Switch Quay to using an in-container memcached for data model caching

data/cache/test/test_cache.py

@@ -1,8 +1,21 @@
 import pytest
 
-from data.cache import InMemoryDataModelCache, NoopDataModelCache
+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),
@@ -12,5 +25,32 @@ def test_caching(cache_type):
   cache = cache_type()
 
   # Perform two retrievals, and make sure both return.
-  assert cache.retrieve(key, lambda: 1234) == 1234
-  assert cache.retrieve(key, lambda: 1234) == 1234
+  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}