dbus/signal.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*
   3  * LADI Session Handler (ladish)
   4  *
   5  * Copyright (C) 2009 Nedko Arnaudov <nedko@arnaudov.name>
   6  * Copyright (C) 2008 Juuso Alasuutari <juuso.alasuutari@gmail.com>
   7  *
   8  **************************************************************************
   9  * This file contains D-Bus signal helpers
  10  **************************************************************************
  11  *
  12  * Licensed under the Academic Free License version 2.1
  13  *
  14  * LADI Session Handler is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * LADI Session Handler is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
  26  * or write to the Free Software Foundation, Inc.,
  27  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  28  */
  29
  30 #include "../common.h"
  31 #include <stdarg.h>
  32 #include "helpers.h"
  33
  34 static void dbus_signal_send(DBusConnection * connection_ptr, DBusMessage * message_ptr)
  35 {
  36   if (!dbus_connection_send(connection_ptr, message_ptr, NULL))
  37   {
  38     log_error("Ran out of memory trying to queue signal");
  39   }
  40
  41   dbus_connection_flush(connection_ptr);
  42 }
  43
  44 void
  45 dbus_signal_emit(
  46   DBusConnection * connection_ptr,
  47   const char * path,
  48   const char * interface,
  49   const char * name,
  50   const char * signature,
  51   ...)
  52 {
  53   DBusMessage * message_ptr;
  54   va_list ap;
  55   int type;
  56   DBusSignatureIter sig_iter;
  57   DBusMessageIter iter;
  58   void * parameter_ptr;
  59
  60   log_debug("Sending signal %s.%s from %s", interface, name, path);
  61
  62   va_start(ap, signature);
  63
  64   if (signature != NULL)
  65   {
  66     if (!dbus_signature_validate(signature, NULL))
  67     {
  68       log_error("signature '%s' is invalid", signature);
  69       goto exit;
  70     }
  71
  72     dbus_signature_iter_init(&sig_iter, signature);
  73
  74     message_ptr = dbus_message_new_signal(path, interface, name);
  75     if (message_ptr == NULL)
  76     {
  77       log_error("dbus_message_new_signal() failed.");
  78       goto exit;
  79     }
  80
  81     dbus_message_iter_init_append(message_ptr, &iter);
  82
  83     while (*signature != '\0')
  84     {
  85       type = dbus_signature_iter_get_current_type(&sig_iter);
  86       if (!dbus_type_is_basic(type))
  87       {
  88         log_error("non-basic input parameter '%c' (%d)", *signature, type);
  89         goto unref;
  90       }
  91
  92       parameter_ptr = va_arg(ap, void *);
  93
  94       if (!dbus_message_iter_append_basic(&iter, type, parameter_ptr))
  95       {
  96         log_error("dbus_message_iter_append_basic() failed.");
  97         goto unref;
  98       }
  99
 100       dbus_signature_iter_next(&sig_iter);
 101       signature++;
 102     }
 103
 104     dbus_signal_send(connection_ptr, message_ptr);
 105
 106   unref:
 107     dbus_message_unref(message_ptr);
 108   }
 109   else
 110   {
 111     message_ptr = va_arg(ap, DBusMessage *);
 112     dbus_signal_send(connection_ptr, message_ptr);
 113   }
 114
 115 exit:
 116   va_end(ap);
 117 }