Cache LoadLocation results - #34
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time.LoadLocation re-parses the zoneinfo out of the tzdata database on every call (~10µs and several KB of garbage for a typical zone) and does not cache internally. zmanim.New loads a timezone from its tzid string on every construction, which for a multi-day date range means re-parsing the same zone once per day. Add a public zmanim.LoadLocation that memoizes successful lookups in a sync.Map (the returned *time.Location is immutable and safe to share), and use it in zmanim.New. Cached hits drop from ~10µs/~8KB to ~20ns/0 allocs. Only successful lookups are cached, since an unknown tzid is caller-controlled, potentially unbounded input. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01SnNqQE8n9SckYpeaHgcWsV
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time.LoadLocationre-parses the zoneinfo out of the tzdata database on every call and does not cache internally (onlyUTC/Localare special-cased).zmanim.Newloads a timezone from itsTimeZoneIdstring on every construction, so a multi-day date range re-parses the same zone once per day.Measured against the standard library (embedded tzdata):
time.LoadLocation("America/New_York")time.LoadLocation("Asia/Jerusalem")Change
zmanim.LoadLocation(name string) (*time.Location, error)that memoizes successful lookups in async.Map. The returned*time.Locationis immutable and safe to share.zmanim.New.Verification
go build ./...,go vet ./zmanim/,gofmt -l, and the fullgo test ./...are clean; a newTestLoadLocationcovers the cached-pointer identity and the invalid-tz error path.This is the shared home for the cache that
hebcal-api-gowill reuse (it has several of its owntime.LoadLocationcall sites for tzid validation and responseExpiresheaders).🤖 Generated with Claude Code
https://claude.ai/code/session_01SnNqQE8n9SckYpeaHgcWsV
Generated by Claude Code