# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
#
# 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
#
# http://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.
import importlib
import inspect
import logging
import pkgutil
from typing import Dict, List, Optional
from nvflare.security.logging import secure_format_exception
DEPRECATED_PACKAGES = ["nvflare.app_common.pt", "nvflare.app_common.homomorphic_encryption"]
[docs]def get_class(class_path):
module_name, class_name = class_path.rsplit(".", 1)
try:
module_ = importlib.import_module(module_name)
try:
class_ = getattr(module_, class_name)
except AttributeError:
raise ValueError("Class {} does not exist".format(class_path))
except AttributeError:
raise ValueError("Module {} does not exist".format(class_path))
return class_
[docs]def instantiate_class(class_path, init_params):
"""Method for creating an instance for the class.
Args:
class_path: full path of the class
init_params: A dictionary that contains the name of the transform and constructor input
arguments. The transform name will be appended to `medical.common.transforms` to make a
full name of the transform to be built.
"""
c = get_class(class_path)
try:
if init_params:
instance = c(**init_params)
else:
instance = c()
except TypeError as e:
raise ValueError(f"Class {class_path} has parameters error: {secure_format_exception(e)}.")
return instance
class _ModuleScanResult:
"""Data class for ModuleScanner."""
def __init__(self, class_name: str, module_name: str):
self.class_name = class_name
self.module_name = module_name
def __str__(self):
return f"{self.class_name}:{self.module_name}"
[docs]class ModuleScanner:
def __init__(self, base_pkgs: List[str], module_names: List[str], exclude_libs=True):
"""Loads specified modules from base packages and then constructs a class to module name mapping.
Args:
base_pkgs: base packages to look for modules in
module_names: module names to load
exclude_libs: excludes modules containing .libs if True. Defaults to True.
"""
self.base_pkgs = base_pkgs
self.module_names = module_names
self.exclude_libs = exclude_libs
self._logger = logging.getLogger(self.__class__.__name__)
self._class_table: Dict[str, str] = {}
self._create_classes_table()
def _create_classes_table(self):
scan_result_table = {}
for base in self.base_pkgs:
package = importlib.import_module(base)
for module_info in pkgutil.walk_packages(path=package.__path__, prefix=package.__name__ + "."):
module_name = module_info.name
if any(module_name.startswith(deprecated_package) for deprecated_package in DEPRECATED_PACKAGES):
continue
if module_name.startswith(base):
if not self.exclude_libs or (".libs" not in module_name):
if any(module_name.startswith(base + "." + name + ".") for name in self.module_names):
try:
module = importlib.import_module(module_name)
for name, obj in inspect.getmembers(module):
if (
not name.startswith("_")
and inspect.isclass(obj)
and obj.__module__ == module_name
):
# same class name exists in multiple modules
if name in scan_result_table:
scan_result = scan_result_table[name]
if name in self._class_table:
self._class_table.pop(name)
self._class_table[f"{scan_result.module_name}.{name}"] = module_name
self._class_table[f"{module_name}.{name}"] = module_name
else:
scan_result = _ModuleScanResult(class_name=name, module_name=module_name)
scan_result_table[name] = scan_result
self._class_table[name] = module_name
except (ModuleNotFoundError, RuntimeError) as e:
self._logger.debug(
f"Try to import module {module_name}, but failed: {secure_format_exception(e)}. "
f"Can't use name in config to refer to classes in module: {module_name}."
)
pass
[docs] def get_module_name(self, class_name) -> Optional[str]:
"""Gets the name of the module that contains this class.
Args:
class_name: The name of the class
Returns:
The module name if found.
"""
return self._class_table.get(class_name, None)