added GetPID to registry

actor/engine_test.go

@@ -36,6 +36,16 @@ func newTickReceiver(wg *sync.WaitGroup) Producer {
 	}
 }
 
+func TestRegistryGetPID(t *testing.T) {
+	e, _ := NewEngine(nil)
+	expectedPID1 := e.SpawnFunc(func(c *Context) {}, "foo", WithID("1"))
+	expectedPID2 := e.SpawnFunc(func(c *Context) {}, "foo", WithID("2"))
+	pid := e.Registry.GetPID("foo", "1")
+	assert.True(t, pid.Equals(expectedPID1))
+	pid = e.Registry.GetPID("foo", "2")
+	assert.True(t, pid.Equals(expectedPID2))
+}
+
 func TestSendToNilPID(t *testing.T) {
 	e, _ := NewEngine(nil)
 	e.Send(nil, "foo")

actor/registry.go

@@ -19,6 +19,16 @@ func newRegistry(e *Engine) *Registry {
 	}
 }
 
+// GetPID returns the process id associated for the given kind and its id.
+// GetPID returns nil if the process was not found.
+func (r *Registry) GetPID(kind, id string) *PID {
+	proc := r.getByID(kind + pidSeparator + id)
+	if proc != nil {
+		return proc.PID()
+	}
+	return nil
+}
+
 // Remove removes the given PID from the registry.
 func (r *Registry) Remove(pid *PID) {
 	r.mu.Lock()