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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Tests for the lru_cache module."""
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class TestLRUCache(tests.TestCase):
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"""Test that LRU cache properly keeps track of entries."""
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def test_cache_size(self):
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cache = lru_cache.LRUCache(max_cache=10)
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self.assertEqual(10, cache.cache_size())
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cache = lru_cache.LRUCache(max_cache=256)
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self.assertEqual(256, cache.cache_size())
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self.assertEqual(512, cache.cache_size())
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def test_missing(self):
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cache = lru_cache.LRUCache(max_cache=10)
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self.failUnless('foo' in cache)
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self.failIf('bar' in cache)
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def test_map_None(self):
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# Make sure that we can properly map None as a key.
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cache = lru_cache.LRUCache(max_cache=10)
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self.failIf(None in cache)
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self.assertEqual(1, cache[None])
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self.assertEqual(2, cache[None])
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# Test the various code paths of __getitem__, to make sure that we can
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# handle when None is the key for the LRU and the MRU
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self.assertEqual([None, 1], [n.key for n in cache._walk_lru()])
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def test_add__null_key(self):
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cache = lru_cache.LRUCache(max_cache=10)
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self.assertRaises(ValueError, cache.add, lru_cache._null_key, 1)
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def test_overflow(self):
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"""Adding extra entries will pop out old ones."""
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cache = lru_cache.LRUCache(max_cache=1, after_cleanup_count=1)
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# 'foo' is now most recent, so final cleanup will call it last
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self.assertEqual([('baz', '1'), ('biz', '3'), ('foo', '2')], cleanup_called)
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self.assertEqual([('baz', '1'), ('biz', '3'), ('foo', '2')],
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def test_cleanup_on_replace(self):
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"""Replacing an object should cleanup the old value."""
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self.assertEqual(10, len(cache))
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self.assertEqual([11, 10, 9, 1, 8, 7, 6, 5, 4, 3],
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[n.key for n in cache._walk_lru()])
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def test_cleanup_shrinks_to_after_clean_count(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_count=3)
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self.assertEqual([1, 2, 3, 4, 5], list(cache._queue))
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self.assertEqual([5, 4, 3, 2, 1], [n.key for n in cache._walk_lru()])
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# Now access some randomly
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self.assertEqual([1, 2, 3, 4, 5, 2, 5, 3, 2], list(cache._queue))
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self.assertEqual({1:1, 2:3, 3:2, 4:1, 5:2}, cache._refcount)
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# Compacting should save the last position
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cache._compact_queue()
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self.assertEqual([1, 4, 5, 3, 2], list(cache._queue))
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self.assertEqual({1:1, 2:1, 3:1, 4:1, 5:1}, cache._refcount)
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self.assertEqual([2, 3, 5, 4, 1], [n.key for n in cache._walk_lru()])
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def test_get(self):
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cache = lru_cache.LRUCache(max_cache=5)
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self.assertIs(None, cache.get(3))
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self.assertIs(obj, cache.get(3, obj))
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self.assertEqual([2, 1], [n.key for n in cache._walk_lru()])
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self.assertEqual(10, cache.get(1))
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self.assertEqual([1, 2], [n.key for n in cache._walk_lru()])
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def test_keys(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_count=5)
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def test_basic_init(self):
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cache = lru_cache.LRUSizeCache()
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self.assertEqual(2048, cache._max_cache)
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self.assertEqual(4*2048, cache._compact_queue_length)
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self.assertEqual(int(cache._max_size*0.8), cache._after_cleanup_size)
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self.assertEqual(0, cache._value_size)
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def test_add__null_key(self):
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cache = lru_cache.LRUSizeCache()
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self.assertRaises(ValueError, cache.add, lru_cache._null_key, 1)
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def test_add_tracks_size(self):
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cache = lru_cache.LRUSizeCache()
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self.assertEqual(0, cache._value_size)
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self.assertEqual(0, cache._value_size)
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cache.add('my key', 'my value text')
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self.assertEqual(13, cache._value_size)
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cache._remove('my key')
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node = cache._cache['my key']
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cache._remove_node(node)
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self.assertEqual(0, cache._value_size)
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def test_no_add_over_size(self):
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"""Adding a large value may not be cached at all."""
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cache = lru_cache.LRUSizeCache(max_size=10, after_cleanup_size=5)
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self.assertEqual(0, cache._value_size)
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self.assertEqual({}, cache._cache)
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self.assertEqual({}, cache.items())
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cache.add('test', 'key')
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self.assertEqual(3, cache._value_size)
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self.assertEqual({'test':'key'}, cache._cache)
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self.assertEqual({'test': 'key'}, cache.items())
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cache.add('test2', 'key that is too big')
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self.assertEqual(3, cache._value_size)
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self.assertEqual({'test':'key'}, cache._cache)
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self.assertEqual({'test':'key'}, cache.items())
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# If we would add a key, only to cleanup and remove all cached entries,
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# then obviously that value should not be stored
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cache.add('test3', 'bigkey')
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self.assertEqual(3, cache._value_size)
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self.assertEqual({'test':'key'}, cache._cache)
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self.assertEqual({'test':'key'}, cache.items())
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cache.add('test4', 'bikey')
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self.assertEqual(3, cache._value_size)
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self.assertEqual({'test':'key'}, cache._cache)
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self.assertEqual({'test':'key'}, cache.items())
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def test_no_add_over_size_cleanup(self):
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"""If a large value is not cached, we will call cleanup right away."""
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def cleanup(key, value):
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cleanup_calls.append((key, value))
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cache = lru_cache.LRUSizeCache(max_size=10, after_cleanup_size=5)
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self.assertEqual(0, cache._value_size)
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self.assertEqual({}, cache.items())
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cache.add('test', 'key that is too big', cleanup=cleanup)
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self.assertEqual(0, cache._value_size)
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self.assertEqual({}, cache.items())
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# and cleanup was called
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self.assertEqual([('test', 'key that is too big')], cleanup_calls)
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def test_adding_clears_cache_based_on_size(self):
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"""The cache is cleared in LRU order until small enough"""
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cache.add('key4', 'value234') # 8 chars, over limit
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# We have to remove 3 keys to get back under limit
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self.assertEqual(8, cache._value_size)
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self.assertEqual({'key4':'value234'}, cache._cache)
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self.assertEqual({'key4':'value234'}, cache.items())
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def test_custom_sizes(self):
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def size_of_list(lst):
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cache.add('key4', ['value', '234']) # 8 chars, over limit
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# We have to remove 3 keys to get back under limit
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self.assertEqual(8, cache._value_size)
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self.assertEqual({'key4':['value', '234']}, cache._cache)
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self.assertEqual({'key4':['value', '234']}, cache.items())
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def test_cleanup(self):
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cache = lru_cache.LRUSizeCache(max_size=20, after_cleanup_size=10)