// Implementation of io.Writer interface.
func (p *Port) Write(b []byte) (int, error) {
var c int32
var start time.Time
if Debug {
start = time.Now()
}
buf, size := unsafe.Pointer(&b[0]), C.size_t(len(b))
if p.writeDeadline.IsZero() {
// no deadline
c = C.sp_blocking_write(p.p, buf, size, 0)
} else if millis := deadline2millis(p.writeDeadline); millis <= 0 {
// call nonblocking write
c = C.sp_nonblocking_write(p.p, buf, size)
} else {
// call blocking write
c = C.sp_blocking_write(p.p, buf, size, C.uint(millis))
}
if Debug {
log.Printf("write time: %d ns", time.Since(start).Nanoseconds())
}
n := int(c)
// check for error
if n < 0 {
return 0, errmsg(c)
} else if n != len(b) {
return n, ErrTimeout
}
return n, nil
}
// BlockingWrite attempts to write the string or buffer supplied to the port
// blocks while writing, timeout is the number of mS to wait or set 0 to wait
// indefinitely.
func BlockingWrite(port Port, txBuf []byte, timeout uint16) (int32, error) {
var result int32 = SP_OK
result = C.sp_blocking_write(port, (unsafe.Pointer(&txBuf[0])), C.size_t(len(txBuf)), C.uint(timeout))
return result, checkResult(result)
}