[mqtt] Implements mqtt publish tooling

vendor/github.com/containerd/continuity/fs/copy_unix.go

@@ -0,0 +1,112 @@
+// +build solaris darwin freebsd
+
+/*
+   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 fs
+
+import (
+	"io"
+	"os"
+	"syscall"
+
+	"github.com/containerd/continuity/sysx"
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+func copyFileInfo(fi os.FileInfo, name string) error {
+	st := fi.Sys().(*syscall.Stat_t)
+	if err := os.Lchown(name, int(st.Uid), int(st.Gid)); err != nil {
+		if os.IsPermission(err) {
+			// Normally if uid/gid are the same this would be a no-op, but some
+			// filesystems may still return EPERM... for instance NFS does this.
+			// In such a case, this is not an error.
+			if dstStat, err2 := os.Lstat(name); err2 == nil {
+				st2 := dstStat.Sys().(*syscall.Stat_t)
+				if st.Uid == st2.Uid && st.Gid == st2.Gid {
+					err = nil
+				}
+			}
+		}
+		if err != nil {
+			return errors.Wrapf(err, "failed to chown %s", name)
+		}
+	}
+
+	if (fi.Mode() & os.ModeSymlink) != os.ModeSymlink {
+		if err := os.Chmod(name, fi.Mode()); err != nil {
+			return errors.Wrapf(err, "failed to chmod %s", name)
+		}
+	}
+
+	timespec := []syscall.Timespec{StatAtime(st), StatMtime(st)}
+	if err := syscall.UtimesNano(name, timespec); err != nil {
+		return errors.Wrapf(err, "failed to utime %s", name)
+	}
+
+	return nil
+}
+
+func copyFileContent(dst, src *os.File) error {
+	buf := bufferPool.Get().(*[]byte)
+	_, err := io.CopyBuffer(dst, src, *buf)
+	bufferPool.Put(buf)
+
+	return err
+}
+
+func copyXAttrs(dst, src string, xeh XAttrErrorHandler) error {
+	xattrKeys, err := sysx.LListxattr(src)
+	if err != nil {
+		e := errors.Wrapf(err, "failed to list xattrs on %s", src)
+		if xeh != nil {
+			e = xeh(dst, src, "", e)
+		}
+		return e
+	}
+	for _, xattr := range xattrKeys {
+		data, err := sysx.LGetxattr(src, xattr)
+		if err != nil {
+			e := errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
+		}
+		if err := sysx.LSetxattr(dst, xattr, data, 0); err != nil {
+			e := errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
+		}
+	}
+
+	return nil
+}
+
+func copyDevice(dst string, fi os.FileInfo) error {
+	st, ok := fi.Sys().(*syscall.Stat_t)
+	if !ok {
+		return errors.New("unsupported stat type")
+	}
+	return unix.Mknod(dst, uint32(fi.Mode()), int(st.Rdev))
+}