Try to fix when server have heavy loading cache might not update to db properly

Author: jackycute

lib/history.js

@@ -27,10 +27,10 @@ var updater = setInterval(function () {
         if (cache.isDirty) {
             if (config.debug) logger.info("history updater found dirty history: " + key);
             var history = parseHistoryToArray(cache.history);
+            cache.isDirty = false;
             finishUpdateHistory(key, history, function (err, count) {
                 if (err) return callback(err, null);
                 if (!count) return callback(null, null);
-                cache.isDirty = false;
                 cache.updateAt = Date.now();
                 return callback(null, null);
             });

lib/realtime.js

@@ -84,6 +84,7 @@ var updater = setInterval(function () {
         var note = notes[key];
         if (note.server.isDirty) {
             if (config.debug) logger.info("updater found dirty note: " + key);
+            note.server.isDirty = false;
             updateNote(note, function(err, _note) {
                 // handle when note already been clean up
                 if (!notes[key] || !notes[key].server) return callback(null, null);
@@ -104,7 +105,6 @@ var updater = setInterval(function () {
                     }
                     return callback(err, null);
                 }
-                note.server.isDirty = false;
                 note.updatetime = moment(_note.lastchangeAt).valueOf();
                 emitCheck(note);
                 return callback(null, null);