mime: speed up ParseMediaType
Add benchmarks for ParseMediaType.
Eschew UTF-8 decoding and strings.IndexFunc where possible, and rely
on 128-bit bitmaps instead. Eliminate some bounds checks.
Some benchmark results (no changes to allocations):
goos: darwin
goarch: amd64
pkg: mime
cpu: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
│ old │ new │
│ sec/op │ sec/op vs base │
ParseMediaType-8 71.75µ ± 0% 55.53µ ± 0% -22.60% (p=0.000 n=20)
ParseMediaTypeBogus-8 5.330µ ± 0% 3.603µ ± 0% -32.41% (p=0.000 n=20)
geomean 19.56µ 14.14µ -27.67%
Change-Id: I324c9990fe43581484916ecff61ca6c708467a89
GitHub-Last-Rev:
e2293d64b3852722bef920169eaa44e7ded3111c
GitHub-Pull-Request: golang/go#73436
Reviewed-on: https://go-review.googlesource.com/c/go/+/666655
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sean Liao <sean@liao.dev>