Skip to content

Set tzbounds to limit number of tzdata polygons to evaluate #21

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
albertyw wants to merge 2 commits into
base: master
Choose a base branch
from
Open

Set tzbounds to limit number of tzdata polygons to evaluate #21

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
80fadc4
Add tzid into tzdata
albertyw Feb 25, 2023
76b4476
Use a precomputed set of bounds to limit the number of timezones to c…
albertyw Feb 25, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 23 additions & 11 deletions localtimezone.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -86,15 +86,17 @@ type LocalTimeZone interface {
}

type tzData struct {
tzid string
polygon *orb.Polygon
multiPolygon *orb.MultiPolygon
bound *orb.Bound
centers []orb.Point
}

type immutableCache struct {
tzids []string
tzData map[string]tzData
tzids []string
tzData map[string]tzData
tzBounds map[float64][]tzData
}

type localTimeZone struct {
Expand Down Expand Up @@ -161,14 +163,13 @@ func (z *localTimeZone) getZone(point Point, single bool) (tzids []string, err e
return nil, ErrOutOfRange
}
cache := z.data.Load()
for _, id := range cache.tzids {
d := cache.tzData[id]
for _, d := range cache.tzBounds[math.Floor(point.Lon)] {
if !d.bound.Contains(p) {
continue
}
if d.polygon != nil {
if planar.PolygonContains(*d.polygon, p) {
tzids = append(tzids, id)
tzids = append(tzids, d.tzid)
if single {
return
}
Expand All @@ -177,7 +178,7 @@ func (z *localTimeZone) getZone(point Point, single bool) (tzids []string, err e
}
if d.multiPolygon != nil {
if planar.MultiPolygonContains(*d.multiPolygon, p) {
tzids = append(tzids, id)
tzids = append(tzids, d.tzid)
if single {
return
}
Expand Down Expand Up @@ -227,13 +228,16 @@ func (z *localTimeZone) buildCache(features []*geojson.Feature) {
var wg sync.WaitGroup
var m sync.Mutex
tzDatas := make(map[string]tzData, len(features))
tzBounds := make(map[float64][]tzData)
for _, f := range features {
wg.Add(1)
go func(f *geojson.Feature) {
defer wg.Done()
id := f.Properties.MustString("tzid")
var multiPolygon orb.MultiPolygon
d := tzData{}
d := tzData{
tzid: id,
}
polygon, ok := f.Geometry.(orb.Polygon)
if ok {
d.polygon = &polygon
Expand All @@ -254,6 +258,9 @@ func (z *localTimeZone) buildCache(features []*geojson.Feature) {
d.centers = tzCenters
m.Lock()
tzDatas[id] = d
for lon := math.Floor(bound.Left()); lon < math.Ceil(bound.Right()); lon += 1 {
tzBounds[lon] = append(tzBounds[lon], d)
}
m.Unlock()
}(f)
}
Expand All @@ -266,9 +273,13 @@ func (z *localTimeZone) buildCache(features []*geojson.Feature) {
i++
}
sort.Strings(tzids)
for _, tzDatas := range tzBounds {
sort.Slice(tzDatas, func(i, j int) bool { return tzDatas[i].tzid < tzDatas[j].tzid })
}
cache := immutableCache{
tzData: tzDatas,
tzids: tzids,
tzData: tzDatas,
tzids: tzids,
tzBounds: tzBounds,
}
z.data.Store(&cache)
}
Expand All @@ -283,8 +294,9 @@ func (z *localTimeZone) LoadGeoJSON(r io.Reader) error {
orbData, err := geojson.UnmarshalFeatureCollection(buf.Bytes())
if err != nil {
cache := immutableCache{
tzData: make(map[string]tzData),
tzids: []string{},
tzData: make(map[string]tzData),
tzids: []string{},
tzBounds: make(map[float64][]tzData),
}
z.data.Store(&cache)
return err
Expand Down