buildkit/session/sshforward/copy.go

70 lines
1.2 KiB
Go

package sshforward
import (
io "io"
"github.com/pkg/errors"
context "golang.org/x/net/context"
"golang.org/x/sync/errgroup"
)
type Stream interface {
SendMsg(m interface{}) error
RecvMsg(m interface{}) error
}
func Copy(ctx context.Context, conn io.ReadWriteCloser, stream Stream, closeStream func() error) error {
g, ctx := errgroup.WithContext(ctx)
g.Go(func() (retErr error) {
p := &BytesMessage{}
for {
if err := stream.RecvMsg(p); err != nil {
conn.Close()
if err == io.EOF {
return nil
}
return errors.WithStack(err)
}
select {
case <-ctx.Done():
conn.Close()
return ctx.Err()
default:
}
if _, err := conn.Write(p.Data); err != nil {
conn.Close()
return errors.WithStack(err)
}
p.Data = p.Data[:0]
}
})
g.Go(func() (retErr error) {
for {
buf := make([]byte, 32*1024)
n, err := conn.Read(buf)
switch {
case err == io.EOF:
if closeStream != nil {
closeStream()
}
return nil
case err != nil:
return errors.WithStack(err)
}
select {
case <-ctx.Done():
return ctx.Err()
default:
}
p := &BytesMessage{Data: buf[:n]}
if err := stream.SendMsg(p); err != nil {
return errors.WithStack(err)
}
}
})
return g.Wait()
}