whatstyle.py 文件源码

def apply(func,         # type: Callable[..., bytes]
              args=(),      # type: Sequence[AnyStr]
              exe=None,     # type: Optional[str]
              depfiles=(),  # type: Sequence[str]
              cache=None    # type: Optional[Cache]
              ):
        """Applies func(*args) when the result is not present in the cache.
        The result of func(*args) must be bytes and must not be None which is used as
        cache-miss indicator. After evaluation of func the result is stored in the cache.
        """
        key, value = None, None
        if cache is not None:
            hashobj = cache.mixtohash(args, exe=exe, depfiles=depfiles)
            key = hashobj.hexdigest()
            value = cache.get(key)
        if value is None:
            value = func(*args)
            if key is not None:
                cache.set(key, value)
        return value