An interval tree is a balanced binary search tree designed to efficiently store and query intervals. It allows for queries of the form "find all intervals that overlap with a given interval" or "find an interval that contains a specific point."
This library is extracted from etcd
$ go get github.com/arjunsk/intervalst
package main
import (
"fmt"
"github.com/arjunsk/intervalst"
)
func main() {
ist := intervalst.NewIntervalTree()
ist.Insert(intervalst.NewInt64Interval(1, 3), "user1")
ist.Insert(intervalst.NewInt64Interval(9, 13), "user2")
ist.Insert(intervalst.NewInt64Interval(7, 20), "user3")
// Output :
// given interval {Begin:4 End:8} overlaps with these existing intervals
// interval_st interval: &{Ivl:{Begin:7 End:20} Val:user3}
findIntervalIntersections(ist, intervalst.NewInt64Interval(4, 8))
// Output :
// given point {Begin:10 End:11} overlaps with these existing intervals
// interval_st interval: &{Ivl:{Begin:7 End:20} Val:user3}
// interval_st interval: &{Ivl:{Begin:9 End:13} Val:user2}
findPointIntersections(ist, intervalst.NewInt64Point(10))
// Output : 3
fmt.Println(ist.Len())
// Output:
// given interval {Begin:4 End:8} does not overlap with any existing intervals
ist.Delete(intervalst.NewInt64Interval(7, 20))
findIntervalIntersections(ist, intervalst.NewInt64Interval(4, 8))
}
func findPointIntersections(ist intervalst.IntervalTree, newPoint intervalst.Interval) {
if ist.Intersects(newPoint) {
fmt.Printf("given point %+v overlaps with these existing intervals \n", newPoint)
rs := ist.Stab(newPoint)
for _, v := range rs {
fmt.Printf("interval_st interval: %+v\n", v)
}
fmt.Println()
}
}
func findIntervalIntersections(ist intervalst.IntervalTree, newInterval intervalst.Interval) {
if ist.Intersects(newInterval) {
fmt.Printf("given interval %+v overlaps with these existing intervals \n", newInterval)
rs := ist.Stab(newInterval)
for _, v := range rs {
fmt.Printf("interval_st interval: %+v\n", v)
}
fmt.Println()
} else {
fmt.Printf("given interval %+v does not overlap with any existing intervals \n", newInterval)
}
}