Commit 3792b2cd authored by Russell Keith-Magee's avatar Russell Keith-Magee
Browse files

[1.1.X] Fixed #12399 -- Added handling for memcache timeouts longer than 30... 

[1.1.X] Fixed #12399 -- Added handling for memcache timeouts longer than 30 days. Thanks to houdinihound for the report, and gciotta for the patch.

Backport of r12408 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12412 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent ad08f077

django/core/cache/backends/memcached.py

+20 −2
Original line number Diff line number Diff line 
"Memcached cache backend"



import time



from django.core.cache.backends.base import BaseCache, InvalidCacheBackendError

from django.utils.encoding import smart_unicode, smart_str
@@ -16,10 +18,26 @@ class CacheClass(BaseCache): 
        BaseCache.__init__(self, params)

        self._cache = memcache.Client(server.split(';'))



    def _get_memcache_timeout(self, timeout):

        """

        Memcached deals with long (> 30 days) timeouts in a special

        way. Call this function to obtain a safe value for your timeout.

        """

        timeout = timeout or self.default_timeout

        if timeout > 2592000: # 60*60*24*30, 30 days

            # See http://code.google.com/p/memcached/wiki/FAQ

            # "You can set expire times up to 30 days in the future. After that

            # memcached interprets it as a date, and will expire the item after

            # said date. This is a simple (but obscure) mechanic."

            #

            # This means that we have to switch to absolute timestamps.

            timeout += int(time.time())

        return timeout



    def add(self, key, value, timeout=0):

        if isinstance(value, unicode):

            value = value.encode('utf-8')

        return self._cache.add(smart_str(key), value, timeout or self.default_timeout)

        return self._cache.add(smart_str(key), value, self._get_memcache_timeout(timeout))



    def get(self, key, default=None):

        val = self._cache.get(smart_str(key))
@@ -34,7 +52,7 @@ class CacheClass(BaseCache): 
    def set(self, key, value, timeout=0):

        if isinstance(value, unicode):

            value = value.encode('utf-8')

        self._cache.set(smart_str(key), value, timeout or self.default_timeout)

        self._cache.set(smart_str(key), value, self._get_memcache_timeout(timeout))



    def delete(self, key):

        self._cache.delete(smart_str(key))

tests/regressiontests/cache/tests.py

+16 −0
Original line number Diff line number Diff line
@@ -278,6 +278,22 @@ class BaseCacheTests(object): 
            self.cache.set(key, value)

            self.assertEqual(self.cache.get(key), value)



    def test_long_timeout(self):

        '''

        Using a timeout greater than 30 days makes memcached think

        it is an absolute expiration timestamp instead of a relative

        offset. Test that we honour this convention. Refs #12399.

        '''

        self.cache.set('key1', 'eggs', 60*60*24*30 + 1) #30 days + 1 second

        self.assertEqual(self.cache.get('key1'), 'eggs')



        self.cache.add('key2', 'ham', 60*60*24*30 + 1)

        self.assertEqual(self.cache.get('key2'), 'ham')



        self.cache.set_many({'key3': 'sausage', 'key4': 'lobster bisque'}, 60*60*24*30 + 1)

        self.assertEqual(self.cache.get('key3'), 'sausage')

        self.assertEqual(self.cache.get('key4'), 'lobster bisque')



class DBCacheTests(unittest.TestCase, BaseCacheTests):

    def setUp(self):

        management.call_command('createcachetable', 'test_cache_table', verbosity=0, interactive=False)