first commit

txflow/adapter.go

@@ -0,0 +1,142 @@
+package txflow
+
+import (
+	"errors"
+	"sync"
+	"sync/atomic"
+)
+
+type Adapter struct {
+	handle Handle
+	worlds WorldResolver
+
+	currentTx SafeBox[Tx]
+
+	mu              sync.Mutex
+	pendingTeleport *Position
+	queuedTeleport  atomic.Bool
+	processing      atomic.Bool
+}
+
+func NewAdapter(handle Handle, worlds WorldResolver) *Adapter {
+	return &Adapter{handle: handle, worlds: worlds}
+}
+
+func (a *Adapter) WithTx(tx Tx, fn func()) {
+	if fn == nil {
+		return
+	}
+	a.currentTx.Set(tx)
+	defer a.currentTx.Set(nil)
+	fn()
+}
+
+func (a *Adapter) WithPlayerTx(fn func(Tx, Entity)) {
+	if a == nil || a.handle == nil || fn == nil {
+		return
+	}
+	if tx := a.currentTx.Get(); tx != nil {
+		if e, ok := a.handle.Entity(tx); ok {
+			fn(tx, e)
+			return
+		}
+	}
+	a.handle.ExecWorld(func(tx Tx, e Entity) {
+		fn(tx, e)
+	})
+}
+
+func (a *Adapter) Teleport(pos Position) error {
+	if a == nil || a.handle == nil {
+		return errors.New("adapter is nil")
+	}
+	if pos.World == "" {
+		a.WithPlayerTx(func(_ Tx, e Entity) { e.Teleport(pos) })
+		return nil
+	}
+	target, err := a.worlds.Resolve(pos.World)
+	if err != nil {
+		return err
+	}
+	if target == nil {
+		return errors.New("target world not found")
+	}
+	if tx := a.currentTx.Get(); tx != nil && tx.World() != nil {
+		if tx.World() == target {
+			a.WithPlayerTx(func(_ Tx, e Entity) { e.Teleport(pos) })
+			return nil
+		}
+		a.queueTeleport(pos)
+		go a.ProcessQueuedTeleport(nil)
+		return nil
+	}
+	a.queueTeleport(pos)
+	a.ProcessQueuedTeleport(nil)
+	return nil
+}
+
+func (a *Adapter) queueTeleport(pos Position) {
+	a.mu.Lock()
+	cp := pos
+	a.pendingTeleport = &cp
+	a.mu.Unlock()
+	a.queuedTeleport.Store(true)
+}
+
+func (a *Adapter) peekQueuedTeleport() *Position {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if a.pendingTeleport == nil {
+		return nil
+	}
+	cp := *a.pendingTeleport
+	return &cp
+}
+
+func (a *Adapter) clearQueuedTeleport() {
+	a.mu.Lock()
+	a.pendingTeleport = nil
+	a.mu.Unlock()
+	a.queuedTeleport.Store(false)
+}
+
+func (a *Adapter) HasQueuedTeleport() bool {
+	return a.queuedTeleport.Load()
+}
+
+func (a *Adapter) ProcessQueuedTeleport(tx Tx) {
+	if a == nil || a.handle == nil {
+		return
+	}
+	if !a.processing.CompareAndSwap(false, true) {
+		return
+	}
+	defer a.processing.Store(false)
+
+	pos := a.peekQueuedTeleport()
+	if pos == nil {
+		return
+	}
+	target, err := a.worlds.Resolve(pos.World)
+	if err != nil || target == nil {
+		return
+	}
+	exec := func(currentTx Tx) {
+		if currentTx == nil || currentTx.World() == nil {
+			return
+		}
+		if e, ok := a.handle.Entity(currentTx); ok {
+			// В примере просто телепортируем.
+			// В реальном движке здесь обычно remove/add entity между мирами.
+			e.Teleport(*pos)
+			a.clearQueuedTeleport()
+		}
+	}
+	if tx != nil {
+		exec(tx)
+		return
+	}
+	target.Exec(func(t Tx) {
+		exec(t)
+	})
+}

txflow/interfaces.go

@@ -0,0 +1,49 @@
+package txflow
+
+import "sync"
+
+type Position struct {
+	X, Y, Z float64
+	World   string
+}
+
+type World interface {
+	Name() string
+	Exec(func(Tx))
+}
+
+type Tx interface {
+	World() World
+}
+
+type Entity interface {
+	Teleport(Position)
+}
+
+type Handle interface {
+	Entity(tx Tx) (Entity, bool)
+	ExecWorld(func(tx Tx, e Entity))
+}
+
+type WorldResolver interface {
+	Resolve(name string) (World, error)
+}
+
+type SafeBox[T any] struct {
+	mu sync.RWMutex
+	v  T
+}
+
+func (s *SafeBox[T]) Set(v T) {
+	s.mu.Lock()
+	s.v = v
+	s.mu.Unlock()
+}
+
+func (s *SafeBox[T]) Get() T {
+	s.mu.RLock()
+	v := s.v
+	s.mu.RUnlock()
+	return v
+}
+