[5.3] Changed startsWith and endsWith to use substr (non mbstring) #15380
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… ok here because it doesn't matter whether it's multi-byte unicode chars or not, just that the same number of bytes match at the start or the end. The performance of the existing methods becomes increasingly slow with larger strings due to mbstring functions.
GrahamCampbell
changed the title
| @@ -403,7 +403,7 @@ public static function snake($value, $delimiter = '_') | |||
| public static function startsWith($haystack, $needles) | |||
| { | |||
| foreach ((array) $needles as $needle) { | |||
| if ($needle != '' && mb_strpos($haystack, $needle) === 0) { | |||
| if ($needle != '' && substr($haystack, 0, strlen($needle)) === $needle) { | |||
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@Perturbatio Why not just strpos($haystack, $needle) === 0 ?
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@vlakoff strpos only bails when it finds a match, in the case of a non-match it runs from the start to the end of the string, if you have a large string (i.e. 4.5MB as in my example) you have to check the entire string which is inefficient since we only care about the first strlen($needle) bytes.
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Got it, great change then :)
One issue though, $needle should be cast to string. I'll make a PR for this tonight.
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This is OK here because it doesn't
matter whether it's multi-byte unicode chars or not, just that the same number of bytes match at
the start or the end.
The performance of the existing methods becomes increasingly slow with larger strings due to
mbstring functions.
See https://gist.github.com/Perturbatio/adfe10304f65fb7bdd1adda0435c2f93 for a test.
Running this on my machine using an extreme example of 4.5MB text@10K iterations returns: