feat: use strings.Replacer

[orisano]

Signed-off-by: Nao YONASHIRO [email protected]

improve performance.

name               old time/op  new time/op  delta
Create-4           13.1µs ± 2%   8.7µs ±10%  -33.99%  (p=0.000 n=9+10)
CreateBuildInfo-4   920ns ± 1%   422ns ±10%  -54.12%  (p=0.000 n=9+10)

[beorn7]

The problem with the strings.Replacer is that it causes allocs, see https://golang.org/src/strings/strings.go?s=22223:22269#L840

The runtime gain is significant, but allocations can bite us in different ways.

I think, however, most of the speed gain happens because most strings don't need escaping at all and could just be copied directly. Thus, we could try to use the same strategy as in strings.Replacer, i.e. first check if escaping is needed at all, and if not, just call w.WriteString directly. That should have an even better effect than the one in this PR.

[beorn7]

Sorry, misread Replace vs. Replacer.

I now think this is doing exactly the right thing. Will just test for allocs to be sure onec I'm at my development computer.

[beorn7]

Confirmed allocation-free-ness. This is exactly what I was looking for but failed to spot in the scrings package. Many thanks for this.

Compared to the original benchmark in #148, this is a reduction in runtime of 54% for Create and 67% for CreateBuildInfo`. Really nice.