internal/cache: add (and move clock to internal/cache/clock)

1 files changed, 33 insertions, 0 deletions

diff --git a/internal/cache/clock/shard_read.go b/internal/cache/clock/shard_read.go
new file mode 100644
index 00000000..624e3409
--- /dev/null
+++ b/internal/cache/clock/shard_read.go
@@ -0,0 +1,33 @@
+package clock
+
+// get returns the value for key and marks it referenced.
+//
+//nolint:ireturn
+func (shard *shard[K, V]) get(key K) (V, bool) {
+	e, ok := shard.items.Load(key)
+	if !ok {
+		var zero V
+
+		return zero, false
+	}
+
+	if !e.referenced.Load() {
+		e.referenced.Store(true)
+	}
+
+	return e.value, true
+}
+
+// peek returns the value for key without affecting eviction.
+//
+//nolint:ireturn
+func (shard *shard[K, V]) peek(key K) (V, bool) {
+	e, ok := shard.items.Load(key)
+	if !ok {
+		var zero V
+
+		return zero, false
+	}
+
+	return e.value, true
+}