Implement generic way to save/load db and make it low disk safe.

2003-05-23  Marco Pesenti Gritti  <marco@it.gnome.org>

	* embed/ephy-favicon-cache.c: (ephy_favicon_cache_load),
	(ephy_favicon_cache_save), (ephy_favicon_cache_init),
	(ephy_favicon_cache_finalize):
	* embed/ephy-history.c: (ephy_history_load), (ephy_history_save),
	(ephy_history_init):
	* lib/ephy-node-db.c: (ephy_node_db_set_version),
	(ephy_node_db_get_property), (ephy_node_db_set_property),
	(ephy_node_db_class_init), (ephy_node_db_init),
	(ephy_node_db_finalize), (ephy_node_db_new),
	(_ephy_node_db_remove_id), (ephy_node_db_load_from_xml),
	(ephy_node_db_save_to_xml):
	* lib/ephy-node-db.h:
	* lib/ephy-node.c: (ephy_node_to_xml):
	* lib/ephy-node.h:
	* lib/ephy-state.c: (ephy_states_load), (ephy_states_save),
	(ensure_states):
	* src/bookmarks/ephy-bookmarks.c: (ephy_bookmarks_load),
	(ephy_bookmarks_save), (ephy_bookmarks_init),
	(ephy_bookmarks_finalize):

	Implement generic way to save/load db and make it
	low disk safe.

5 files changed, 168 insertions, 49 deletions

diff --git a/lib/ephy-node-db.c b/lib/ephy-node-db.c
index 86913d93c..bb10759ec 100644
--- a/lib/ephy-node-db.c
+++ b/lib/ephy-node-db.c
@@ -19,6 +19,9 @@
  */
 
 #include "ephy-node-db.h"
+#include "ephy-debug.h"
+
+#include <unistd.h>
 
 static void ephy_node_db_class_init (EphyNodeDbClass *klass);
 static void ephy_node_db_init (EphyNodeDb *node);
@@ -30,12 +33,14 @@ static void ephy_node_db_finalize (GObject *object);
 enum
 {
 	PROP_0,
-	PROP_NAME
+	PROP_NAME,
+	PROP_VERSION
 };
 
 struct EphyNodeDbPrivate
 {
 	char *name;
+	char *version;
 
 	GMutex *id_factory_lock;
 	long id_factory;
@@ -75,6 +80,12 @@ ephy_node_db_get_type (void)
 }
 
 static void
+ephy_node_db_set_version (EphyNodeDb *db, const char *version)
+{
+	db->priv->version = g_strdup (version);
+}
+
+static void
 ephy_node_db_set_name (EphyNodeDb *db, const char *name)
 {
 	db->priv->name = g_strdup (name);
@@ -102,6 +113,9 @@ ephy_node_db_get_property (GObject *object,
 		case PROP_NAME:
 			g_value_set_string (value, db->priv->name);
 			break;
+		case PROP_VERSION:
+			g_value_set_string (value, db->priv->version);
+			break;
 	}
 }
 
@@ -121,6 +135,9 @@ ephy_node_db_set_property (GObject *object,
 		case PROP_NAME:
 			ephy_node_db_set_name (db, g_value_get_string (value));
 			break;
+		case PROP_VERSION:
+			ephy_node_db_set_version (db, g_value_get_string (value));
+			break;
 	}
 }
 
@@ -142,6 +159,14 @@ ephy_node_db_class_init (EphyNodeDbClass *klass)
                                                                "Name",
                                                                NULL,
                                                                G_PARAM_READWRITE));
+	g_object_class_install_property (object_class,
+                                         PROP_VERSION,
+                                         g_param_spec_string  ("version",
+                                                               "Version",
+                                                               "Version",
+                                                               NULL,
+                                                               G_PARAM_READWRITE));
+
 }
 
 static void
@@ -150,6 +175,7 @@ ephy_node_db_init (EphyNodeDb *db)
 	db->priv = g_new0 (EphyNodeDbPrivate, 1);
 
 	db->priv->name = NULL;
+	db->priv->version = NULL;
 
 	/* id to node */
 	db->priv->id_to_node = g_ptr_array_new ();
@@ -186,6 +212,7 @@ ephy_node_db_finalize (GObject *object)
 	g_mutex_free (db->priv->id_factory_lock);
 
 	g_free (db->priv->name);
+	g_free (db->priv->version);
 
 	g_free (db->priv);
 
@@ -203,12 +230,13 @@ ephy_node_db_get_by_name (const char *name)
 }
 
 EphyNodeDb *
-ephy_node_db_new (const char *name)
+ephy_node_db_new (const char *name, const char *version)
 {
 	EphyNodeDb *db;
 
 	db = EPHY_NODE_DB (g_object_new (EPHY_TYPE_NODE_DB,
 					 "name", name,
+					 "version", version,
 				         NULL));
 
 	g_return_val_if_fail (db->priv != NULL, NULL);
@@ -295,3 +323,123 @@ _ephy_node_db_remove_id (EphyNodeDb *db,
 
 	g_static_rw_lock_writer_unlock (db->priv->id_to_node_lock);
 }
+
+gboolean
+ephy_node_db_load_from_xml (EphyNodeDb *db, const char *xml_file)
+{
+	xmlDocPtr doc;
+	xmlNodePtr root, child;
+
+	if (g_file_test (xml_file, G_FILE_TEST_EXISTS) == FALSE)
+	{
+		return FALSE;
+	}
+
+	doc = xmlParseFile (xml_file);
+	g_return_val_if_fail (doc != NULL, FALSE);
+
+	root = xmlDocGetRootElement (doc);
+
+	for (child = root->children; child != NULL; child = child->next)
+	{
+		EphyNode *node;
+
+		node = ephy_node_new_from_xml (db, child);
+	}
+
+	xmlFreeDoc (doc);
+
+	return TRUE;
+}
+
+gboolean
+ephy_node_db_save_to_xml (EphyNodeDb *db, const char *xml_file)
+{
+	xmlDocPtr doc;
+	xmlNodePtr root;
+	GPtrArray *children;
+	int i;
+	char *tmp_file;
+	char *old_file;
+	gboolean old_exist;
+	gboolean retval = TRUE;
+
+	LOG ("Build the xml file %s", xml_file)
+
+	tmp_file = g_strconcat (xml_file, ".tmp", NULL);
+	old_file = g_strconcat (xml_file, ".old", NULL);
+
+	/* save nodes to xml */
+	xmlIndentTreeOutput = TRUE;
+	doc = xmlNewDoc ("1.0");
+
+	root = xmlNewDocNode (doc, NULL, "ephy_node_db", NULL);
+	xmlDocSetRootElement (doc, root);
+
+	xmlSetProp (root, "name", db->priv->name);
+	xmlSetProp (root, "version", db->priv->version);
+
+	g_static_rw_lock_reader_lock (db->priv->id_to_node_lock);
+
+	children = db->priv->id_to_node;
+
+	for (i = RESERVED_IDS; i < children->len; i++)
+	{
+		EphyNode *kid;
+
+		kid = g_ptr_array_index (children, i);
+
+		if (kid)
+		{
+			ephy_node_to_xml (kid, root);
+		}
+	}
+
+	g_static_rw_lock_reader_unlock (db->priv->id_to_node_lock);
+
+	LOG ("Save it")
+
+	if (!xmlSaveFormatFile (tmp_file, doc, 1))
+	{
+		g_warning ("Failed to write XML data to %s", tmp_file);
+		goto failed;
+	}
+
+	old_exist = g_file_test (xml_file, G_FILE_TEST_EXISTS);
+
+	if (old_exist)
+	{
+		if (rename (xml_file, old_file) < 0)
+		{
+			g_warning ("Failed to rename %s to %s", xml_file, old_file);
+			retval = FALSE;
+			goto failed;
+		}
+	}
+
+	if (rename (tmp_file, xml_file) < 0)
+	{
+		g_warning ("Failed to rename %s to %s", tmp_file, xml_file);
+
+		if (rename (old_file, xml_file) < 0)
+		{
+			g_warning ("Failed to restore %s from %s", xml_file, tmp_file);
+		}
+		retval = FALSE;
+		goto failed;
+	}
+
+	if (old_exist)
+	{
+		if (unlink (old_file) < 0)
+		{
+			g_warning ("Failed to delete old file %s", old_file);
+		}
+	}
+
+	failed:
+	g_free (old_file);
+	g_free (tmp_file);
+
+	return retval;
+}
diff --git a/lib/ephy-node-db.h b/lib/ephy-node-db.h
index 2b1f8fd7d..d801c4743 100644
--- a/lib/ephy-node-db.h
+++ b/lib/ephy-node-db.h
@@ -54,13 +54,23 @@ GType         ephy_node_db_get_type		(void);
 
 EphyNodeDb   *ephy_node_db_get_by_name		(const char *name);
 
-EphyNodeDb   *ephy_node_db_new			(const char *name);
+EphyNodeDb   *ephy_node_db_new			(const char *name,
+						 const char *version);
 
 const char   *ephy_node_db_get_name		(EphyNodeDb *db);
 
 EphyNode     *ephy_node_db_get_node_from_id	(EphyNodeDb *db,
 						 long id);
 
+EphyNode     *ephy_node_db_get_root_from_id     (EphyNodeDb *db,
+						 long id);
+
+gboolean      ephy_node_db_load_from_xml        (EphyNodeDb *db,
+						 const char *xml_file);
+
+gboolean      ephy_node_db_save_to_xml          (EphyNodeDb *db,
+						 const char *xml_file);
+
 long	      _ephy_node_db_new_id		(EphyNodeDb *db);
 
 void	      _ephy_node_db_add_id		(EphyNodeDb *db,
diff --git a/lib/ephy-node.c b/lib/ephy-node.c
index d155aae78..b9f0c0695 100644
--- a/lib/ephy-node.c
+++ b/lib/ephy-node.c
@@ -719,8 +719,8 @@ save_parent (gulong id,
 }
 
 void
-ephy_node_save_to_xml (EphyNode *node,
-		       xmlNodePtr parent_xml_node)
+ephy_node_to_xml (EphyNode *node,
+		  xmlNodePtr parent_xml_node)
 {
 	xmlNodePtr xml_node;
 	char *xml;
@@ -736,8 +736,6 @@ ephy_node_save_to_xml (EphyNode *node,
 	xmlSetProp (xml_node, "id", xml);
 	g_free (xml);
 
-	xmlSetProp (xml_node, "type", G_OBJECT_TYPE_NAME (node));
-
 	for (i = 0; i < node->properties->len; i++) {
 		GValue *value;
 		xmlNodePtr value_xml_node;
diff --git a/lib/ephy-node.h b/lib/ephy-node.h
index 846d5fa41..591e5118a 100644
--- a/lib/ephy-node.h
+++ b/lib/ephy-node.h
@@ -96,7 +96,7 @@ char       *ephy_node_get_property_time     (EphyNode *node,
 					     guint property_id);
 
 /* xml storage */
-void          ephy_node_save_to_xml         (EphyNode *node,
+void          ephy_node_to_xml              (EphyNode *node,
 					     xmlNodePtr parent_xml_node);
 EphyNode     *ephy_node_new_from_xml        (EphyNodeDb *db,
 					     xmlNodePtr xml_node);
diff --git a/lib/ephy-state.c b/lib/ephy-state.c
index 90d06883c..0703ebddf 100644
--- a/lib/ephy-state.c
+++ b/lib/ephy-state.c
@@ -31,6 +31,7 @@
 
 #define STATES_FILE "states.xml"
 #define WINDOW_POSITION_UNSET -1
+#define EPHY_STATES_XML_VERSION "0.1"
 
 enum
 {
@@ -48,30 +49,13 @@ static EphyNodeDb *states_db = NULL;
 static void
 ephy_states_load (void)
 {
-	xmlDocPtr doc;
-	xmlNodePtr root, child;
 	char *xml_file;
 
 	xml_file = g_build_filename (ephy_dot_dir (),
                                      STATES_FILE,
                                      NULL);
 
-	if (g_file_test (xml_file, G_FILE_TEST_EXISTS) == FALSE)
-		return;
-
-	doc = xmlParseFile (xml_file);
-	g_assert (doc != NULL);
-
-	root = xmlDocGetRootElement (doc);
-
-	for (child = root->children; child != NULL; child = child->next)
-	{
-		EphyNode *node;
-
-		node = ephy_node_new_from_xml (states_db, child);
-	}
-
-	xmlFreeDoc (doc);
+	ephy_node_db_load_from_xml (states_db, xml_file);
 
 	g_free (xml_file);
 }
@@ -79,10 +63,6 @@ ephy_states_load (void)
 static void
 ephy_states_save (void)
 {
-	xmlDocPtr doc;
-	xmlNodePtr root;
-	GPtrArray *children;
-	int i;
 	char *xml_file;
 
 	if (states == NULL) return;
@@ -91,25 +71,8 @@ ephy_states_save (void)
                                      STATES_FILE,
                                      NULL);
 
-	/* save nodes to xml */
-	xmlIndentTreeOutput = TRUE;
-	doc = xmlNewDoc ("1.0");
-
-	root = xmlNewDocNode (doc, NULL, "ephy_bookmarks", NULL);
-	xmlDocSetRootElement (doc, root);
-
-	children = ephy_node_get_children (states);
-	for (i = 0; i < children->len; i++)
-	{
-		EphyNode *kid;
-
-		kid = g_ptr_array_index (children, i);
-
-		ephy_node_save_to_xml (kid, root);
-	}
-	ephy_node_thaw (states);
+	ephy_node_db_save_to_xml (states_db, xml_file);
 
-	xmlSaveFormatFile (xml_file, doc, 1);
 	g_free (xml_file);
 }
 
@@ -145,7 +108,7 @@ ensure_states (void)
 {
 	if (states == NULL)
 	{
-		states_db = ephy_node_db_new ("EphyStates");
+		states_db = ephy_node_db_new ("EphyStates", EPHY_STATES_XML_VERSION);
 		states = ephy_node_new_with_id (states_db, STATES_NODE_ID);
 		ephy_states_load ();
 	}