String optimize

[pixelherodev]

Slight speed-up for a few string conversions.

Strings are immutable. As such, string([]byte(foo)), given a mutable buffer, must copy the string, so that changes to the underlying slice do not break the language's requirements.

unsafe.String(foo, length), instead, crafts a string header pointing to the existing buffer. So long as that buffer is never modified for the lifetime of the string, this can be totally safe, and is faster.

Since the flatbufs will never be modified, it's totally safe to craft strings that point directly into its innards. The string pointer is sufficient to prevent GC, and we never modify that flatbuf data on read paths.

Tests pass and there's a small but measurable performance improvement in profiles I was looking at.

[zeroshade]

do we see any measurable performance difference in the existing benchmarks?

[pixelherodev]

I don't think so.

For the profiles I was looking at, the rate of timestamps was sufficient that this minor savings was happening millions of times per second, and was still pretty small, I think. I can double check, but this one might be worth skipping, yeah.

[zeroshade]

@pixelherodev can you fix the lint issue any the failures here?