Files
2026-07-13 12:40:42 +08:00

156 lines
4.8 KiB
Python

# Copyright (c) 2023 PaddlePaddle Authors. 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.
from __future__ import annotations
import os
from typing import Generic, TypeVar
from typing_extensions import Self
T = TypeVar("T")
def strtobool(val):
val = val.lower()
if val in ['y', 'yes', 't', 'true', 'on', '1']:
return True
elif val in ['n', 'no', 'f', 'false', 'off', '0']:
return False
else:
raise ValueError(f"Invalid truth value {val!r}")
class EnvironmentVariable(Generic[T]):
name: str
default: T
def __init__(self, name: str, default: T):
self.name = name
self.default = default
self._last_env_value: str | None = None
self._cached_value: T | None = None
def get(self) -> T:
_current_env_value = os.getenv(self.name)
if (
self._cached_value is None
or self._last_env_value != _current_env_value
):
self._cached_value = self.parse_from_string()
self._last_env_value = _current_env_value
return self._cached_value
def set(self, value: T) -> None:
os.environ[self.name] = self.convert_to_string(value)
self._cached_value = value
def parse_from_string(self) -> T:
raise NotImplementedError
def convert_to_string(self, value: T) -> str:
raise NotImplementedError
def delete(self) -> None:
del os.environ[self.name]
def __repr__(self) -> str:
return f"Env({self.name}={self.get()!r})"
class StringEnvironmentVariable(EnvironmentVariable[str]):
def __init__(self, name: str, default: str):
super().__init__(name, default)
assert isinstance(default, str), "default must be a string"
def parse_from_string(self) -> str:
return os.getenv(self.name, self.default)
def convert_to_string(self, value: str) -> str:
assert isinstance(value, str), "value must be a string"
return value
class BooleanEnvironmentVariable(EnvironmentVariable[bool]):
def __init__(self, name: str, default: bool):
super().__init__(name, default)
assert isinstance(default, bool), "default must be a boolean"
def parse_from_string(self) -> bool:
default = str(self.default)
env_str = os.getenv(self.name, default)
return strtobool(env_str)
def convert_to_string(self, value: bool) -> str:
assert isinstance(value, bool), "value must be a boolean"
return str(value).lower()
def __bool__(self) -> bool:
raise ValueError(
"BooleanEnvironmentVariable does not support bool(), "
"please use get() instead."
)
class IntegerEnvironmentVariable(EnvironmentVariable[int]):
def __init__(self, name: str, default: int):
super().__init__(name, default)
assert isinstance(default, int) and not isinstance(default, bool), (
"default must be an integer"
)
def parse_from_string(self) -> int:
try:
return int(os.getenv(self.name, str(self.default)))
except ValueError:
return self.default
def convert_to_string(self, value: int) -> str:
assert isinstance(value, int) and not isinstance(value, bool), (
"value must be an integer"
)
return str(value)
class StringListEnvironmentVariable(EnvironmentVariable[list[str]]):
def __init__(self, name: str, default: list[str]):
super().__init__(name, default)
assert isinstance(default, list), "default must be a list"
def parse_from_string(self) -> list[str]:
return os.getenv(self.name, ",".join(self.default)).split(",")
def convert_to_string(self, value: list[str]) -> str:
assert isinstance(value, list), "value must be a list"
assert all(isinstance(x, str) for x in value), (
"value must be a list of strings"
)
return ",".join(value)
class EnvironmentVariableGuard(Generic[T]):
variable: EnvironmentVariable[T]
original_value: T
def __init__(self, variable: EnvironmentVariable[T], value: T):
self.variable = variable
self.original_value = variable.get()
self.variable.set(value)
def __enter__(self) -> Self:
return self
def __exit__(self, exc_type, exc_value, traceback) -> None:
self.variable.set(self.original_value)