From 0dea724fc0a8ac6599bb0d33aa3792ff1bd3a0aa Mon Sep 17 00:00:00 2001
From: Guanjun Gong <gongguanjun@hotmail.com>
Date: Thu, 10 Sep 2020 15:12:44 +0800
Subject: [PATCH] NewTask avoid unnecessary cio.NewCreator calls

Signed-off-by: Guanjun Gong <gongguanjun@hotmail.com>
---
 cmd/ctr/commands/tasks/tasks_unix.go | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/cmd/ctr/commands/tasks/tasks_unix.go b/cmd/ctr/commands/tasks/tasks_unix.go
index 12917f201..0ec6dc010 100644
--- a/cmd/ctr/commands/tasks/tasks_unix.go
+++ b/cmd/ctr/commands/tasks/tasks_unix.go
@@ -72,7 +72,6 @@ func NewTask(ctx gocontext.Context, client *containerd.Client, container contain
 	stdinC := &stdinCloser{
 		stdin: os.Stdin,
 	}
-	stdio := cio.NewCreator(append([]cio.Opt{cio.WithStreams(stdinC, os.Stdout, os.Stderr)}, ioOpts...)...)
 	if checkpoint != "" {
 		im, err := client.GetImage(ctx, checkpoint)
 		if err != nil {
@@ -80,22 +79,22 @@ func NewTask(ctx gocontext.Context, client *containerd.Client, container contain
 		}
 		opts = append(opts, containerd.WithTaskCheckpoint(im))
 	}
-	ioCreator := stdio
+	var ioCreator cio.Creator
 	if con != nil {
-		ioCreator = cio.NewCreator(append([]cio.Opt{cio.WithStreams(con, con, nil), cio.WithTerminal}, ioOpts...)...)
-	}
-	if nullIO {
-		if con != nil {
+		if nullIO {
 			return nil, errors.New("tty and null-io cannot be used together")
 		}
+		ioCreator = cio.NewCreator(append([]cio.Opt{cio.WithStreams(con, con, nil), cio.WithTerminal}, ioOpts...)...)
+	} else if nullIO {
 		ioCreator = cio.NullIO
-	}
-	if logURI != "" {
+	} else if logURI != "" {
 		u, err := url.Parse(logURI)
 		if err != nil {
 			return nil, err
 		}
 		ioCreator = cio.LogURI(u)
+	} else {
+		ioCreator = cio.NewCreator(append([]cio.Opt{cio.WithStreams(stdinC, os.Stdout, os.Stderr)}, ioOpts...)...)
 	}
 	t, err := container.NewTask(ctx, ioCreator, opts...)
 	if err != nil {