commands/files: Added SizeFile interface

files/file.go

@@ -38,8 +38,14 @@ type StatFile interface {
 }
 
 type PeekFile interface {
-	File
+	SizeFile
 
 	Peek(n int) File
 	Length() int
 }
+
+type SizeFile interface {
+	File
+
+	Size() (int64, error)
+}

files/readerfile.go

 package files
 
 import (
+	"errors"
 	"io"
 	"os"
 )
@@ -40,3 +41,10 @@ func (f *ReaderFile) Close() error {
 func (f *ReaderFile) Stat() os.FileInfo {
 	return f.stat
 }
+
+func (f *ReaderFile) Size() (int64, error) {
+	if f.stat == nil {
+		return 0, errors.New("File size unknown")
+	}
+	return f.stat.Size(), nil
+}

files/serialfile.go

@@ -118,3 +118,33 @@ func (f *serialFile) Close() error {
 func (f *serialFile) Stat() os.FileInfo {
 	return f.stat
 }
+
+func (f *serialFile) Size() (int64, error) {
+	return size(f.stat, f.FileName())
+}
+
+func size(stat os.FileInfo, filename string) (int64, error) {
+	if !stat.IsDir() {
+		return stat.Size(), nil
+	}
+
+	file, err := os.Open(filename)
+	if err != nil {
+		return 0, err
+	}
+	files, err := file.Readdir(0)
+	if err != nil {
+		return 0, err
+	}
+	file.Close()
+
+	var output int64
+	for _, child := range files {
+		s, err := size(child, fp.Join(filename, child.Name()))
+		if err != nil {
+			return 0, err
+		}
+		output += s
+	}
+	return output, nil
+}

files/slicefile.go

 package files
 
-import "io"
+import (
+	"errors"
+	"io"
+)
 
 // SliceFile implements File, and provides simple directory handling.
 // It contains children files, and is created from a `[]File`.
@@ -47,3 +50,22 @@ func (f *SliceFile) Peek(n int) File {
 func (f *SliceFile) Length() int {
 	return len(f.files)
 }
+
+func (f *SliceFile) Size() (int64, error) {
+	var size int64
+
+	for _, file := range f.files {
+		sizeFile, ok := file.(SizeFile)
+		if !ok {
+			return 0, errors.New("Could not get size of child file")
+		}
+
+		s, err := sizeFile.Size()
+		if err != nil {
+			return 0, err
+		}
+		size += s
+	}
+
+	return size, nil
+}