/
timeline.go
63 lines (54 loc) · 1.12 KB
/
timeline.go
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package pktque
import (
"time"
)
/*
pop push
seg seg seg
|--------| |---------| |---|
20ms 40ms 5ms
----------------- time -------------------->
headtm tailtm
*/
type tlSeg struct {
tm, dur time.Duration
}
// Timeline struct
type Timeline struct {
segs []tlSeg
headtm time.Duration
}
// Push func
func (inst *Timeline) Push(tm time.Duration, dur time.Duration) {
if len(inst.segs) > 0 {
tail := inst.segs[len(inst.segs)-1]
diff := tm - (tail.tm + tail.dur)
if diff < 0 {
tm -= diff
}
}
inst.segs = append(inst.segs, tlSeg{tm, dur})
}
// Pop func
func (inst *Timeline) Pop(dur time.Duration) (tm time.Duration) {
if len(inst.segs) == 0 {
return inst.headtm
}
tm = inst.segs[0].tm
for dur > 0 && len(inst.segs) > 0 {
seg := &inst.segs[0]
sub := dur
if seg.dur < sub {
sub = seg.dur
}
seg.dur -= sub
dur -= sub
seg.tm += sub
inst.headtm += sub
if seg.dur == 0 {
copy(inst.segs[0:], inst.segs[1:])
inst.segs = inst.segs[:len(inst.segs)-1]
}
}
return
}