From d22fb9e157281004f75b1861c1ad18d67a11ba22 Mon Sep 17 00:00:00 2001
From: Hongkuan Wang <thewhk@outlook.com>
Date: Sat, 24 Aug 2024 16:53:59 +0800
Subject: [PATCH] Exclude expired keys in data retrieval methods

---
 cache.go      | 30 ++++++++++++++++++++----------
 cache_test.go | 36 ++++++++----------------------------
 2 files changed, 28 insertions(+), 38 deletions(-)

diff --git a/cache.go b/cache.go
index 5168762..3f2bd2d 100644
--- a/cache.go
+++ b/cache.go
@@ -339,8 +339,8 @@ func (c *Cache[K, V]) Has(key K) bool {
 	c.items.mu.RLock()
 	defer c.items.mu.RUnlock()
 
-	_, ok := c.items.values[key]
-	return ok
+	elem, ok := c.items.values[key]
+	return ok && !elem.Value.(*Item[K, V]).isExpiredUnsafe()
 }
 
 // GetOrSet retrieves an item from the cache by the provided key.
@@ -440,22 +440,31 @@ func (c *Cache[K, V]) Touch(key K) {
 	c.items.mu.Unlock()
 }
 
-// Len returns the total number of items in the cache.
+// Len returns the number of unexpired items in the cache.
 func (c *Cache[K, V]) Len() int {
 	c.items.mu.RLock()
 	defer c.items.mu.RUnlock()
 
-	return len(c.items.values)
+	size := 0
+	for _, elem := range c.items.values {
+		if !elem.Value.(*Item[K, V]).isExpiredUnsafe() {
+			size++
+		}
+	}
+
+	return size
 }
 
-// Keys returns all keys currently present in the cache.
+// Keys returns all unexpired keys in the cache.
 func (c *Cache[K, V]) Keys() []K {
 	c.items.mu.RLock()
 	defer c.items.mu.RUnlock()
 
-	res := make([]K, 0, len(c.items.values))
-	for k := range c.items.values {
-		res = append(res, k)
+	res := make([]K, 0)
+	for k, elem := range c.items.values {
+		if !elem.Value.(*Item[K, V]).isExpiredUnsafe() {
+			res = append(res, k)
+		}
 	}
 
 	return res
@@ -478,7 +487,7 @@ func (c *Cache[K, V]) Items() map[K]*Item[K, V] {
 	return items
 }
 
-// Range calls fn for each item present in the cache. If fn returns false,
+// Range calls fn for each unexpired item in the cache. If fn returns false,
 // Range stops the iteration.
 func (c *Cache[K, V]) Range(fn func(item *Item[K, V]) bool) {
 	c.items.mu.RLock()
@@ -491,9 +500,10 @@ func (c *Cache[K, V]) Range(fn func(item *Item[K, V]) bool) {
 
 	for item := c.items.lru.Front(); item != c.items.lru.Back().Next(); item = item.Next() {
 		i := item.Value.(*Item[K, V])
+		expired := i.isExpiredUnsafe()
 		c.items.mu.RUnlock()
 
-		if !fn(i) {
+		if !expired && !fn(i) {
 			return
 		}
 
diff --git a/cache_test.go b/cache_test.go
index 3b250a9..ac7db42 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -652,35 +652,12 @@ func Test_Cache_Delete(t *testing.T) {
 }
 
 func Test_Cache_Has(t *testing.T) {
-	cc := map[string]struct {
-		keys      []string
-		searchKey string
-		has       bool
-	}{
-		"Empty cache": {
-			keys:      []string{},
-			searchKey: "key1",
-			has:       false,
-		},
-		"Key exists": {
-			keys:      []string{"key1", "key2", "key3"},
-			searchKey: "key2",
-			has:       true,
-		},
-		"Key doesn't exist": {
-			keys:      []string{"key1", "key2", "key3"},
-			searchKey: "key4",
-			has:       false,
-		},
-	}
+	cache := prepCache(time.Hour, "1")
+	addToCache(cache, time.Nanosecond, "2")
 
-	for name, tc := range cc {
-		t.Run(name, func(t *testing.T) {
-			c := prepCache(NoTTL, tc.keys...)
-			has := c.Has(tc.searchKey)
-			assert.Equal(t, tc.has, has)
-		})
-	}
+	assert.True(t, cache.Has("1"))
+	assert.False(t, cache.Has("2"))
+	assert.False(t, cache.Has("3"))
 }
 
 func Test_Cache_GetOrSet(t *testing.T) {
@@ -827,11 +804,13 @@ func Test_Cache_Touch(t *testing.T) {
 
 func Test_Cache_Len(t *testing.T) {
 	cache := prepCache(time.Hour, "1", "2")
+	addToCache(cache, time.Nanosecond, "3")
 	assert.Equal(t, 2, cache.Len())
 }
 
 func Test_Cache_Keys(t *testing.T) {
 	cache := prepCache(time.Hour, "1", "2", "3")
+	addToCache(cache, time.Nanosecond, "4")
 	assert.ElementsMatch(t, []string{"1", "2", "3"}, cache.Keys())
 }
 
@@ -851,6 +830,7 @@ func Test_Cache_Items(t *testing.T) {
 
 func Test_Cache_Range(t *testing.T) {
 	c := prepCache(DefaultTTL, "1", "2", "3", "4", "5")
+	addToCache(c, time.Nanosecond, "6")
 	var results []string
 
 	c.Range(func(item *Item[string, string]) bool {