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# SPDX-FileCopyrightText: 2015 Eric Larson
#
# SPDX-License-Identifier: Apache-2.0
"""
The cache object API for implementing caches. The default is a thread
safe in-memory dictionary.
"""
from __future__ import annotations
from threading import Lock
from typing import IO, TYPE_CHECKING, MutableMapping
if TYPE_CHECKING:
from datetime import datetime
class BaseCache:
def get(self, key: str) -> bytes | None:
raise NotImplementedError()
def set(
self, key: str, value: bytes, expires: int | datetime | None = None
) -> None:
raise NotImplementedError()
def delete(self, key: str) -> None:
raise NotImplementedError()
def close(self) -> None:
pass
class DictCache(BaseCache):
def __init__(self, init_dict: MutableMapping[str, bytes] | None = None) -> None:
self.lock = Lock()
self.data = init_dict or {}
def get(self, key: str) -> bytes | None:
return self.data.get(key, None)
def set(
self, key: str, value: bytes, expires: int | datetime | None = None
) -> None:
with self.lock:
self.data.update({key: value})
def delete(self, key: str) -> None:
with self.lock:
if key in self.data:
self.data.pop(key)
class SeparateBodyBaseCache(BaseCache):
"""
In this variant, the body is not stored mixed in with the metadata, but is
passed in (as a bytes-like object) in a separate call to ``set_body()``.
That is, the expected interaction pattern is::
cache.set(key, serialized_metadata)
cache.set_body(key)
Similarly, the body should be loaded separately via ``get_body()``.
"""
def set_body(self, key: str, body: bytes) -> None:
raise NotImplementedError()
def get_body(self, key: str) -> IO[bytes] | None:
"""
Return the body as file-like object.
"""
raise NotImplementedError()
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