Merge pull request #12 from theanalyst/f/rw_xattr

ioctx: get/set xattr added

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>

rados/ioctx.go

@@ -191,3 +191,46 @@ func (ioctx *IOContext) ListObjects(listFn ObjectListFunc) error {
 
 	panic("invalid state")
 }
+
+// GetXattr gets an xattr with key `name`, it returns the length of
+// the key read or an error if not successful
+func (ioctx *IOContext) GetXattr(object string, name string, data []byte) (int, error) {
+	c_object := C.CString(object)
+	c_name := C.CString(name)
+	defer C.free(unsafe.Pointer(c_object))
+	defer C.free(unsafe.Pointer(c_name))
+
+	ret := C.rados_getxattr(
+		ioctx.ioctx,
+		c_object,
+		c_name,
+		(*C.char)(unsafe.Pointer(&data[0])),
+		(C.size_t)(len(data)))
+
+	if ret >= 0 {
+		return int(ret), nil
+	} else {
+		return 0, RadosError(int(ret))
+	}
+}
+
+// Sets an xattr for an object with key `name` with value as `data`
+func (ioctx *IOContext) SetXattr(object string, name string, data []byte) error {
+	c_object := C.CString(object)
+	c_name := C.CString(name)
+	defer C.free(unsafe.Pointer(c_object))
+	defer C.free(unsafe.Pointer(c_name))
+
+	ret := C.rados_setxattr(
+		ioctx.ioctx,
+		c_object,
+		c_name,
+		(*C.char)(unsafe.Pointer(&data[0])),
+		(C.size_t)(len(data)))
+
+	if ret == 0 {
+		return nil
+	} else {
+		return RadosError(int(ret))
+	}
+}

rados/rados_test.go

@@ -441,3 +441,33 @@ func TestNewConnWithUser(t *testing.T) {
 	_, err := rados.NewConnWithUser("admin")
 	assert.Equal(t, err, nil)
 }
+
+func TestReadWriteXattr(t *testing.T) {
+	conn, _ := rados.NewConn()
+	conn.ReadDefaultConfigFile()
+	conn.Connect()
+
+	// make pool
+	pool_name := GetUUID()
+	err := conn.MakePool(pool_name)
+	assert.NoError(t, err)
+
+	pool, err := conn.OpenIOContext(pool_name)
+	assert.NoError(t, err)
+
+	bytes_in := []byte("input data")
+	err = pool.Write("obj", bytes_in, 0)
+	assert.NoError(t, err)
+
+	my_xattr_in := []byte("my_value")
+	err = pool.SetXattr("obj", "my_key", my_xattr_in)
+	assert.NoError(t, err)
+
+	my_xattr_out := make([]byte, len(my_xattr_in))
+	n_out, err := pool.GetXattr("obj", "my_key", my_xattr_out)
+
+	assert.Equal(t, n_out, len(my_xattr_in))
+	assert.Equal(t, my_xattr_in, my_xattr_out)
+
+	pool.Destroy()
+}