diff --git a/cache/cache.go b/cache/cache.go
index 898efc3..04d75ef 100644
--- a/cache/cache.go
+++ b/cache/cache.go
@@ -4,6 +4,7 @@ package cache
 import (
     "crypto/sha256"
     "encoding/hex"
+    "strconv"
     "sync"
     "time"
 )
@@ -17,11 +18,11 @@ type CacheEntry struct {
 }
 
 type MemoryCache struct {
-    entries    sync.Map
-    maxSize    int64
+    entries     sync.Map
+    maxSize     int64
     currentSize int64
-    ttl        time.Duration
-    mu         sync.Mutex
+    ttl         time.Duration
+    mu          sync.Mutex
 }
 
 func NewMemoryCache(maxSize int64, ttl time.Duration) *MemoryCache {
@@ -31,20 +32,24 @@ func NewMemoryCache(maxSize int64, ttl time.Duration) *MemoryCache {
     }
     
     // 启动清理协程
-    go mc.cleanup()
+    if ttl > 0 {
+        go mc.cleanup()
+    }
     
     return mc
 }
 
+// Age 返回缓存条目的年龄（秒）
 func (e *CacheEntry) Age() string {
-    age := time.Since(e.Timestamp)
+    age := time.Since(e.CreatedAt)
     return strconv.FormatInt(int64(age.Seconds()), 10)
 }
 
-func (mc *MemoryCache) Get(key string) (*CacheEntry, bool) {
+// Get 获取缓存条目
+func (mc *MemoryCache) Get(key string) *CacheEntry {
     val, ok := mc.entries.Load(key)
     if !ok {
-        return nil, false
+        return nil
     }
     
     entry := val.(*CacheEntry)
@@ -52,15 +57,26 @@ func (mc *MemoryCache) Get(key string) (*CacheEntry, bool) {
     // 检查是否过期
     if time.Now().After(entry.ExpiresAt) {
         mc.Delete(key)
-        return nil, false
+        return nil
     }
     
-    return entry, true
+    return entry
 }
 
+// Set 设置缓存条目
 func (mc *MemoryCache) Set(key string, data []byte, headers map[string]string) bool {
+    // 如果禁用缓存（maxSize = 0），直接返回
+    if mc.maxSize == 0 {
+        return false
+    }
+    
     size := int64(len(data))
     
+    // 如果单个条目超过最大缓存大小，不缓存
+    if size > mc.maxSize {
+        return false
+    }
+    
     mc.mu.Lock()
     defer mc.mu.Unlock()
     
@@ -84,12 +100,19 @@ func (mc *MemoryCache) Set(key string, data []byte, headers map[string]string) b
         Size:      size,
     }
     
+    // 如果 key 已存在，先删除旧的
+    if oldVal, exists := mc.entries.Load(key); exists {
+        oldEntry := oldVal.(*CacheEntry)
+        mc.currentSize -= oldEntry.Size
+    }
+    
     mc.entries.Store(key, entry)
     mc.currentSize += size
     
     return true
 }
 
+// Delete 删除缓存条目
 func (mc *MemoryCache) Delete(key string) {
     val, ok := mc.entries.LoadAndDelete(key)
     if ok {
@@ -100,11 +123,26 @@ func (mc *MemoryCache) Delete(key string) {
     }
 }
 
+// Clear 清空所有缓存
+func (mc *MemoryCache) Clear() {
+    mc.mu.Lock()
+    defer mc.mu.Unlock()
+    
+    mc.entries.Range(func(key, value interface{}) bool {
+        mc.entries.Delete(key)
+        return true
+    })
+    
+    mc.currentSize = 0
+}
+
+// GenerateKey 生成缓存键
 func (mc *MemoryCache) GenerateKey(url string) string {
     hash := sha256.Sum256([]byte(url))
     return hex.EncodeToString(hash[:])
 }
 
+// evictExpired 清理过期条目
 func (mc *MemoryCache) evictExpired() {
     now := time.Now()
     mc.entries.Range(func(key, value interface{}) bool {
@@ -117,6 +155,7 @@ func (mc *MemoryCache) evictExpired() {
     })
 }
 
+// evictOldest 清理最旧的条目
 func (mc *MemoryCache) evictOldest(needed int64) {
     type entryWithKey struct {
         key   string
@@ -133,7 +172,7 @@ func (mc *MemoryCache) evictOldest(needed int64) {
         return true
     })
     
-    // 按创建时间排序
+    // 按创建时间排序（最旧的在前）
     for i := 0; i < len(entries)-1; i++ {
         for j := i + 1; j < len(entries); j++ {
             if entries[i].entry.CreatedAt.After(entries[j].entry.CreatedAt) {
@@ -154,6 +193,7 @@ func (mc *MemoryCache) evictOldest(needed int64) {
     }
 }
 
+// cleanup 定期清理过期条目
 func (mc *MemoryCache) cleanup() {
     ticker := time.NewTicker(10 * time.Minute)
     defer ticker.Stop()
@@ -165,6 +205,30 @@ func (mc *MemoryCache) cleanup() {
     }
 }
 
+// Stats 返回缓存统计信息
+func (mc *MemoryCache) Stats() (entries int, size int64) {
+    count := 0
+    mc.entries.Range(func(key, value interface{}) bool {
+        count++
+        return true
+    })
+    return count, mc.currentSize
+}
+
+// GetStats 返回详细的缓存统计信息
+func (mc *MemoryCache) GetStats() map[string]interface{} {
+    entries, size := mc.Stats()
+    
+    return map[string]interface{}{
+        "entries":      entries,
+        "size":         size,
+        "max_size":     mc.maxSize,
+        "utilization":  float64(size) / float64(mc.maxSize) * 100,
+        "ttl_seconds":  int64(mc.ttl.Seconds()),
+    }
+}
+
+
 func (mc *MemoryCache) Stats() (entries int, size int64) {
     count := 0
     mc.entries.Range(func(key, value interface{}) bool {