move code from Podman so it can be shared with conmon-rs

pkg/resize/resize.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2015 The Kubernetes 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
+
+    https://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 resize
+
+// TerminalSize represents the width and height of a terminal.
+type TerminalSize struct {
+	Width  uint16
+	Height uint16
+}
+
+// HandleResizing spawns a goroutine that processes the resize channel, calling resizeFunc for each
+// TerminalSize received from the channel. The resize channel must be closed elsewhere to stop the
+// goroutine.
+func HandleResizing(resize <-chan TerminalSize, resizeFunc func(size TerminalSize)) {
+	if resize == nil {
+		return
+	}
+
+	go func() {
+		for {
+			size, ok := <-resize
+			if !ok {
+				return
+			}
+			if size.Height < 1 || size.Width < 1 {
+				continue
+			}
+			resizeFunc(size)
+		}
+	}()
+}

pkg/util/copy.go

@@ -0,0 +1,57 @@
+package util
+
+import (
+	"errors"
+	"io"
+)
+
+// ErrDetach indicates that an attach session was manually detached by
+// the user.
+var ErrDetach = errors.New("detached from container")
+
+// CopyDetachable is similar to io.Copy but support a detach key sequence to break out.
+func CopyDetachable(dst io.Writer, src io.Reader, keys []byte) (written int64, err error) {
+	buf := make([]byte, 32*1024)
+	for {
+		nr, er := src.Read(buf)
+		if nr > 0 {
+			preservBuf := []byte{}
+			for i, key := range keys {
+				preservBuf = append(preservBuf, buf[0:nr]...)
+				if nr != 1 || buf[0] != key {
+					break
+				}
+				if i == len(keys)-1 {
+					return 0, ErrDetach
+				}
+				nr, er = src.Read(buf)
+			}
+			var nw int
+			var ew error
+			if len(preservBuf) > 0 {
+				nw, ew = dst.Write(preservBuf)
+				nr = len(preservBuf)
+			} else {
+				nw, ew = dst.Write(buf[0:nr])
+			}
+			if nw > 0 {
+				written += int64(nw)
+			}
+			if ew != nil {
+				err = ew
+				break
+			}
+			if nr != nw {
+				err = io.ErrShortWrite
+				break
+			}
+		}
+		if er != nil {
+			if er != io.EOF {
+				err = er
+			}
+			break
+		}
+	}
+	return written, err
+}