Move directory size calculation to pkg/ (fixes #10970)

Signed-off-by: Martijn Dwars <ikben@martijndwars.nl>

directory/directory.go

@@ -0,0 +1,39 @@
+// +build linux
+
+package directory
+
+import (
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// Size walks a directory tree and returns its total size in bytes.
+func Size(dir string) (size int64, err error) {
+	data := make(map[uint64]struct{})
+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, e error) error {
+		// Ignore directory sizes
+		if fileInfo == nil {
+			return nil
+		}
+
+		s := fileInfo.Size()
+		if fileInfo.IsDir() || s == 0 {
+			return nil
+		}
+
+		// Check inode to handle hard links correctly
+		inode := fileInfo.Sys().(*syscall.Stat_t).Ino
+		// inode is not a uint64 on all platforms. Cast it to avoid issues.
+		if _, exists := data[uint64(inode)]; exists {
+			return nil
+		}
+		// inode is not a uint64 on all platforms. Cast it to avoid issues.
+		data[uint64(inode)] = struct{}{}
+
+		size += s
+
+		return nil
+	})
+	return
+}

directory/directory_test.go

@@ -0,0 +1,120 @@
+package directory
+
+import (
+	"os"
+	"testing"
+)
+
+// Size of an empty directory should be 0
+func TestSizeEmpty(t *testing.T) {
+	var err error
+	if err = os.Mkdir("/tmp/testSizeEmptyDirectory", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeEmptyDirectory"); size != 0 {
+		t.Fatalf("empty directory has size: %d", size)
+	}
+}
+
+// Size of a directory with one empty file should be 0
+func TestSizeEmptyFile(t *testing.T) {
+	var err error
+	if err = os.Mkdir("/tmp/testSizeEmptyFile", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	if _, err = os.Create("/tmp/testSizeEmptyFile/file"); err != nil {
+		t.Fatalf("failed to create file: %s", err)
+	}
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeEmptyFile"); size != 0 {
+		t.Fatalf("directory with one file has size: %d", size)
+	}
+}
+
+// Size of a directory with one 5-byte file should be 5
+func TestSizeNonemptyFile(t *testing.T) {
+	var err error
+	if err = os.Mkdir("/tmp/testSizeNonemptyFile", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	var file *os.File
+	if file, err = os.Create("/tmp/testSizeNonemptyFile/file"); err != nil {
+		t.Fatalf("failed to create file: %s", err)
+	}
+
+	d := []byte{97, 98, 99, 100, 101}
+	file.Write(d)
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeNonemptyFile"); size != 5 {
+		t.Fatalf("directory with one 5-byte file has size: %d", size)
+	}
+}
+
+// Size of a directory with one empty directory should be 0
+func TestSizeNestedDirectoryEmpty(t *testing.T) {
+	var err error
+	if err = os.MkdirAll("/tmp/testSizeNestedDirectoryEmpty/nested", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeNestedDirectoryEmpty"); size != 0 {
+		t.Fatalf("directory with one empty directory has size: %d", size)
+	}
+}
+
+// Test directory with 1 file and 1 empty directory
+func TestSizeFileAndNestedDirectoryEmpty(t *testing.T) {
+	var err error
+	if err = os.MkdirAll("/tmp/testSizeFileAndNestedDirectoryEmpty/nested", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	var file *os.File
+	if file, err = os.Create("/tmp/testSizeFileAndNestedDirectoryEmpty/file"); err != nil {
+		t.Fatalf("failed to create file: %s", err)
+	}
+
+	d := []byte{100, 111, 99, 107, 101, 114}
+	file.Write(d)
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeFileAndNestedDirectoryEmpty"); size != 6 {
+		t.Fatalf("directory with 6-byte file and empty directory has size: %d", size)
+	}
+}
+
+// Test directory with 1 file and 1 non-empty directory
+func TestSizeFileAndNestedDirectoryNonempty(t *testing.T) {
+	var err error
+	if err = os.MkdirAll("/tmp/testSizeFileAndNestedDirectoryEmpty/nested", 0777); err != nil {
+		t.Fatalf("failed to create directory: %s", err)
+	}
+
+	var file *os.File
+	if file, err = os.Create("/tmp/testSizeFileAndNestedDirectoryEmpty/file"); err != nil {
+		t.Fatalf("failed to create file: %s", err)
+	}
+
+	data := []byte{100, 111, 99, 107, 101, 114}
+	file.Write(data)
+
+	var nestedFile *os.File
+	if nestedFile, err = os.Create("/tmp/testSizeFileAndNestedDirectoryEmpty/nested/file"); err != nil {
+		t.Fatalf("failed to create file: %s", err)
+	}
+
+	nestedData := []byte{100, 111, 99, 107, 101, 114}
+	nestedFile.Write(nestedData)
+
+	var size int64
+	if size, _ = Size("/tmp/testSizeFileAndNestedDirectoryEmpty"); size != 12 {
+		t.Fatalf("directory with 6-byte file and empty directory has size: %d", size)
+	}
+}