febdac0499
tstime: write Parse3339 parse that doesn't use time.Parse
...
It doesn't allocate and it's half the time of time.Parse (which
allocates), and 2/3rds the time of time.ParseInLocation (which
doesn't).
Go with a UTC time:
BenchmarkGoParse3339/Z-8 2200995 534 ns/op 0 B/op 0 allocs/op
BenchmarkGoParse3339/Z-8 2254816 554 ns/op 0 B/op 0 allocs/op
BenchmarkGoParse3339/Z-8 2159504 522 ns/op 0 B/op 0 allocs/op
Go allocates with a "-08:00" suffix instead of ending in "Z":
BenchmarkGoParse3339/TZ-8 1276491 884 ns/op 144 B/op 3 allocs/op
BenchmarkGoParse3339/TZ-8 1355858 942 ns/op 144 B/op 3 allocs/op
BenchmarkGoParse3339/TZ-8 1385484 911 ns/op 144 B/op 3 allocs/op
Go doesn't allocate if you use time.ParseInLocation, but then you need
to parse the string to find the location anyway, so might as well go
all the way (below).
BenchmarkGoParse3339InLocation-8 1912254 597 ns/op 0 B/op 0 allocs/op
BenchmarkGoParse3339InLocation-8 1980043 612 ns/op 0 B/op 0 allocs/op
BenchmarkGoParse3339InLocation-8 1891366 612 ns/op 0 B/op 0 allocs/op
Parsing RFC3339 ourselves, UTC:
BenchmarkParse3339/Z-8 3889220 307 ns/op 0 B/op 0 allocs/op
BenchmarkParse3339/Z-8 3718500 309 ns/op 0 B/op 0 allocs/op
BenchmarkParse3339/Z-8 3621231 303 ns/op 0 B/op 0 allocs/op
Parsing RFC3339 ourselves, with timezone (w/ *time.Location fetched
from sync.Map)
BenchmarkParse3339/TZ-8 3019612 418 ns/op 0 B/op 0 allocs/op
BenchmarkParse3339/TZ-8 2921618 401 ns/op 0 B/op 0 allocs/op
BenchmarkParse3339/TZ-8 3031671 408 ns/op 0 B/op 0 allocs/op
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-06 08:19:17 -07:00
David Anderson
Brad Fitzpatrick