gio/gsocketconnectable.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2008 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, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "config.h"
  20 #include "gsocketconnectable.h"
  21 #include "glibintl.h"
  22
  23
  24 /**
  25  * SECTION:gsocketconnectable
  26  * @short_description: Interface for potential socket endpoints
  27  * @include: gio/gio.h
  28  *
  29  * Objects that describe one or more potential socket endpoints
  30  * implement #GSocketConnectable. Callers can then use
  31  * g_socket_connectable_enumerate() to get a #GSocketAddressEnumerator
  32  * to try out each socket address in turn until one succeeds, as shown
  33  * in the sample code below.
  34  *
  35  * |[<!-- language="C" -->
  36  * MyConnectionType *
  37  * connect_to_host (const char    *hostname,
  38  *                  guint16        port,
  39  *                  GCancellable  *cancellable,
  40  *                  GError       **error)
  41  * {
  42  *   MyConnection *conn = NULL;
  43  *   GSocketConnectable *addr;
  44  *   GSocketAddressEnumerator *enumerator;
  45  *   GSocketAddress *sockaddr;
  46  *   GError *conn_error = NULL;
  47  *
  48  *   addr = g_network_address_new (hostname, port);
  49  *   enumerator = g_socket_connectable_enumerate (addr);
  50  *   g_object_unref (addr);
  51  *
  52  *   // Try each sockaddr until we succeed. Record the first connection error,
  53  *   // but not any further ones (since they'll probably be basically the same
  54  *   // as the first).
  55  *   while (!conn && (sockaddr = g_socket_address_enumerator_next (enumerator, cancellable, error))
  56  *     {
  57  *       conn = connect_to_sockaddr (sockaddr, conn_error ? NULL : &conn_error);
  58  *       g_object_unref (sockaddr);
  59  *     }
  60  *   g_object_unref (enumerator);
  61  *
  62  *   if (conn)
  63  *     {
  64  *       if (conn_error)
  65  *         {
  66  *           // We couldn't connect to the first address, but we succeeded
  67  *           // in connecting to a later address.
  68  *           g_error_free (conn_error);
  69  *         }
  70  *       return conn;
  71  *     }
  72  *   else if (error)
  73  *     {
  74  *       /// Either initial lookup failed, or else the caller cancelled us.
  75  *       if (conn_error)
  76  *         g_error_free (conn_error);
  77  *       return NULL;
  78  *     }
  79  *   else
  80  *     {
  81  *       g_error_propagate (error, conn_error);
  82  *       return NULL;
  83  *     }
  84  * }
  85  * ]|
  86  */
  87
  88
  89 typedef GSocketConnectableIface GSocketConnectableInterface;
  90 G_DEFINE_INTERFACE (GSocketConnectable, g_socket_connectable, G_TYPE_OBJECT)
  91
  92 static void
  93 g_socket_connectable_default_init (GSocketConnectableInterface *iface)
  94 {
  95 }
  96
  97 /**
  98  * g_socket_connectable_enumerate:
  99  * @connectable: a #GSocketConnectable
 100  *
 101  * Creates a #GSocketAddressEnumerator for @connectable.
 102  *
 103  * Returns: (transfer full): a new #GSocketAddressEnumerator.
 104  *
 105  * Since: 2.22
 106  */
 107 GSocketAddressEnumerator *
 108 g_socket_connectable_enumerate (GSocketConnectable *connectable)
 109 {
 110   GSocketConnectableIface *iface;
 111
 112   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
 113
 114   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
 115
 116   return (* iface->enumerate) (connectable);
 117 }
 118
 119 /**
 120  * g_socket_connectable_proxy_enumerate:
 121  * @connectable: a #GSocketConnectable
 122  *
 123  * Creates a #GSocketAddressEnumerator for @connectable that will
 124  * return #GProxyAddresses for addresses that you must connect
 125  * to via a proxy.
 126  *
 127  * If @connectable does not implement
 128  * g_socket_connectable_proxy_enumerate(), this will fall back to
 129  * calling g_socket_connectable_enumerate().
 130  *
 131  * Returns: (transfer full): a new #GSocketAddressEnumerator.
 132  *
 133  * Since: 2.26
 134  */
 135 GSocketAddressEnumerator *
 136 g_socket_connectable_proxy_enumerate (GSocketConnectable *connectable)
 137 {
 138   GSocketConnectableIface *iface;
 139
 140   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
 141
 142   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
 143
 144   if (iface->proxy_enumerate)
 145     return (* iface->proxy_enumerate) (connectable);
 146   else
 147     return (* iface->enumerate) (connectable);
 148 }
 149
 150 /**
 151  * g_socket_connectable_to_string:
 152  * @connectable: a #GSocketConnectable
 153  *
 154  * Format a #GSocketConnectable as a string. This is a human-readable format for
 155  * use in debugging output, and is not a stable serialization format. It is not
 156  * suitable for use in user interfaces as it exposes too much information for a
 157  * user.
 158  *
 159  * If the #GSocketConnectable implementation does not support string formatting,
 160  * the implementation’s type name will be returned as a fallback.
 161  *
 162  * Returns: (transfer full): the formatted string
 163  *
 164  * Since: 2.48
 165  */
 166 gchar *
 167 g_socket_connectable_to_string (GSocketConnectable *connectable)
 168 {
 169   GSocketConnectableIface *iface;
 170
 171   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
 172
 173   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
 174
 175   if (iface->to_string != NULL)
 176     return iface->to_string (connectable);
 177   else
 178     return g_strdup (G_OBJECT_TYPE_NAME (connectable));
 179 }