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# Copyright (C) 2006 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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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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"""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_missing(self):
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cache = lru_cache.LRUCache(max_cache=10)
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self.failIf('foo' in cache)
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self.assertRaises(KeyError, cache.__getitem__, 'foo')
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self.assertEqual('bar', cache['foo'])
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self.failUnless('foo' in cache)
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self.failIf('bar' in cache)
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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)
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# With a max cache of 1, adding 'baz' should pop out 'foo'
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self.failIf('foo' in cache)
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self.failUnless('baz' in cache)
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self.assertEqual('biz', cache['baz'])
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def test_by_usage(self):
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"""Accessing entries bumps them up in priority."""
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cache = lru_cache.LRUCache(max_cache=2)
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self.assertEqual('biz', cache['baz'])
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# This must kick out 'foo' because it was the last accessed
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self.failIf('foo' in cache)
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def test_queue_stays_bounded(self):
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"""Lots of accesses does not cause the queue to grow without bound."""
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cache = lru_cache.LRUCache(max_cache=10)
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for i in xrange(1000):
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self.failUnless(len(cache._queue) < 40)
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def test_cleanup(self):
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"""Test that we can use a cleanup function."""
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def cleanup_func(key, val):
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cleanup_called.append((key, val))
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cache = lru_cache.LRUCache(max_cache=2)
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cache.add('baz', '1', cleanup=cleanup_func)
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cache.add('foo', '2', cleanup=cleanup_func)
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cache.add('biz', '3', cleanup=cleanup_func)
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self.assertEqual([('baz', '1')], cleanup_called)
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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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def test_cleanup_on_replace(self):
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"""Replacing an object should cleanup the old value."""
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def cleanup_func(key, val):
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cleanup_called.append((key, val))
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cache = lru_cache.LRUCache(max_cache=2)
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cache.add(1, 10, cleanup=cleanup_func)
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cache.add(2, 20, cleanup=cleanup_func)
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cache.add(2, 25, cleanup=cleanup_func)
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self.assertEqual([(2, 20)], cleanup_called)
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self.assertEqual(25, cache[2])
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# Even __setitem__ should make sure cleanup() is called
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self.assertEqual([(2, 20), (2, 25)], cleanup_called)
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cache = lru_cache.LRUCache(max_cache=10)
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self.assertEqual(4, len(cache))
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self.assertEqual(8, len(cache))
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cache[1] = 15 # replacement
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self.assertEqual(8, len(cache))
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self.assertEqual(10, len(cache))
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def test_cleanup_shrinks_to_after_clean_size(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_size=3)
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self.assertEqual(5, len(cache))
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# This will bump us over the max, which causes us to shrink down to
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# after_cleanup_cache size
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self.assertEqual(3, len(cache))
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def test_after_cleanup_larger_than_max(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_size=10)
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self.assertEqual(5, cache._after_cleanup_size)
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def test_after_cleanup_none(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_size=None)
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self.assertEqual(5, cache._after_cleanup_size)
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def test_cleanup(self):
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cache = lru_cache.LRUCache(max_cache=5, after_cleanup_size=2)
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self.assertEqual(5, len(cache))
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self.assertEqual(2, len(cache))
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def test_compact_preserves_last_access_order(self):
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cache = lru_cache.LRUCache(max_cache=5)
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self.assertEqual([1, 2, 3, 4, 5], list(cache._queue))
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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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cache = lru_cache.LRUCache(max_cache=5)
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self.assertEqual(20, cache.get(2))
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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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cache = lru_cache.LRUCache(max_cache=5)
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self.assertEqual([1, 2, 3], sorted(cache.keys()))
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self.assertEqual([2, 3, 4, 5, 6], sorted(cache.keys()))
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class TestLRUSizeCache(tests.TestCase):
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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(cache._max_size, cache._after_cleanup_size)
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self.assertEqual(0, cache._value_size)
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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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cache.add('my key', 'my value text')
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self.assertEqual(13, cache._value_size)
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def test_remove_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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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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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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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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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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# 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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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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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 = lru_cache.LRUSizeCache(max_size=20)
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cache.add('key1', 'value') # 5 chars
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cache.add('key2', 'value2') # 6 chars
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cache.add('key3', 'value23') # 7 chars
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self.assertEqual(5+6+7, cache._value_size)
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cache['key2'] # reference key2 so it gets a newer reference time
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cache.add('key4', 'value234') # 8 chars, over limit
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# We have to remove 2 keys to get back under limit
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self.assertEqual(6+8, cache._value_size)
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self.assertEqual({'key2':'value2', 'key4':'value234'},
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def test_adding_clears_to_after_cleanup_size(self):
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cache = lru_cache.LRUSizeCache(max_size=20, after_cleanup_size=10)
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cache.add('key1', 'value') # 5 chars
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cache.add('key2', 'value2') # 6 chars
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cache.add('key3', 'value23') # 7 chars
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self.assertEqual(5+6+7, cache._value_size)
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cache['key2'] # reference key2 so it gets a newer reference time
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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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def test_custom_sizes(self):
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def size_of_list(lst):
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return sum(len(x) for x in lst)
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cache = lru_cache.LRUSizeCache(max_size=20, after_cleanup_size=10,
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compute_size=size_of_list)
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cache.add('key1', ['val', 'ue']) # 5 chars
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cache.add('key2', ['val', 'ue2']) # 6 chars
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cache.add('key3', ['val', 'ue23']) # 7 chars
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self.assertEqual(5+6+7, cache._value_size)
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cache['key2'] # reference key2 so it gets a newer reference time
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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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def test_cleanup(self):
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cache = lru_cache.LRUSizeCache(max_size=20, after_cleanup_size=10)
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cache.add('key1', 'value') # 5 chars
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cache.add('key2', 'value2') # 6 chars
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cache.add('key3', 'value23') # 7 chars
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self.assertEqual(5+6+7, cache._value_size)
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# Only the most recent fits after cleaning up
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self.assertEqual(7, cache._value_size)
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cache = lru_cache.LRUSizeCache(max_size=10)
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self.assertEqual([1, 2, 3], sorted(cache.keys()))
added
removed
bzrlib/tests/test_lru_cache.py
