[datafeed] make cnxset handling of datafeed source more robust
currently we may run in some cases where the session has no more cnxset
depending on errors and parser's handling of the cnxset.
Also, free the cnxset and reacquire it later, letting a chance to other
threads to run.
# copyright 2003-2012 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/>."""Security hooks: check permissions to add/delete/update entities according tothe user connected to a session"""__docformat__="restructuredtext en"fromlogilab.common.registryimportobjectify_predicatefromcubicwebimportUnauthorizedfromcubicweb.serverimportBEFORE_ADD_RELATIONS,ON_COMMIT_ADD_RELATIONS,hookdefcheck_entity_attributes(session,entity,editedattrs=None,creation=False):eid=entity.eideschema=entity.e_schema# ._cw_skip_security_attributes is there to bypass security for attributes# set by hooks by modifying the entity's dictionaryifeditedattrsisNone:editedattrs=entity.cw_editeddontcheck=editedattrs.skip_securityforattrineditedattrs:ifattrindontcheck:continuerdef=eschema.rdef(attr)ifrdef.final:# non final relation are checked by other hooks# add/delete should be equivalent (XXX: unify them into 'update' ?)ifcreationandnotrdef.permissions.get('update'):continuerdef.check_perm(session,'update',eid=eid)classCheckEntityPermissionOp(hook.DataOperationMixIn,hook.LateOperation):defprecommit_event(self):session=self.sessionforeid,action,editedinself.get_data():entity=session.entity_from_eid(eid)entity.cw_check_perm(action)check_entity_attributes(session,entity,edited,creation=(action=='add'))classCheckRelationPermissionOp(hook.DataOperationMixIn,hook.LateOperation):defprecommit_event(self):session=self.sessionforaction,rschema,eidfrom,eidtoinself.get_data():rdef=rschema.rdef(session.describe(eidfrom)[0],session.describe(eidto)[0])rdef.check_perm(session,action,fromeid=eidfrom,toeid=eidto)@objectify_predicatedefwrite_security_enabled(cls,req,**kwargs):ifreqisNoneornotreq.write_security:return0return1classSecurityHook(hook.Hook):__abstract__=Truecategory='security'__select__=hook.Hook.__select__&write_security_enabled()classAfterAddEntitySecurityHook(SecurityHook):__regid__='securityafteraddentity'events=('after_add_entity',)def__call__(self):CheckEntityPermissionOp.get_instance(self._cw).add_data((self.entity.eid,'add',self.entity.cw_edited))classAfterUpdateEntitySecurityHook(SecurityHook):__regid__='securityafterupdateentity'events=('after_update_entity',)def__call__(self):try:# check user has permission right now, if not retry at commit timeself.entity.cw_check_perm('update')check_entity_attributes(self._cw,self.entity)exceptUnauthorized:self.entity._cw_clear_local_perm_cache('update')# save back editedattrs in case the entity is reedited later in the# same transaction, which will lead to cw_edited being# overwrittenCheckEntityPermissionOp.get_instance(self._cw).add_data((self.entity.eid,'update',self.entity.cw_edited))classBeforeDelEntitySecurityHook(SecurityHook):__regid__='securitybeforedelentity'events=('before_delete_entity',)def__call__(self):self.entity.cw_check_perm('delete')classBeforeAddRelationSecurityHook(SecurityHook):__regid__='securitybeforeaddrelation'events=('before_add_relation',)def__call__(self):ifself.rtypeinBEFORE_ADD_RELATIONS:nocheck=self._cw.transaction_data.get('skip-security',())if(self.eidfrom,self.rtype,self.eidto)innocheck:returnrschema=self._cw.repo.schema[self.rtype]rdef=rschema.rdef(self._cw.describe(self.eidfrom)[0],self._cw.describe(self.eidto)[0])rdef.check_perm(self._cw,'add',fromeid=self.eidfrom,toeid=self.eidto)classAfterAddRelationSecurityHook(SecurityHook):__regid__='securityafteraddrelation'events=('after_add_relation',)def__call__(self):ifnotself.rtypeinBEFORE_ADD_RELATIONS:nocheck=self._cw.transaction_data.get('skip-security',())if(self.eidfrom,self.rtype,self.eidto)innocheck:returnrschema=self._cw.repo.schema[self.rtype]ifself.rtypeinON_COMMIT_ADD_RELATIONS:CheckRelationPermissionOp.get_instance(self._cw).add_data(('add',rschema,self.eidfrom,self.eidto))else:rdef=rschema.rdef(self._cw.describe(self.eidfrom)[0],self._cw.describe(self.eidto)[0])rdef.check_perm(self._cw,'add',fromeid=self.eidfrom,toeid=self.eidto)classBeforeDeleteRelationSecurityHook(SecurityHook):__regid__='securitybeforedelrelation'events=('before_delete_relation',)def__call__(self):nocheck=self._cw.transaction_data.get('skip-security',())if(self.eidfrom,self.rtype,self.eidto)innocheck:returnrschema=self._cw.repo.schema[self.rtype]rdef=rschema.rdef(self._cw.describe(self.eidfrom)[0],self._cw.describe(self.eidto)[0])rdef.check_perm(self._cw,'delete',fromeid=self.eidfrom,toeid=self.eidto)