gattc: always return pointers to DeviceService and DeviceCharacteristic types to ensure consistency

Signed-off-by: deadprogram <ron@hybridgroup.com>

gattc_darwin.go

@@ -14,7 +14,7 @@ import (
 //
 // Passing a nil slice of UUIDs will return a complete list of
 // services.
-func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
+func (d *Device) DiscoverServices(uuids []UUID) ([]*DeviceService, error) {
 	cbuuids := []cbgo.UUID{}
 	for _, u := range uuids {
 		uuid, _ := cbgo.ParseUUID(u.String())
@@ -29,16 +29,16 @@ func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 	// wait on channel for service discovery
 	select {
 	case <-d.servicesChan:
-		svcs := []DeviceService{}
+		svcs := []*DeviceService{}
 		for _, dsvc := range d.prph.Services() {
 			uuid, _ := ParseUUID(dsvc.UUID().String())
-			svc := DeviceService{
+			svc := &DeviceService{
 				uuidWrapper: uuid,
 				device:      d,
 				service:     dsvc,
 			}
 			svcs = append(svcs, svc)
-			d.services[svc.uuidWrapper] = &svc
+			d.services[svc.uuidWrapper] = svc
 		}
 		return svcs, nil
 	case <-time.NewTimer(10 * time.Second).C:
@@ -73,7 +73,7 @@ func (s *DeviceService) UUID() UUID {
 //
 // Passing a nil slice of UUIDs will return a complete list of
 // characteristics.
-func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacteristic, error) {
+func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]*DeviceCharacteristic, error) {
 	cbuuids := []cbgo.UUID{}
 	for _, u := range uuids {
 		uuid, _ := cbgo.ParseUUID(u.String())
@@ -88,16 +88,16 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 	// wait on channel for characteristic discovery
 	select {
 	case <-s.device.charsChan:
-		chars := []DeviceCharacteristic{}
+		chars := []*DeviceCharacteristic{}
 		for _, dchar := range s.service.Characteristics() {
 			uuid, _ := ParseUUID(dchar.UUID().String())
-			char := DeviceCharacteristic{
+			char := &DeviceCharacteristic{
 				uuidWrapper:    uuid,
 				service:        s,
 				characteristic: dchar,
 			}
 			chars = append(chars, char)
-			s.device.characteristics[char.uuidWrapper] = &char
+			s.device.characteristics[char.uuidWrapper] = char
 		}
 		return chars, nil
 	case <-time.NewTimer(10 * time.Second).C:
@@ -125,7 +125,7 @@ func (c *DeviceCharacteristic) UUID() UUID {
 // call will return before all data has been written. A limited number of such
 // writes can be in flight at any given time. This call is also known as a
 // "write command" (as opposed to a write request).
-func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
+func (c *DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
 	c.service.device.prph.WriteCharacteristic(p, c.characteristic, false)
 
 	return len(p), nil
@@ -135,7 +135,7 @@ func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error)
 // Configuration Descriptor (CCCD). This means that most peripherals will send a
 // notification with a new value every time the value of the characteristic
 // changes.
-func (c DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
+func (c *DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
 	if callback == nil {
 		return errors.New("must provide a callback for EnableNotifications")
 	}

gattc_linux.go

@@ -37,7 +37,7 @@ func (s *DeviceService) UUID() UUID {
 //
 // On Linux with BlueZ, this just waits for the ServicesResolved signal (if
 // services haven't been resolved yet) and uses this list of cached services.
-func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
+func (d *Device) DiscoverServices(uuids []UUID) ([]*DeviceService, error) {
 	for {
 		resolved, err := d.device.GetServicesResolved()
 		if err != nil {
@@ -50,7 +50,7 @@ func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 		time.Sleep(10 * time.Millisecond)
 	}
 
-	services := []DeviceService{}
+	services := []*DeviceService{}
 	uuidServices := make(map[string]string)
 	servicesFound := 0
 
@@ -98,7 +98,7 @@ func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 		}
 
 		uuid, _ := ParseUUID(service.Properties.UUID)
-		ds := DeviceService{uuidWrapper: uuid,
+		ds := &DeviceService{uuidWrapper: uuid,
 			service: service,
 		}
 
@@ -136,8 +136,8 @@ func (c *DeviceCharacteristic) UUID() UUID {
 //
 // Passing a nil slice of UUIDs will return a complete
 // list of characteristics.
-func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacteristic, error) {
+func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]*DeviceCharacteristic, error) {
-	chars := []DeviceCharacteristic{}
+	chars := []*DeviceCharacteristic{}
 	uuidChars := make(map[string]string)
 	characteristicsFound := 0
 
@@ -185,7 +185,8 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 		}
 
 		uuid, _ := ParseUUID(char.Properties.UUID)
-		dc := DeviceCharacteristic{uuidWrapper: uuid,
+		dc := &DeviceCharacteristic{
+			uuidWrapper:    uuid,
 			characteristic: char,
 		}
 
@@ -205,7 +206,7 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 // call will return before all data has been written. A limited number of such
 // writes can be in flight at any given time. This call is also known as a
 // "write command" (as opposed to a write request).
-func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
+func (c *DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
 	err = c.characteristic.WriteValue(p, nil)
 	if err != nil {
 		return 0, err
@@ -217,7 +218,7 @@ func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error)
 // Configuration Descriptor (CCCD). This means that most peripherals will send a
 // notification with a new value every time the value of the characteristic
 // changes.
-func (c DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
+func (c *DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
 	ch, err := c.characteristic.WatchProperties()
 	if err != nil {
 		return err

gattc_sd.go

@@ -62,7 +62,7 @@ func (s *DeviceService) UUID() UUID {
 //
 // On the Nordic SoftDevice, only one service discovery procedure may be done at
 // a time.
-func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
+func (d *Device) DiscoverServices(uuids []UUID) ([]*DeviceService, error) {
 	if discoveringService.state.Get() != 0 {
 		// Not concurrency safe, but should catch most concurrency misuses.
 		return nil, errAlreadyDiscovering
@@ -72,7 +72,7 @@ func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 	if len(uuids) > 0 {
 		sz = len(uuids)
 	}
-	services := make([]DeviceService, 0, sz)
+	services := make([]*DeviceService, 0, sz)
 
 	var shortUUIDs []C.ble_uuid_t
 
@@ -133,7 +133,7 @@ func (d *Device) DiscoverServices(uuids []UUID) ([]DeviceService, error) {
 		}
 
 		// Store the discovered service.
-		svc := DeviceService{
+		svc := &DeviceService{
 			uuid:             suuid,
 			connectionHandle: d.connectionHandle,
 			startHandle:      startHandle,
@@ -191,7 +191,7 @@ var discoveringCharacteristic struct {
 //
 // Passing a nil slice of UUIDs will return a complete
 // list of characteristics.
-func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacteristic, error) {
+func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]*DeviceCharacteristic, error) {
 	if discoveringCharacteristic.handle_value.Get() != 0 {
 		return nil, errAlreadyDiscovering
 	}
@@ -200,7 +200,7 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 	if len(uuids) > 0 {
 		sz = len(uuids)
 	}
-	characteristics := make([]DeviceCharacteristic, 0, sz)
+	characteristics := make([]*DeviceCharacteristic, 0, sz)
 
 	var shortUUIDs []C.ble_uuid_t
 
@@ -276,7 +276,7 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 			permissions |= CharacteristicIndicatePermission
 		}
 
-		dc := DeviceCharacteristic{uuid: discoveringCharacteristic.uuid}
+		dc := &DeviceCharacteristic{uuid: discoveringCharacteristic.uuid}
 		dc.permissions = permissions
 		dc.valueHandle = foundCharacteristicHandle
 
@@ -319,7 +319,7 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
 // call will return before all data has been written. A limited number of such
 // writes can be in flight at any given time. This call is also known as a
 // "write command" (as opposed to a write request).
-func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
+func (c *DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error) {
 	if len(p) == 0 {
 		return 0, nil
 	}
@@ -356,7 +356,7 @@ var gattcNotificationCallbacks []gattcNotificationCallback
 // Warning: when using the SoftDevice, the callback is called from an interrupt
 // which means there are various limitations (such as not being able to allocate
 // heap memory).
-func (c DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
+func (c *DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
 	if c.permissions&CharacteristicNotifyPermission == 0 {
 		return errNoNotify
 	}