[seed] Start implementing the method call machinery for DBus module

[Robert Carr <racarr src gnome org>]

commit d7f083d8f653f333501b58765ad1460db0aaff1b
Author: Robert Carr <racarr svn gnome org>
Date:   Sat May 9 17:46:09 2009 -0400

    Start implementing the method call machinery for DBus module
---
 modules/dbus/module.c |  190 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 190 insertions(+), 0 deletions(-)

diff --git a/modules/dbus/module.c b/modules/dbus/module.c
index 1a6599d..b0cf493 100644
--- a/modules/dbus/module.c
+++ b/modules/dbus/module.c
@@ -24,6 +24,196 @@ get_bus_type_from_object (SeedContext ctx,
   
   return seed_value_to_int (ctx, jsbus_type, exception);
 }
+
+static gboolean
+bus_check(SeedContext ctx, DBusBusType bus_type, SeedException *exception)
+{
+    gboolean bus_weakref_added;
+    DBusConnection **bus_connection;
+
+    bus_weakref_added = bus_type == DBUS_BUS_SESSION ? session_bus_weakref_added :
+        system_bus_weakref_added;
+
+    bus_connection = bus_type == DBUS_BUS_SESSION ? &session_bus : &system_bus;
+
+    /* This is all done lazily only if a dbus-related method is actually invoked */
+
+    if (!bus_weakref_added) {
+        big_dbus_add_bus_weakref(bus_type, bus_connection);
+    }
+
+    if (*bus_connection == NULL)
+        big_dbus_try_connecting_now(bus_type); /* force a synchronous connection attempt */
+
+    /* Throw exception if connection attempt failed */
+    if (*bus_connection == NULL) {
+        const char *bus_type_name = bus_type == DBUS_BUS_SESSION ? "session" : "system";
+        seed_make_exception(ctx, exception, "BusError",
+			    "Not connected to %s message bus", 
+			    bus_type_name);
+	return FALSE;
+    }
+
+    return TRUE;
+}
+
+static DBusMessage*
+prepare_call(SeedContext ctx,
+	     SeedObject obj,
+             guint        argc,
+             SeedValue *argv,
+             DBusBusType  bus_type,
+	     SeedException *exception)
+{
+    DBusMessage *message;
+    const char *bus_name;
+    const char *path;
+    const char *interface;
+    const char *method;
+    gboolean    auto_start;
+    const char *out_signature;
+    const char *in_signature;
+    DBusMessageIter arg_iter;
+    DBusSignatureIter sig_iter;
+
+    if (!bus_check(ctx, bus_type, exception))
+        return NULL;
+
+    bus_name = seed_value_to_string (ctx, argv[0], exception);
+    if (bus_name == NULL)
+      return NULL;
+
+    path = seed_value_to_string (ctx, argv[1], exception);
+    if (path == NULL)
+      return NULL;
+
+    if (seed_value_is_null(ctx, argv[2])) {
+        interface = NULL;
+    } else {
+      interface = seed_value_to_string (ctx, argv[2], exception);
+      if (interface == NULL)
+	return NULL; /* exception was set */
+    }
+
+    method = seed_value_to_string (ctx, argv[3], exception);
+    if (method == NULL)
+        return NULL;
+
+    out_signature = seed_value_to_string (ctx, argv[4], exception);
+    if (out_signature == NULL)
+        return NULL;
+
+    in_signature = seed_value_to_string (ctx, argv[5], exception);
+    if (in_signature == NULL)
+        return NULL;
+
+    g_assert(bus_name && path && method && in_signature && out_signature);
+
+    auto_start = seed_value_to_boolean(ctx, argv[6], exception);
+
+    /* FIXME should validate the bus_name, path, interface, method really, but
+     * we should just not write buggy JS ;-)
+     */
+
+    message = dbus_message_new_method_call(bus_name,
+                                           path,
+                                           interface,
+                                           method);
+    if (message == NULL)
+      {
+	seed_make_exception (ctx, exception, "DBusError", "Could not create new method call. (OOM?)");
+	return NULL;
+      }
+
+    dbus_message_set_auto_start(message, auto_start);
+
+    dbus_message_iter_init_append(message, &arg_iter);
+
+    if (in_signature)
+        dbus_signature_iter_init(&sig_iter, in_signature);
+    else
+        dbus_signature_iter_init(&sig_iter, "a{sv}");
+
+    if (!seed_js_values_to_dbus(ctx, 0, argv[8], &arg_iter, &sig_iter, exception)) {
+      //  big_debug(BIG_DEBUG_JS_DBUS, "Failed to marshal call from JS to dbus");
+        dbus_message_unref(message);
+        return NULL;
+    }
+
+    return message;
+}
+
+static gboolean
+complete_call(SeedContext ctx,
+	      SeedValue *retval, 
+              DBusMessage *reply,
+              DBusError   *derror,
+	      SeedException *exception)
+{
+    DBusMessageIter arg_iter;
+    GArray *ret_values;
+    int array_length;
+
+    if (dbus_error_is_set(derror))
+      {
+	//        big_debug(BIG_DEBUG_JS_DBUS,
+	//          "Error sending call: %s: %s",
+	//          derror->name, derror->message);
+	seed_make_exception(ctx, exception, "DBusError",
+			    "DBus error: %s: %s",
+			    derror->name,
+			    derror->message);
+	dbus_error_free(derror);
+	return FALSE;
+    }
+
+    if (reply == NULL) 
+      {
+	// big_debug(BIG_DEBUG_JS_DBUS,
+	//        "No reply received to call");
+	return FALSE;
+      }
+
+    if (dbus_message_get_type(reply) == DBUS_MESSAGE_TYPE_ERROR) 
+      {
+	seed_make_exception (ctx, exception, "DBusError",
+			     "DBus error: %s: %s",
+			     derror->name,
+			     derror->message);
+        dbus_error_free(derror);
+
+	return FALSE;
+    }
+
+    dbus_message_iter_init(reply, &arg_iter);
+    if (!seed_js_values_from_dbus(ctx, &arg_iter, &ret_values, exception)) 
+      {
+	//        big_debug(BIG_DEBUG_JS_DBUS, "Failed to marshal dbus call reply back to JS");
+	return FALSE;
+      }
+
+    g_assert(ret_values != NULL);
+    // TODO: I AM HERE
+
+    array_length = ret_values->len;
+    if (array_length == 1) {
+        /* If the array only has one element return that element alone */
+      *retval = g_array_index (ret_values, SeedValue, 0);
+    } else {
+        /* Otherwise return an array with all the return values. The
+         * funny assignment is to avoid creating a temporary JSObject
+         * we'd need to root
+         */
+      *retval = seed_make_array (ctx, ret_values->data, array_length, exception);
+    }
+
+    g_array_free (ret_values, TRUE);    
+
+    seed_js_add_dbus_props(ctx, reply, *retval);
+
+    return TRUE;
+}
+
 			  
 
 static SeedValue