status-go/vendor/github.com/whyrusleeping/timecache/timecache.go

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package timecache
import (
"container/list"
"time"
)
type TimeCache struct {
Q *list.List
M map[string]time.Time
span time.Duration
}
func NewTimeCache(span time.Duration) *TimeCache {
return &TimeCache{
Q: list.New(),
M: make(map[string]time.Time),
span: span,
}
}
func (tc *TimeCache) Add(s string) {
_, ok := tc.M[s]
if ok {
panic("putting the same entry twice not supported")
}
tc.sweep()
tc.M[s] = time.Now()
tc.Q.PushFront(s)
}
func (tc *TimeCache) sweep() {
for {
back := tc.Q.Back()
if back == nil {
return
}
v := back.Value.(string)
t, ok := tc.M[v]
if !ok {
panic("inconsistent cache state")
}
if time.Since(t) > tc.span {
tc.Q.Remove(back)
delete(tc.M, v)
} else {
return
}
}
}
func (tc *TimeCache) Has(s string) bool {
_, ok := tc.M[s]
return ok
}