From 83889405f9125530a54363546c08b894af081396 Mon Sep 17 00:00:00 2001
From: David Weber | geOps <david.weber@geops.de>
Date: Thu, 11 Mar 2021 17:10:51 +0100
Subject: [PATCH] fix blocking of tileserver while serving index

we noticed sporadic long blocks of the entier tileserver on version 3.1.1
They always happend when somebody accessed the frontPage.
Our guess is, that clone() blocks the object and takes very long to finish.

We replaced the clone with ES6 magic from https://stackoverflow.com/a/42988763
and the problem is gone.

Also the time to generate the index goesm from ~3s to ~0.2s
This should primarily affect user with many large styles
---
 src/server.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/server.js b/src/server.js
index 9fedc02..b56eb83 100644
--- a/src/server.js
+++ b/src/server.js
@@ -330,7 +330,7 @@ function start(opts) {
   };
 
   serveTemplate('/$', 'index', req => {
-    const styles = clone(serving.styles || {});
+    const styles = Object.assign({}, serving.styles || {}, {});
     for (const id of Object.keys(styles)) {
       const style = styles[id];
       style.name = (serving.styles[id] || serving.rendered[id] || {}).name;
@@ -350,7 +350,7 @@ function start(opts) {
           `styles/${id}`, style.serving_rendered.tileJSON.format, opts.publicUrl)[0];
       }
     }
-    const data = clone(serving.data || {});
+    const data = Object.assign({}, serving.data || {}, {});
     for (const id of Object.keys(data)) {
       const data_ = data[id];
       const tilejson = data[id].tileJSON;