virt-manager/virtinst/pollhelpers.py
Radostin Stoyanov b93cc3bbc9 pycodestyle: Do not use bare 'except:'
A bare 'except:' catches all exceptions [1], including SystemExit,
KeyboardInterrupt, and GeneratorExit (which is not an error and should
not normally be caught by user code). In situations where you need to
catch all “normal” errors, you can catch the base class for all normal
exceptions, Exception [2].

[1] https://docs.python.org/2/howto/doanddont.html#except
[2] https://docs.python.org/2/library/exceptions.html#Exception
2017-08-02 13:57:43 -04:00

286 lines
9.2 KiB
Python

#
# Copyright (C) 2013 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301 USA.
#
import logging
# Debugging helper to force old style polling
# Can be enabled with virt-manager --test-old-poll
FORCE_OLD_POLL = False
def _new_poll_helper(origmap, typename, listfunc, buildfunc):
"""
Helper for new style listAll* APIs
"""
current = {}
new = {}
objs = []
try:
objs = listfunc()
except Exception as e:
logging.debug("Unable to list all %ss: %s", typename, e)
for obj in objs:
connkey = obj.name()
if connkey not in origmap:
# Object is brand new this period
current[connkey] = buildfunc(obj, connkey)
new[connkey] = current[connkey]
else:
# Previously known object
current[connkey] = origmap[connkey]
del(origmap[connkey])
return (origmap.values(), new.values(), current.values())
def _old_poll_helper(origmap, typename,
active_list, inactive_list,
lookup_func, build_func):
"""
Helper routine for old style split API libvirt polling.
@origmap: Pre-existing mapping of objects, with connkey->obj mapping.
objects must have an is_active and set_active API
@typename: string describing type of objects we are polling for use
in debug messages.
@active_list: Function that returns the list of active objects
@inactive_list: Function that returns the list of inactive objects
@lookup_func: Function to get an object handle for the passed name
@build_func: Function that builds a new object class. It is passed
args of (raw libvirt object, connkey)
"""
current = {}
new = {}
newActiveNames = []
newInactiveNames = []
try:
newActiveNames = active_list()
except Exception as e:
logging.debug("Unable to list active %ss: %s", typename, e)
try:
newInactiveNames = inactive_list()
except Exception as e:
logging.debug("Unable to list inactive %ss: %s", typename, e)
def check_obj(name):
obj = None
connkey = name
if connkey not in origmap:
try:
obj = lookup_func(name)
except Exception as e:
logging.debug("Could not fetch %s '%s': %s",
typename, connkey, e)
return
# Object is brand new this period
current[connkey] = build_func(obj, connkey)
new[connkey] = current[connkey]
else:
# Previously known object
current[connkey] = origmap[connkey]
del(origmap[connkey])
for name in newActiveNames + newInactiveNames:
try:
check_obj(name)
except Exception:
logging.exception("Couldn't fetch %s '%s'", typename, name)
return (origmap.values(), new.values(), current.values())
def fetch_nets(backend, origmap, build_func):
name = "network"
if backend.check_support(
backend.SUPPORT_CONN_LISTALLNETWORKS) and not FORCE_OLD_POLL:
return _new_poll_helper(origmap, name,
backend.listAllNetworks, build_func)
else:
active_list = backend.listNetworks
inactive_list = backend.listDefinedNetworks
lookup_func = backend.networkLookupByName
return _old_poll_helper(origmap, name,
active_list, inactive_list,
lookup_func, build_func)
def fetch_pools(backend, origmap, build_func):
name = "pool"
if backend.check_support(
backend.SUPPORT_CONN_LISTALLSTORAGEPOOLS) and not FORCE_OLD_POLL:
return _new_poll_helper(origmap, name,
backend.listAllStoragePools, build_func)
else:
active_list = backend.listStoragePools
inactive_list = backend.listDefinedStoragePools
lookup_func = backend.storagePoolLookupByName
return _old_poll_helper(origmap, name,
active_list, inactive_list,
lookup_func, build_func)
def fetch_volumes(backend, pool, origmap, build_func):
name = "volume"
if backend.check_support(
backend.SUPPORT_POOL_LISTALLVOLUMES, pool) and not FORCE_OLD_POLL:
return _new_poll_helper(origmap, name,
pool.listAllVolumes, build_func)
else:
active_list = pool.listVolumes
def inactive_list():
return []
lookup_func = pool.storageVolLookupByName
return _old_poll_helper(origmap, name,
active_list, inactive_list,
lookup_func, build_func)
def fetch_interfaces(backend, origmap, build_func):
name = "interface"
if backend.check_support(
backend.SUPPORT_CONN_LISTALLINTERFACES) and not FORCE_OLD_POLL:
return _new_poll_helper(origmap, name,
backend.listAllInterfaces, build_func)
else:
active_list = backend.listInterfaces
inactive_list = backend.listDefinedInterfaces
lookup_func = backend.interfaceLookupByName
return _old_poll_helper(origmap, name,
active_list, inactive_list,
lookup_func, build_func)
def fetch_nodedevs(backend, origmap, build_func):
name = "nodedev"
if backend.check_support(
backend.SUPPORT_CONN_LISTALLDEVICES) and not FORCE_OLD_POLL:
return _new_poll_helper(origmap, name,
backend.listAllDevices, build_func)
else:
def active_list():
return backend.listDevices(None, 0)
def inactive_list():
return []
lookup_func = backend.nodeDeviceLookupByName
return _old_poll_helper(origmap, name,
active_list, inactive_list,
lookup_func, build_func)
def _old_fetch_vms(backend, origmap, build_func):
# We can't easily use _old_poll_helper here because the domain API
# doesn't always return names like other objects, it returns
# IDs for active VMs
newActiveIDs = []
newInactiveNames = []
oldActiveIDs = {}
oldInactiveNames = {}
current = {}
new = {}
# Build list of previous vms with proper id/name mappings
for vm in origmap.values():
if vm.is_active():
oldActiveIDs[vm.get_id()] = vm
else:
oldInactiveNames[vm.get_name()] = vm
try:
newActiveIDs = backend.listDomainsID()
except Exception as e:
logging.debug("Unable to list active domains: %s", e)
try:
newInactiveNames = backend.listDefinedDomains()
except Exception as e:
logging.exception("Unable to list inactive domains: %s", e)
def add_vm(vm):
connkey = vm.get_name()
current[connkey] = vm
del(origmap[connkey])
def check_new(rawvm, connkey):
if connkey in origmap:
vm = origmap[connkey]
del(origmap[connkey])
else:
vm = build_func(rawvm, connkey)
new[connkey] = vm
current[connkey] = vm
for _id in newActiveIDs:
if _id in oldActiveIDs:
# No change, copy across existing VM object
vm = oldActiveIDs[_id]
add_vm(vm)
else:
# Check if domain is brand new, or old one that changed state
try:
vm = backend.lookupByID(_id)
connkey = vm.name()
check_new(vm, connkey)
except Exception:
logging.exception("Couldn't fetch domain id '%s'", _id)
for name in newInactiveNames:
if name in oldInactiveNames:
# No change, copy across existing VM object
vm = oldInactiveNames[name]
add_vm(vm)
else:
# Check if domain is brand new, or old one that changed state
try:
vm = backend.lookupByName(name)
connkey = name
check_new(vm, connkey)
except Exception:
logging.exception("Couldn't fetch domain '%s'", name)
return (origmap.values(), new.values(), current.values())
def fetch_vms(backend, origmap, build_func):
name = "domain"
if backend.check_support(
backend.SUPPORT_CONN_LISTALLDOMAINS):
return _new_poll_helper(origmap, name,
backend.listAllDomains, build_func)
else:
return _old_fetch_vms(backend, origmap, build_func)