new_contents: # This file is part of the MapProxy project.
  # Copyright (C) 2017 Omniscale <http://omniscale.de>
  #
  # 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.
  
  from __future__ import with_statement
  
  try:
      import redis
  except ImportError:
      redis = None
  
  import time
  import os
  
  from nose.plugins.skip import SkipTest
  
  from mapproxy.cache.tile import Tile
  from mapproxy.cache.redis import RedisCache
  
  from mapproxy.test.unit.test_cache_tile import TileCacheTestBase
  
  class TestRedisCache(TileCacheTestBase):
      always_loads_metadata = False
      def setup(self):
          if not redis:
              raise SkipTest("redis required for Redis tests")
  
          redis_host = os.environ.get('MAPPROXY_TEST_REDIS')
          if not redis_host:
              raise SkipTest()
          self.host, self.port = redis_host.split(':')
  
          TileCacheTestBase.setup(self)
  
          self.cache = RedisCache(self.host, int(self.port), prefix='mapproxy-test', db=1)
  
      def teardown(self):
          for k in self.cache.r.keys('mapproxy-test-*'):
              self.cache.r.delete(k)
  
      def test_expire(self):
          cache = RedisCache(self.host, int(self.port), prefix='mapproxy-test', db=1, ttl=0)
          t1 = self.create_tile(coord=(9382, 1234, 9))
          assert cache.store_tile(t1)
          time.sleep(0.1)
          t2 = Tile(t1.coord)
          assert cache.is_cached(t2)
  
          cache = RedisCache(self.host, int(self.port), prefix='mapproxy-test', db=1, ttl=0.05)
          t1 = self.create_tile(coord=(5382, 2234, 9))
          assert cache.store_tile(t1)
          time.sleep(0.1)
          t2 = Tile(t1.coord)
          assert not cache.is_cached(t2)
  
      def test_double_remove(self):
          tile = self.create_tile()
          self.create_cached_tile(tile)
          assert self.cache.remove_tile(tile)
          assert self.cache.remove_tile(tile)
  
subject: add redis cache tests