From 4a10e24f29d4d4d3ac7415611308cf0e6293ae7c Mon Sep 17 00:00:00 2001
From: BugLesser <17674638850@163.com>
Date: Thu, 29 Dec 2022 13:08:49 +0800
Subject: [PATCH 1/3] add Rename() support

---
 cache.go      | 12 ++++++++++++
 cache_test.go | 13 +++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/cache.go b/cache.go
index db88d2f..51f1876 100644
--- a/cache.go
+++ b/cache.go
@@ -115,6 +115,18 @@ func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
 	return nil
 }
 
+func (c *cache) Rename(oldk, newk string) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	item, found := c.get(oldk)
+	if !found {
+		return fmt.Errorf("Item %s doesn't exist", oldk)
+	}
+	delete(c.items, oldk)
+	c.items[newk] = item
+	return nil
+}
+
 // Get an item from the cache. Returns the item or nil, and a bool indicating
 // whether the key was found.
 func (c *cache) Get(k string) (interface{}, bool) {
diff --git a/cache_test.go b/cache_test.go
index de3e9d6..3146ad7 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1137,6 +1137,19 @@ func TestReplace(t *testing.T) {
 	}
 }
 
+func TestRename(t *testing.T) {
+	tc := New(DefaultExpiration, 0)
+	err := tc.Rename("foo", "bar")
+	if err != nil {
+		t.Error(err)
+	}
+	tc.Set("foo", 123, DefaultExpiration)
+	err = tc.Rename("foo", "bar")
+	if err != nil {
+		t.Error(err)
+	}
+}
+
 func TestDelete(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
 	tc.Set("foo", "bar", DefaultExpiration)

From e521233701ec685d6aa0ca33b0727992230c74dc Mon Sep 17 00:00:00 2001
From: BugLesser <17674638850@163.com>
Date: Thu, 29 Dec 2022 05:32:13 +0000
Subject: [PATCH 2/3] add Rename() support

---
 cache.go      | 4 ++--
 cache_test.go | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/cache.go b/cache.go
index 51f1876..4f7630f 100644
--- a/cache.go
+++ b/cache.go
@@ -118,10 +118,10 @@ func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
 func (c *cache) Rename(oldk, newk string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	item, found := c.get(oldk)
-	if !found {
+	if _, found := c.get(oldk); !found {
 		return fmt.Errorf("Item %s doesn't exist", oldk)
 	}
+	item := c.items[oldk]
 	delete(c.items, oldk)
 	c.items[newk] = item
 	return nil
diff --git a/cache_test.go b/cache_test.go
index 3146ad7..57c09be 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1140,8 +1140,8 @@ func TestReplace(t *testing.T) {
 func TestRename(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
 	err := tc.Rename("foo", "bar")
-	if err != nil {
-		t.Error(err)
+	if err == nil {
+		t.Error("Renamed foo when it shouldn't exist")
 	}
 	tc.Set("foo", 123, DefaultExpiration)
 	err = tc.Rename("foo", "bar")

From c0459cf8967306eb1e3f1b9b5249ccfc210fbef1 Mon Sep 17 00:00:00 2001
From: BugLesser <17674638850@163.com>
Date: Thu, 29 Dec 2022 05:35:39 +0000
Subject: [PATCH 3/3] add Rename() support

---
 cache.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cache.go b/cache.go
index 4f7630f..4c33353 100644
--- a/cache.go
+++ b/cache.go
@@ -115,6 +115,8 @@ func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
 	return nil
 }
 
+// Rename for the cache key only if it already exists, and the existing
+// item hasn't expired. Returns an error otherwise.
 func (c *cache) Rename(oldk, newk string) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()