openstack/swift
Code Issues Proposed changes

Extend MemcacheRing.delete() API to manage server_key

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Memcachering provided set_multi/get_multi to set/get list of key on an
unique memcached server selected in ring with server_key value. But
current api doesn't allow to deleted value save with set_multi.

This change add a server_key optional keyword to delete method to allow
to delete entry in the memcached selected with server_key instead of key.

Change-Id: I24c29540ee4b91adeb7b9f44fe84bc4d46f89218
This commit is contained in:
Romain de Joux 2019-10-07 18:02:21 +02:00
parent b4b0ebd4aa
commit bbea88cb1a
2 changed files with 43 additions and 2 deletions
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7
swift/common/memcached.py
View File

@ -399,14 +399,17 @@ class MemcacheRing(object):
"""
return self.incr(key, delta=-delta, time=time)
def delete(self, key):
def delete(self, key, server_key=None):
"""
Deletes a key/value pair from memcache.
:param key: key to be deleted
:param server_key: key to use in determining which server in the ring
is used
"""
key = md5hash(key)
for (server, fp, sock) in self._get_conns(key):
server_key = md5hash(server_key) if server_key else key
for (server, fp, sock) in self._get_conns(server_key):
try:
with Timeout(self._io_timeout):
sock.sendall(b'delete ' + key + b'\r\n')

38
test/unit/common/test_memcached.py
View File

@ -558,6 +558,44 @@ class TestMemcached(unittest.TestCase):
None)
self.assertFalse(not_expected in mock_stderr.getvalue())
def test_multi_delete(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211',
'1.2.3.5:11211'])
mock1 = MockMemcached()
mock2 = MockMemcached()
memcache_client._client_cache['1.2.3.4:11211'] = MockedMemcachePool(
[(mock1, mock1)] * 2)
memcache_client._client_cache['1.2.3.5:11211'] = MockedMemcachePool(
[(mock2, mock2)] * 2)
# MemcacheRing will put 'some_key0' on server 1.2.3.5:11211 and
# 'some_key1' and 'multi_key' on '1.2.3.4:11211'
memcache_client.set_multi(
{'some_key0': [1, 2, 3], 'some_key1': [4, 5, 6]}, 'multi_key')
self.assertEqual(
memcache_client.get_multi(('some_key1', 'some_key0'), 'multi_key'),
[[4, 5, 6], [1, 2, 3]])
for key in (b'some_key0', b'some_key1'):
key = md5(key).hexdigest().encode('ascii')
self.assertIn(key, mock1.cache)
_junk, cache_timeout, _junk = mock1.cache[key]
self.assertEqual(cache_timeout, b'0')
memcache_client.set('some_key0', [7, 8, 9])
self.assertEqual(memcache_client.get('some_key0'), [7, 8, 9])
key = md5(b'some_key0').hexdigest().encode('ascii')
self.assertIn(key, mock2.cache)
# Delete 'some_key0' with server_key='multi_key'
memcache_client.delete('some_key0', server_key='multi_key')
self.assertEqual(memcache_client.get_multi(
('some_key0', 'some_key1'), 'multi_key'),
[None, [4, 5, 6]])
# 'some_key0' have to be available on 1.2.3.5:11211
self.assertEqual(memcache_client.get('some_key0'), [7, 8, 9])
self.assertIn(key, mock2.cache)
def test_serialization(self):
memcache_client = memcached.MemcacheRing(['1.2.3.4:11211'],
allow_pickle=True)