Engine for live queries to calendars. A query object watches a CalBackend

2001-03-29  Federico Mena Quintero  <federico@ximian.com>

	Engine for live queries to calendars.  A query object watches a
	CalBackend in the PCS and is otherwise completely separate from
	it; backends need to do nothing to support live queries.  Right
	now we have the following functions:

		(get-vtype)

			Returns a string indicating the type of component
			(VEVENT, VTODO, VJOURNAL, VFREEBUSY, VTIMEZONE,
			UNKNOWN).

		(occur-in-time-range? START END)

			START - int, time_t start of the time range
			END - int, time_t end of the time range

			Returns a boolean indicating whether the component
			has any occurrences in the specified time range.

	* idl/evolution-calendar.idl (Cal::getQuery): New method that
	initiates a live query.
	(Query): New interface for a handle to a live query.
	(QueryListener): New interface for a listener to changes in a live
	query.

	* pcs/query.[ch]: New files with the live query engine.

	* pcs/cal-backend.h (CalBackendClass): Added notification signals
	so that the query system can catch them.
	(CalBackendClass): New virtual method ::get_load_state().

	* pcs/cal-backend.c (cal_backend_opened):
	(cal_backend_obj_updated):
	(cal_backend_obj_updated): New functions to emit the notification
	signals; to be used only by backend implementations.
	(cal_backend_get_load_state): New function.

	* pcs/cal-backend-file.c (notify_update): Call
	cal_backend_obj_updated().
	(notify_remove): Call call_backend_obj_removed().
	(open_cal): Free the icalcomp if it is not of the correct type.
	(cal_backend_file_get_load_state): Implemented new method.

	* pcs/cal-backend-db.c (cal_backend_db_update_object): Call
	cal_backend_obj_updated().
	(cal_backend_db_remove_object): Call cal_backend_obj_removed().
	(cal_backend_db_get_load_state): Implemented new method.

	* pcs/cal.c (Cal_get_query): Implementation of the ::getQuery()
	method.

svn path=/trunk/; revision=9013

1 files changed, 30 insertions, 1 deletions

diff --git a/calendar/pcs/cal-backend-file.c b/calendar/pcs/cal-backend-file.c
index b3b3196324..a624db9f12 100644
--- a/calendar/pcs/cal-backend-file.c
+++ b/calendar/pcs/cal-backend-file.c
@@ -69,6 +69,7 @@ static GnomeVFSURI *cal_backend_file_get_uri (CalBackend *backend);
 static void cal_backend_file_add_cal (CalBackend *backend, Cal *cal);
 static CalBackendOpenStatus cal_backend_file_open (CalBackend *backend, GnomeVFSURI *uri,
 						   gboolean only_if_exists);
+static gboolean cal_backend_file_is_loaded (CalBackend *backend);
 
 static int cal_backend_file_get_n_objects (CalBackend *backend, CalObjType type);
 static char *cal_backend_file_get_object (CalBackend *backend, const char *uid);
@@ -143,6 +144,7 @@ cal_backend_file_class_init (CalBackendFileClass *class)
 	backend_class->get_uri = cal_backend_file_get_uri;
 	backend_class->add_cal = cal_backend_file_add_cal;
 	backend_class->open = cal_backend_file_open;
+	backend_class->is_loaded = cal_backend_file_is_loaded;
 	backend_class->get_n_objects = cal_backend_file_get_n_objects;
 	backend_class->get_object = cal_backend_file_get_object;
 	backend_class->get_type_by_uid = cal_backend_file_get_type_by_uid;
@@ -163,6 +165,14 @@ cal_backend_file_init (CalBackendFile *cbfile)
 
 	priv = g_new0 (CalBackendFilePrivate, 1);
 	cbfile->priv = priv;
+
+	priv->uri = NULL;
+	priv->clients = NULL;
+	priv->icalcomp = NULL;
+	priv->comp_uid_hash = NULL;
+	priv->events = NULL;
+	priv->todos = NULL;
+	priv->journals = NULL;
 }
 
 /* g_hash_table_foreach() callback to destroy a CalComponent */
@@ -640,8 +650,10 @@ open_cal (CalBackendFile *cbfile, GnomeVFSURI *uri, FILE *file)
 	 * individual components as well?
 	 */
 
-	if (icalcomponent_isa (icalcomp) != ICAL_VCALENDAR_COMPONENT)
+	if (icalcomponent_isa (icalcomp) != ICAL_VCALENDAR_COMPONENT) {
+		icalcomponent_free (icalcomp);
 		return CAL_BACKEND_OPEN_ERROR;
+	}
 
 	priv->icalcomp = icalcomp;
 
@@ -734,6 +746,19 @@ cal_backend_file_open (CalBackend *backend, GnomeVFSURI *uri, gboolean only_if_e
 	}
 }
 
+/* is_loaded handler for the file backend */
+static gboolean
+cal_backend_file_is_loaded (CalBackend *backend)
+{
+	CalBackendFile *cbfile;
+	CalBackendFilePrivate *priv;
+
+	cbfile = CAL_BACKEND_FILE (backend);
+	priv = cbfile->priv;
+
+	return (priv->icalcomp != NULL);
+}
+
 /* Get_n_objects handler for the file backend */
 static int
 cal_backend_file_get_n_objects (CalBackend *backend, CalObjType type)
@@ -1469,6 +1494,8 @@ notify_update (CalBackendFile *cbfile, const char *uid)
 
 	priv = cbfile->priv;
 
+	cal_backend_obj_updated (CAL_BACKEND (cbfile), uid);
+
 	for (l = priv->clients; l; l = l->next) {
 		Cal *cal;
 
@@ -1486,6 +1513,8 @@ notify_remove (CalBackendFile *cbfile, const char *uid)
 
 	priv = cbfile->priv;
 
+	cal_backend_obj_removed (CAL_BACKEND (cbfile), uid);
+
 	for (l = priv->clients; l; l = l->next) {
 		Cal *cal;