Added multiple download option

server/routes/params.js

@@ -0,0 +1,32 @@
+const storage = require('../storage');
+
+function validateID(route_id) {
+  return route_id.match(/^[0-9a-fA-F]{10}$/) !== null;
+}
+
+module.exports = async function(req, res) {
+  const id = req.params.id;
+  if (!validateID(id)) {
+    return res.sendStatus(404);
+  }
+  const ownerToken = req.body.owner_token;
+  if (!ownerToken) {
+    return res.sendStatus(400);
+  }
+
+  const dlimit = req.body.dlimit;
+  if (!dlimit || dlimit > 20) {
+    return res.sendStatus(400);
+  }
+
+  try {
+    const meta = await storage.metadata(id);
+    if (meta.owner !== ownerToken) {
+      return res.sendStatus(400);
+    }
+    storage.setField(id, 'dlimit', dlimit);
+    res.sendStatus(200);
+  } catch (e) {
+    res.sendStatus(404);
+  }
+};