From a979a2fea5415849773fdfb37765ffedef6f50f2 Mon Sep 17 00:00:00 2001 From: Michael Manfre Date: Mon, 23 Sep 2013 11:04:48 -0400 Subject: [PATCH] [1.6.x] Fixed #21146 - DatabaseCache converts expires to python value DatabaseCache uses raw cursors to bypass the ORM. This prevents it from being used by database backends that require special handling of datetime values. There is no easy way to test this, so no tests added. Backport of d5606b5763 from master --- django/core/cache/backends/db.py | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/django/core/cache/backends/db.py b/django/core/cache/backends/db.py index 0e59c6d65e..8844bc8f61 100644 --- a/django/core/cache/backends/db.py +++ b/django/core/cache/backends/db.py @@ -11,6 +11,7 @@ except ImportError: from django.conf import settings from django.core.cache.backends.base import BaseCache, DEFAULT_TIMEOUT from django.db import connections, transaction, router, DatabaseError +from django.db.backends.utils import typecast_timestamp from django.utils import timezone, six from django.utils.encoding import force_bytes @@ -65,8 +66,13 @@ class DatabaseCache(BaseDatabaseCache): if row is None: return default now = timezone.now() - - if row[2] < now: + expires = row[2] + if connections[db].features.needs_datetime_string_cast and not isinstance(expires, datetime): + # Note: typecasting is needed by some 3rd party database backends. + # All core backends work without typecasting, so be careful about + # changes here - test suite will NOT pick regressions here. + expires = typecast_timestamp(str(expires)) + if expires < now: db = router.db_for_write(self.cache_model_class) cursor = connections[db].cursor() cursor.execute("DELETE FROM %s " @@ -112,12 +118,21 @@ class DatabaseCache(BaseDatabaseCache): if six.PY3: b64encoded = b64encoded.decode('latin1') try: + # Note: typecasting for datetimes is needed by some 3rd party + # database backends. All core backends work without typecasting, + # so be careful about changes here - test suite will NOT pick + # regressions. with transaction.atomic(using=db): cursor.execute("SELECT cache_key, expires FROM %s " "WHERE cache_key = %%s" % table, [key]) result = cursor.fetchone() + if result: + current_expires = result[1] + if (connections[db].features.needs_datetime_string_cast and not + isinstance(current_expires, datetime)): + current_expires = typecast_timestamp(str(current_expires)) exp = connections[db].ops.value_to_db_datetime(exp) - if result and (mode == 'set' or (mode == 'add' and result[1] < now)): + if result and (mode == 'set' or (mode == 'add' and current_expires < now)): cursor.execute("UPDATE %s SET value = %%s, expires = %%s " "WHERE cache_key = %%s" % table, [b64encoded, exp, key])