chore: cleanup the patch code

component/fakeip/memory.go

@@ -67,8 +67,9 @@ func (m *memoryStore) CloneTo(store store) {
 
 // FlushFakeIP implements store.FlushFakeIP
 func (m *memoryStore) FlushFakeIP() error {
-	_ = m.cacheIP.Clear()
-	return m.cacheHost.Clear()
+	m.cacheIP.Clear()
+	m.cacheHost.Clear()
+	return nil
 }
 
 func newMemoryStore(size int) *memoryStore {

component/mmdb/patch_android.go

@@ -1,18 +0,0 @@
-//go:build android && cmfa
-
-package mmdb
-
-import "github.com/oschwald/maxminddb-golang"
-
-func InstallOverride(override *maxminddb.Reader) {
-	newReader := IPReader{Reader: override}
-	switch override.Metadata.DatabaseType {
-	case "sing-geoip":
-		ipReader.databaseType = typeSing
-	case "Meta-geoip0":
-		ipReader.databaseType = typeMetaV0
-	default:
-		ipReader.databaseType = typeMaxmind
-	}
-	ipReader = newReader
-}

component/resolver/resolver.go

@@ -46,6 +46,7 @@ type Resolver interface {
 	LookupIPv6(ctx context.Context, host string) (ips []netip.Addr, err error)
 	ExchangeContext(ctx context.Context, m *dns.Msg) (msg *dns.Msg, err error)
 	Invalid() bool
+	ClearCache()
 }
 
 // LookupIPv4WithResolver same as LookupIPv4, but with a resolver