From 45742005cade9356f34a5fe7e07be7192bdfc2bd Mon Sep 17 00:00:00 2001
From: Li Xinrui <lixinrui000@gmail.com>
Date: Mon, 30 Aug 2021 15:09:05 +0800
Subject: [PATCH] Speed up app identification greatly by using compiled regex
 and substring.

---
 src/HandyWinget/Common/Helper.cs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/HandyWinget/Common/Helper.cs b/src/HandyWinget/Common/Helper.cs
index 3056431..334d4da 100644
--- a/src/HandyWinget/Common/Helper.cs
+++ b/src/HandyWinget/Common/Helper.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Text;
+using System.Globalization;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
@@ -329,10 +331,16 @@ public static IEnumerable<string> GetInstalledAppList()
         /// <param name="line">installed app line details, extracted from winget list command</param>
         /// <param name="packageId"></param>
         /// <returns></returns>
+        private static Regex re = new Regex("[ ]{2,}", RegexOptions.Compiled | RegexOptions.IgnoreCase);
         public static (string packageId, string version, string availableVersion) ParseInstalledApp(string line, string packageId)
         {
-            line = Regex.Replace(line, "[ ]{2,}", " ", RegexOptions.IgnoreCase); // remove more than 2 spaces
-            line = Regex.Replace(line, $@".*(?=({Regex.Escape(packageId)}))", "", RegexOptions.IgnoreCase); // remove everythings before package id
+            line = re.Replace(line, " ");
+            int startIndex = line.IndexOf(packageId);
+            if(startIndex < 0)
+            {
+                return (packageId: null, version: null, availableVersion: null);
+            }
+            line = line.Substring(startIndex);
             var lines = line.Split(" ");
             if (lines.Count() >= 3) // available version exist
             {