vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/containerd/console/console.go

@@ -0,0 +1,78 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package console
+
+import (
+	"errors"
+	"io"
+	"os"
+)
+
+var ErrNotAConsole = errors.New("provided file is not a console")
+
+type Console interface {
+	io.Reader
+	io.Writer
+	io.Closer
+
+	// Resize resizes the console to the provided window size
+	Resize(WinSize) error
+	// ResizeFrom resizes the calling console to the size of the
+	// provided console
+	ResizeFrom(Console) error
+	// SetRaw sets the console in raw mode
+	SetRaw() error
+	// DisableEcho disables echo on the console
+	DisableEcho() error
+	// Reset restores the console to its orignal state
+	Reset() error
+	// Size returns the window size of the console
+	Size() (WinSize, error)
+	// Fd returns the console's file descriptor
+	Fd() uintptr
+	// Name returns the console's file name
+	Name() string
+}
+
+// WinSize specifies the window size of the console
+type WinSize struct {
+	// Height of the console
+	Height uint16
+	// Width of the console
+	Width uint16
+	x     uint16
+	y     uint16
+}
+
+// Current returns the current processes console
+func Current() Console {
+	c, err := ConsoleFromFile(os.Stdin)
+	if err != nil {
+		// stdin should always be a console for the design
+		// of this function
+		panic(err)
+	}
+	return c
+}
+
+// ConsoleFromFile returns a console using the provided file
+func ConsoleFromFile(f *os.File) (Console, error) {
+	if err := checkConsole(f); err != nil {
+		return nil, err
+	}
+	return newMaster(f)
+}