Use tofile directly

Signed-off-by: Justin Chu <[email protected]>

Author: justinchuby

src/onnx_ir/_core.py

@@ -1041,13 +1041,7 @@ def tobytes(self) -> bytes:
         return self._evaluate().tobytes()
 
     def tofile(self, file) -> None:
-        tensor = self._evaluate()
-        if hasattr(tensor, "tofile"):
-            # Some existing implementation (e.g. PyTorch <2.10) of TensorProtocol
-            # may not have tofile() as it was introduced in v0.1.11
-            tensor.tofile(file)
-        else:
-            super().tofile(file)
+        self._evaluate().tofile(file)
 
 
 class PackedTensor(TensorBase, _protocols.TensorProtocol, Generic[TArrayCompatible]):  # pylint: disable=too-many-ancestors

src/onnx_ir/_protocols.py

@@ -147,6 +147,18 @@ def tobytes(self) -> bytes:
         """Return the tensor as a byte string conformed to the ONNX specification, in little endian."""
         ...
 
+    def tofile(self, file) -> None:
+        """Write the tensor as a byte string conformed to the ONNX specification to the given file-like object.
+
+        The file-like object must support ``file.write(bytes)``.
+        If the file-like object also supports ``file.fileno()``, it will be used
+        to write the data directly to the underlying file descriptor. This is
+        more efficient for large tensors.
+
+        .. versionadded:: 0.1.11
+        """
+        ...
+
 
 @typing.runtime_checkable
 class ValueProtocol(Protocol):

src/onnx_ir/external_data.py

@@ -210,15 +210,7 @@ def _write_external_data(
             if current_offset > file_size:
                 data_file.write(b"\0" * (current_offset - file_size))
 
-            if hasattr(tensor, "tofile"):
-                # Some existing implementation (e.g. PyTorch <2.10) of TensorProtocol
-                # may not have tofile() as it was introduced in v0.1.11
-                tensor.tofile(data_file)
-            else:
-                raw_data = tensor.tobytes()
-                if isinstance(tensor, _core.ExternalTensor):
-                    tensor.release()
-                data_file.write(raw_data)
+            tensor.tofile(data_file)
 
 
 def _create_external_tensor(