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"""
Serializer code for cobbler
Now adapted to support different storage backends
Copyright 2006-2007, Red Hat, Inc
Michael DeHaan <mdehaan@redhat.com>
This software may be freely redistributed under the terms of the GNU
general public license.
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., 675 Mass Ave, Cambridge, MA 02139, USA.
"""
import errno
import os
from utils import _
import fcntl
from cexceptions import *
import utils
import api as cobbler_api
LOCK_ENABLED = True
LOCK_HANDLE = None
def __grab_lock():
if not LOCK_ENABLED:
return
if not os.path.exists("/var/lib/cobbler/lock"):
fd = open("/var/lib/cobbler/lock","w+")
fd.close()
LOCK_HANDLE = open("/var/lib/cobbler/lock","r")
fcntl.flock(LOCK_HANDLE.fileno(), fcntl.LOCK_EX)
def __release_lock():
if not LOCK_ENABLED:
return
LOCK_HANDLE = open("/var/lib/cobbler/lock","r")
fcntl.flock(LOCK_HANDLE.fileno(), fcntl.LOCK_UN)
LOCK_HANDLE.close()
def serialize(obj):
"""
Save a collection to disk or other storage.
"""
__grab_lock()
storage_module = __get_storage_module(obj.collection_type())
storage_module.serialize(obj)
__release_lock()
return True
def serialize_item(collection, item):
"""
Save an item.
"""
__grab_lock()
storage_module = __get_storage_module(collection.collection_type())
save_fn = getattr(storage_module, "serialize_item", None)
if save_fn is None:
rc = storage_module.serialize(collection)
else:
rc = save_fn(collection,item)
__release_lock()
return rc
def serialize_delete(collection, item):
"""
Delete an object from a saved state.
"""
__grab_lock()
storage_module = __get_storage_module(collection.collection_type())
delete_fn = getattr(storage_module, "serialize_delete", None)
if delete_fn is None:
rc = storage_module.serialize(collection)
else:
rc = delete_fn(collection,item)
__release_lock()
return rc
def deserialize(obj,topological=False):
"""
Fill in an empty collection from disk or other storage
"""
__grab_lock()
storage_module = __get_storage_module(obj.collection_type())
rc = storage_module.deserialize(obj,topological)
__release_lock()
return rc
def deserialize_raw(collection_type):
"""
Return the datastructure corresponding to the serialized
disk state, without going through the Cobbler object system.
Much faster, when you don't need the objects.
"""
__grab_lock()
storage_module = __get_storage_module(collection_type)
rc = storage_module.deserialize_raw(collection_type)
__release_lock()
return rc
def __get_storage_module(collection_type):
"""
Look up serializer in /etc/cobbler/modules.conf
"""
capi = cobbler_api.BootAPI()
return capi.get_module_from_file("serializers",collection_type,"serializer_yaml")
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