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all: don't use a pointer receiver for many method calls
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This is unnecessary because the values are passed by value in other
cases, and can in some cases lead to more (heap or stack) allocation
than is necessary.
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@aykevl @deadprogram
aykevl authored and deadprogram committed Jan 4, 2024
1 parent 83fba1b commit 5746ccf
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Showing 4 changed files with 22 additions and 22 deletions.
10 changes: 5 additions & 5 deletions gattc_darwin.go
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Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,7 @@ type deviceService struct {
}

// UUID returns the UUID for this DeviceService.
func (s *DeviceService) UUID() UUID {
func (s DeviceService) UUID() UUID {
return s.uuidWrapper
}

Expand All @@ -89,7 +89,7 @@ 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{}

s.device.prph.DiscoverCharacteristics(cbuuids, s.service)
Expand Down Expand Up @@ -142,7 +142,7 @@ func (s *DeviceService) DiscoverCharacteristics(uuids []UUID) ([]DeviceCharacter
}

// Small helper to create a DeviceCharacteristic object.
func (s *DeviceService) makeCharacteristic(uuid UUID, dchar cbgo.Characteristic) DeviceCharacteristic {
func (s DeviceService) makeCharacteristic(uuid UUID, dchar cbgo.Characteristic) DeviceCharacteristic {
char := DeviceCharacteristic{
deviceCharacteristic: &deviceCharacteristic{
uuidWrapper: uuid,
Expand All @@ -163,15 +163,15 @@ type DeviceCharacteristic struct {
type deviceCharacteristic struct {
uuidWrapper

service *DeviceService
service DeviceService

characteristic cbgo.Characteristic
callback func(buf []byte)
readChan chan error
}

// UUID returns the UUID for this DeviceCharacteristic.
func (c *DeviceCharacteristic) UUID() UUID {
func (c DeviceCharacteristic) UUID() UUID {
return c.uuidWrapper
}

Expand Down
12 changes: 6 additions & 6 deletions gattc_linux.go
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Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,7 @@ type DeviceService struct {
}

// UUID returns the UUID for this DeviceService.
func (s *DeviceService) UUID() UUID {
func (s DeviceService) UUID() UUID {
return s.uuidWrapper
}

Expand All @@ -41,7 +41,7 @@ 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) {
start := time.Now()

for {
Expand Down Expand Up @@ -137,7 +137,7 @@ type DeviceCharacteristic struct {
}

// UUID returns the UUID for this DeviceCharacteristic.
func (c *DeviceCharacteristic) UUID() UUID {
func (c DeviceCharacteristic) UUID() UUID {
return c.uuidWrapper
}

Expand All @@ -150,7 +150,7 @@ 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) {
var chars []DeviceCharacteristic
if len(uuids) > 0 {
// The caller wants to get a list of characteristics in a specific
Expand Down Expand Up @@ -235,7 +235,7 @@ func (c DeviceCharacteristic) WriteWithoutResponse(p []byte) (n int, err error)
// changes.
//
// Users may call EnableNotifications with a nil callback to disable notifications.
func (c *DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
func (c DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) error {
switch callback {
default:
if c.property != nil {
Expand Down Expand Up @@ -295,7 +295,7 @@ func (c DeviceCharacteristic) GetMTU() (uint16, error) {
}

// Read reads the current characteristic value.
func (c *DeviceCharacteristic) Read(data []byte) (int, error) {
func (c DeviceCharacteristic) Read(data []byte) (int, error) {
options := make(map[string]interface{})
var result []byte
err := c.characteristic.Call("org.bluez.GattCharacteristic1.ReadValue", 0, options).Store(&result)
Expand Down
8 changes: 4 additions & 4 deletions gattc_sd.go
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@ type DeviceService struct {
}

// UUID returns the UUID for this DeviceService.
func (s *DeviceService) UUID() UUID {
func (s DeviceService) UUID() UUID {
return s.uuid.UUID()
}

Expand Down Expand Up @@ -167,7 +167,7 @@ type DeviceCharacteristic struct {
}

// UUID returns the UUID for this DeviceCharacteristic.
func (c *DeviceCharacteristic) UUID() UUID {
func (c DeviceCharacteristic) UUID() UUID {
return c.uuid.UUID()
}

Expand All @@ -188,7 +188,7 @@ 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
}
Expand Down Expand Up @@ -424,7 +424,7 @@ var readingCharacteristic struct {
// Read reads the current characteristic value up to MTU length.
// A future enhancement would be to be able to retrieve a longer
// value by making multiple calls.
func (c *DeviceCharacteristic) Read(data []byte) (n int, err error) {
func (c DeviceCharacteristic) Read(data []byte) (n int, err error) {
// global will copy bytes from read operation into data slice
readingCharacteristic.value = data

Expand Down
14 changes: 7 additions & 7 deletions gattc_windows.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@ type DeviceService struct {
}

// UUID returns the UUID for this DeviceService.
func (s *DeviceService) UUID() UUID {
func (s DeviceService) UUID() UUID {
return s.uuidWrapper
}

Expand All @@ -150,7 +150,7 @@ func (s *DeviceService) UUID() UUID {
//
// Passing a nil slice of UUIDs will return a complete
// list of characteristics.
func (s *DeviceService) DiscoverCharacteristics(filterUUIDs []UUID) ([]DeviceCharacteristic, error) {
func (s DeviceService) DiscoverCharacteristics(filterUUIDs []UUID) ([]DeviceCharacteristic, error) {
getCharacteristicsOp, err := s.service.GetCharacteristicsWithCacheModeAsync(bluetooth.BluetoothCacheModeUncached)
if err != nil {
return nil, err
Expand Down Expand Up @@ -234,20 +234,20 @@ type DeviceCharacteristic struct {
characteristic *genericattributeprofile.GattCharacteristic
properties genericattributeprofile.GattCharacteristicProperties

service *DeviceService
service DeviceService
}

// UUID returns the UUID for this DeviceCharacteristic.
func (c *DeviceCharacteristic) UUID() UUID {
func (c DeviceCharacteristic) UUID() UUID {
return c.uuidWrapper
}

func (c *DeviceCharacteristic) Properties() uint32 {
func (c DeviceCharacteristic) Properties() uint32 {
return uint32(c.properties)
}

// GetMTU returns the MTU for the characteristic.
func (c *DeviceCharacteristic) GetMTU() (uint16, error) {
func (c DeviceCharacteristic) GetMTU() (uint16, error) {
return c.service.device.session.GetMaxPduSize()
}

Expand Down Expand Up @@ -314,7 +314,7 @@ func (c DeviceCharacteristic) write(p []byte, mode genericattributeprofile.GattW
}

// Read reads the current characteristic value.
func (c *DeviceCharacteristic) Read(data []byte) (int, error) {
func (c DeviceCharacteristic) Read(data []byte) (int, error) {
if c.properties&genericattributeprofile.GattCharacteristicPropertiesRead == 0 {
return 0, errNoRead
}
Expand Down

2 comments on commit 5746ccf

@raifrg
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@raifrg raifrg commented on 5746ccf Dec 4, 2024

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Method func (c *DeviceCharacteristic) EnableNotifications(callback func(buf []byte)) needs pointer receiver, because the channel c.property created when notifications were enabled (i.e. with non-nil callback) isn't saved in the structure after the method returns and is therefore not available when the same method is used to disable notifications (i.e. with nil callback).

@aykevl
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@aykevl aykevl commented on 5746ccf Dec 14, 2024

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@raifrg not necessarily! See for example how this is done on MacOS:

bluetooth/gap_darwin.go

Lines 87 to 103 in a668e1b

type Device struct {
Address Address
*deviceInternal
}
type deviceInternal struct {
delegate *peripheralDelegate
cm cbgo.CentralManager
prph cbgo.Peripheral
servicesChan chan error
charsChan chan error
services map[UUID]DeviceService
}

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