63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
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package ifname
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import (
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"runtime"
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"time"
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)
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type TTLValType struct {
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time time.Time // when entry was added
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val valType
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}
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type timeFunc func() time.Time
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type TTLCache struct {
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validDuration time.Duration
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lru LRUCache
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now timeFunc
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}
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func NewTTLCache(valid time.Duration, capacity uint) TTLCache {
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return TTLCache{
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lru: NewLRUCache(capacity),
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validDuration: valid,
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now: time.Now,
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}
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}
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func (c *TTLCache) Get(key keyType) (valType, bool, time.Duration) {
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v, ok := c.lru.Get(key)
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if !ok {
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return valType{}, false, 0
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}
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if runtime.GOOS == "windows" {
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// Sometimes on Windows `c.now().Sub(v.time) == 0` due to clock resolution issues:
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// https://github.com/golang/go/issues/17696
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// https://github.com/golang/go/issues/29485
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// Force clock to refresh:
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time.Sleep(time.Nanosecond)
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}
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age := c.now().Sub(v.time)
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if age < c.validDuration {
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return v.val, ok, age
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}
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c.lru.Delete(key)
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return valType{}, false, 0
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}
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func (c *TTLCache) Put(key keyType, value valType) {
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v := TTLValType{
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val: value,
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time: c.now(),
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}
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c.lru.Put(key, v)
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}
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func (c *TTLCache) Delete(key keyType) {
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c.lru.Delete(key)
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}
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