Function TestSimpleWriteRead

pkg/sentry/fsimpl/tmpfs/regular_file_test.go:32–76

Test that we can write some data to a file and read it back.`

(t *testing.T)

// Test that we can write some data to a file and read it back.`
func TestSimpleWriteRead(t *testing.T) {
	ctx := contexttest.Context(t)
	fd, cleanup, err := newFileFD(ctx, 0644)
	if err != nil {
		t.Fatal(err)
	}
	defer cleanup()

	// Write.
	data := []byte("foobarbaz")
	n, err := fd.Write(ctx, usermem.BytesIOSequence(data), vfs.WriteOptions{})
	if err != nil {
		t.Fatalf("fd.Write failed: %v", err)
	}
	if n != int64(len(data)) {
		t.Errorf("fd.Write got short write length %d, want %d", n, len(data))
	}
	if got, want := fd.Impl().(*regularFileFD).off, int64(len(data)); got != want {
		t.Errorf("fd.Write left offset at %d, want %d", got, want)
	}

	// Seek back to beginning.
	if _, err := fd.Seek(ctx, 0, linux.SEEK_SET); err != nil {
		t.Fatalf("fd.Seek failed: %v", err)
	}
	if got, want := fd.Impl().(*regularFileFD).off, int64(0); got != want {
		t.Errorf("fd.Seek(0) left offset at %d, want %d", got, want)
	}

	// Read.
	buf := make([]byte, len(data))
	n, err = fd.Read(ctx, usermem.BytesIOSequence(buf), vfs.ReadOptions{})
	if err != nil && err != io.EOF {
		t.Fatalf("fd.Read failed: %v", err)
	}
	if n != int64(len(data)) {
		t.Errorf("fd.Read got short read length %d, want %d", n, len(data))
	}
	if got, want := string(buf), string(data); got != want {
		t.Errorf("Read got %q want %s", got, want)
	}
	if got, want := fd.Impl().(*regularFileFD).off, int64(len(data)); got != want {
		t.Errorf("fd.Write left offset at %d, want %d", got, want)
	}
}

func TestPWrite(t *testing.T) {
	ctx := contexttest.Context(t)