add SetMustMany

* to set many properties at once and to emit only one signal

Author: Stefan Schubert

prop/prop.go

@@ -278,32 +278,40 @@ func (p *Properties) Introspection(iface string) []introspect.Property {
 
 // set sets the given property and emits PropertyChanged if appropriate. p.mut
 // must already be locked.
-func (p *Properties) set(iface, property string, v interface{}) error {
-	prop := p.m[iface][property]
-	err := dbus.Store([]interface{}{v}, prop.Value)
+func (p *Properties) set(iface string, properties []string, v ...interface{}) error {
+	var props []interface{}
+	for _, property := range properties {
+		props = append(props, p.m[iface][property].Value)
+	}
+	err := dbus.Store(v, props...)
 	if err != nil {
 		return err
 	}
-	return p.emitChange(iface, property)
+	return p.emitChange(iface, properties...)
 }
 
-func (p *Properties) emitChange(iface, property string) error {
-	prop := p.m[iface][property]
-	switch prop.Emit {
-	case EmitFalse:
-		return nil // do nothing
-	case EmitInvalidates:
-		return p.conn.Emit(p.path, "org.freedesktop.DBus.Properties.PropertiesChanged",
-			iface, map[string]dbus.Variant{}, []string{property})
-	case EmitTrue:
-		return p.conn.Emit(p.path, "org.freedesktop.DBus.Properties.PropertiesChanged",
-			iface, map[string]dbus.Variant{property: dbus.MakeVariant(prop.Value)},
-			[]string{})
-	case EmitConst:
-		return nil
-	default:
-		panic("invalid value for EmitType")
+func (p *Properties) emitChange(iface string, properties ...string) error {
+	changes := make(map[string]dbus.Variant)
+	invalidates := []string{}
+
+	for _, property := range properties {
+		prop := p.m[iface][property]
+		switch prop.Emit {
+		case EmitFalse:
+			return nil // do nothing
+		case EmitInvalidates:
+			invalidates = append(invalidates, property)
+		case EmitTrue:
+			changes[property] = dbus.MakeVariant(prop.Value)
+		case EmitConst:
+			return nil
+		default:
+			panic("invalid value for EmitType")
+		}
 	}
+
+	return p.conn.Emit(p.path, "org.freedesktop.DBus.Properties.PropertiesChanged",
+		iface, changes, invalidates)
 }
 
 // Set implements org.freedesktop.Properties.Set.
@@ -330,7 +338,7 @@ func (p *Properties) Set(iface, property string, newv dbus.Variant) *dbus.Error
 			return err
 		}
 	}
-	if err := p.set(iface, property, newv.Value()); err != nil {
+	if err := p.set(iface, []string{property}, newv.Value()); err != nil {
 		return dbus.MakeFailedError(err)
 	}
 	return nil
@@ -341,7 +349,25 @@ func (p *Properties) Set(iface, property string, newv dbus.Variant) *dbus.Error
 func (p *Properties) SetMust(iface, property string, v interface{}) {
 	p.mut.Lock()
 	defer p.mut.Unlock() // unlock in case of panic
-	err := p.set(iface, property, v)
+	err := p.set(iface, []string{property}, v)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// SetMustMany sets the values of the given property value map and panics if any interface or
+// property name are invalid.
+func (p *Properties) SetMustMany(iface string, newValues map[string]interface{}) {
+	p.mut.Lock()
+	defer p.mut.Unlock()
+
+	properties := make([]string, 0, len(newValues))
+	values := make([]interface{}, 0, len(newValues))
+	for key, val := range newValues {
+		properties = append(properties, key)
+		values = append(values, val)
+	}
+	err := p.set(iface, properties, values...)
 	if err != nil {
 		panic(err)
 	}

prop/prop_test.go

@@ -159,3 +159,73 @@ func TestInt32(t *testing.T) {
 		t.Errorf("expected r to be int32(101), but was %#v", r)
 	}
 }
+
+func TestMany(t *testing.T) {
+	srv, err := dbus.SessionBus()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer srv.Close()
+
+	cli, err := dbus.SessionBus()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cli.Close()
+
+	propsSpec := map[string]map[string]*Prop{
+		"org.guelfey.DBus.Test": {
+			"one": {
+				"oneValue",
+				true,
+				EmitTrue,
+				nil,
+			},
+			"two": {
+				0,
+				true,
+				EmitInvalidates,
+				nil,
+			},
+		},
+	}
+	props := New(srv, "/org/guelfey/DBus/Test", propsSpec)
+
+	r := props.GetMust("org.guelfey.DBus.Test", "one")
+	if r != "oneValue" {
+		t.Errorf("expected r to be 'oneValue', but was %#v", r)
+	}
+	r = props.GetMust("org.guelfey.DBus.Test", "two")
+	if r != 0 {
+		t.Errorf("expected r to be 0, but was %#v", r)
+	}
+
+	ready := make(chan struct{})
+	c := make(chan *dbus.Signal, 1)
+	go func() {
+		cli.AddMatchSignal(dbus.WithMatchMember("PropertiesChanged"))
+		defer cli.RemoveMatchSignal(dbus.WithMatchMember("PropertiesChanged"))
+
+		cli.Signal(c)
+		close(ready)
+		for sig := range c {
+			if sig.Name == "org.freedesktop.DBus.Properties.PropertiesChanged" {
+				c <- sig
+			}
+		}
+	}()
+
+	<-ready
+	props.SetMustMany("org.guelfey.DBus.Test", map[string]interface{}{"one": "otherValue", "two": 1})
+	sig := <-c
+
+	changed := sig.Body[1].(map[string]dbus.Variant)
+	invalidated := sig.Body[2].([]string)
+	if len(changed) != 1 || len(invalidated) != 1 {
+		t.Fatalf("changed len or invalidated len mismatch")
+	}
+	if changed["one"].Value() != "otherValue" {
+		t.Fatalf("changed value mismatch")
+	}
+
+}