修复缓存策略无法切换文件和内存的问题

internal/caches/storage_file.go

@@ -111,6 +111,15 @@ func (this *FileStorage) Policy() *serverconfigs.HTTPCachePolicy {
 
 // CanUpdatePolicy 检查策略是否可以更新
 func (this *FileStorage) CanUpdatePolicy(newPolicy *serverconfigs.HTTPCachePolicy) bool {
+	if newPolicy == nil {
+		return false
+	}
+
+	// 检查类型
+	if newPolicy.Type != serverconfigs.CachePolicyStorageFile {
+		return false
+	}
+
 	// 检查路径是否有变化
 	oldOptionsJSON, err := json.Marshal(this.policy.Options)
 	if err != nil {

internal/caches/storage_memory.go

@@ -366,7 +366,7 @@ func (this *MemoryStorage) UpdatePolicy(newPolicy *serverconfigs.HTTPCachePolicy
 
 // CanUpdatePolicy 检查策略是否可以更新
 func (this *MemoryStorage) CanUpdatePolicy(newPolicy *serverconfigs.HTTPCachePolicy) bool {
-	return true
+	return newPolicy != nil && newPolicy.Type == serverconfigs.CachePolicyStorageMemory
 }
 
 // AddToList 将缓存添加到列表