Bug #81378 [Opn]: mb_detect_encoding() performance regression in PHP 8.1

Edit report at https://bugs.php.net/bug.php?id=81378&edit=1 ID: 81378 Updated by: nikic@php.net Reported by: gfpuba+php at gmail dot com -Summary: Performance problem +Summary: mb_detect_encoding() performance regression in PHP 8.1 Status: Open Type: Bug Package: Scripting Engine problem Operating System: Win10 Apache/2.4.48 PHP Version: 8.1.0beta3 Block user comment: N Private report: N New Comment: Encoding detection now scores encodings based on character properties, and the property lookups are very expensive and make up the majority of the execution time now. We don't actually need them for the case of a single encoding, but I assume that was just a minimal reduction, because calling mb_detect_encoding() with a single encoding doesn't make sense (mb_check_encoding() should be used instead). Previous Comments: ------------------------------------------------------------------------ [2021-08-23 20:10:41] gfpuba+php at gmail dot com Description: ------------ The following code takes 10 times longer to execute on PHP/8.1.0beta3 compare to PHP 8.0.8 Test script: --------------- $a = str_repeat('abcdef', 10000); $b = mb_detect_encoding($a, 'UTF-8', true); ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81378&edit=1