Source code for relstorage.adapters.stats
##############################################################################
#
# Copyright (c) 2009 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Stats implementations
"""
import abc
from zope.interface import implementer
from .._compat import ABC
from .interfaces import IDBStats
from ._util import DatabaseHelpersMixin
from .schema import Schema
from .sql import func
[docs]
@implementer(IDBStats)
class AbstractStats(DatabaseHelpersMixin, ABC):
def __init__(self, connmanager, keep_history):
self.connmanager = connmanager
self.keep_history = keep_history
_get_object_count_query = Schema.all_current_object.select(
func.count()
)
[docs]
def get_object_count(self):
"""Returns the approximate number of objects in the database"""
conn, cursor = self.connmanager.open_for_load()
try:
self._get_object_count_query.execute(cursor)
return cursor.fetchone()[0]
finally:
self.connmanager.close(conn, cursor)
[docs]
@abc.abstractmethod
def get_db_size(self):
"""Returns the approximate size of the database in bytes"""
raise NotImplementedError()
[docs]
def large_database_change(self):
"""
Call this when the database has changed substantially,
and it would be a good time to perform any updates or
optimizations.
"""