freelru: Fix purge

contrab/freelru/lru.go

@@ -592,7 +592,8 @@ func (lru *LRU[K, V]) Keys() []K {
 // The evict function is called for each expired item.
 // The LRU metrics are reset.
 func (lru *LRU[K, V]) Purge() {
-	for i := uint32(0); i < lru.len; i++ {
+	lruLen := lru.len
+	for i := uint32(0); i < lruLen; i++ {
 		_, _, _ = lru.RemoveOldest()
 	}
 
@@ -602,7 +603,8 @@ func (lru *LRU[K, V]) Purge() {
 // PurgeExpired purges all expired items from the LRU.
 // The evict function is called for each expired item.
 func (lru *LRU[K, V]) PurgeExpired() {
-	for i := uint32(0); i < lru.len; i++ {
+	lruLen := lru.len
+	for i := uint32(0); i < lruLen; i++ {
 		pos := lru.elements[lru.head].next
 		if lru.elements[pos].expire != 0 {
 			if lru.elements[pos].expire > now() {

contrab/freelru/lru_test.go

@@ -76,3 +76,20 @@ func TestUpdateLifetime2(t *testing.T) {
 	_, ok = lru.Get("hello")
 	require.False(t, ok)
 }
+
+func TestPeekWithLifetime(t *testing.T) {
+	t.Parallel()
+	lru, err := freelru.New[string, string](1024, maphash.NewHasher[string]().Hash32)
+	require.NoError(t, err)
+	lru.SetLifetime(time.Second)
+	lru.Add("1", "")
+	time.Sleep(300 * time.Millisecond)
+	lru.Add("2", "")
+	time.Sleep(300 * time.Millisecond)
+	lru.Add("3", "")
+	time.Sleep(300 * time.Millisecond)
+	lru.Add("4", "")
+	time.Sleep(time.Second)
+	lru.PurgeExpired()
+	require.Equal(t, 0, lru.Len())
+}