66 lines
1.3 KiB
Go
66 lines
1.3 KiB
Go
package shared
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import (
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"bytes"
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"fmt"
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"io"
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"time"
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log "github.com/sirupsen/logrus"
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)
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// receive at maximum the requested number of bytes from serial port and stop after the given timeout
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func ReceiveBytes(port io.Reader, count int, timeout time.Duration) ([]byte, error) {
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readCh := make(chan []byte, 1)
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errCh := make(chan error, 1)
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go func() {
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buffer := bytes.NewBuffer([]byte{})
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for remainder := count; remainder > 0; {
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data := make([]byte, remainder)
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if readBytes, err := port.Read(data); err != nil {
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errCh <- err
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return
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} else if readBytes > 0 {
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buffer.Write(data[0:readBytes])
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remainder -= readBytes
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log.Tracef("%d bytes read, remaining %d", readBytes, remainder)
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}
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}
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readCh <- buffer.Bytes()
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close(readCh)
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}()
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buffer := bytes.NewBuffer([]byte{})
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select {
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case <-time.After(timeout):
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return nil, fmt.Errorf("timeout passed %v", timeout)
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case err := <-errCh:
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return nil, err
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case data := <-readCh:
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log.Tracef("received %d bytes from channel", len(data))
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if data == nil {
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break
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}
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buffer.Write(data)
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}
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return buffer.Bytes(), nil
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}
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func SendBytes(port io.Writer, data []byte) error {
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n, err := port.Write(data)
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if err != nil {
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return fmt.Errorf("could not send bytes: %w", err)
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}
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log.Tracef("wrote %d bytes", n)
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return nil
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}
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