From 3a596791b89625afc94a57bf1d81571c96402cb9 Mon Sep 17 00:00:00 2001
From: hooke <yuri.houk@gmail.com>
Date: Thu, 7 Apr 2016 15:33:46 +0300
Subject: [PATCH 1/2] Set and use TTL value when store page to cache

---
 lib/memjsCache.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/memjsCache.js b/lib/memjsCache.js
index 3d0f9fa..fe1dd17 100644
--- a/lib/memjsCache.js
+++ b/lib/memjsCache.js
@@ -5,6 +5,8 @@ memjs = MemJS.create();
 
 var cache_manager = require('cache-manager');
 
+var pageTTL = process.env.PAGE_TTL || 0;
+
 console.log('using memjs cache');
 
 module.exports = {
@@ -29,7 +31,7 @@ module.exports = {
     },
 
     afterPhantomRequest: function(req, res, next) {
-        this.cache.set(req.prerender.url, req.prerender.documentHTML);
+        this.cache.set(req.prerender.url, req.prerender.documentHTML, function(err,val){}, pageTTL);
         next();
     }
 };
@@ -42,7 +44,7 @@ var memjs_cache = {
         callback(err, stringValue);
       });
     },
-    set: function(key, value, callback) {
-      memjs.set(key, value, callback);
+    set: function(key, value, callback, ttl) {
+      memjs.set(key, value, callback, ttl);
     }
 };

From aae08b4c1791bb584050a76d2a6ade13f7dbf0f8 Mon Sep 17 00:00:00 2001
From: hooke <yuri.houk@gmail.com>
Date: Wed, 20 Apr 2016 18:14:08 +0300
Subject: [PATCH 2/2] Cache pages with 200 status code only

---
 lib/memjsCache.js | 72 ++++++++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 32 deletions(-)

diff --git a/lib/memjsCache.js b/lib/memjsCache.js
index fe1dd17..df6c6db 100644
--- a/lib/memjsCache.js
+++ b/lib/memjsCache.js
@@ -1,7 +1,7 @@
 
 var MemJS = require("memjs").Client;
 
-memjs = MemJS.create();
+var memjs = MemJS.create();
 
 var cache_manager = require('cache-manager');
 
@@ -10,41 +10,49 @@ var pageTTL = process.env.PAGE_TTL || 0;
 console.log('using memjs cache');
 
 module.exports = {
-    init: function() {
-        this.cache = cache_manager.caching({
-            store: memjs_cache
-        });
-    },
-
-    beforePhantomRequest: function(req, res, next) {
-        if(req.method !== 'GET') {
-            return next();
-        }
-
-        this.cache.get(req.prerender.url, function (err, result) {
-            if (!err && result) {
-                res.send(200, result);
-            } else {
-                next();
-            }
-        });
-    },
-
-    afterPhantomRequest: function(req, res, next) {
-        this.cache.set(req.prerender.url, req.prerender.documentHTML, function(err,val){}, pageTTL);
+  init: function() {
+    this.cache = cache_manager.caching({
+      store: memjs_cache
+    });
+  },
+
+  beforePhantomRequest: function(req, res, next) {
+    if (req.method !== 'GET') {
+      return next();
+    }
+    //console.log('[memjs cache] gettting page from cache with an URL ', req.prerender.url);
+
+    this.cache.get(req.prerender.url, function(err, result) {
+      if (!err && result) {
+        //console.log('[memjs cache] successfully got page from cache');
+        res.send(200, result);
+      } else {
+        //console.log('[memjs cache] no such page in cache');
         next();
+      }
+    });
+  },
+
+  afterPhantomRequest: function(req, res, next) {
+    // Cache only pages with status code 200. This is to avoid caching of 3xx/4xx/5xx status codes
+    if (req.prerender.statusCode === 200) {
+      //console.log('[memjs cache] saving page with  pageTTL ', pageTTL, ' and URL ', req.prerender.url);
+      this.cache.set(req.prerender.url, req.prerender.documentHTML, function(err, val) {}, pageTTL);
     }
+    next();
+  }
+
 };
 
 
 var memjs_cache = {
-    get: function(key, callback) {
-      memjs.get(key, function(err, value) {
-        var stringValue = value ? value.toString() : null;
-        callback(err, stringValue);
-      });
-    },
-    set: function(key, value, callback, ttl) {
-      memjs.set(key, value, callback, ttl);
-    }
+  get: function(key, callback) {
+    memjs.get(key, function(err, value) {
+      var stringValue = value ? value.toString() : null;
+      callback(err, stringValue);
+    });
+  },
+  set: function(key, value, callback, ttl) {
+    memjs.set(key, value, callback, ttl);
+  }
 };