57 lines
902 B
Go
57 lines
902 B
Go
package timecache
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import (
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"context"
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"sync"
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"time"
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)
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// FirstSeenCache is a time cache that only marks the expiry of a message when first added.
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type FirstSeenCache struct {
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lk sync.RWMutex
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m map[string]time.Time
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ttl time.Duration
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done func()
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}
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var _ TimeCache = (*FirstSeenCache)(nil)
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func newFirstSeenCache(ttl time.Duration) *FirstSeenCache {
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tc := &FirstSeenCache{
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m: make(map[string]time.Time),
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ttl: ttl,
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}
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ctx, done := context.WithCancel(context.Background())
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tc.done = done
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go background(ctx, &tc.lk, tc.m)
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return tc
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}
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func (tc *FirstSeenCache) Done() {
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tc.done()
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}
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func (tc *FirstSeenCache) Has(s string) bool {
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tc.lk.RLock()
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defer tc.lk.RUnlock()
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_, ok := tc.m[s]
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return ok
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}
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func (tc *FirstSeenCache) Add(s string) bool {
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tc.lk.Lock()
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defer tc.lk.Unlock()
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_, ok := tc.m[s]
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if ok {
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return false
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}
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tc.m[s] = time.Now().Add(tc.ttl)
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return true
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}
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