fs: prepare fd based metadataHandle

Add the skeleton, but leave filling in the details to later commits.

internal/fs/meta_fd.go

@@ -0,0 +1,36 @@
+//go:build darwin || linux || windows
+
+package fs
+
+import "os"
+
+type fdMetadataHandle struct {
+	name string
+	f    *os.File
+}
+
+var _ metadataHandle = &fdMetadataHandle{}
+
+func newFdMetadataHandle(name string, f *os.File) *fdMetadataHandle {
+	return &fdMetadataHandle{
+		name: name,
+		f:    f,
+	}
+}
+
+func (p *fdMetadataHandle) Name() string {
+	return p.name
+}
+
+func (p *fdMetadataHandle) Stat() (*ExtendedFileInfo, error) {
+	fi, err := p.f.Stat()
+	if err != nil {
+		return nil, err
+	}
+	return extendedStat(fi), nil
+}
+
+func (p *fdMetadataHandle) Readlink() (string, error) {
+	// FIXME
+	return os.Readlink(fixpath(p.name))
+}

internal/fs/meta_fd_notwindows.go

@@ -0,0 +1,14 @@
+//go:build darwin || linux
+
+package fs
+
+import "github.com/restic/restic/internal/restic"
+
+func (p *fdMetadataHandle) Xattr(ignoreListError bool) ([]restic.ExtendedAttribute, error) {
+	// FIXME
+	return xattrFromPath(p.Name(), ignoreListError)
+}
+
+func (p *fdMetadataHandle) SecurityDescriptor() (*[]byte, error) {
+	return nil, nil
+}

internal/fs/meta_windows.go

@@ -8,23 +8,26 @@ import (
 )
 
 func (p *pathMetadataHandle) Xattr(_ bool) ([]restic.ExtendedAttribute, error) {
-	allowExtended, err := checkAndStoreEASupport(p.name)
+	return xattrFromPath(p.name)
+}
+
+func xattrFromPath(path string) ([]restic.ExtendedAttribute, error) {
+	allowExtended, err := checkAndStoreEASupport(path)
 	if err != nil || !allowExtended {
 		return nil, err
 	}
 
 	var fileHandle windows.Handle
-	if fileHandle, err = openHandleForEA(p.name, false); err != nil {
-		return nil, errors.Errorf("get EA failed while opening file handle for path %v, with: %v", p.name, err)
+	if fileHandle, err = openHandleForEA(path, false); err != nil {
+		return nil, errors.Errorf("get EA failed while opening file handle for path %v, with: %v", path, err)
 	}
-	defer closeFileHandle(fileHandle, p.name)
-
+	defer closeFileHandle(fileHandle, path)
 	//Get the windows Extended Attributes using the file handle
 	var extAtts []extendedAttribute
 	extAtts, err = fgetEA(fileHandle)
-	debug.Log("fillExtendedAttributes(%v) %v", p.name, extAtts)
+	debug.Log("fillExtendedAttributes(%v) %v", path, extAtts)
 	if err != nil {
-		return nil, errors.Errorf("get EA failed for path %v, with: %v", p.name, err)
+		return nil, errors.Errorf("get EA failed for path %v, with: %v", path, err)
 	}
 	if len(extAtts) == 0 {
 		return nil, nil
@@ -45,3 +48,13 @@ func (p *pathMetadataHandle) Xattr(_ bool) ([]restic.ExtendedAttribute, error) {
 func (p *pathMetadataHandle) SecurityDescriptor() (*[]byte, error) {
 	return getSecurityDescriptor(p.name)
 }
+
+func (p *fdMetadataHandle) Xattr(_ bool) ([]restic.ExtendedAttribute, error) {
+	// FIXME
+	return xattrFromPath(p.name)
+}
+
+func (p *fdMetadataHandle) SecurityDescriptor() (*[]byte, error) {
+	// FIXME
+	return getSecurityDescriptor(p.name)
+}

internal/fs/meta_xattr.go

@@ -12,8 +12,12 @@ import (
 )
 
 func (p *pathMetadataHandle) Xattr(ignoreListError bool) ([]restic.ExtendedAttribute, error) {
-	xattrs, err := listxattr(p.name)
-	debug.Log("fillExtendedAttributes(%v) %v %v", p.name, xattrs, err)
+	return xattrFromPath(p.Name(), ignoreListError)
+}
+
+func xattrFromPath(path string, ignoreListError bool) ([]restic.ExtendedAttribute, error) {
+	xattrs, err := listxattr(path)
+	debug.Log("fillExtendedAttributes(%v) %v %v", path, xattrs, err)
 	if err != nil {
 		if ignoreListError && isListxattrPermissionError(err) {
 			return nil, nil
@@ -23,9 +27,9 @@ func (p *pathMetadataHandle) Xattr(ignoreListError bool) ([]restic.ExtendedAttri
 
 	extendedAttrs := make([]restic.ExtendedAttribute, 0, len(xattrs))
 	for _, attr := range xattrs {
-		attrVal, err := getxattr(p.name, attr)
+		attrVal, err := getxattr(path, attr)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "can not obtain extended attribute %v for %v:\n", attr, p.name)
+			fmt.Fprintf(os.Stderr, "can not obtain extended attribute %v for %v:\n", attr, path)
 			continue
 		}
 		attr := restic.ExtendedAttribute{