mirror of
git://sourceware.org/git/lvm2.git
synced 2024-12-22 17:35:59 +03:00
b81186e535
The object manager method get_object_by_lvm_id was used in many cases for the sole reason of getting the object path for the object. Instead of retrieving the object and then calling 'dbus_object_path' on the object, we are adding a method which returns the object path.
309 lines
9.1 KiB
Python
309 lines
9.1 KiB
Python
# Copyright (C) 2015-2016 Red Hat, Inc. All rights reserved.
|
|
#
|
|
# This copyrighted material is made available to anyone wishing to use,
|
|
# modify, copy, or redistribute it subject to the terms and conditions
|
|
# of the GNU General Public License v.2.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
import sys
|
|
import threading
|
|
import traceback
|
|
import dbus
|
|
import os
|
|
from . import cfg
|
|
from .utils import log_debug
|
|
from .automatedproperties import AutomatedProperties
|
|
|
|
|
|
# noinspection PyPep8Naming
|
|
class ObjectManager(AutomatedProperties):
|
|
"""
|
|
Implements the org.freedesktop.DBus.ObjectManager interface
|
|
"""
|
|
|
|
def __init__(self, object_path, interface):
|
|
super(ObjectManager, self).__init__(object_path, interface)
|
|
self.set_interface(interface)
|
|
self._ap_o_path = object_path
|
|
self._objects = {}
|
|
self._id_to_object_path = {}
|
|
self.rlock = threading.RLock()
|
|
|
|
@dbus.service.method(
|
|
dbus_interface="org.freedesktop.DBus.ObjectManager",
|
|
out_signature='a{oa{sa{sv}}}')
|
|
def GetManagedObjects(self):
|
|
with self.rlock:
|
|
rc = {}
|
|
try:
|
|
for k, v in list(self._objects.items()):
|
|
path, props = v[0].emit_data()
|
|
rc[path] = props
|
|
except Exception:
|
|
traceback.print_exc(file=sys.stdout)
|
|
sys.exit(1)
|
|
return rc
|
|
|
|
def locked(self):
|
|
"""
|
|
If some external code need to run across a number of different
|
|
calls into ObjectManager while blocking others they can use this method
|
|
to lock others out.
|
|
:return:
|
|
"""
|
|
return ObjectManagerLock(self.rlock)
|
|
|
|
@dbus.service.signal(
|
|
dbus_interface="org.freedesktop.DBus.ObjectManager",
|
|
signature='oa{sa{sv}}')
|
|
def InterfacesAdded(self, object_path, int_name_prop_dict):
|
|
log_debug(
|
|
('SIGNAL: InterfacesAdded(%s, %s)' %
|
|
(str(object_path), str(int_name_prop_dict))))
|
|
|
|
@dbus.service.signal(
|
|
dbus_interface="org.freedesktop.DBus.ObjectManager",
|
|
signature='oas')
|
|
def InterfacesRemoved(self, object_path, interface_list):
|
|
log_debug(('SIGNAL: InterfacesRemoved(%s, %s)' %
|
|
(str(object_path), str(interface_list))))
|
|
|
|
def _lookup_add(self, obj, path, lvm_id, uuid):
|
|
"""
|
|
Store information about what we added to the caches so that we
|
|
can remove it cleanly
|
|
:param obj: The dbus object we are storing
|
|
:param lvm_id: The user name for the asset
|
|
:param uuid: The uuid for the asset
|
|
:return:
|
|
"""
|
|
# Note: Only called internally, lock implied
|
|
|
|
# We could have a temp entry from the forward creation of a path
|
|
self._lookup_remove(path)
|
|
|
|
self._objects[path] = (obj, lvm_id, uuid)
|
|
self._id_to_object_path[lvm_id] = path
|
|
|
|
if uuid:
|
|
self._id_to_object_path[uuid] = path
|
|
|
|
def _lookup_remove(self, obj_path):
|
|
# Note: Only called internally, lock implied
|
|
if obj_path in self._objects:
|
|
(obj, lvm_id, uuid) = self._objects[obj_path]
|
|
del self._id_to_object_path[lvm_id]
|
|
del self._id_to_object_path[uuid]
|
|
del self._objects[obj_path]
|
|
|
|
def lookup_update(self, dbus_obj, new_uuid, new_lvm_id):
|
|
with self.rlock:
|
|
obj_path = dbus_obj.dbus_object_path()
|
|
self._lookup_remove(obj_path)
|
|
self._lookup_add(
|
|
dbus_obj, obj_path,
|
|
new_lvm_id, new_uuid)
|
|
|
|
def object_paths_by_type(self, o_type):
|
|
with self.rlock:
|
|
rc = {}
|
|
|
|
for k, v in list(self._objects.items()):
|
|
if isinstance(v[0], o_type):
|
|
rc[k] = True
|
|
return rc
|
|
|
|
def register_object(self, dbus_object, emit_signal=False):
|
|
"""
|
|
Given a dbus object add it to the collection
|
|
:param dbus_object: Dbus object to register
|
|
:param emit_signal: If true emit a signal for interfaces added
|
|
"""
|
|
with self.rlock:
|
|
path, props = dbus_object.emit_data()
|
|
|
|
# print('Registering object path %s for %s' %
|
|
# (path, dbus_object.lvm_id))
|
|
|
|
# We want fast access to the object by a number of different ways
|
|
# so we use multiple hashs with different keys
|
|
self._lookup_add(dbus_object, path, dbus_object.lvm_id,
|
|
dbus_object.Uuid)
|
|
|
|
if emit_signal:
|
|
self.InterfacesAdded(path, props)
|
|
|
|
def remove_object(self, dbus_object, emit_signal=False):
|
|
"""
|
|
Given a dbus object, remove it from the collection and remove it
|
|
from the dbus framework as well
|
|
:param dbus_object: Dbus object to remove
|
|
:param emit_signal: If true emit the interfaces removed signal
|
|
"""
|
|
with self.rlock:
|
|
# Store off the object path and the interface first
|
|
path = dbus_object.dbus_object_path()
|
|
interfaces = dbus_object.interface()
|
|
|
|
# print 'UN-Registering object path %s for %s' % \
|
|
# (path, dbus_object.lvm_id)
|
|
|
|
self._lookup_remove(path)
|
|
|
|
# Remove from dbus library
|
|
dbus_object.remove_from_connection(cfg.bus, path)
|
|
|
|
# Optionally emit a signal
|
|
if emit_signal:
|
|
self.InterfacesRemoved(path, interfaces)
|
|
|
|
def get_object_by_path(self, path):
|
|
"""
|
|
Given a dbus path return the object registered for it
|
|
:param path: The dbus path
|
|
:return: The object
|
|
"""
|
|
with self.rlock:
|
|
if path in self._objects:
|
|
return self._objects[path][0]
|
|
return None
|
|
|
|
def get_object_by_uuid_lvm_id(self, uuid, lvm_id):
|
|
with self.rlock:
|
|
return self.get_object_by_path(
|
|
self.get_object_path_by_uuid_lvm_id(uuid, lvm_id, None, False))
|
|
|
|
def get_object_by_lvm_id(self, lvm_id):
|
|
"""
|
|
Given an lvm identifier, return the object registered for it
|
|
:param lvm_id: The lvm identifier
|
|
"""
|
|
with self.rlock:
|
|
if lvm_id in self._id_to_object_path:
|
|
return self.get_object_by_path(self._id_to_object_path[lvm_id])
|
|
return None
|
|
|
|
def get_object_path_by_lvm_id(self, lvm_id):
|
|
"""
|
|
Given an lvm identifier, return the object path for it
|
|
:param lvm_id: The lvm identifier
|
|
:return: Object path or '/' if not found
|
|
"""
|
|
with self.rlock:
|
|
if lvm_id in self._id_to_object_path:
|
|
return self._id_to_object_path[lvm_id]
|
|
return '/'
|
|
|
|
def _uuid_verify(self, path, uuid, lvm_id):
|
|
"""
|
|
Ensure uuid is present for a successful lvm_id lookup
|
|
NOTE: Internal call, assumes under object manager lock
|
|
:param path: Path to object we looked up
|
|
:param uuid: lvm uuid to verify
|
|
:param lvm_id: lvm_id used to find object
|
|
:return: None
|
|
"""
|
|
# This gets called when we found an object based on lvm_id, ensure
|
|
# uuid is correct too, as they can change
|
|
if lvm_id != uuid:
|
|
if uuid not in self._id_to_object_path:
|
|
obj = self.get_object_by_path(path)
|
|
self._lookup_add(obj, path, lvm_id, uuid)
|
|
|
|
def _return_lookup(self, uuid, lvm_identifier):
|
|
"""
|
|
We found an identifier, so lets return the path to the found object
|
|
:param uuid: The lvm uuid
|
|
:param lvm_identifier: The lvm_id used to find object
|
|
:return:
|
|
"""
|
|
path = self._id_to_object_path[lvm_identifier]
|
|
self._uuid_verify(path, uuid, lvm_identifier)
|
|
return path
|
|
|
|
def get_object_path_by_uuid_lvm_id(self, uuid, lvm_id, path_create=None,
|
|
gen_new=True):
|
|
"""
|
|
For a given lvm asset return the dbus object registered to it. If the
|
|
object is not found and gen_new == True and path_create is a valid
|
|
function we will create a new path, register it and return it.
|
|
:param uuid: The uuid for the lvm object
|
|
:param lvm_id: The lvm name
|
|
:param path_create: If true create an object path if not found
|
|
:param gen_new: The function used to create the new path
|
|
"""
|
|
with self.rlock:
|
|
assert lvm_id
|
|
assert uuid
|
|
|
|
if gen_new:
|
|
assert path_create
|
|
|
|
path = None
|
|
|
|
if lvm_id in self._id_to_object_path:
|
|
self._return_lookup(uuid, lvm_id)
|
|
|
|
if "/" in lvm_id:
|
|
vg, lv = lvm_id.split("/", 1)
|
|
int_lvm_id = vg + "/" + ("[%s]" % lv)
|
|
if int_lvm_id in self._id_to_object_path:
|
|
self._return_lookup(uuid, int_lvm_id)
|
|
elif lvm_id.startswith('/'):
|
|
# We could have a pv device path lookup that failed,
|
|
# lets try canonical form and try again.
|
|
canonical = os.path.realpath(lvm_id)
|
|
if canonical in self._id_to_object_path:
|
|
self._return_lookup(uuid, canonical)
|
|
|
|
if uuid and uuid in self._id_to_object_path:
|
|
# If we get here it indicates that we found the object, but
|
|
# the lvm_id lookup failed. In the case of a rename, the uuid
|
|
# will be correct, but the lvm_id will be wrong and vise versa.
|
|
# If the lvm_id does not equal the uuid, lets fix up the table
|
|
# so that lookups will be handled correctly.
|
|
path = self._id_to_object_path[uuid]
|
|
|
|
# In some cases we are looking up by one or the other, don't
|
|
# update when they are the same.
|
|
if uuid != lvm_id:
|
|
obj = self.get_object_by_path(path)
|
|
self._lookup_add(obj, path, lvm_id, uuid)
|
|
else:
|
|
if gen_new:
|
|
path = path_create()
|
|
self._lookup_add(None, path, lvm_id, uuid)
|
|
|
|
# pprint('get_object_path_by_lvm_id(%s, %s, %s, %s: return %s' %
|
|
# (uuid, lvm_id, str(path_create), str(gen_new), path))
|
|
|
|
return path
|
|
|
|
|
|
class ObjectManagerLock(object):
|
|
"""
|
|
The sole purpose of this class is to allow other code the ability to
|
|
lock the object manager using a `with` statement, eg.
|
|
|
|
with cfg.om.locked():
|
|
# Do stuff with object manager
|
|
|
|
This will ensure that the lock is always released (assuming this is done
|
|
correctly)
|
|
"""
|
|
|
|
def __init__(self, recursive_lock):
|
|
self._lock = recursive_lock
|
|
|
|
def __enter__(self):
|
|
# Acquire lock
|
|
self._lock.acquire()
|
|
|
|
# noinspection PyUnusedLocal
|
|
def __exit__(self, e_type, e_value, e_traceback):
|
|
# Release lock
|
|
self._lock.release()
|
|
self._lock = None
|