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