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cache

cachetoolz.decorator.Cache

Cache a function call and stores it in the namespace.

Bare decorator, @cache, is supported as well as a call with keyword arguments @cache(ttl=7200).

Parameters:

Name Type Description Default
backend AsyncBackendABC | BackendABC

Cache backend.

 required

Examples:

With redis async backend

>>> from cachetoolz import AsyncRedisBackend, Cache
>>> cache = Cache(AsyncRedisBackend())

With redis sync backend

>>> from cachetoolz import RedisBackend, Cache
>>> cache = Cache(RedisBackend())
Source code in cachetoolz/decorator.py 
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class Cache:
    """
    Cache a function call and stores it in the namespace.

    Bare decorator, ``@cache``, is supported as well as a call with
    keyword arguments ``@cache(ttl=7200)``.

    Parameters
    ----------
    backend : AsyncBackendABC | BackendABC
        Cache backend.

    Examples
    --------
    With redis async backend
    >>> from cachetoolz import AsyncRedisBackend, Cache
    >>> cache = Cache(AsyncRedisBackend())

    With redis sync backend
    >>> from cachetoolz import RedisBackend, Cache
    >>> cache = Cache(RedisBackend())
    """

    def __init__(self, backend: Union[AsyncBackendABC, BackendABC]):
        """
        Initialize the cache instance.

        Parameters
        ----------
        backend : AsyncBackendABC | BackendABC
            Cache backend.
        """
        self.backend = backend
        self._logger = get_logger()

    async def _cache(
        self,
        ttl: timedelta,
        keygen: AsyncKeyGenerator,
        backend: Optional[Union[AsyncBackendABC, BackendABC]],
        func: Func,
        *args,
        **kwargs,
    ):
        backend = backend or self.backend
        key = await keygen(func, *args, **kwargs)

        if (result := await ensure_async(backend.get, key)) is not None:
            result = cast(str, result)
            return coder.decode(result)

        result = coder.encode(await ensure_async(func, *args, **kwargs))

        try:
            await ensure_async(backend.set, key, result, ttl)
        except Exception as exception:
            self._logger.error(
                "Error to set cache 'key=%s': exception=%s", key, exception
            )

        return coder.decode(result)

    def __call__(
        self,
        func: Optional[Func] = None,
        /,
        *,
        ttl: Union[int, float, timedelta] = inf,
        namespace: str = 'default',
        typed: bool = False,
        keygen: Optional[KeyGenerator] = None,
        backend: Optional[Union[AsyncBackendABC, BackendABC]] = None,
    ) -> Union[Decorator, Func]:
        """
        Cache a function call and stores it in the namespace (``@cache``).

        Decorator for caching a function call.

        Parameters
        ----------
        func : Func, optional
            Function to be decorated.
        ttl : int | float | timedelta, default=math.inf
            Cache ttl (time to live).
        namespace : str, default='default'
            Namespace to cache.
        typed : bool, default=False
            If typed is set to true, function arguments of different types
            will be cached separately.
        keygen : Optional[cachetoolz.types.KeyGenerator], default=None
            Function to generate a cache identifier key.
        backend : AsyncBackendABC | BackendABC, optional
            Dynamic backend.

        Returns
        -------
        Decorator
            Function Decorator.
        Func
            Decorated function.

        Examples
        --------
        A simple cache

        >>> @cache
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Specific a namespace

        >>> @cache(namespace='bar')
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Set an expiration time in seconds

        >>> @cache(ttl=60)
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Use timedelta to set the expiration

        >>> from datetime import timedelta
        >>> @cache(ttl=timedelta(days=1))
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Differentiate caching based on argument types

        >>> @cache(typed=True)
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Using a custom keygen

        >>> def custom_keygen(
        ...     typed: bool, func: Func, *args: P.args, **kwargs: P.kwargs
        ... ) -> str:
        ...     '''Build a key to a function.
        ...
        ...     Parameters
        ...     ----------
        ...     typed
        ...         If typed is set to true, function arguments of different
        ...         types will be cached separately.
        ...     func
        ...         Function
        ...     args
        ...         Function positional arguments
        ...     kwargs
        ...         Named function arguments
        ...
        ...     Returns
        ...     -------
        ...         Cache identifier key
        ...
        ...     '''
        ...
        >>> @cache(keygen=custom_keygen)
        ... def func(*args, **kwargs):
        ...     ...
        ...

        Change the backend cache that will be used in a specific function

        >>> @cache(backend=RedisBackend())
        ... def func(): ...
        """
        if isinstance(ttl, (int, float)) and not isinf(ttl):
            ttl = timedelta(seconds=ttl)
        elif isinstance(ttl, timedelta):
            pass
        elif isinf(ttl):
            ttl = timedelta(weeks=20e3)

        ttl = cast(timedelta, ttl)
        key_gen: AsyncKeyGenerator = partial(
            make_key, namespace, keygen, typed
        )

        # keygen = curry(make_key)(namespace, keygen, typed)
        manipulator = manipulate(partial(self._cache, ttl, key_gen, backend))

        if func:
            # @cache
            return manipulator(func)
        # @cache()
        return manipulator

    async def _clear(
        self,
        namespaces: Sequence[str],
        backend: Optional[Union[AsyncBackendABC, BackendABC]],
        func: Func,
        *args,
        **kwargs,
    ):
        backend = backend or self.backend
        try:
            await asyncio.gather(
                *[ensure_async(backend.clear, ns) for ns in namespaces]
            )
        except Exception as exception:
            self._logger.error(
                "Error to clear cache 'namespaces=%s': exception=%s",
                namespaces,
                exception,
            )

        result = coder.encode(await ensure_async(func, *args, **kwargs))
        return coder.decode(result)

    def clear(
        self,
        func: Optional[Func] = None,
        /,
        *,
        namespaces: Sequence[str] = ('default',),
        backend: Optional[Union[AsyncBackendABC, BackendABC]] = None,
    ) -> Union[Decorator, Func]:
        """
        Clear all caches for all namespaces.

        This decorator will clear all caches contained in the specified
        namespaces once the decorated function is executed.

        Parameters
        ----------
        func : Func, optional
            Function to be decorated.
        namespaces : Sequence[str], default=('default',)
            Namespace to be cleaned.
        backend : AsyncBackendABC | BackendABC, optional
            Dynamic backend.

        Returns
        -------
        Decorator
            Function Decorator.
        Func
            Decorated function.

        Examples
        --------
        A simple clear cache

        >>> @cache.clear
        ... def func(*args, **kwargs):
        ...     ...

        Defining the namespaces to be cleaned up

        >>> @cache.clear(namespaces=['foo'])
        ... def func(*args, **kwargs):
        ...     ...

        Change the backend clear that will be used in a specific function

        >>> @cache.clear(backend=RedisBackend())
        ... def func(): ...
        """
        manipulator = manipulate(partial(self._clear, namespaces, backend))

        if func:
            # @cache.clear
            return manipulator(func)
        # @cache.clear(namespaces=['ns1'])
        return manipulator

cachetoolz.decorator.Cache.__call__

Cache a function call and stores it in the namespace (@cache).

Decorator for caching a function call.

Parameters:

Name Type Description Default
func Func

Function to be decorated.

 None
ttl int | float | timedelta

Cache ttl (time to live).

 math.inf
namespace str

Namespace to cache.

 'default'
typed bool

If typed is set to true, function arguments of different types will be cached separately.

 False
keygen Optional[cachetoolz.types.KeyGenerator]

Function to generate a cache identifier key.

 None
backend AsyncBackendABC | BackendABC

Dynamic backend.

 None

Returns:

Type Description
Decorator

Function Decorator.
Func

Decorated function.

Examples:

A simple cache

>>> @cache
... def func(*args, **kwargs):
...     ...
...

Specific a namespace

>>> @cache(namespace='bar')
... def func(*args, **kwargs):
...     ...
...

Set an expiration time in seconds

>>> @cache(ttl=60)
... def func(*args, **kwargs):
...     ...
...

Use timedelta to set the expiration

>>> from datetime import timedelta
>>> @cache(ttl=timedelta(days=1))
... def func(*args, **kwargs):
...     ...
...

Differentiate caching based on argument types

>>> @cache(typed=True)
... def func(*args, **kwargs):
...     ...
...

Using a custom keygen

>>> def custom_keygen(
...     typed: bool, func: Func, *args: P.args, **kwargs: P.kwargs
... ) -> str:
...     '''Build a key to a function.
...
...     Parameters
...     ----------
...     typed
...         If typed is set to true, function arguments of different
...         types will be cached separately.
...     func
...         Function
...     args
...         Function positional arguments
...     kwargs
...         Named function arguments
...
...     Returns
...     -------
...         Cache identifier key
...
...     '''
...
>>> @cache(keygen=custom_keygen)
... def func(*args, **kwargs):
...     ...
...

Change the backend cache that will be used in a specific function

>>> @cache(backend=RedisBackend())
... def func(): ...
Source code in cachetoolz/decorator.py 
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def __call__(
    self,
    func: Optional[Func] = None,
    /,
    *,
    ttl: Union[int, float, timedelta] = inf,
    namespace: str = 'default',
    typed: bool = False,
    keygen: Optional[KeyGenerator] = None,
    backend: Optional[Union[AsyncBackendABC, BackendABC]] = None,
) -> Union[Decorator, Func]:
    """
    Cache a function call and stores it in the namespace (``@cache``).

    Decorator for caching a function call.

    Parameters
    ----------
    func : Func, optional
        Function to be decorated.
    ttl : int | float | timedelta, default=math.inf
        Cache ttl (time to live).
    namespace : str, default='default'
        Namespace to cache.
    typed : bool, default=False
        If typed is set to true, function arguments of different types
        will be cached separately.
    keygen : Optional[cachetoolz.types.KeyGenerator], default=None
        Function to generate a cache identifier key.
    backend : AsyncBackendABC | BackendABC, optional
        Dynamic backend.

    Returns
    -------
    Decorator
        Function Decorator.
    Func
        Decorated function.

    Examples
    --------
    A simple cache

    >>> @cache
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Specific a namespace

    >>> @cache(namespace='bar')
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Set an expiration time in seconds

    >>> @cache(ttl=60)
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Use timedelta to set the expiration

    >>> from datetime import timedelta
    >>> @cache(ttl=timedelta(days=1))
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Differentiate caching based on argument types

    >>> @cache(typed=True)
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Using a custom keygen

    >>> def custom_keygen(
    ...     typed: bool, func: Func, *args: P.args, **kwargs: P.kwargs
    ... ) -> str:
    ...     '''Build a key to a function.
    ...
    ...     Parameters
    ...     ----------
    ...     typed
    ...         If typed is set to true, function arguments of different
    ...         types will be cached separately.
    ...     func
    ...         Function
    ...     args
    ...         Function positional arguments
    ...     kwargs
    ...         Named function arguments
    ...
    ...     Returns
    ...     -------
    ...         Cache identifier key
    ...
    ...     '''
    ...
    >>> @cache(keygen=custom_keygen)
    ... def func(*args, **kwargs):
    ...     ...
    ...

    Change the backend cache that will be used in a specific function

    >>> @cache(backend=RedisBackend())
    ... def func(): ...
    """
    if isinstance(ttl, (int, float)) and not isinf(ttl):
        ttl = timedelta(seconds=ttl)
    elif isinstance(ttl, timedelta):
        pass
    elif isinf(ttl):
        ttl = timedelta(weeks=20e3)

    ttl = cast(timedelta, ttl)
    key_gen: AsyncKeyGenerator = partial(
        make_key, namespace, keygen, typed
    )

    # keygen = curry(make_key)(namespace, keygen, typed)
    manipulator = manipulate(partial(self._cache, ttl, key_gen, backend))

    if func:
        # @cache
        return manipulator(func)
    # @cache()
    return manipulator

cachetoolz.decorator.Cache.clear

Clear all caches for all namespaces.

This decorator will clear all caches contained in the specified namespaces once the decorated function is executed.

Parameters:

Name Type Description Default
func Func

Function to be decorated.

 None
namespaces Sequence[str]

Namespace to be cleaned.

 ('default',)
backend AsyncBackendABC | BackendABC

Dynamic backend.

 None

Returns:

Type Description
Decorator

Function Decorator.
Func

Decorated function.

Examples:

A simple clear cache

>>> @cache.clear
... def func(*args, **kwargs):
...     ...

Defining the namespaces to be cleaned up

>>> @cache.clear(namespaces=['foo'])
... def func(*args, **kwargs):
...     ...

Change the backend clear that will be used in a specific function

>>> @cache.clear(backend=RedisBackend())
... def func(): ...
Source code in cachetoolz/decorator.py 
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def clear(
    self,
    func: Optional[Func] = None,
    /,
    *,
    namespaces: Sequence[str] = ('default',),
    backend: Optional[Union[AsyncBackendABC, BackendABC]] = None,
) -> Union[Decorator, Func]:
    """
    Clear all caches for all namespaces.

    This decorator will clear all caches contained in the specified
    namespaces once the decorated function is executed.

    Parameters
    ----------
    func : Func, optional
        Function to be decorated.
    namespaces : Sequence[str], default=('default',)
        Namespace to be cleaned.
    backend : AsyncBackendABC | BackendABC, optional
        Dynamic backend.

    Returns
    -------
    Decorator
        Function Decorator.
    Func
        Decorated function.

    Examples
    --------
    A simple clear cache

    >>> @cache.clear
    ... def func(*args, **kwargs):
    ...     ...

    Defining the namespaces to be cleaned up

    >>> @cache.clear(namespaces=['foo'])
    ... def func(*args, **kwargs):
    ...     ...

    Change the backend clear that will be used in a specific function

    >>> @cache.clear(backend=RedisBackend())
    ... def func(): ...
    """
    manipulator = manipulate(partial(self._clear, namespaces, backend))

    if func:
        # @cache.clear
        return manipulator(func)
    # @cache.clear(namespaces=['ns1'])
    return manipulator