Add update function to add meta column

lib/database/update.js

@@ -1,7 +1,8 @@
 var db = require("../database");
 var Logger = require("../logger");
+var Q = require("q");
 
-const DB_VERSION = 1;
+const DB_VERSION = 2;
 
 module.exports.checkVersion = function () {
     db.query("SELECT `key`,`value` FROM `meta` WHERE `key`=?", ["db_version"], function (err, rows) {
@@ -32,5 +33,31 @@ module.exports.checkVersion = function () {
 };
 
 function update(version, cb) {
-    setImmediate(cb);
+    if (version === 1) {
+        addMetaColumnToLibraries(cb);
+    }
+}
+
+function addMetaColumnToLibraries(cb) {
+    Q.nfcall(db.query, "SHOW TABLES")
+    .then(function (rows) {
+        rows = rows.map(function (r) {
+            return r[Object.keys(r)[0]];
+        }).filter(function (r) {
+            return r.match(/_library$/);
+        });
+
+        var queue = [];
+        rows.forEach(function (table) {
+            queue.push(Q.nfcall(db.query, "ALTER TABLE `" + table + "` ADD meta TEXT")
+                .then(function () {
+                    Logger.syslog.log("Added meta column to " + table);
+                })
+            );
+        });
+
+        return Q.all(queue);
+    }).catch(function (err) {
+        Logger.errlog.log("Adding meta column to library tables failed: " + err);
+    }).done(cb);
 }