chore: allow embedded xsync.Map to be lazily initialized

adapter/adapter.go

@@ -35,7 +35,7 @@ type Proxy struct {
 	C.ProxyAdapter
 	alive   atomic.Bool
 	history *queue.Queue[C.DelayHistory]
-	extra   *xsync.Map[string, *internalProxyState]
+	extra   xsync.Map[string, *internalProxyState]
 }
 
 // Adapter implements C.Proxy
@@ -293,7 +293,7 @@ func NewProxy(adapter C.ProxyAdapter) *Proxy {
 		ProxyAdapter: adapter,
 		history:      queue.New[C.DelayHistory](defaultHistoriesNum),
 		alive:        atomic.NewBool(true),
-		extra:        xsync.NewMap[string, *internalProxyState]()}
+	}
 }
 
 func urlToMetadata(rawURL string) (addr C.Metadata, err error) {

common/xsync/map.go

@@ -3,7 +3,9 @@ package xsync
 // copy and modified from https://github.com/puzpuzpuz/xsync/blob/v4.1.0/map.go
 // which is licensed under Apache v2.
 //
-// parallel Map resize has been removed to decrease the memory using
+// mihomo modified:
+// 1. parallel Map resize has been removed to decrease the memory using.
+// 2. the zero Map is ready for use.
 
 import (
 	"fmt"
@@ -95,6 +97,7 @@ const (
 // and C++'s absl::flat_hash_map (meta memory and SWAR-based
 // lookups).
 type Map[K comparable, V any] struct {
+	initOnce     sync.Once
 	totalGrowths atomic.Int64
 	totalShrinks atomic.Int64
 	resizing     atomic.Bool // resize in progress flag
@@ -172,28 +175,30 @@ func WithGrowOnly() func(*MapConfig) {
 // NewMap creates a new Map instance configured with the given
 // options.
 func NewMap[K comparable, V any](options ...func(*MapConfig)) *Map[K, V] {
-	c := &MapConfig{
+	c := &MapConfig{}
-		sizeHint: defaultMinMapTableLen * entriesPerMapBucket,
-	}
 	for _, o := range options {
 		o(c)
 	}
 
 	m := &Map[K, V]{}
-	m.resizeCond = *sync.NewCond(&m.resizeMu)
+	if c.sizeHint > defaultMinMapTableLen*entriesPerMapBucket {
-	var table *mapTable[K, V]
-	if c.sizeHint <= defaultMinMapTableLen*entriesPerMapBucket {
-		table = newMapTable[K, V](defaultMinMapTableLen)
-	} else {
 		tableLen := nextPowOf2(uint32((float64(c.sizeHint) / entriesPerMapBucket) / mapLoadFactor))
-		table = newMapTable[K, V](int(tableLen))
+		m.minTableLen = int(tableLen)
 	}
-	m.minTableLen = len(table.buckets)
 	m.growOnly = c.growOnly
-	m.table.Store(table)
 	return m
 }
 
+func (m *Map[K, V]) init() {
+	if m.minTableLen == 0 {
+		m.minTableLen = defaultMinMapTableLen
+	}
+	m.resizeCond = *sync.NewCond(&m.resizeMu)
+	table := newMapTable[K, V](m.minTableLen)
+	m.minTableLen = len(table.buckets)
+	m.table.Store(table)
+}
+
 func newMapTable[K comparable, V any](minTableLen int) *mapTable[K, V] {
 	buckets := make([]bucketPadded[K, V], minTableLen)
 	for i := range buckets {
@@ -233,6 +238,7 @@ func ToPlainMap[K comparable, V any](m *Map[K, V]) map[K]V {
 // of type V if no value is present.
 // The ok result indicates whether value was found in the map.
 func (m *Map[K, V]) Load(key K) (value V, ok bool) {
+	m.initOnce.Do(m.init)
 	table := m.table.Load()
 	hash := maphash.Comparable(table.seed, key)
 	h1 := h1(hash)
@@ -389,6 +395,7 @@ func (m *Map[K, V]) doCompute(
 	loadOp loadOp,
 	computeOnly bool,
 ) (V, bool) {
+	m.initOnce.Do(m.init)
 	for {
 	compute_attempt:
 		var (
@@ -672,6 +679,7 @@ func copyBucket[K comparable, V any](
 // modification rule apply, i.e. the changes may be not reflected
 // in the subsequently iterated entries.
 func (m *Map[K, V]) Range(f func(key K, value V) bool) {
+	m.initOnce.Do(m.init)
 	// Pre-allocate array big enough to fit entries for most hash tables.
 	bentries := make([]*entry[K, V], 0, 16*entriesPerMapBucket)
 	table := m.table.Load()
@@ -709,11 +717,13 @@ func (m *Map[K, V]) Range(f func(key K, value V) bool) {
 
 // Clear deletes all keys and values currently stored in the map.
 func (m *Map[K, V]) Clear() {
+	m.initOnce.Do(m.init)
 	m.resize(m.table.Load(), mapClearHint)
 }
 
 // Size returns current size of the map.
 func (m *Map[K, V]) Size() int {
+	m.initOnce.Do(m.init)
 	return int(m.table.Load().sumSize())
 }
 
@@ -828,6 +838,7 @@ func (s *MapStats) ToString() string {
 // methods, this one is thread-safe. Yet it's an O(N) operation,
 // so it should be used only for diagnostics or debugging purposes.
 func (m *Map[K, V]) Stats() MapStats {
+	m.initOnce.Do(m.init)
 	stats := MapStats{
 		TotalGrowths: m.totalGrowths.Load(),
 		TotalShrinks: m.totalShrinks.Load(),

component/loopback/detector.go

@@ -25,22 +25,19 @@ func init() {
 var ErrReject = errors.New("reject loopback connection")
 
 type Detector struct {
-	connMap       *xsync.Map[netip.AddrPort, struct{}]
+	connMap       xsync.Map[netip.AddrPort, struct{}]
-	packetConnMap *xsync.Map[uint16, struct{}]
+	packetConnMap xsync.Map[uint16, struct{}]
 }
 
 func NewDetector() *Detector {
 	if disableLoopBackDetector {
 		return nil
 	}
-	return &Detector{
+	return &Detector{}
-		connMap:       xsync.NewMap[netip.AddrPort, struct{}](),
-		packetConnMap: xsync.NewMap[uint16, struct{}](),
-	}
 }
 
 func (l *Detector) NewConn(conn C.Conn) C.Conn {
-	if l == nil || l.connMap == nil {
+	if l == nil {
 		return conn
 	}
 	metadata := C.Metadata{}
@@ -58,7 +55,7 @@ func (l *Detector) NewConn(conn C.Conn) C.Conn {
 }
 
 func (l *Detector) NewPacketConn(conn C.PacketConn) C.PacketConn {
-	if l == nil || l.packetConnMap == nil {
+	if l == nil {
 		return conn
 	}
 	metadata := C.Metadata{}
@@ -77,7 +74,7 @@ func (l *Detector) NewPacketConn(conn C.PacketConn) C.PacketConn {
 }
 
 func (l *Detector) CheckConn(metadata *C.Metadata) error {
-	if l == nil || l.connMap == nil {
+	if l == nil {
 		return nil
 	}
 	connAddr := metadata.SourceAddrPort()
@@ -91,7 +88,7 @@ func (l *Detector) CheckConn(metadata *C.Metadata) error {
 }
 
 func (l *Detector) CheckPacketConn(metadata *C.Metadata) error {
-	if l == nil || l.packetConnMap == nil {
+	if l == nil {
 		return nil
 	}
 	connAddr := metadata.SourceAddrPort()

component/nat/table.go

@@ -9,21 +9,19 @@ import (
 )
 
 type Table struct {
-	mapping *xsync.Map[string, *entry]
+	mapping xsync.Map[string, *entry]
 }
 
 type entry struct {
 	PacketSender    C.PacketSender
-	LocalUDPConnMap *xsync.Map[string, *net.UDPConn]
+	LocalUDPConnMap xsync.Map[string, *net.UDPConn]
-	LocalLockMap    *xsync.Map[string, *sync.Cond]
+	LocalLockMap    xsync.Map[string, *sync.Cond]
 }
 
 func (t *Table) GetOrCreate(key string, maker func() C.PacketSender) (C.PacketSender, bool) {
 	item, loaded := t.mapping.LoadOrStoreFn(key, func() *entry {
 		return &entry{
-			PacketSender:    maker(),
+			PacketSender: maker(),
-			LocalUDPConnMap: xsync.NewMap[string, *net.UDPConn](),
-			LocalLockMap:    xsync.NewMap[string, *sync.Cond](),
 		}
 	})
 	return item.PacketSender, loaded
@@ -97,7 +95,5 @@ func makeLock() *sync.Cond {
 
 // New return *Cache
 func New() *Table {
-	return &Table{
+	return &Table{}
-		mapping: xsync.NewMap[string, *entry](),
-	}
 }

transport/tuic/v4/client.go

@@ -48,7 +48,7 @@ type clientImpl struct {
 	openStreams atomic.Int64
 	closed      atomic.Bool
 
-	udpInputMap *xsync.Map[uint32, net.Conn]
+	udpInputMap xsync.Map[uint32, net.Conn]
 
 	// only ready for PoolClient
 	dialerRef   C.Dialer
@@ -422,7 +422,6 @@ func NewClient(clientOption *ClientOption, udp bool, dialerRef C.Dialer) *Client
 		ClientOption: clientOption,
 		udp:          udp,
 		dialerRef:    dialerRef,
-		udpInputMap:  xsync.NewMap[uint32, net.Conn](),
 	}
 	c := &Client{ci}
 	runtime.SetFinalizer(c, closeClient)

transport/tuic/v4/server.go

@@ -34,7 +34,6 @@ func NewServerHandler(option *ServerOption, quicConn *quic.Conn, uuid uuid.UUID)
 		quicConn:     quicConn,
 		uuid:         uuid,
 		authCh:       make(chan struct{}),
-		udpInputMap:  xsync.NewMap[uint32, *atomic.Bool](),
 	}
 }
 
@@ -47,7 +46,7 @@ type serverHandler struct {
 	authOk   atomic.Bool
 	authOnce sync.Once
 
-	udpInputMap *xsync.Map[uint32, *atomic.Bool]
+	udpInputMap xsync.Map[uint32, *atomic.Bool]
 }
 
 func (s *serverHandler) AuthOk() bool {

transport/tuic/v5/client.go

@@ -47,7 +47,7 @@ type clientImpl struct {
 	openStreams atomic.Int64
 	closed      atomic.Bool
 
-	udpInputMap *xsync.Map[uint16, net.Conn]
+	udpInputMap xsync.Map[uint16, net.Conn]
 
 	// only ready for PoolClient
 	dialerRef   C.Dialer
@@ -406,7 +406,6 @@ func NewClient(clientOption *ClientOption, udp bool, dialerRef C.Dialer) *Client
 		ClientOption: clientOption,
 		udp:          udp,
 		dialerRef:    dialerRef,
-		udpInputMap:  xsync.NewMap[uint16, net.Conn](),
 	}
 	c := &Client{ci}
 	runtime.SetFinalizer(c, closeClient)

transport/tuic/v5/server.go

@@ -33,7 +33,6 @@ func NewServerHandler(option *ServerOption, quicConn *quic.Conn, uuid uuid.UUID)
 		quicConn:     quicConn,
 		uuid:         uuid,
 		authCh:       make(chan struct{}),
-		udpInputMap:  xsync.NewMap[uint16, *serverUDPInput](),
 	}
 }
 
@@ -47,7 +46,7 @@ type serverHandler struct {
 	authUUID atomic.TypedValue[string]
 	authOnce sync.Once
 
-	udpInputMap *xsync.Map[uint16, *serverUDPInput]
+	udpInputMap xsync.Map[uint16, *serverUDPInput]
 }
 
 func (s *serverHandler) AuthOk() bool {

tunnel/statistic/manager.go

@@ -14,7 +14,6 @@ var DefaultManager *Manager
 
 func init() {
 	DefaultManager = &Manager{
-		connections:   xsync.NewMap[string, Tracker](),
 		uploadTemp:    atomic.NewInt64(0),
 		downloadTemp:  atomic.NewInt64(0),
 		uploadBlip:    atomic.NewInt64(0),
@@ -28,7 +27,7 @@ func init() {
 }
 
 type Manager struct {
-	connections   *xsync.Map[string, Tracker]
+	connections   xsync.Map[string, Tracker]
 	uploadTemp    atomic.Int64
 	downloadTemp  atomic.Int64
 	uploadBlip    atomic.Int64