[entity] introduce a new 'adapters' registry
This changeset introduces the notion in adapters (as in Zope Component Architecture)
in a cubicweb way, eg using a specific registry of appobjects.
This allows nicer code structure, by avoid clutering entity classes and moving
code usually specific to a place of the ui (or something else) together with the
code that use the interface.
We don't use actual interface anymore, they are implied by adapters (which
may be abstract), whose reg id is an interface name.
Appobjects that used to 'implements(IFace)' should now be rewritten by:
* coding an IFaceAdapter(EntityAdapter) defining (implementing if desired)
the interface, usually with __regid__ = 'IFace'
* use "adaptable('IFace')" as selector instead
Also, the implements_adapter_compat decorator eases backward compatibility
with adapter's methods that may still be found on entities implementing
the interface.
Notice that unlike ZCA, we don't support automatic adapters chain (yagni?).
All interfaces defined in cubicweb have been turned into adapters, also
some new ones have been introduced to cleanup Entity / AnyEntity classes
namespace. At the end, the pluggable mixins mecanism should disappear in
favor of adapters as well.
# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""CubicWeb server connections pool : the repository has a limited number of
connections pools, each of them dealing with a set of connections on each source
used by the repository. A connections pools (`ConnectionsPool`) is an
abstraction for a group of connection to each source.
"""
__docformat__ = "restructuredtext en"
import sys
class ConnectionsPool(object):
"""handle connections on a set of sources, at some point associated to a
user session
"""
def __init__(self, sources):
# dictionnary of (source, connection), indexed by sources'uri
self.source_cnxs = {}
for source in sources:
self.source_cnxs[source.uri] = (source, source.get_connection())
if not 'system' in self.source_cnxs:
self.source_cnxs['system'] = self.source_cnxs[sources[0].uri]
self._cursors = {}
def __getitem__(self, uri):
"""subscription notation provide access to sources'cursors"""
try:
cursor = self._cursors[uri]
except KeyError:
cursor = self.source_cnxs[uri][1].cursor()
if cursor is not None:
# None possible on sources without cursor support such as ldap
self._cursors[uri] = cursor
return cursor
def commit(self):
"""commit the current transaction for this user"""
# FIXME: what happends if a commit fail
# would need a two phases commit or like, but I don't know how to do
# this using the db-api...
for source, cnx in self.source_cnxs.values():
# let exception propagates
cnx.commit()
def rollback(self):
"""rollback the current transaction for this user"""
for source, cnx in self.source_cnxs.values():
# catch exceptions, rollback other sources anyway
try:
cnx.rollback()
except:
source.critical('rollback error', exc_info=sys.exc_info())
def close(self, i_know_what_i_do=False):
"""close all connections in the pool"""
if i_know_what_i_do is not True: # unexpected closing safety belt
raise RuntimeError('pool shouldn\'t be closed')
for cu in self._cursors.values():
try:
cu.close()
except:
continue
for _, cnx in self.source_cnxs.values():
try:
cnx.close()
except:
continue
# internals ###############################################################
def pool_set(self):
"""pool is being set"""
self.check_connections()
def pool_reset(self):
"""pool is being reseted"""
for source, cnx in self.source_cnxs.values():
source.pool_reset(cnx)
def sources(self):
"""return the source objects handled by this pool"""
# implementation details of flying insert requires the system source
# first
yield self.source_cnxs['system'][0]
for uri, (source, cnx) in self.source_cnxs.items():
if uri == 'system':
continue
yield source
#return [source_cnx[0] for source_cnx in self.source_cnxs.values()]
def source(self, uid):
"""return the source object with the given uri"""
return self.source_cnxs[uid][0]
def connection(self, uid):
"""return the connection on the source object with the given uri"""
return self.source_cnxs[uid][1]
def reconnect(self, source=None):
"""reopen a connection for this source or all sources if none specified
"""
if source is None:
sources = self.sources()
else:
sources = (source,)
for source in sources:
try:
# properly close existing connection if any
self.source_cnxs[source.uri][1].close()
except:
pass
source.info('trying to reconnect')
self.source_cnxs[source.uri] = (source, source.get_connection())
self._cursors.pop(source.uri, None)
def check_connections(self):
for source, cnx in self.source_cnxs.itervalues():
newcnx = source.check_connection(cnx)
if newcnx is not None:
self.reset_connection(source, newcnx)
def reset_connection(self, source, cnx):
self.source_cnxs[source.uri] = (source, cnx)
self._cursors.pop(source.uri, None)
from cubicweb.server.hook import (Operation, LateOperation, SingleOperation,
SingleLastOperation)
from logilab.common.deprecation import class_moved, class_renamed
Operation = class_moved(Operation)
PreCommitOperation = class_renamed('PreCommitOperation', Operation)
LateOperation = class_moved(LateOperation)
SingleOperation = class_moved(SingleOperation)
SingleLastOperation = class_moved(SingleLastOperation)