rocm_jax/jax/_src/lazy_loader.py
Sergei Lebedev 28a65589f7 lazy_loader.attach now only imports the submodule once on first access
This is a partial roll-forward of #22998.

PiperOrigin-RevId: 668633307
2024-08-28 15:37:28 -07:00

57 lines
1.8 KiB
Python

# Copyright 2022 The JAX Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""A LazyLoader class."""
from collections.abc import Callable, Sequence
import importlib
import sys
from typing import Any
def attach(package_name: str, submodules: Sequence[str]) -> tuple[
Callable[[str], Any],
Callable[[], list[str]],
list[str],
]:
"""Lazily loads submodules of a package.
Returns:
A tuple of ``__getattr__``, ``__dir__`` function and ``__all__`` --
a list of available global names, which can be used to replace the
corresponding definitions in the package.
Raises:
RuntimeError: If the ``__name__`` of the caller cannot be determined.
"""
owner_name = sys._getframe(1).f_globals.get("__name__")
if owner_name is None:
raise RuntimeError("Cannot determine the ``__name__`` of the caller.")
__all__ = list(submodules)
def __getattr__(name: str) -> Any:
if name in submodules:
value = importlib.import_module(f"{package_name}.{name}")
# Update module-level globals to avoid calling ``__getattr__`` again
# for this ``name``.
setattr(sys.modules[owner_name], name, value)
return value
raise AttributeError(f"module '{package_name}' has no attribute '{name}")
def __dir__() -> list[str]:
return __all__
return __getattr__, __dir__, __all__