# Copyright 2017 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import functools
import logging


def Memoize(f):
    """Decorator to cache return values of function."""
    memoize_dict = {}

    @functools.wraps(f)
    def wrapper(*args, **kwargs):
        key = repr((args, kwargs))
        if key not in memoize_dict:
            memoize_dict[key] = f(*args, **kwargs)
        return memoize_dict[key]

    return wrapper


def NoRaiseException(
    default_return_value=None, exception_type=None, exception_message=''
):
    """Returns decorator that catches and logs uncaught Exceptions.

    Args:
      default_return_value: Value to return in the case of uncaught Exception.
      exception_type: Type of exception to catch. If None, all exceptions are
        caught.
      exception_message: Message for uncaught exceptions.
    """

    def decorator(f):

        @functools.wraps(f)
        def wrapper(*args, **kwargs):
            _exception_type = exception_type or Exception
            try:
                return f(*args, **kwargs)
            except _exception_type as e:  # pylint: disable=broad-except
                logging.exception(exception_message, e)
                return default_return_value

        return wrapper

    return decorator