added nn.RecordBytesDecoder with its test

oneflow/python/nn/modules/dataset.py

@@ -621,6 +621,21 @@ def __init__(self, shape: Sequence[int], dtype: flow.dtype, alignment: int):
     def forward(self, input):
         return self._op(input)[0]
 
+@oneflow_export("nn.OFRecordBytesDecoder")
+@experimental_api
+class OFRecordBytesDecoder(Module):
+    def __init__(self, blob_name: str,name: Optional[str] = None):
+        super().__init__()
+        self._op = (
+            flow.builtin_op("ofrecord_bytes_decoder",name)
+            .Input("in")
+            .Output("out")
+            .Attr("name", blob_name)
+            .Build()
+        )
+
+    def forward(self, input):
+        return self._op(input)[0]
 
 if __name__ == "__main__":
     import doctest

oneflow/python/test/modules/test_dataset.py

@@ -315,6 +315,30 @@ def test_coco_reader(test_case):
                     np.array_equal(segm_index_list[i], sample["poly_index"])
                 )
 
+@flow.unittest.skip_unless_1n1d()                
+@unittest.skipIf(
+    not flow.unittest.env.eager_execution_enabled(),
+    ".numpy() doesn't work in lazy mode",
+)
+
+class TestOFRecordBytesDecoder(flow.unittest.TestCase):
+    def test_OFRecordBytesDecoder(test_case):
+        batch_size = 16
+        record_reader = flow.nn.OfrecordReader(
+            "dataset/imagenette/ofrecord",
+            batch_size=batch_size,
+            part_name_suffix_length=5,
+        )
+        val_record = record_reader()
+
+        bytesdecoder_img = flow.nn.OFRecordBytesDecoder("encoded")
+
+        image_raw_buffer = bytesdecoder_img(val_record)
+
+        image_raw_buffer_nd = image_raw_buffer.numpy()[0]
+        gt_np = cv2.imread("dataset/imagenette/ofrecord/gt_tensor_buffer_image.png")
+        img = cv2.imdecode(image_raw_buffer_nd,cv2.IMREAD_COLOR)
+        test_case.assertTrue(np.array_equal(img, gt_np))
 
 if __name__ == "__main__":
     unittest.main()