Switch to go mod

vendor/github.com/vbatts/go-mtree/updatefuncs.go

@@ -0,0 +1,201 @@
+package mtree
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/sirupsen/logrus"
+	"github.com/vbatts/go-mtree/pkg/govis"
+)
+
+// UpdateKeywordFunc is the signature for a function that will restore a file's
+// attributes. Where path is relative path to the file, and value to be
+// restored to.
+type UpdateKeywordFunc func(path string, kv KeyVal) (os.FileInfo, error)
+
+// UpdateKeywordFuncs is the registered list of functions to update file attributes.
+// Keyed by the keyword as it would show up in the manifest
+var UpdateKeywordFuncs = map[Keyword]UpdateKeywordFunc{
+	"mode":     modeUpdateKeywordFunc,
+	"time":     timeUpdateKeywordFunc,
+	"tar_time": tartimeUpdateKeywordFunc,
+	"uid":      uidUpdateKeywordFunc,
+	"gid":      gidUpdateKeywordFunc,
+	"xattr":    xattrUpdateKeywordFunc,
+	"link":     linkUpdateKeywordFunc,
+}
+
+func uidUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	uid, err := strconv.Atoi(kv.Value())
+	if err != nil {
+		return nil, err
+	}
+
+	stat, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+	if statIsUID(stat, uid) {
+		return stat, nil
+	}
+
+	if err := os.Lchown(path, uid, -1); err != nil {
+		return nil, err
+	}
+	return os.Lstat(path)
+}
+
+func gidUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	gid, err := strconv.Atoi(kv.Value())
+	if err != nil {
+		return nil, err
+	}
+
+	stat, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+	if statIsGID(stat, gid) {
+		return stat, nil
+	}
+
+	if err := os.Lchown(path, -1, gid); err != nil {
+		return nil, err
+	}
+	return os.Lstat(path)
+}
+
+func modeUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	info, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	// don't set mode on symlinks, as it passes through to the backing file
+	if info.Mode()&os.ModeSymlink != 0 {
+		return info, nil
+	}
+	vmode, err := strconv.ParseInt(kv.Value(), 8, 32)
+	if err != nil {
+		return nil, err
+	}
+
+	stat, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+	if stat.Mode() == os.FileMode(vmode) {
+		return stat, nil
+	}
+
+	logrus.Debugf("path: %q, kv.Value(): %q, vmode: %o", path, kv.Value(), vmode)
+	if err := os.Chmod(path, os.FileMode(vmode)); err != nil {
+		return nil, err
+	}
+	return os.Lstat(path)
+}
+
+// since tar_time will only be second level precision, then when restoring the
+// filepath from a tar_time, then compare the seconds first and only Chtimes if
+// the seconds value is different.
+func tartimeUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	info, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	v := strings.SplitN(kv.Value(), ".", 2)
+	if len(v) != 2 {
+		return nil, fmt.Errorf("expected a number like 1469104727.000000000")
+	}
+	sec, err := strconv.ParseInt(v[0], 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("expected seconds, but got %q", v[0])
+	}
+
+	// if the seconds are the same, don't do anything, because the file might
+	// have nanosecond value, and if using tar_time it would zero it out.
+	if info.ModTime().Unix() == sec {
+		return info, nil
+	}
+
+	vtime := time.Unix(sec, 0)
+
+	// if times are same then don't modify anything
+	// comparing Unix, since it does not include Nano seconds
+	if info.ModTime().Unix() == vtime.Unix() {
+		return info, nil
+	}
+
+	// symlinks are strange and most of the time passes through to the backing file
+	if info.Mode()&os.ModeSymlink != 0 {
+		if err := lchtimes(path, vtime, vtime); err != nil {
+			return nil, err
+		}
+	} else if err := os.Chtimes(path, vtime, vtime); err != nil {
+		return nil, err
+	}
+	return os.Lstat(path)
+}
+
+// this is nano second precision
+func timeUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	info, err := os.Lstat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	v := strings.SplitN(kv.Value(), ".", 2)
+	if len(v) != 2 {
+		return nil, fmt.Errorf("expected a number like 1469104727.871937272")
+	}
+	nsec, err := strconv.ParseInt(v[0]+v[1], 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("expected nano seconds, but got %q", v[0]+v[1])
+	}
+	logrus.Debugf("arg: %q; nsec: %d", v[0]+v[1], nsec)
+
+	vtime := time.Unix(0, nsec)
+
+	// if times are same then don't modify anything
+	if info.ModTime().Equal(vtime) {
+		return info, nil
+	}
+
+	// symlinks are strange and most of the time passes through to the backing file
+	if info.Mode()&os.ModeSymlink != 0 {
+		if err := lchtimes(path, vtime, vtime); err != nil {
+			return nil, err
+		}
+	} else if err := os.Chtimes(path, vtime, vtime); err != nil {
+		return nil, err
+	}
+	return os.Lstat(path)
+}
+
+func linkUpdateKeywordFunc(path string, kv KeyVal) (os.FileInfo, error) {
+	linkname, err := govis.Unvis(kv.Value(), DefaultVisFlags)
+	if err != nil {
+		return nil, err
+	}
+	got, err := os.Readlink(path)
+	if err != nil {
+		return nil, err
+	}
+	if got == linkname {
+		return os.Lstat(path)
+	}
+
+	logrus.Debugf("linkUpdateKeywordFunc: removing %q to link to %q", path, linkname)
+	if err := os.Remove(path); err != nil {
+		return nil, err
+	}
+	if err := os.Symlink(linkname, path); err != nil {
+		return nil, err
+	}
+
+	return os.Lstat(path)
+}