The manifestViewer tool of Dev Tools Pro is written by Kotlin, it’s so slowly on some devices. I found it’s caused by String.replace after performance tuning.

The size of the source text is about 1.1m, call replace three times, replace of Kotlin takes about 2123ms, replace of Java takes about 250ms.

why the performance is so poor. The source code of Kotlin is here, will found it use split and join. but Java use regx.