From 260b263e6f4a46227fc4c196b8e31e371b300ca3 Mon Sep 17 00:00:00 2001
From: argirok <argirokokogiannaki@gmail.com>
Date: Wed, 3 Apr 2024 10:20:58 +0300
Subject: [PATCH] [develop | DONE | CHANGED] cache.js add compression library,
 reload content based on forceReload parameter or cache control headers

---
 services/cache/mecache/cache.js     | 21 +++++++++++++++------
 services/cache/mecache/package.json |  1 +
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/services/cache/mecache/cache.js b/services/cache/mecache/cache.js
index a525742e..18a34898 100644
--- a/services/cache/mecache/cache.js
+++ b/services/cache/mecache/cache.js
@@ -6,6 +6,7 @@ const { LRUCache } = require('lru-cache');
 const request = require('superagent');
 const prom = require('prom-client');
 const URL = require('url');
+let compression = require("compression");
 const PropertiesReader = require('properties-reader');
 const properties = PropertiesReader('./properties.file');
 const environment = properties.get("environment");
@@ -14,6 +15,7 @@ const preloadRequests = properties.get("preloadRequests").split(',');;
 const cacheMaxSize = 1000;
 let cors = require('cors');
 app.use(cors());
+app.use(compression());
 const lruCache = new LRUCache({ max: cacheMaxSize });
 const register = new prom.Registry();
 prom.collectDefaultMetrics({register: register});
@@ -42,18 +44,25 @@ const histogram = new prom.Histogram({
 let cache = () => {
     return (req, res, next) => {
         if (req.query.url) {
-            let key = '__express__' + req.query.url;
+            let key = req.query.url;
             const url = new URL.parse(req.query.url);
+            // console.log(req.headers.origin, req.headers.referrer, req.headers.origin)
+            const cacheControlHeader = req.headers['cache-control'];
+            // Log the Cache-Control header
+            // console.log('Cache-Control header sent by client:', cacheControlHeader);
+            let forceReload = req.query.forceReload && req.query.forceReload == 'true'?true:false;
+            forceReload = forceReload || (cacheControlHeader && (cacheControlHeader.indexOf("no-cache") || cacheControlHeader.indexOf("no-store") || cacheControlHeader.indexOf("must-revalidate")))?true:false;
+
             const target = url.host + '/' + url.pathname.split('/')[1];
             const scheme = url.protocol.replace(':', '');
-            if (lruCache.has(key)) {
-//                console.log( key, "hit")
+            if (lruCache.has(key) && !forceReload) {
+               // console.log( key, "hit")
                 const end = histogram.startTimer({scheme: scheme, target: target, cache: 'hit'});
                 res.send(JSON.parse(lruCache.get(key)));
                 responses.inc({scheme: scheme, target: target, code: res.statusCode});
                 end();
             } else {
-  //              console.log( key, "miss")
+               // console.log( key, "miss", forceReload)
                     const end = histogram.startTimer({scheme: scheme, target: target, cache: 'miss'});
                     res.sendResponse = res.send;
                     res.send = (body) => {
@@ -85,9 +94,9 @@ let cache = () => {
 };
 function isAllowedToBeCached(scheme, target){
     if(environment != "development"){
-        return scheme.indexOf("https")!=-1 && ( target.indexOf(".openaire.eu/") !=-1 || target.indexOf(".zenodo.org/api/") !=-1 || target.indexOf("lab.idiap.ch/enermaps" != -1))
+        return scheme.indexOf("https")!=-1 && ( target.indexOf(".openaire.eu/") !=-1 || target.indexOf("zenodo.org/api") !=-1 || target.indexOf("lab.idiap.ch/enermaps" != -1))
     } else if(environment == "development"){
-        return target.indexOf(".openaire.eu/") !=-1 || target.indexOf(".di.uoa.gr") !=-1 ||  target.indexOf("dev-openaire.d4science.org") !=-1 || target.indexOf("lab.idiap.ch/enermaps") != -1
+        return target.indexOf(".openaire.eu/") !=-1 || target.indexOf(".di.uoa.gr") !=-1 || target.indexOf("zenodo.org/api") !=-1 || target.indexOf("dev-openaire.d4science.org") !=-1 || target.indexOf("lab.idiap.ch/enermaps") != -1
     }
     return true;
 }
diff --git a/services/cache/mecache/package.json b/services/cache/mecache/package.json
index c5b9a32e..f35341f4 100644
--- a/services/cache/mecache/package.json
+++ b/services/cache/mecache/package.json
@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "axios": "^1.6.7",
+    "compression": "^1.7.4",
     "cors": "^2.8.5",
     "express": "^4.18.2",
     "lru-cache": "^10.2.0",