diff options
Diffstat (limited to 'django/core/cache')
| -rw-r--r-- | django/core/cache/backends/db.py | 129 |
1 files changed, 65 insertions, 64 deletions
diff --git a/django/core/cache/backends/db.py b/django/core/cache/backends/db.py index a21777aaba..959095026b 100644 --- a/django/core/cache/backends/db.py +++ b/django/core/cache/backends/db.py @@ -59,11 +59,11 @@ class DatabaseCache(BaseDatabaseCache): self.validate_key(key) db = router.db_for_read(self.cache_model_class) table = connections[db].ops.quote_name(self._table) - cursor = connections[db].cursor() - cursor.execute("SELECT cache_key, value, expires FROM %s " - "WHERE cache_key = %%s" % table, [key]) - row = cursor.fetchone() + with connections[db].cursor() as cursor: + cursor.execute("SELECT cache_key, value, expires FROM %s " + "WHERE cache_key = %%s" % table, [key]) + row = cursor.fetchone() if row is None: return default now = timezone.now() @@ -75,9 +75,9 @@ class DatabaseCache(BaseDatabaseCache): 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 " - "WHERE cache_key = %%s" % table, [key]) + with connections[db].cursor() as cursor: + cursor.execute("DELETE FROM %s " + "WHERE cache_key = %%s" % table, [key]) return default value = connections[db].ops.process_clob(row[1]) return pickle.loads(base64.b64decode(force_bytes(value))) @@ -96,55 +96,55 @@ class DatabaseCache(BaseDatabaseCache): timeout = self.get_backend_timeout(timeout) db = router.db_for_write(self.cache_model_class) table = connections[db].ops.quote_name(self._table) - cursor = connections[db].cursor() - cursor.execute("SELECT COUNT(*) FROM %s" % table) - num = cursor.fetchone()[0] - now = timezone.now() - now = now.replace(microsecond=0) - if timeout is None: - exp = datetime.max - elif settings.USE_TZ: - exp = datetime.utcfromtimestamp(timeout) - else: - exp = datetime.fromtimestamp(timeout) - exp = exp.replace(microsecond=0) - if num > self._max_entries: - self._cull(db, cursor, now) - pickled = pickle.dumps(value, pickle.HIGHEST_PROTOCOL) - b64encoded = base64.b64encode(pickled) - # The DB column is expecting a string, so make sure the value is a - # string, not bytes. Refs #19274. - 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 current_expires < now)): - cursor.execute("UPDATE %s SET value = %%s, expires = %%s " - "WHERE cache_key = %%s" % table, - [b64encoded, exp, key]) - else: - cursor.execute("INSERT INTO %s (cache_key, value, expires) " - "VALUES (%%s, %%s, %%s)" % table, - [key, b64encoded, exp]) - except DatabaseError: - # To be threadsafe, updates/inserts are allowed to fail silently - return False - else: - return True + with connections[db].cursor() as cursor: + cursor.execute("SELECT COUNT(*) FROM %s" % table) + num = cursor.fetchone()[0] + now = timezone.now() + now = now.replace(microsecond=0) + if timeout is None: + exp = datetime.max + elif settings.USE_TZ: + exp = datetime.utcfromtimestamp(timeout) + else: + exp = datetime.fromtimestamp(timeout) + exp = exp.replace(microsecond=0) + if num > self._max_entries: + self._cull(db, cursor, now) + pickled = pickle.dumps(value, pickle.HIGHEST_PROTOCOL) + b64encoded = base64.b64encode(pickled) + # The DB column is expecting a string, so make sure the value is a + # string, not bytes. Refs #19274. + 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 current_expires < now)): + cursor.execute("UPDATE %s SET value = %%s, expires = %%s " + "WHERE cache_key = %%s" % table, + [b64encoded, exp, key]) + else: + cursor.execute("INSERT INTO %s (cache_key, value, expires) " + "VALUES (%%s, %%s, %%s)" % table, + [key, b64encoded, exp]) + except DatabaseError: + # To be threadsafe, updates/inserts are allowed to fail silently + return False + else: + return True def delete(self, key, version=None): key = self.make_key(key, version=version) @@ -152,9 +152,9 @@ class DatabaseCache(BaseDatabaseCache): db = router.db_for_write(self.cache_model_class) table = connections[db].ops.quote_name(self._table) - cursor = connections[db].cursor() - cursor.execute("DELETE FROM %s WHERE cache_key = %%s" % table, [key]) + with connections[db].cursor() as cursor: + cursor.execute("DELETE FROM %s WHERE cache_key = %%s" % table, [key]) def has_key(self, key, version=None): key = self.make_key(key, version=version) @@ -162,17 +162,18 @@ class DatabaseCache(BaseDatabaseCache): db = router.db_for_read(self.cache_model_class) table = connections[db].ops.quote_name(self._table) - cursor = connections[db].cursor() if settings.USE_TZ: now = datetime.utcnow() else: now = datetime.now() now = now.replace(microsecond=0) - cursor.execute("SELECT cache_key FROM %s " - "WHERE cache_key = %%s and expires > %%s" % table, - [key, connections[db].ops.value_to_db_datetime(now)]) - return cursor.fetchone() is not None + + with connections[db].cursor() as cursor: + cursor.execute("SELECT cache_key FROM %s " + "WHERE cache_key = %%s and expires > %%s" % table, + [key, connections[db].ops.value_to_db_datetime(now)]) + return cursor.fetchone() is not None def _cull(self, db, cursor, now): if self._cull_frequency == 0: @@ -197,8 +198,8 @@ class DatabaseCache(BaseDatabaseCache): def clear(self): db = router.db_for_write(self.cache_model_class) table = connections[db].ops.quote_name(self._table) - cursor = connections[db].cursor() - cursor.execute('DELETE FROM %s' % table) + with connections[db].cursor() as cursor: + cursor.execute('DELETE FROM %s' % table) # For backwards compatibility |