[libgtop/wip/libgtop-ng] Added initial almost-empty implementation of dbus service

[Robert Roth <robertroth src gnome org>]

commit 2ab7ad075cb00443065ad08e09980fb5f96ed074
Author: Robert Roth <robert roth off gmail com>
Date:   Mon Sep 2 02:55:31 2013 +0300

    Added initial almost-empty implementation of dbus service

 .gitignore                  |    3 +
 Makefile.am                 |    2 +-
 configure.ac                |   10 ++-
 service/Makefile.am         |    8 ++
 service/gtop-dbus-service.c |  207 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 228 insertions(+), 2 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index f0b1704..98f3a93 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
+service/*.o
+service/.deps
+service/gtop-dbus-service
 sysdeps/Makefile
 sysdeps/Makefile.in
 sysdeps/*/Makefile
diff --git a/Makefile.am b/Makefile.am
index eca41ff..1e6a334 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -6,7 +6,7 @@ else
 EXAMPLES_DIR = 
 endif
 
-SUBDIRS = po misc include sysdeps lib src $(EXAMPLES_DIR) doc
+SUBDIRS = po misc include sysdeps lib src $(EXAMPLES_DIR) doc service
 
 libgtopinclude_HEADERS = glibtop.h libgtopconfig.h
 libgtopincludedir = $(includedir)/libgtop-2.0
diff --git a/configure.ac b/configure.ac
index dc4e654..b6cf7a4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -226,7 +226,7 @@ GLIB_DEFINE_LOCALEDIR([GTOPLOCALEDIR])
 AC_PATH_XTRA
 
 dnl For Solaris
-dnl Please don't move this before AC_PATH_XTRA
+dnl Please don\'t move this before AC_PATH_XTRA
 AC_CHECK_FUNC(gethostbyname,,[AC_CHECK_LIB(nsl,gethostbyname)])
 AC_CHECK_FUNC(connect,,[AC_CHECK_LIB(socket,connect)])
 AC_CHECK_FUNC(inet_aton,,[AC_CHECK_LIB(resolv,inet_aton)])
@@ -364,12 +364,20 @@ AC_SUBST(sysdeps_suid_lib)
 AC_SUBST(server_programs)
 
 GTK_DOC_CHECK(1.4)
+GLIB_REQUIRED=2.37.3
+
+PKG_CHECK_MODULES(GTOP_DBUS,
+   glib-2.0 >= $GLIB_REQUIRED
+   gio-2.0 >= $GLIB_REQUIRED
+   gio-unix-2.0 >= $GLIB_REQUIRED
+)
 
 AC_CONFIG_FILES([
 Makefile
 libgtop.spec
 po/Makefile.in
 misc/Makefile
+service/Makefile
 include/Makefile
 include/glibtop/Makefile
 sysdeps/Makefile
diff --git a/service/Makefile.am b/service/Makefile.am
new file mode 100644
index 0000000..5277f35
--- /dev/null
+++ b/service/Makefile.am
@@ -0,0 +1,8 @@
+LINK = $(LIBTOOL) --mode=link $(CC) $(CFLAGS) $(AM_LDFLAGS) -o $@
+
+noinst_PROGRAMS = gtop-dbus-service
+
+AM_CPPFLAGS= ${GTOP_DBUS_CFLAGS}
+
+gtop_dbus_service_SOURCES = gtop-dbus-service.c
+gtop_dbus_service_LDADD = $(GTOP_DBUS_LIBS)
diff --git a/service/gtop-dbus-service.c b/service/gtop-dbus-service.c
new file mode 100644
index 0000000..e690919
--- /dev/null
+++ b/service/gtop-dbus-service.c
@@ -0,0 +1,207 @@
+#include <gio/gio.h>
+#include <stdlib.h>
+#include <config.h>
+#include <glib.h>
+
+#define MSG_PREFIX "[libgtop dbus server] "
+
+static const gchar service[] = "org.gnome.gtopServer";
+
+static const gchar object_name[] = "/org/gnome/gtopServer";
+/* ---------------------------------------------------------------------------------------------------- */
+
+static GDBusNodeInfo *introspection_data = NULL;
+
+/* Introspection data for the service we are exporting */
+static const gchar introspection_xml[] =
+  "<node>"
+  "  <interface name='org.gnome.gtop'>"
+  "    <property type='s' name='Version' access='read'/>"
+  "  </interface>"
+  "</node>";
+
+/** 
+ * Handle a call to a method.  (Parameters should be obvious.)
+ */
+static void
+handle_method_call (GDBusConnection       *connection,
+                    const gchar           *sender,
+                    const gchar           *object_path,
+                    const gchar           *interface_name,
+                    const gchar           *method_name,
+                    GVariant              *parameters,
+                    GDBusMethodInvocation *invocation,
+                    gpointer               user_data)
+{
+#ifdef VERBOSE
+  gchar *paramstr = g_variant_print (parameters, TRUE);
+  fprintf (stderr, "[server 0] "
+           "handle_method_call (%p,\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",(invocation),%p)\n",
+           connection, sender, object_path, interface_name, method_name, 
+           paramstr, user_data);
+  g_free (paramstr);
+#endif
+
+  // Default: No such method
+     g_dbus_method_invocation_return_error (invocation,
+                                            G_IO_ERROR,
+                                            G_IO_ERROR_INVALID_ARGUMENT,
+                                            MSG_PREFIX "Invalid method: '%s'",
+                                            method_name);
+} // handle_method_call
+
+/**
+ * Handle a request to set a property.
+ */
+static gboolean
+handle_set_property (GDBusConnection  *connection,
+                     const gchar      *sender,
+                     const gchar      *object_path,
+                     const gchar      *interface_name,
+                     const gchar      *property_name,
+                     GVariant         *value,
+                     GError          **error,
+                     gpointer          user_data)
+{
+    // Print an optional log message
+#ifdef VERBOSE
+    gchar *valstr = g_variant_print (value, TRUE);
+    fprintf (stderr, MSG_PREFIX
+             "handle_set_property (%p,\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",(error),%p)\n",
+             connection, sender, object_path, interface_name, property_name, 
+             valstr, user_data);
+    g_free (valstr);
+#endif
+
+    g_set_error (error,
+                 G_IO_ERROR,
+                 G_IO_ERROR_FAILED,
+                 MSG_PREFIX "No such property: '%s'",
+                 property_name);
+    return 0;
+} // handle_set_property
+
+/**
+ * Handle a request for a property.  (Parameters should be obvious.)
+ */
+static GVariant *
+handle_get_property (GDBusConnection  *connection,
+                     const gchar      *sender,
+                     const gchar      *object_path,
+                     const gchar      *interface_name,
+                     const gchar      *property_name,
+                     GError          **error,
+                     gpointer          user_data)
+{
+  // Print an optional log message
+#ifdef VERBOSE
+    fprintf (stderr, MSG_PREFIX
+             "handle_get_property (%p,\"%s\",\"%s\",\"%s\",\"%s\",(error),%p)\n",
+             connection, sender, object_path, interface_name, property_name, 
+             user_data);
+#endif
+
+    if (g_strcmp0 (property_name, "Version") == 0)
+    {
+        return g_variant_new_string (LIBGTOP_VERSION);
+    }
+
+    // Anything else is an error.
+    else
+    {
+        g_set_error (error,
+                     G_IO_ERROR,
+                     G_IO_ERROR_FAILED,
+                     MSG_PREFIX "Invalid property '%s'",
+                     property_name);
+        return NULL;
+    } // unknown property
+} // handle_get_property
+
+/**
+ * What to do when the bus gets acquired.
+ */
+static void
+on_bus_acquired (GDBusConnection *connection,
+                 const gchar     *name,
+                 gpointer        user_data)
+{
+    static GDBusInterfaceVTable interface_vtable =
+      {
+        handle_method_call,
+        handle_get_property,
+        handle_set_property
+      };
+
+    guint registration_id;
+    GError *error = NULL;
+
+  // A bit of (optional) notification
+#ifdef VERBOSE
+    fprintf (stderr, MSG_PREFIX "on_bus_acquired (%p, \"%s\", %p)\n", 
+             connection, name, user_data);
+#endif
+
+    registration_id = 
+      g_dbus_connection_register_object (connection,
+                                         object_name,
+                                         introspection_data->interfaces[0],
+                                         &interface_vtable,
+                                         NULL,    // Optional user data
+                                         NULL,    // Func. for freeing user data
+                                         &error);
+
+} // on_bus_acquired
+
+static void
+on_name_acquired (GDBusConnection *connection,
+                  const gchar     *name,
+                  gpointer         user_data)
+{
+  // A bit of (optional) notification
+#ifdef VERBOSE
+    fprintf (stderr, MSG_PREFIX "on_name_acquired (%p, \"%s\", %p)\n", 
+             connection, name, user_data);
+#endif
+} // on_name_acquired
+
+static void
+on_name_lost (GDBusConnection *connection,
+              const gchar     *name,
+              gpointer         user_data)
+{
+  // A bit of (optional) notification
+#ifdef VERBOSE
+    fprintf (stderr, MSG_PREFIX "on_name_lost (%p, \"%s\", %p)\n", 
+             connection, name, user_data);
+#endif
+  // Things seem to have gone badly wrong, so give up
+    exit (1);
+} // on_name_lost
+
+int main ( int argc, char ** argv ) {
+    guint owner_id;
+    GMainLoop *loop;
+    
+    introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
+    
+    owner_id = g_bus_own_name (G_BUS_TYPE_SESSION,
+                               service,
+                               G_BUS_NAME_OWNER_FLAGS_NONE,
+                               on_bus_acquired,
+                               on_name_acquired,
+                               on_name_lost,
+                               NULL,
+                               NULL);
+                               
+    loop = g_main_loop_new (NULL, FALSE);
+    g_main_loop_run (loop);
+    
+    // Tell the bus that we're done with the name
+    g_bus_unown_name (owner_id);
+
+    // Clean up after ourselves
+    g_dbus_node_info_unref (introspection_data);
+  
+    return 0;
+}