refactor(重构代码): 重构并保持接口兼容

qqwry_cache.go

@@ -0,0 +1,66 @@
+package qqwry
+
+import (
+	"container/list"
+	"sync"
+)
+
+// cacheEntry 缓存条目
+type cacheEntry struct {
+	key   string
+	value *Location
+}
+
+// Cache 简单的LRU缓存实现
+// 字段: capacity 容量, list 双向链表, items哈希表, lock 互斥锁
+type Cache struct {
+	capacity int
+	list     *list.List
+	items    map[string]*list.Element
+	lock     sync.Mutex
+}
+
+// NewCache 创建新的LRU缓存
+// 入参: capacity 缓存容量
+// 返回: *Cache 缓存实例
+func NewCache(capacity int) *Cache {
+	return &Cache{
+		capacity: capacity,
+		list:     list.New(),
+		items:    make(map[string]*list.Element),
+	}
+}
+
+// Get 获取缓存
+// 入参: key 键
+// 返回: value 值, ok 是否存在
+func (c *Cache) Get(key string) (value *Location, ok bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if ent, ok := c.items[key]; ok {
+		c.list.MoveToFront(ent)
+		return ent.Value.(*cacheEntry).value, true
+	}
+	return nil, false
+}
+
+// Add 添加缓存
+// 入参: key 键, value 值
+func (c *Cache) Add(key string, value *Location) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if ent, ok := c.items[key]; ok {
+		c.list.MoveToFront(ent)
+		ent.Value.(*cacheEntry).value = value
+		return
+	}
+	ent := c.list.PushFront(&cacheEntry{key: key, value: value})
+	c.items[key] = ent
+	if c.list.Len() > c.capacity {
+		back := c.list.Back()
+		if back != nil {
+			c.list.Remove(back)
+			delete(c.items, back.Value.(*cacheEntry).key)
+		}
+	}
+}