Source code for kedro.framework.session.store

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"""This module implements a dict-like store object used to persist Kedro sessions."""
import dbm
import logging
import shelve
from collections import UserDict
from multiprocessing import Lock
from pathlib import Path
from typing import Any, Dict


[docs]class BaseSessionStore(UserDict): """``BaseSessionStore`` is the base class for all session stores. ``BaseSessionStore`` is an ephemeral store implementation that doesn't persist the session data. """ def __init__(self, path: str, session_id: str): self._path = path self._session_id = session_id super().__init__(self.read()) @property def _logger(self) -> logging.Logger: return logging.getLogger(__name__) def read(self) -> Dict[str, Any]: """Read the data from the session store. Returns: A mapping containing the session store data. """ self._logger.info( "`read()` not implemented for `%s`. Assuming empty store.", self.__class__.__name__, ) return {} def save(self): """Persist the session store""" self._logger.info( "`save()` not implemented for `%s`. Skipping the step.", self.__class__.__name__, )
[docs]class ShelveStore(BaseSessionStore): """Stores the session data on disk using `shelve` package.""" _lock = Lock() @property def _location(self) -> Path: return Path(self._path).expanduser().resolve() / self._session_id / "store" def read(self) -> Dict[str, Any]: """Read the data from disk using `shelve` package.""" data = {} # type: Dict[str, Any] try: with shelve.open(str(self._location), flag="r") as _sh: # nosec data = dict(_sh) except dbm.error: pass return data def save(self) -> None: """Save the data on disk using `shelve` package.""" location = self._location location.parent.mkdir(parents=True, exist_ok=True) with self._lock, shelve.open(str(location)) as _sh: # nosec keys_to_del = _sh.keys() - self.data.keys() for key in keys_to_del: del _sh[key] _sh.update(self.data)