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|
package stream
import (
"fmt"
"io"
"gitlab.com/gitlab-org/gitaly/v16/internal/git/pktline"
)
// Conn represents a bi-directional client side connection.
type Conn interface {
io.Reader
io.Writer
CloseWrite() error
}
// BandStdout and BandStderr are the pktline band ID's for stdout and
// stderr, respectively.
const (
BandStdout = 1
BandStderr = 2
)
// ProxyPktLine lets a client de-multiplex and proxy stdin, stdout and
// stderr streams. Stdout and stderr are interleaved with Git's pktline
// format.
func ProxyPktLine(c Conn, stdin io.Reader, stdout, stderr io.Writer) error {
copyRequest := func(c Conn) error {
if _, err := io.Copy(c, stdin); err != nil {
return fmt.Errorf("copy request: %w", err)
}
if err := c.CloseWrite(); err != nil {
return fmt.Errorf("close request: %w", err)
}
return nil
}
copyResponse := func(c Conn) error {
if err := pktline.EachSidebandPacket(c, func(band byte, data []byte) (err error) {
switch band {
case BandStdout:
_, err = stdout.Write(data)
case BandStderr:
_, err = stderr.Write(data)
default:
err = fmt.Errorf("unexpected band: %d", band)
}
return err
}); err != nil {
return fmt.Errorf("copy response: %w", err)
}
return nil
}
request := make(chan error, 1)
go func() { request <- copyRequest(c) }()
response := make(chan error, 1)
go func() { response <- copyResponse(c) }()
for {
select {
case err := <-response:
// Server is done. No point in waiting for client.
return err
case err := <-request:
if err != nil {
return err
}
// Client is now done. Wait for server to finish too.
}
}
}
|
