#!/usr/bin/python2.5

#

# Copyright 2009 the Melange authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#   http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Module containing some basic caching functions.

"""

__authors__ = [

    '"Sverre Rabbelier" <sverre@rabbelier.nl>',

  ]

from functools import wraps

def getCacher(get, put):

  """Returns a caching decorator that uses get and put.

  """

  # TODO(SRabbelier) possibly accept 'key' instead, and define

  # get and put in terms of key, depends on further usage

  def cache(func):

    """Decorator that caches the result from func.

    """

    @wraps(func)

    def wrapper(*args, **kwargs):

      result, key = get(*args, **kwargs)

      if result:

        return result

      result = func(*args, **kwargs)

      if key:

        put(result, key, *args, **kwargs)

      return result

    return wrapper

  return cache