[TASK] Iterate over characters #21
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added 2 commits
May 16, 2022 14:54
The complexity of splitting a string once into an array and iterating over it is O(2n) as where having to `mb_substr` for each character is O(n^2). This can lead to quite harsh performance issues when trying to calculate a diff for longer texts. See the TYPO3 [TypoScript Tokenizer][1] for another example of this implementation. [1]: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74285/28..29/typo3/sysext/core/Classes/TypoScript/Tokenizer/Tokenizer.php
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As discussed on typo3.slack.com, here's my contribution to improving the performance of finediff.
The complexity of splitting a string once into an array and iterating over it is O(2n) as where having to
mb_substrfor each character is O(n^2). This can lead to quite harsh performance issues when trying to calculate a diff for longer texts.See the TYPO3 [TypoScript Tokenizer][1] for another example of this implementation.
[1]: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74285/28..29/typo3/sysext/core/Classes/TypoScript/Tokenizer/Tokenizer.php