feat: public extend

Signed-off-by: rfyiamcool <rfyiamcool@163.com>

cache.go

@@ -163,6 +163,17 @@ func (c *Cache[T]) Replace(key string, value T) bool {
 	return true
 }
 
+// Extend change the expiry of the item by the specified duration relative to the current time.
+func (c *Cache[T]) Extend(key string, duration time.Duration) bool {
+	item := c.bucket(key).get(key)
+	if item == nil {
+		return false
+	}
+
+	item.Extend(duration)
+	return true
+}
+
 // Attempts to get the value from the cache and calles fetch on a miss (missing
 // or stale item). If fetch returns an error, no value is cached and the error
 // is returned back to the caller.

cache_test.go

@@ -33,6 +33,31 @@ func Test_Setnx(t *testing.T) {
 	assert.Equal(t, cache.ItemCount(), 1)
 }
 
+func Test_Extend(t *testing.T) {
+	cache := New(Configure[string]())
+	defer cache.Stop()
+	assert.Equal(t, cache.ItemCount(), 0)
+
+	// non exist
+	ok := cache.Extend("spice", time.Minute*10)
+	assert.Equal(t, false, ok)
+
+	// exist
+	cache.Set("spice", "flow", time.Minute)
+	assert.Equal(t, cache.ItemCount(), 1)
+
+	ok = cache.Extend("spice", time.Minute*10) // 10 + 10
+	assert.Equal(t, true, ok)
+
+	item := cache.Get("spice")
+	less := time.Minute*22 < time.Duration(item.expires)
+	assert.Equal(t, true, less)
+	more := time.Minute*18 < time.Duration(item.expires)
+	assert.Equal(t, true, more)
+
+	assert.Equal(t, cache.ItemCount(), 1)
+}
+
 func Test_CacheDeletesAValue(t *testing.T) {
 	cache := New(Configure[string]())
 	defer cache.Stop()

readme.md

@@ -111,8 +111,19 @@ cache.Delete("user:4")
 `Clear` clears the cache. If the cache's gc is running, `Clear` waits for it to finish.
 
 ### Extend
+
 The life of an item can be changed via the `Extend` method. This will change the expiry of the item by the specified duration relative to the current time.
 
+```go
+cache.Extend("user:4", time.Minute * 10)
+
+// or
+item := cache.Get("user:4")
+if item != nil {
+  item.Extend(time.Minute * 10)
+}
+```
+
 ### Replace
 The value of an item can be updated to a new value without renewing the item's TTL or it's position in the LRU: