new class for implementing a backend cache for the calendar queries.

2002-07-31  Rodrigo Moya <rodrigo@ximian.com>

	* pcs/query-backend.[ch]: new class for implementing a backend cache
	for the calendar queries.

	* pcs/Makefile.am: added new files.

svn path=/trunk/; revision=17668

4 files changed, 331 insertions, 0 deletions

diff --git a/calendar/ChangeLog b/calendar/ChangeLog
index 187c8ee528..1dba1b375d 100644
--- a/calendar/ChangeLog
+++ b/calendar/ChangeLog
@@ -1,3 +1,10 @@
+2002-07-31  Rodrigo Moya <rodrigo@ximian.com>
+
+	* pcs/query-backend.[ch]: new class for implementing a backend cache
+	for the calendar queries.
+
+	* pcs/Makefile.am: added new files.
+
 2002-07-31  Ettore Perazzoli  <ettore@ximian.com>
 
 	* gui/component-factory.c (create_object): Change the order of the
diff --git a/calendar/pcs/Makefile.am b/calendar/pcs/Makefile.am
index 0c7590f91a..a8c2749e27 100644
--- a/calendar/pcs/Makefile.am
+++ b/calendar/pcs/Makefile.am
@@ -41,6 +41,7 @@ pcsinclude_HEADERS = 		\
 	cal-common.h		\
 	cal-factory.h		\
 	job.h			\
+	query-backend.h		\
 	query.h
 
 libpcs_a_SOURCES =		\
@@ -51,6 +52,7 @@ libpcs_a_SOURCES =		\
 	cal-backend-util.c	\
 	cal-factory.c		\
 	job.c			\
+	query-backend.c		\
 	query.c
 
 libpcsfile_a_SOURCES =		\
diff --git a/calendar/pcs/query-backend.c b/calendar/pcs/query-backend.c
new file mode 100644
index 0000000000..d3ec5a761d
--- /dev/null
+++ b/calendar/pcs/query-backend.c
@@ -0,0 +1,269 @@
+/* Evolution calendar - Backend cache for calendar queries.
+ *
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Author: Rodrigo Moya <rodrigo@ximian.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <glib.h>
+#include <libgnome/gnome-defs.h>
+#include <libgnome/gnome-i18n.h>
+#include <gtk/gtksignal.h>
+#include <cal-util/cal-component.h>
+#include "query.h"
+#include "query-backend.h"
+
+static void query_backend_class_init (QueryBackendClass *klass);
+static void query_backend_init       (QueryBackend *qb);
+static void query_backend_destroy    (GtkObject *object);
+
+typedef struct {
+	CalComponent *comp;
+} QueryBackendComponent;
+
+/* Private part of the QueryBackend structure */
+struct _QueryBackendPrivate {
+	char *uri;
+	CalBackend *backend;
+	GHashTable *components;
+	GList *queries;
+};
+
+static GHashTable *loaded_backends = NULL;
+static GtkObjectClass *parent_class = NULL;
+
+/* Class initialization function for the backend cache */
+static void
+query_backend_class_init (QueryBackendClass *klass)
+{
+	GtkObjectClass *object_class = GTK_OBJECT_CLASS (klass);
+
+	parent_class = gtk_type_class (GTK_TYPE_OBJECT);
+
+	object_class->destroy = query_backend_destroy;
+}
+
+/* Object initialization function for the backend cache */
+static void
+query_backend_init (QueryBackend *qb)
+{
+	QueryBackendPrivate *priv;
+
+	priv = g_new0 (QueryBackendPrivate, 1);
+	qb->priv = priv;
+
+	priv->uri = NULL;
+	priv->backend = NULL;
+	priv->components = g_hash_table_new (g_str_hash, g_str_equal);
+	priv->queries = NULL;
+}
+
+/* Destroy handler for the backend cache */
+static void
+query_backend_destroy (GtkObject *object)
+{
+	QueryBackend *qb = (QueryBackend *) object;
+
+	g_return_if_fail (object != NULL);
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	/* remove the QueryBackend from the internal hash table */
+	g_hash_table_remove (loaded_backends, qb->priv->uri);
+
+	/* free memory */
+	qb->priv->backend = NULL;
+
+	g_free (qb->priv->uri);
+	qb->priv->uri = NULL;
+
+	g_hash_table_destroy (qb->priv->components);
+	qb->priv->components = NULL;
+
+	g_list_free (qb->priv->queries);
+	qb->priv->queries = NULL;
+
+	g_free (qb->priv);
+	qb->priv = NULL;
+
+	if (GTK_OBJECT_CLASS (parent_class)->destroy)
+		(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
+}
+
+/**
+ * query_backend_get_type:
+ * @void:
+ *
+ * Registers the #QueryBackend class if necessary, and returns the type ID
+ * associated to it.
+ *
+ * Return value: The type ID of the #QueryBackend class.
+ **/
+GtkType
+query_backend_get_type (void)
+{
+	static GtkType type = 0;
+
+	if (!type) {
+		static const GtkTypeInfo info = {
+			"QueryBackend",
+			sizeof (QueryBackend),
+			sizeof (QueryBackendClass),
+			(GtkClassInitFunc) query_backend_class_init,
+			(GtkObjectInitFunc) query_backend_init,
+			NULL, /* reserved_1 */
+			NULL, /* reserved_2 */
+			(GtkClassInitFunc) NULL
+		};
+
+		type = gtk_type_unique (GTK_TYPE_OBJECT, &info);
+	}
+
+	return type;
+}
+
+static void
+backend_destroyed_cb (GtkObject *object, gpointer user_data)
+{
+	CalBackend *backend = (CalBackend *) object;
+	QueryBackend *qb = (QueryBackend *) user_data;
+
+	g_return_if_fail (IS_CAL_BACKEND (backend));
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	gtk_object_unref (GTK_OBJECT (qb));
+}
+
+static void
+object_updated_cb (CalBackend *backend, const char *uid, gpointer user_data)
+{
+	gpointer orig_key, orig_value;
+	char *tmp_uid;
+	CalComponent *comp;
+	QueryBackend *qb = (QueryBackend *) user_data;
+
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	if (g_hash_table_lookup_extended (qb->priv->components, uid, &orig_key, &orig_value)) {
+		g_hash_table_remove (qb->priv->components, uid);
+	}
+
+	comp = cal_backend_get_object_component (qb->priv->backend, uid);
+	if (IS_CAL_COMPONENT (comp)) {
+		cal_component_get_uid (comp, &tmp_uid);
+		g_hash_table_insert (qb->priv->components, tmp_uid, comp);
+	}
+}
+
+static void
+object_removed_cb (CalBackend *backend, const char *uid, gpointer user_data)
+{
+	gpointer orig_key, orig_value;
+	QueryBackend *qb = (QueryBackend *) user_data;
+
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	if (g_hash_table_lookup_extended (qb->priv->components, uid, &orig_key, &orig_value)) {
+		g_hash_table_remove (qb->priv->components, uid);
+	}
+}
+
+static void
+query_destroyed_cb (GtkObject *object, gpointer user_data)
+{
+	Query *query = (Query *) object;
+	QueryBackend *qb = (QueryBackend *) user_data;
+
+	g_return_if_fail (IS_QUERY (query));
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	qb->priv->queries = g_list_remove (qb->priv->queries, query);
+}
+
+static void
+foreach_uid_cb (gpointer data, gpointer user_data)
+{
+	CalComponent *comp;
+	char *uid;
+	QueryBackend *qb = (QueryBackend *) user_data;
+
+	g_return_if_fail (data != NULL);
+	g_return_if_fail (IS_QUERY_BACKEND (qb));
+
+	comp = cal_backend_get_object_component (qb->priv->backend, (const char *) data);
+	if (IS_CAL_COMPONENT (comp)) {
+		cal_component_get_uid (comp, &uid);
+		g_hash_table_insert (qb->priv->components, uid, comp);
+	}
+	else
+		g_warning (_("Could not get component with UID = %s"), (const char *) data);
+}
+
+/**
+ * query_backend_new
+ * @query: The #Query object that issues the query.
+ * @backend: A #CalBackend object.
+ *
+ * Create a new #QueryBackend instance, which is a class to
+ * have a cache of objects for the calendar queries, so that
+ * we don't have to ask the calendar backend to get the objects
+ * everytime.
+ *
+ * Returns: the newly-created object.
+ */
+QueryBackend *
+query_backend_new (Query *query, CalBackend *backend)
+{
+	QueryBackend *qb = NULL;
+
+	g_return_val_if_fail (IS_QUERY (query), NULL);
+	g_return_val_if_fail (IS_CAL_BACKEND (backend), NULL);
+
+	/* see if we already have the backend loaded */
+	qb = g_hash_table_lookup (loaded_backends,
+				  cal_backend_get_uri (backend));
+	if (!qb) {
+		GList *uidlist;
+
+		qb = gtk_type_new (QUERY_BACKEND_TYPE);
+
+		qb->priv->uri = g_strdup (cal_backend_get_uri (backend));
+		qb->priv->backend = backend;
+
+		/* load all UIDs */
+		uidlist = cal_backend_get_uids (backend, CALOBJ_TYPE_ANY);
+		g_list_foreach (uidlist, foreach_uid_cb, qb);
+		cal_obj_uid_list_free (uidlist);
+
+		gtk_signal_connect (GTK_OBJECT (backend), "destroy",
+				    GTK_SIGNAL_FUNC (backend_destroyed_cb), qb);
+		gtk_signal_connect (GTK_OBJECT (backend), "obj_updated",
+				    GTK_SIGNAL_FUNC (object_updated_cb), qb);
+		gtk_signal_connect (GTK_OBJECT (backend), "obj_removed",
+				    GTK_SIGNAL_FUNC (object_removed_cb), qb);
+
+		g_hash_table_insert (loaded_backends, qb->priv->uri, qb);
+	}
+
+	qb->priv->queries = g_list_append (qb->priv->queries, query);
+	gtk_signal_connect (GTK_OBJECT (query), "destroy",
+			    GTK_SIGNAL_FUNC (query_destroyed_cb), qb);
+
+	return qb;
+}
diff --git a/calendar/pcs/query-backend.h b/calendar/pcs/query-backend.h
new file mode 100644
index 0000000000..835c42a8fd
--- /dev/null
+++ b/calendar/pcs/query-backend.h
@@ -0,0 +1,53 @@
+/* Evolution calendar - Backend cache for calendar queries.
+ *
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Author: Rodrigo Moya <rodrigo@ximian.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef QUERY_BACKEND_H
+#define QUERY_BACKEND_H
+
+#include "cal-backend.h"
+#include "query.h"
+
+BEGIN_GNOME_DECLS
+
+#define QUERY_BACKEND_TYPE            (query_backend_get_type ())
+#define QUERY_BACKEND(obj)            (GTK_CHECK_CAST ((obj), QUERY_BACKEND_TYPE, QueryBackend))
+#define QUERY_BACKEND_CLASS(klass)    (GTK_CHECK_CLASS_CAST ((klass), QUERY_BACKEND_TYPE, QueryBackendClass))
+#define IS_QUERY_BACKEND(obj)         (GTK_CHECK_TYPE ((obj), QUERY_BACKEND_TYPE))
+#define IS_QUERY_BACKEND_CLASS(klass) (GTK_CHECK_CLASS_TYPE ((klass), QUERY_BACKEND_TYPE))
+
+typedef struct _QueryBackendPrivate QueryBackendPrivate;
+
+typedef struct {
+	GtkObject object;
+
+	/* Private data */
+	QueryBackendPrivate *priv;
+} QueryBackend;
+
+typedef struct {
+	GtkObjectClass parent;
+} QueryBackendClass;
+
+GtkType       query_backend_get_type (void);
+QueryBackend *query_backend_new (Query *query, CalBackend *backend);
+
+END_GNOME_DECLS
+
+#endif