These functions were very naive and slow. We haven't done much about
them because they pretty much don't matter at all for Syncthing
performance. They are however called very often in the discovery server
and these optimizations have a huge effect on the CPU load on the
public discovery servers.
The code isn't exactly obvious, but we have good test coverage on all
these functions.
benchmark old ns/op new ns/op delta
BenchmarkLuhnify-8 12458 1045 -91.61%
BenchmarkUnluhnify-8 12598 1074 -91.47%
BenchmarkChunkify-8 10792 104 -99.04%
benchmark old allocs new allocs delta
BenchmarkLuhnify-8 18 1 -94.44%
BenchmarkUnluhnify-8 18 1 -94.44%
BenchmarkChunkify-8 44 2 -95.45%
benchmark old bytes new bytes delta
BenchmarkLuhnify-8 1278 64 -94.99%
BenchmarkUnluhnify-8 1278 64 -94.99%
BenchmarkChunkify-8 42552 128 -99.70%
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4346
9682bbfbda