added support for Model migrations

now we have a table core.migration and each model (User, Group, Item, ItemContent and a new Migration) have its own
row in the table with a version number

added to config:
db_make_migration_if_needed and db_stop_if_migration_fails (need description yet)

winixd/models/item.cpp

@@ -223,7 +223,64 @@ return !is_that_url;
 }
 
 
-void Item::do_migration(morm::ModelConnector * model_connector, Log & log)
+
+void Item::propagate_connector()
+{
+	item_content.set_connector(model_connector);
+}
+
+
+
+
+
+bool Item::do_migration(int & current_table_version)
+{
+	bool ok = true;
+
+	ok = ok && morm::Model::do_migration(current_table_version, 1, this, &Item::do_migration_to_1);
+	ok = ok && morm::Model::do_migration(current_table_version, 2, this, &Item::do_migration_to_2);
+	ok = ok && morm::Model::do_migration(current_table_version, 3, this, &Item::do_migration_to_3);
+	ok = ok && morm::Model::do_migration(current_table_version, 4, this, &Item::do_migration_to_4);
+
+	return ok;
+}
+
+
+bool Item::do_migration_to_1()
+{
+	const char * str = R"sql(
+		CREATE TABLE core.item (
+			user_id integer,
+			group_id integer,
+			privileges integer,
+			date_creation timestamp without time zone,
+			date_modification timestamp without time zone,
+			parent_id bigint,
+			type smallint,
+			id integer NOT NULL,
+			url character varying(255),
+			content_id bigint,
+			subject character varying(255),
+			guest_name character varying(20),
+			modification_user_id integer,
+			template character varying(255),
+			link_to character varying(2048),
+			link_redirect smallint,
+			sort_index integer,
+			meta text,
+			ameta text
+		);
+	)sql";
+
+	db_query(str);
+	return true; // IMPROVEME remove me in the future: this is only for a moment until we do migration on all our sites
+}
+
+
+/*
+ * directories didn't have an ItemContent object, so now we create such objects
+ */
+bool Item::do_migration_to_2()
 {
 	morm::Finder<Item> finder(model_connector);
 
@@ -234,17 +291,76 @@ void Item::do_migration(morm::ModelConnector * model_connector, Log & log)
 			eq(L"content_id", -1).
 			get_list();
 
+	PT::Log * log = model_connector->get_logger();
+
 	for(Item & item : list)
 	{
-		log << "updating item id: " << item.id << ", type: " << (int)item.type << ", url: " << item.url << ", subject: " << item.subject << logend << logsave;
+		if( log )
+		{
+			(*log) << "Item: adding a content row corresponding to item id: " << item.id << ", type: " << (int)item.type << ", url: " << item.url
+				   << ", subject: " << item.subject << PT::Log::logend;
+		}
+
 		item.item_content.set_save_mode(morm::Model::DO_INSERT_ON_SAVE);
-		item.save();
+
+		if( !item.save() )
+			return false;
 	}
+
+	return true;
 }
 
-void Item::propagate_connector()
+
+
+bool Item::do_migration_to_3()
 {
-	item_content.set_connector(model_connector);
+	const char * str[] = {
+		"update core.content set user_id = (select user_id from core.item where item.content_id = content.id limit 1);",
+		"update core.content set group_id = (select group_id from core.item where item.content_id = content.id limit 1);",
+		"update core.content set guest_name = (select guest_name from core.item where item.content_id = content.id limit 1);",
+		"update core.content set modification_user_id = (select modification_user_id from core.item where item.content_id = content.id limit 1);",
+		"update core.content set privileges = (select privileges from core.item where item.content_id = content.id limit 1);",
+		"update core.content set date_creation = (select date_creation from core.item where item.content_id = content.id limit 1);",
+		"update core.content set date_modification = (select date_modification from core.item where item.content_id = content.id limit 1);",
+		"update core.content set link_to = (select link_to from core.item where item.content_id = content.id limit 1);",
+		"update core.content set link_redirect = (select link_redirect from core.item where item.content_id = content.id limit 1);",
+		"update core.content set meta = (select meta from core.item where item.content_id = content.id limit 1);",
+		"update core.content set meta_admin = (select ameta from core.item where item.content_id = content.id limit 1);",
+	};
+
+	size_t len = sizeof(str) / sizeof(const char*);
+
+	for(size_t i=0 ; i < len ; ++i)
+	{
+		if( !db_query(str[i]) )
+		{
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+
+bool Item::do_migration_to_4()
+{
+	const char * str = R"sql(
+		alter table core.item
+		drop column user_id,
+		drop column group_id,
+		drop column guest_name,
+		drop column modification_user_id,
+		drop column privileges,
+		drop column date_creation,
+		drop column date_modification,
+		drop column link_to,
+		drop column link_redirect,
+		drop column meta,
+		drop column ameta;
+	)sql";
+
+	return db_query(str);
 }