diff --git a/common/cache/lrucache.go b/common/cache/lrucache.go index 1b1e492a..4246d841 100644 --- a/common/cache/lrucache.go +++ b/common/cache/lrucache.go @@ -146,6 +146,23 @@ func (c *LruCache) SetWithExpire(key interface{}, value interface{}, expires tim c.maybeDeleteOldest() } +// CloneTo clone and overwrite elements to another LruCache +func (c *LruCache) CloneTo(n *LruCache) { + c.mu.Lock() + defer c.mu.Unlock() + + n.mu.Lock() + defer n.mu.Unlock() + + n.lru = list.New() + n.cache = make(map[interface{}]*list.Element) + + for e := c.lru.Front(); e != nil; e = e.Next() { + elm := e.Value.(*entry) + n.cache[elm.key] = n.lru.PushBack(elm) + } +} + func (c *LruCache) get(key interface{}) *entry { c.mu.Lock() defer c.mu.Unlock() diff --git a/common/cache/lrucache_test.go b/common/cache/lrucache_test.go index c3c629d9..13675bff 100644 --- a/common/cache/lrucache_test.go +++ b/common/cache/lrucache_test.go @@ -164,3 +164,21 @@ func TestStale(t *testing.T) { assert.Equal(t, tenSecBefore, expires) assert.Equal(t, true, exist) } + +func TestCloneTo(t *testing.T) { + o := NewLRUCache(WithSize(10)) + o.Set("1", 1) + o.Set("2", 2) + + n := NewLRUCache(WithSize(2)) + n.Set("3", 3) + n.Set("4", 4) + + o.CloneTo(n) + + assert.False(t, n.Exist("3")) + assert.True(t, n.Exist("1")) + + n.Set("5", 5) + assert.False(t, n.Exist("1")) +} diff --git a/dns/resolver.go b/dns/resolver.go index 04ea41bb..21ebb00a 100644 --- a/dns/resolver.go +++ b/dns/resolver.go @@ -186,6 +186,11 @@ func (r *Resolver) IsFakeIP(ip net.IP) bool { return false } +// PatchCache overwrite lruCache to the new resolver +func (r *Resolver) PatchCache(n *Resolver) { + r.lruCache.CloneTo(n.lruCache) +} + func (r *Resolver) batchExchange(clients []dnsClient, m *D.Msg) (msg *D.Msg, err error) { fast, ctx := picker.WithTimeout(context.Background(), time.Second*5) for _, client := range clients { diff --git a/hub/executor/executor.go b/hub/executor/executor.go index 3bb29f57..f0f4c9b6 100644 --- a/hub/executor/executor.go +++ b/hub/executor/executor.go @@ -120,6 +120,14 @@ func updateDNS(c *config.DNS) { }, Default: c.DefaultNameserver, }) + + // reuse cache of old resolver + if resolver.DefaultResolver != nil { + if o, ok := resolver.DefaultResolver.(*dns.Resolver); ok { + o.PatchCache(r) + } + } + resolver.DefaultResolver = r tunnel.SetResolver(r) if err := dns.ReCreateServer(c.Listen, r); err != nil {