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package helper
import (
"io"
)
// NewReceiveReader turns receiver into an io.Reader. Errors from the
// receiver function are passed on unmodified. This means receiver should
// emit io.EOF when done.
func NewReceiveReader(receiver func() ([]byte, error)) io.Reader {
return &receiveReader{receiver: receiver}
}
type receiveReader struct {
receiver func() ([]byte, error)
data []byte
err error
}
func (rr *receiveReader) Read(p []byte) (int, error) {
if len(rr.data) == 0 {
rr.data, rr.err = rr.receiver()
}
n := copy(p, rr.data)
rr.data = rr.data[n:]
if len(rr.data) == 0 {
return n, rr.err
}
return n, nil
}
// NewSendWriter turns sender into an io.Writer. The number of 'bytes
// written' reported back is always len(p).
func NewSendWriter(sender func(p []byte) error) io.Writer {
return &sendWriter{sender: sender}
}
type sendWriter struct {
sender func([]byte) error
}
func (sw *sendWriter) Write(p []byte) (int, error) {
return len(p), sw.sender(p)
}
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