Added key.js

Author: guymorita

lib/algorithms.js

@@ -1,7 +1,8 @@
 
 const async = require('async'),
   config = require('./config.js'),
-  _ = require('underscore');
+  _ = require('underscore'),
+  Key = require('./key');
 
 const CLASSNAME = config.className;
 
@@ -50,7 +51,7 @@ exports.updateSimilarityFor = function(userId, cb){
   // initializing variables
   let userRatedItemIds, itemLiked, itemDisliked, itemLikeDislikeKeys;
   // setting the redis key for the user's similarity set
-  const similaritySet = [CLASSNAME,userId,'similaritySet'].join(":");
+  const similaritySet = Key.similaritySet(userId);
   // creating a combined set with the all of a users likes and dislikes
   client.sunion([CLASSNAME,'user',userId,'liked'].join(":"),[CLASSNAME,'user',userId,'disliked'].join(":"), function(err, userRatedItemIds){
     // if they have rated anything
@@ -105,7 +106,7 @@ exports.predictFor = function(userId, itemId){
   itemId = String(itemId);
   let finalSimilaritySum = 0.0;
   let prediction = 0.0;
-  const similaritySet = [CLASSNAME, userId, 'similaritySet'].join(':');
+  const similaritySet = Key.similaritySet(userId);
   const likedBySet = [CLASSNAME, 'item', itemId, 'liked'].join(':');
   const dislikedBySet = [CLASSNAME, 'item', itemId, 'disliked'].join(':');
 
@@ -160,8 +161,8 @@ exports.updateRecommendationsFor = function(userId, cb){
   // initializing the redis keys for temp sets, the similarity set and the recommended set
   const tempSet = [CLASSNAME, userId, 'tempSet'].join(":");
   const tempDiffSet = [CLASSNAME, userId, 'tempDiffSet'].join(":");
-  const similaritySet = [CLASSNAME, userId, 'similaritySet'].join(":");
-  const recommendedSet = [CLASSNAME, userId, 'recommendedSet'].join(":");
+  const similaritySet = Key.similaritySet(userId);
+  const recommendedSet = Key.recommendedSet(userId);
   // returns an array of the users that are most similar within k nearest neighbors
   client.zrevrange(similaritySet, 0, config.nearestNeighbors-1, function(err, mostSimilarUserIds){
     // returns an array of the users that are least simimilar within k nearest neighbors

lib/key.js

@@ -0,0 +1,30 @@
+
+const config = require('./config.js');
+
+const CLASSNAME = config.className;
+const USER = 'user';
+
+class Key {
+  constructor() {
+    this.key = '';
+    this.keyArr = [];
+  }
+
+  joinKey() {
+    this.key = this.keyArr.join(':');
+  }
+
+  similaritySet(userId) {
+    this.keyArr = [CLASSNAME, USER, userId, 'similaritySet'];
+    this.joinKey();
+    return this.key;
+  }
+
+  recommendedSet(userId) {
+    this.keyArr = [CLASSNAME, USER, userId, 'recommendedSet'];
+    this.joinKey();
+    return this.key;
+  }
+}
+
+module.exports = exports = new Key();

lib/stat.js

@@ -1,13 +1,14 @@
 
 const config = require('./config.js'),
-  client = require('./client.js');
+  client = require('./client.js'),
+  Key = require('./key');
 
 const CLASSNAME = config.className;
 
 const stat = {
   recommendFor: function(userId, numberOfRecs){
     return new Promise((resolve, reject) => {
-      client.zrevrangeAsync([CLASSNAME, userId, 'recommendedSet'].join(":"), 0, numberOfRecs).then((results) => {
+      client.zrevrangeAsync(Key.recommendedSet(userId), 0, numberOfRecs).then((results) => {
         resolve(results);
       });
     });
@@ -51,7 +52,7 @@ const stat = {
   },
   mostSimilarUsers: function(userId){
     return new Promise((resolve, reject) => {
-      client.zrevrangeAsync([CLASSNAME, userId, 'similaritySet'].join(":"), 0, -1).then((results) => {
+      client.zrevrangeAsync(Key.similaritySet(userId), 0, -1).then((results) => {
         resolve(results);
       });
     });