hooks/syncsources.py
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Mon, 17 Sep 2012 17:52:17 +0200
changeset 8557 8756f932ca83
parent 8556 bbe0d6985e59
child 9448 3e7cad3967c5
permissions -rw-r--r--
[source synchronization hooks] Fix/enhance system source hooks They are broken if launched during repository initialization (this was not the case yet, but will be soon...). Add additional checks to ensure one doesn't try to store system source config in the database, as it will be ignored in favor of the "sources" file.

# copyright 2010-2012 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/>.
"""hooks for repository sources synchronization"""

_ = unicode

from socket import gethostname

from logilab.common.decorators import clear_cache

from cubicweb import validation_error
from cubicweb.predicates import is_instance
from cubicweb.server import SOURCE_TYPES, hook

class SourceHook(hook.Hook):
    __abstract__ = True
    category = 'cw.sources'


# repo sources synchronization #################################################

class SourceAddedOp(hook.Operation):
    entity = None # make pylint happy
    def postcommit_event(self):
        self.session.repo.add_source(self.entity)

class SourceAddedHook(SourceHook):
    __regid__ = 'cw.sources.added'
    __select__ = SourceHook.__select__ & is_instance('CWSource')
    events = ('after_add_entity',)
    def __call__(self):
        try:
            sourcecls = SOURCE_TYPES[self.entity.type]
        except KeyError:
            msg = _('Unknown source type')
            raise validation_error(self.entity, {('type', 'subject'): msg})
        # ignore creation of the system source done during database
        # initialisation, as config for this source is in a file and handling
        # is done separatly (no need for the operation either)
        if self.entity.name != 'system':
            sourcecls.check_conf_dict(self.entity.eid, self.entity.host_config,
                                      fail_if_unknown=not self._cw.vreg.config.repairing)
            SourceAddedOp(self._cw, entity=self.entity)


class SourceRemovedOp(hook.Operation):
    uri = None # make pylint happy
    def postcommit_event(self):
        self.session.repo.remove_source(self.uri)

class SourceRemovedHook(SourceHook):
    __regid__ = 'cw.sources.removed'
    __select__ = SourceHook.__select__ & is_instance('CWSource')
    events = ('before_delete_entity',)
    def __call__(self):
        if self.entity.name == 'system':
            msg = _("You cannot remove the system source")
            raise validation_error(self.entity, {None: msg})
        SourceRemovedOp(self._cw, uri=self.entity.name)


class SourceConfigUpdatedOp(hook.DataOperationMixIn, hook.Operation):

    def precommit_event(self):
        self.__processed = []
        for source in self.get_data():
            if not self.session.deleted_in_transaction(source.eid):
                conf = source.repo_source.check_config(source)
                self.__processed.append( (source, conf) )

    def postcommit_event(self):
        for source, conf in self.__processed:
            source.repo_source.update_config(source, conf)


class SourceRenamedOp(hook.LateOperation):
    oldname = newname = None # make pylint happy

    def precommit_event(self):
        source = self.session.repo.sources_by_uri[self.oldname]
        if source.copy_based_source:
            sql = 'UPDATE entities SET asource=%(newname)s WHERE asource=%(oldname)s'
        else:
            sql = 'UPDATE entities SET source=%(newname)s, asource=%(newname)s WHERE source=%(oldname)s'
        self.session.system_sql(sql, {'oldname': self.oldname,
                                      'newname': self.newname})

    def postcommit_event(self):
        repo = self.session.repo
        # XXX race condition
        source = repo.sources_by_uri.pop(self.oldname)
        source.uri = self.newname
        source.public_config['uri'] = self.newname
        repo.sources_by_uri[self.newname] = source
        repo._type_source_cache.clear()
        clear_cache(repo, 'source_defs')
        if not source.copy_based_source:
            repo._extid_cache.clear()
            repo._clear_planning_caches()
            for cnxset in repo.cnxsets:
                cnxset.source_cnxs[self.oldname] = cnxset.source_cnxs.pop(self.oldname)


class SourceUpdatedHook(SourceHook):
    __regid__ = 'cw.sources.configupdate'
    __select__ = SourceHook.__select__ & is_instance('CWSource')
    events = ('before_update_entity',)
    def __call__(self):
        if 'name' in self.entity.cw_edited:
            oldname, newname = self.entity.cw_edited.oldnewvalue('name')
            if oldname == 'system':
                msg = _("You cannot rename the system source")
                raise validation_error(self.entity, {('name', 'subject'): msg})
            SourceRenamedOp(self._cw, oldname=oldname, newname=newname)
        if 'config' in self.entity.cw_edited:
            if self.entity.name == 'system' and self.entity.config:
                msg = _("Configuration of the system source goes to "
                        "the 'sources' file, not in the database")
                raise validation_error(self.entity, {('config', 'subject'): msg})
            SourceConfigUpdatedOp.get_instance(self._cw).add_data(self.entity)


class SourceHostConfigUpdatedHook(SourceHook):
    __regid__ = 'cw.sources.hostconfigupdate'
    __select__ = SourceHook.__select__ & is_instance('CWSourceHostConfig')
    events = ('after_add_entity', 'after_update_entity', 'before_delete_entity',)
    def __call__(self):
        if self.entity.match(gethostname()):
            if self.event == 'after_update_entity' and \
                   not 'config' in self.entity.cw_edited:
                return
            try:
                SourceConfigUpdatedOp.get_instance(self._cw).add_data(self.entity.cwsource)
            except IndexError:
                # XXX no source linked to the host config yet
                pass


# source mapping synchronization ###############################################
#
# Expect cw_for_source/cw_schema are immutable relations (i.e. can't change from
# a source or schema to another).

class SourceMappingImmutableHook(SourceHook):
    """check cw_for_source and cw_schema are immutable relations

    XXX empty delete perms would be enough?
    """
    __regid__ = 'cw.sources.mapping.immutable'
    __select__ = SourceHook.__select__ & hook.match_rtype('cw_for_source', 'cw_schema')
    events = ('before_add_relation',)
    def __call__(self):
        if not self._cw.added_in_transaction(self.eidfrom):
            msg = _("You can't change this relation")
            raise validation_error(self.eidfrom, {self.rtype: msg})


class SourceMappingChangedOp(hook.DataOperationMixIn, hook.Operation):
    def check_or_update(self, checkonly):
        session = self.session
        # take care, can't call get_data() twice
        try:
            data = self.__data
        except AttributeError:
            data = self.__data = self.get_data()
        for schemacfg, source in data:
            if source is None:
                source = schemacfg.cwsource.repo_source
            if session.added_in_transaction(schemacfg.eid):
                if not session.deleted_in_transaction(schemacfg.eid):
                    source.add_schema_config(schemacfg, checkonly=checkonly)
            elif session.deleted_in_transaction(schemacfg.eid):
                source.del_schema_config(schemacfg, checkonly=checkonly)
            else:
                source.update_schema_config(schemacfg, checkonly=checkonly)

    def precommit_event(self):
        self.check_or_update(True)

    def postcommit_event(self):
        self.check_or_update(False)


class SourceMappingChangedHook(SourceHook):
    __regid__ = 'cw.sources.schemaconfig'
    __select__ = SourceHook.__select__ & is_instance('CWSourceSchemaConfig')
    events = ('after_add_entity', 'after_update_entity')
    def __call__(self):
        if self.event == 'after_add_entity' or (
            self.event == 'after_update_entity' and 'options' in self.entity.cw_edited):
            SourceMappingChangedOp.get_instance(self._cw).add_data(
                (self.entity, None) )

class SourceMappingDeleteHook(SourceHook):
    __regid__ = 'cw.sources.delschemaconfig'
    __select__ = SourceHook.__select__ & hook.match_rtype('cw_for_source')
    events = ('before_delete_relation',)
    def __call__(self):
        SourceMappingChangedOp.get_instance(self._cw).add_data(
            (self._cw.entity_from_eid(self.eidfrom),
             self._cw.entity_from_eid(self.eidto).repo_source) )