Files
deb-python-taskflow/taskflow/logbook/drivers/zk.py
2013-05-07 10:49:44 -07:00

109 lines
3.5 KiB
Python

# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from kazoo import client as kazoo_client
from nova.openstack.common import jsonutils
from nova.workflow.logbook import api
from oslo.config import cfg
CONF = cfg.CONF
CONF.import_opt('address', 'nova.servicegroup.zk', group='zookeeper')
CONF.import_opt('recv_timeout', 'nova.servicegroup.zk', group='zookeeper')
class LogBook(api.LogBook):
prefix = "entry-"
def __init__(self, client, resource_uri):
super(LogBook, self).__init__(self, "%s/logbook" % (resource_uri))
self._client = client
self._paths_made = False
self._paths = [self.uri]
def _ensure_paths(self):
if self._paths_made:
return
for p in self._paths:
self._client.ensure_path(p)
self._paths_made = True
def add_record(self, name, metadata=None):
self._ensure_paths()
(path, value) = self._make_storage(name, metadata)
self._client.create(path, jsonutils.dumps(value), sequence=True)
def _make_storage(self, name, metadata):
path = "{root}/{prefix}".format(root=self.uri, prefix=self.prefix)
value = {
'name': name,
'metadata': metadata,
}
return (path, value)
def __iter__(self):
for c in self._client.get_children(self.uri + "/"):
if not c.startswith(self.prefix):
continue
(value, _zk) = self._client.get("%s/%s" % (self.uri, c))
value = jsonutils.loads(value)
yield (value['name'], value['metadata'])
def __contains__(self, name):
for (n, metadata) in self:
if name == n:
return True
return False
def mark(self, name, metadata, merge_func=None):
if merge_func is None:
merge_func = lambda old,new : new
for c in self._client.get_children(self.uri + "/"):
if not c.startswith(self.prefix):
continue
(value, _zk) = self._client.get("%s/%s" % (self.uri, c))
value = jsonutils.loads(value)
if value['name'] == name:
value['metadata'] = merge_func(value['metadata'], metadata)
self._client.set("%s/%s" % (self.uri, c),
jsonutils.dumps(value))
return
raise api.RecordNotFound()
def fetch_record(self, name):
for n, metadata in self:
if name == n:
return metadata
raise api.RecordNotFound()
class LogBookProvider(api.LogBookProvider):
def __init__(self, *args, **kwargs):
self._client = kazoo_client.KazooClient(hosts=CONF.address,
timeout=CONF.recv_timeout)
self._client.start()
def close(self):
if self._client:
self._client.stop()
def provide(self, resource_uri):
return LogBook(self._client, resource_uri)