Add 4-hour caching for all generated images

index.js

@@ -8,19 +8,70 @@ const { CardCreator } = require('./create-card');
 const creator = new CardCreator();
 creator.init();
 
-app.get('/characters/id/:charaId.png', async (req, res) => {
-    try {
-        const png = await creator.createCard(req.params.charaId);
-
-        res.writeHead(200, {
-            'Content-Type': 'image/png',
-            'Content-Length': png.length,
-            'Cache-Control': 'public, max-age=14400'
-        });
-        res.end(png, 'binary');
-    }catch(error){
-        res.send(error);
+// node cachemanager
+var cacheManager = require('cache-manager');
+// storage for the cachemanager
+var fsStore = require('cache-manager-fs-binary');
+// initialize caching on disk
+var diskCache = cacheManager.caching({
+    store: fsStore,
+    options: {
+        reviveBuffers: true,
+        binaryAsStream: false,
+        ttl: 60 * 60 * 4 /* seconds */,
+        maxsize: 1000 * 1000 * 1000 /* max size in bytes on disk */,
+        path: 'diskcache',
+        preventfill: true
     }
+});
+
+app.get('/characters/id/:charaId.png', async (req, res) => {
+    var cacheKey = `img:${req.params.charaId}`;
+    var ttl = 60 * 60 * 4; // 4 hours
+
+    diskCache.wrap(cacheKey,
+        // called if the cache misses in order to generate the value to cache
+        function (cb) {
+            creator.createCard(req.params.charaId).then(image => cb(null, {
+                binary: {
+                    image: image,
+                }
+            })).catch((reason) => cb(reason, null));
+        },
+        // Options, see node-cache-manager for more examples
+        { ttl: ttl },
+        function (err, result) {
+            if (err !== null) {
+                res.status(500).send("Lodestone did not respond in time.");
+                return;
+            }
+
+            var image = result.binary.image;
+
+            res.writeHead(200, {
+                'Content-Type': 'image/png',
+                'Content-Length': image.length,
+                'Cache-Control': 'public, max-age=14400'
+            });
+
+            res.end(image, 'binary');
+
+            var usedStreams = ['image'];
+            // you have to do the work to close the unused files
+            // to prevent file descriptors leak
+            for (var key in result.binary) {
+                if (!result.binary.hasOwnProperty(key)) continue;
+                if (usedStreams.indexOf(key) < 0
+                    && result.binary[key] instanceof Stream.Readable) {
+                    if (typeof result.binary[key].close === 'function') {
+                        result.binary[key].close(); // close the stream (fs has it)
+                    } else {
+                        result.binary[key].resume(); // resume to the end and close
+                    }
+                }
+            }
+        }
+    );
 })
 
 app.get('/characters/id/:charaId', async (req, res) => {
@@ -30,25 +81,13 @@ app.get('/characters/id/:charaId', async (req, res) => {
 app.get('/characters/name/:world/:charName.png', async (req, res) => {
     var response = await fetch(`https://xivapi.com/character/search?name=${req.params.charName}&server=${req.params.world}`);
     var data = await response.json();
-    
-    if (data.Results[0] === undefined)
-    {
+
+    if (data.Results[0] === undefined) {
         res.status(404).send("Character not found.");
         return;
     }
 
-    try {
-        const png = await creator.createCard(data.Results[0].ID);
-
-        res.writeHead(200, {
-            'Content-Type': 'image/png',
-            'Content-Length': png.length,
-            'Cache-Control': 'public, max-age=14400'
-        });
-        res.end(png, 'binary');
-    }catch(error){
-        res.send(error);
-    }
+    res.redirect(`/characters/id/${data.Results[0].ID}.png`);
 })
 
 app.get('/characters/name/:world/:charName', async (req, res) => {