AlkantarClanX12
Current Path : /opt/alt/python38/lib/python3.8/site-packages/pip/_internal/network/ |
Current File : //opt/alt/python38/lib/python3.8/site-packages/pip/_internal/network/cache.py |
"""HTTP cache implementation. """ import os from contextlib import contextmanager from typing import Generator, Optional from pip._vendor.cachecontrol.cache import BaseCache from pip._vendor.cachecontrol.caches import FileCache from pip._vendor.requests.models import Response from pip._internal.utils.filesystem import adjacent_tmp_file, replace from pip._internal.utils.misc import ensure_dir def is_from_cache(response: Response) -> bool: return getattr(response, "from_cache", False) @contextmanager def suppressed_cache_errors() -> Generator[None, None, None]: """If we can't access the cache then we can just skip caching and process requests as if caching wasn't enabled. """ try: yield except OSError: pass class SafeFileCache(BaseCache): """ A file based cache which is safe to use even when the target directory may not be accessible or writable. """ def __init__(self, directory: str) -> None: assert directory is not None, "Cache directory must not be None." super().__init__() self.directory = directory def _get_cache_path(self, name: str) -> str: # From cachecontrol.caches.file_cache.FileCache._fn, brought into our # class for backwards-compatibility and to avoid using a non-public # method. hashed = FileCache.encode(name) parts = list(hashed[:5]) + [hashed] return os.path.join(self.directory, *parts) def get(self, key: str) -> Optional[bytes]: path = self._get_cache_path(key) with suppressed_cache_errors(): with open(path, "rb") as f: return f.read() def set(self, key: str, value: bytes, expires: Optional[int] = None) -> None: path = self._get_cache_path(key) with suppressed_cache_errors(): ensure_dir(os.path.dirname(path)) with adjacent_tmp_file(path) as f: f.write(value) replace(f.name, path) def delete(self, key: str) -> None: path = self._get_cache_path(key) with suppressed_cache_errors(): os.remove(path)