Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/processors/ifname/ttl_cache.go

@@ -0,0 +1,62 @@
+package ifname
+
+import (
+	"runtime"
+	"time"
+)
+
+type TTLValType struct {
+	time time.Time // when entry was added
+	val  valType
+}
+
+type timeFunc func() time.Time
+
+type TTLCache struct {
+	validDuration time.Duration
+	lru           LRUCache
+	now           timeFunc
+}
+
+func NewTTLCache(valid time.Duration, capacity uint) TTLCache {
+	return TTLCache{
+		lru:           NewLRUCache(capacity),
+		validDuration: valid,
+		now:           time.Now,
+	}
+}
+
+func (c *TTLCache) Get(key keyType) (valType, bool, time.Duration) {
+	v, ok := c.lru.Get(key)
+	if !ok {
+		return valType{}, false, 0
+	}
+
+	if runtime.GOOS == "windows" {
+		// Sometimes on Windows `c.now().Sub(v.time) == 0` due to clock resolution issues:
+		// https://github.com/golang/go/issues/17696
+		// https://github.com/golang/go/issues/29485
+		// Force clock to refresh:
+		time.Sleep(time.Nanosecond)
+	}
+
+	age := c.now().Sub(v.time)
+	if age < c.validDuration {
+		return v.val, ok, age
+	}
+
+	c.lru.Delete(key)
+	return valType{}, false, 0
+}
+
+func (c *TTLCache) Put(key keyType, value valType) {
+	v := TTLValType{
+		val:  value,
+		time: c.now(),
+	}
+	c.lru.Put(key, v)
+}
+
+func (c *TTLCache) Delete(key keyType) {
+	c.lru.Delete(key)
+}