add expires to peek method

cache.go

@@ -175,8 +175,8 @@ func (c *Cache[K, V]) GetOrLoad(key K) (value V, err error, ok bool) {
 	return
 }
 
-// Peek returns value for key, but does not modify its recency.
-func (c *Cache[K, V]) Peek(key K) (value V, ok bool) {
+// Peek returns value and expires nanoseconds for key, but does not modify its recency.
+func (c *Cache[K, V]) Peek(key K) (value V, expires int64, ok bool) {
 	hash := uint32(c.hasher(key))
 	return c.shards[hash&c.mask].Peek(hash, key)
 }

cache_test.go

@@ -185,26 +185,26 @@ func TestCachePeek(t *testing.T) {
 	cache := New[int, int](64)
 
 	cache.Set(10, 10, 0)
-	cache.Set(20, 20, 0)
-	if v, ok := cache.Peek(10); !ok || v != 10 {
-		t.Errorf("10 should be set to 10: %v,", v)
+	cache.Set(20, 20, time.Hour)
+	if v, expires, ok := cache.Peek(10); !ok || v != 10 || expires != 0 {
+		t.Errorf("10 should be set to 10: %v, %v", v, expires)
 	}
 
-	if v, ok := cache.Peek(20); !ok || v != 20 {
+	if v, expires, ok := cache.Peek(20); !ok || v != 20 || expires == 0 {
 		t.Errorf("20 should be set to 20: %v,", v)
 	}
 
-	if v, ok := cache.Peek(30); ok || v != 0 {
+	if v, expires, ok := cache.Peek(30); ok || v != 0 || expires != 0 {
 		t.Errorf("30 should be set to 0: %v,", v)
 	}
 
 	for k := 3; k < 1024; k++ {
 		cache.Set(k, k, 0)
 	}
-	if v, ok := cache.Peek(10); ok || v == 10 {
+	if v, _, ok := cache.Peek(10); ok || v == 10 {
 		t.Errorf("%v should not have updated recent-ness of 10", v)
 	}
-	if v, ok := cache.Peek(30); ok || v != 0 {
+	if v, _, ok := cache.Peek(30); ok || v != 0 {
 		t.Errorf("%v should have updated recent-ness of 30", v)
 	}
 }

clock.go

@@ -11,9 +11,9 @@ import (
 // always use `atomic.LoadUint32(&clock)` for accessing clock value.
 var clock uint32
 
-func clocking() {
-	const clockBase = 1704067200 // 2024-01-01T00:00:00Z
+const clockBase = 1704067200 // 2024-01-01T00:00:00Z
 
+func clocking() {
 	if atomic.LoadUint32(&clock) > 0 {
 		return
 	}

shard.go

@@ -104,11 +104,14 @@ func (s *shard[K, V]) Get(hash uint32, key K) (value V, ok bool) {
 	return
 }
 
-func (s *shard[K, V]) Peek(hash uint32, key K) (value V, ok bool) {
+func (s *shard[K, V]) Peek(hash uint32, key K) (value V, expires int64, ok bool) {
 	s.mu.Lock()
 
 	if index, exists := s.table_Get(hash, key); exists {
 		value = s.list[index].value
+		if e := s.list[index].expires; e > 0 {
+			expires = (int64(e) + clockBase) * int64(time.Second)
+		}
 		ok = true
 	}