# Copyright 2021 MONAI Consortium
# 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 abc import ABC, abstractmethod
from typing import Any, Hashable, KeysView, Optional
[docs]class Datastore(ABC):
"""Base class for data store."""
[docs] @abstractmethod
def get(self, key: Hashable, def_val: Optional[Any] = None) -> Any:
"""Get value from the data store.
Args:
key (Hashable): A key to get.
Returns:
value (Any): A value from the data store.
"""
pass
[docs] @abstractmethod
def put(self, key: Hashable, value: Any):
"""Put value into the data store.
Args:
key (Hashable): A key to put.
value (Any): A value to put.
"""
pass
[docs] @abstractmethod
def delete(self, key: Hashable):
"""Delete value from the data store.
Args:
key (Hashable): A key to delete.
"""
pass
[docs] @abstractmethod
def exists(self, key: Hashable) -> bool:
"""Check if key exists in data store.
Args:
key (Hashable): A key to check.
Returns:
exists (bool): True if key exists, False otherwise.
"""
pass
[docs] @abstractmethod
def size(self) -> int:
"""Get size of data store.
Returns:
size (int): A size of data store.
"""
pass
[docs] @abstractmethod
def keys(self) -> KeysView:
"""Get keys from data store.
Returns:
keys (KeysView): A view of keys.
"""
pass