Add LiveQuery

src/LiveQuery/SessionTokenCache.js

@@ -0,0 +1,38 @@
+import Parse from 'parse/node';
+import LRU from 'lru-cache';
+import PLog from './PLog';
+
+class SessionTokenCache {
+  cache: Object;
+
+  constructor(timeout: number = 30 * 24 * 60 *60 * 1000, maxSize: number = 10000) {
+    this.cache = new LRU({
+      max: maxSize,
+      maxAge: timeout
+    });
+  }
+
+  getUserId(sessionToken: string): any {
+    if (!sessionToken) {
+      return Parse.Promise.error('Empty sessionToken');
+    }
+    let userId = this.cache.get(sessionToken);
+    if (userId) {
+      PLog.verbose('Fetch userId %s of sessionToken %s from Cache', userId, sessionToken);
+      return Parse.Promise.as(userId);
+    }
+    return Parse.User.become(sessionToken).then((user) => {
+      PLog.verbose('Fetch userId %s of sessionToken %s from Parse', user.id, sessionToken);
+      let userId = user.id;
+      this.cache.set(sessionToken, userId);
+      return Parse.Promise.as(userId);
+    }, (error) => {
+      PLog.error('Can not fetch userId for sessionToken %j, error %j', sessionToken, error);
+      return Parse.Promise.error(error);
+    });
+  }
+}
+
+export {
+  SessionTokenCache
+}