quay/data/cache/test/test_cache.py

import pytest

from mock import patch

from data.cache import InMemoryDataModelCache, NoopDataModelCache, MemcachedModelCache
from data.cache.cache_key import CacheKey

class MockClient(object):
  def __init__(self, server, **kwargs):
    self.data = {}

  def get(self, key, default=None):
    return self.data.get(key, default)

  def set(self, key, value, expire=None):
    self.data[key] = value


@pytest.mark.parametrize('cache_type', [
  (NoopDataModelCache),
  (InMemoryDataModelCache),
])
def test_caching(cache_type):
  key = CacheKey('foo', '60m')
  cache = cache_type()

  # Perform two retrievals, and make sure both return.
  assert cache.retrieve(key, lambda: {'a': 1234}) == {'a': 1234}
  assert cache.retrieve(key, lambda: {'a': 1234}) == {'a': 1234}


def test_memcache():
  key = CacheKey('foo', '60m')
  with patch('data.cache.impl.Client', MockClient):
    cache = MemcachedModelCache(('127.0.0.1', '-1'))
    assert cache.retrieve(key, lambda: {'a': 1234}) == {'a': 1234}
    assert cache.retrieve(key, lambda: {'a': 1234}) == {'a': 1234}


def test_memcache_should_cache():
  key = CacheKey('foo', None)

  def sc(value):
    return value['a'] != 1234

  with patch('data.cache.impl.Client', MockClient):
    cache = MemcachedModelCache(('127.0.0.1', '-1'))
    assert cache.retrieve(key, lambda: {'a': 1234}, should_cache=sc) == {'a': 1234}

    # Ensure not cached since it was `1234`.
    assert cache._get_client().get(key.key) is None

    # Ensure cached.
    assert cache.retrieve(key, lambda: {'a': 2345}, should_cache=sc) == {'a': 2345}
    assert cache._get_client().get(key.key) is not None
    assert cache.retrieve(key, lambda: {'a': 2345}, should_cache=sc) == {'a': 2345}