From 89e2ab9b872f34361bed8274f3d90cda6abddced Mon Sep 17 00:00:00 2001
From: Thomas Lange <code@nerdmind.de>
Date: Fri, 16 Jul 2021 23:50:07 +0200
Subject: Improve performance of parseUnicodeEmoticons

Make the function parseUnicodeEmoticons significantly faster by using
a single regex operation to match and process all unicode emoticons.
---
 core/functions.php | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/core/functions.php b/core/functions.php
index a9d103e..b622601 100644
--- a/core/functions.php
+++ b/core/functions.php
@@ -306,14 +306,16 @@ function getUnicodeEmoticons(): array {
 # Wrap emoticons in <span> element with "title" attribute for explanation
 #===============================================================================
 function parseUnicodeEmoticons($string): string {
-	foreach(getUnicodeEmoticons() as $emoticon => $explanation) {
-		$pattern = '#(^|\s)'.preg_quote($emoticon).'#';
-		$replace = "\\1<span title=\"{$explanation}\">{$emoticon}</span>";
-
-		$string = preg_replace($pattern, $replace, $string);
-	}
-
-	return $string;
+	$emoticon_data = getUnicodeEmoticons();
+	$emoticon_list = array_keys($emoticon_data);
+	$emoticon_list = implode('|', $emoticon_list);
+
+	return preg_replace_callback("#($emoticon_list)#", function($matches)
+	use($emoticon_data) {
+		$emoticon = $matches[1];
+		$explanation = $emoticon_data[$emoticon];
+		return sprintf('<span title="%s">%s</span>', $explanation, $emoticon);
+	}, $string);
 }
 
 #===============================================================================
-- 
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