @read_nonblocking: Does a non-blocking read or returns
      46   *   %G_IO_ERROR_WOULD_BLOCK
      47   *
      48   * The interface for pollable input streams.
      49   *
      50   * The default implementation of @can_poll always returns %TRUE.
      51   *
      52   * The default implementation of @read_nonblocking calls
      53   * g_pollable_input_stream_is_readable(), and then calls
      54   * g_input_stream_read() if it returns %TRUE. This means you only need
      55   * to override it if it is possible that your @is_readable
      56   * implementation may return %TRUE when the stream is not actually
      57   * readable.
      58   *
      59   * Since: 2.28
      60   */
      61  struct _GPollableInputStreamInterface
      62  {
      63    GTypeInterface g_iface;
      64  
      65    /* Virtual Table */
      66    gboolean     (*can_poll)         (GPollableInputStream  *stream);
      67  
      68    gboolean     (*is_readable)      (GPollableInputStream  *stream);
      69    GSource *    (*create_source)    (GPollableInputStream  *stream,
      70  				    GCancellable          *cancellable);
      71    gssize       (*read_nonblocking) (GPollableInputStream  *stream,
      72  				    void                  *buffer,
      73  				    gsize                  count,
      74  				    GError               **error);
      75  };
      76  
      77  GIO_AVAILABLE_IN_ALL
      78  GType    g_pollable_input_stream_get_type         (void) G_GNUC_CONST;
      79  
      80  GIO_AVAILABLE_IN_ALL
      81  gboolean g_pollable_input_stream_can_poll         (GPollableInputStream  *stream);
      82  
      83  GIO_AVAILABLE_IN_ALL
      84  gboolean g_pollable_input_stream_is_readable      (GPollableInputStream  *stream);
      85  GIO_AVAILABLE_IN_ALL
      86  GSource *g_pollable_input_stream_create_source    (GPollableInputStream  *stream,
      87  						   GCancellable          *cancellable);
      88  
      89  GIO_AVAILABLE_IN_ALL
      90  gssize   g_pollable_input_stream_read_nonblocking (GPollableInputStream  *stream,
      91  						   void                  *buffer,
      92  						   gsize                  count,
      93  						   GCancellable          *cancellable,
      94  						   GError               **error);
      95  
      96  G_END_DECLS
      97  
      98  
      99  #endif /* __G_POLLABLE_INPUT_STREAM_H__ */