Source code for cement.core.cache

"""Cement core cache module."""

from abc import abstractmethod
from ..core.interface import Interface
from ..core.handler import Handler
from ..utils.misc import minimal_logger

LOG = minimal_logger(__name__)

[docs]class CacheInterface(Interface): """ This class defines the Cache Interface. Handlers that implement this interface must provide the methods and attributes defined below. In general, most implementations should sub-class from the provided :class:`CacheHandler` base class as a starting point. """
[docs] class Meta: """Handler meta-data.""" #: The string identifier of the interface. interface = 'cache'
[docs] @abstractmethod def get(self, key, fallback=None): """ Get the value for a key in the cache. If the key does not exist or the key/value in cache is expired, this functions must return ``fallback`` (which in turn must default to ``None``). Args: key (str): The key of the value stored in cache Keyword Args: fallback: Optional value that is returned if the cache is expired or the key does not exist. Returns: Unknown: Whatever the value is in the cache, or the ``fallback`` """ pass # pragma: nocover
[docs] @abstractmethod def set(self, key, value, time=None): """ Set the key/value in the cache for a set amount of ``time``. Args: key (str): The key of the value to store in cache value (unknown): The value of that key to store in cache Keyword Args: time (int): A one-off expire time in seconds (or ``None``. If no time is given, then a default value is used (determined by the implementation). Returns: None """ pass # pragma: nocover
[docs] @abstractmethod def delete(self, key): """ Deletes a key/value from the cache. Args: key: The key in the cache to delete Returns: bool: ``True`` if the key is successfully deleted, ``False`` otherwise """ pass # pragma: nocover
[docs] @abstractmethod def purge(self): """ Clears all data from the cache. """ pass # pragma: nocover
[docs]class CacheHandler(CacheInterface, Handler): """ Cache handler implementation. """ pass # pragma: nocover