func (h *DeviceHandle) InterruptTransfer(endpoint byte, data []byte, timeout int) (actual int, err error) {
var ptr *byte
if len(data) > 0 {
ptr = &data[0]
}
var n C.int
e := C.libusb_bulk_transfer(h.me(), C.uchar(endpoint), (*C.uchar)(ptr),
C.int(len(data)), &n, C.uint(timeout))
return int(n), toErr(e)
}
func bulkTransfer(ep *EndpointHandle, p []byte, _ bool) (n int, err error) {
var transferred C.int
err0 := returnUsbError(C.libusb_bulk_transfer(
ep.handle.handle,
C.uchar(ep.ep),
(*C.uchar)(unsafe.Pointer(&p[0])),
C.int(len(p)),
&transferred,
0))
if err0 != nil {
err = err0
}
return int(transferred), err
}
func bulk_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
}
data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
var cnt C.int
if errno := C.libusb_bulk_transfer(
e.handle,
C.uchar(e.Address),
(*C.uchar)(unsafe.Pointer(data)),
C.int(len(buf)),
&cnt,
C.uint(timeout/time.Millisecond)); errno < 0 {
return 0, usbError(errno)
}
return int(cnt), nil
}
func (d *Device) transferN(endpoint uint8, data []byte, n int) error {
if m := int(C.libusb_get_max_packet_size(d.dev, C.uchar(endpoint))); n == 0 {
n = m
} else if n > m {
return errors.New("invalid packet size")
}
for len, off := len(data), 0; len > 0; {
var transferred int
if n > len {
n = len
}
if err := C.libusb_bulk_transfer(d.handle, C.uchar(endpoint), (*C.uchar)(&data[off]), C.int(n),
(*C.int)(unsafe.Pointer(&transferred)), 2500); err != C.LIBUSB_SUCCESS {
return &libusbError{err}
}
len -= transferred
off += transferred
}
return nil
}