Empire resources update

* Added a new update that computes the amount of resources possessed and
owed by empires. At the moment this computation ignores fleets, as their
upkeep does not use the resource system.

legacyworlds-server-data/db-structure/parts/030-data/000-typedefs.sql

@@ -29,9 +29,18 @@ CREATE TYPE log_type
 -- Update types
 CREATE TYPE update_type	AS ENUM (
 
-	/* Empires' money is being updated using the previous update's results */
+	/* Empires' money is being updated using the previous update's results
+	 * 
+	 * FIXME: this update type should disappear, as everything it does will
+	 * be replaced by the resources update.
+	 */
 	'EMPIRE_MONEY' ,
-	
+
+	/* Empires' resources are being updated using the previous update's
+	 * results.
+	 */
+	'EMPIRE_RESOURCES' ,
+
 	/* Empire research points are being attributed to technologies */
 	'EMPIRE_RESEARCH' ,
 	

legacyworlds-server-data/db-structure/parts/050-updates/015-empire-resources.sql

@@ -0,0 +1,63 @@
+-- LegacyWorlds Beta 6
+-- PostgreSQL database scripts
+--
+-- Game updates - empire resources
+--
+-- Copyright(C) 2004-2012, DeepClone Development
+-- --------------------------------------------------------
+
+
+/*
+ * Empire resources update
+ * 
+ * For each empire in the update batch, compute the new amount of resources
+ * based on the upkeep and income from planets.
+ * 
+ * FIXME: this should also include fleet upkeeps. This situation will be
+ *        resolved once the system is modified to rely solely on resources.
+ * 
+ * Parameters:
+ *		_tick		The identifier of the game update
+ */
+DROP FUNCTION IF EXISTS sys.process_empire_resources_updates( BIGINT );
+CREATE FUNCTION sys.process_empire_resources_updates( _tick BIGINT )
+	RETURNS VOID
+	STRICT VOLATILE
+	SECURITY INVOKER
+AS $process_empire_resources_updates$
+
+	UPDATE emp.resources _emp_resources
+
+		SET empres_possessed = CASE
+				WHEN _emp_resources.empres_possessed + _pl_resources.pres_income - _pl_resources.pres_upkeep > 0 THEN
+					_emp_resources.empres_possessed + _pl_resources.pres_income - _pl_resources.pres_upkeep
+				ELSE
+					0
+				END ,
+			empres_owed = CASE
+				WHEN _emp_resources.empres_possessed + _pl_resources.pres_income - _pl_resources.pres_upkeep < 0 THEN
+					 _pl_resources.pres_upkeep - _emp_resources.empres_possessed - _pl_resources.pres_income 
+				ELSE
+					0
+				END
+
+		FROM sys.updates _upd_sys
+			INNER JOIN emp.updates _upd_emp
+				ON _upd_emp.update_id = _upd_sys.id
+			INNER JOIN emp.planets _emp_planets
+				USING ( empire_id )
+			INNER JOIN verse.planet_resources _pl_resources
+				USING ( planet_id )
+
+		WHERE _upd_sys.last_tick = $1
+			AND _upd_sys.status = 'PROCESSING'
+			AND _upd_sys.gu_type = 'EMPIRE_RESOURCES'
+			AND _emp_resources.empire_id = _upd_emp.empire_id
+			AND _emp_resources.resource_name_id = _pl_resources.resource_name_id;
+
+$process_empire_resources_updates$ LANGUAGE SQL;
+
+
+REVOKE EXECUTE
+	ON FUNCTION sys.process_empire_resources_updates( BIGINT )
+	FROM PUBLIC;