perf: small performance improvement avoiding Array#unshift

Author: fent

lib/feedsub.js

@@ -122,6 +122,9 @@ module.exports = class FeedReader extends EventEmitter {
     const success = (abort) => {
       if (ended) { return; }
       ended = true;
+      if (sortOrder <= 0) {
+        newItems.reverse();
+      }
       this.news.addHistory('item', newItems.map((item) => [item]));
       if (this.first && !this.options.emitOnStart) {
         newItems = [];
@@ -260,11 +263,11 @@ module.exports = class FeedReader extends EventEmitter {
 
       const getOlderItem = (item) => {
         if (this.first) {
-          newItems.unshift(item);
+          newItems.push(item);
         } else if (!ended) {
           let emitted = this.news.emit('item', item);
           if (emitted) {
-            newItems.unshift(item);
+            newItems.push(item);
           } else {
             // Check if this item has already been read in previous requests
             // if it has, then stop parsing the rest of the document.