From c619bbdcc120c20602f1893c76e4e7e30aff8761 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=B6khan=20=C3=96zelo=C4=9Flu?=
 <33967642+gozeloglu@users.noreply.github.com>
Date: Tue, 30 May 2023 13:33:03 +0300
Subject: [PATCH] Add `Range` method

---
 cache.go      | 17 +++++++++++++++++
 cache_test.go | 12 ++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/cache.go b/cache.go
index 2c9df9a..c58a327 100644
--- a/cache.go
+++ b/cache.go
@@ -561,6 +561,23 @@ func (c *Cache[K, V]) OnEviction(fn func(context.Context, EvictionReason, *Item[
 	}
 }
 
+// Range iterate over all items and calls fn function. It calls fn function
+// until it returns false.
+func (c *Cache[K, V]) Range(fn func(item *Item[K, V]) bool) {
+	c.items.mu.RLock()
+	for item := c.items.lru.Front(); item != c.items.lru.Back().Next(); item = item.Next() {
+		i := item.Value.(*Item[K, V])
+		c.items.mu.RUnlock()
+		if !fn(i) {
+			return
+		}
+
+		if item.Next() != nil {
+			c.items.mu.RLock()
+		}
+	}
+}
+
 // Loader is an interface that handles missing data loading.
 type Loader[K comparable, V any] interface {
 	// Load should execute a custom item retrieval logic and
diff --git a/cache_test.go b/cache_test.go
index 977a6f8..65d9b02 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1006,6 +1006,18 @@ func Test_Cache_OnEviction(t *testing.T) {
 	assert.NotContains(t, cache.events.eviction.fns, uint64(1))
 }
 
+func Test_Cache_Range(t *testing.T) {
+	c := prepCache(DefaultTTL, "1", "2", "3", "4", "5")
+	var results []string
+
+	c.Range(func(item *Item[string, string]) bool {
+		results = append(results, item.Key())
+		return item.Key() != "4"
+	})
+
+	assert.Equal(t, []string{"5", "4"}, results)
+}
+
 func Test_LoaderFunc_Load(t *testing.T) {
 	var called bool