+
−# copyright 2010-2011 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/>.
+
−"""datafeed sources: copy data from an external data stream into the system
+
−database
+
−"""
+
−from __future__ import with_statement
+
−
+
−import urllib2
+
−import StringIO
+
−from datetime import datetime, timedelta
+
−from base64 import b64decode
+
−from cookielib import CookieJar
+
−
+
−from lxml import etree
+
−
+
−from cubicweb import RegistryNotFound, ObjectNotFound, ValidationError, UnknownEid
+
−from cubicweb.server.sources import AbstractSource
+
−from cubicweb.appobject import AppObject
+
−
+
−
+
−class DataFeedSource(AbstractSource):
+
−    copy_based_source = True
+
−    use_cwuri_as_url = True
+
−
+
−    options = (
+
−        ('synchronize',
+
−         {'type' : 'yn',
+
−          'default': True,
+
−          'help': ('Is the repository responsible to automatically import '
+
−                   'content from this source? '
+
−                   'You should say yes unless you don\'t want this behaviour '
+
−                   'or if you use a multiple repositories setup, in which '
+
−                   'case you should say yes on one repository, no on others.'),
+
−          'group': 'datafeed-source', 'level': 2,
+
−          }),
+
−        ('synchronization-interval',
+
−         {'type' : 'time',
+
−          'default': '5min',
+
−          'help': ('Interval in seconds between synchronization with the '
+
−                   'external source (default to 5 minutes, must be >= 1 min).'),
+
−          'group': 'datafeed-source', 'level': 2,
+
−          }),
+
−        ('delete-entities',
+
−         {'type' : 'yn',
+
−          'default': True,
+
−          'help': ('Should already imported entities not found anymore on the '
+
−                   'external source be deleted?'),
+
−          'group': 'datafeed-source', 'level': 2,
+
−          }),
+
−
+
−        )
+
−    def __init__(self, repo, source_config, eid=None):
+
−        AbstractSource.__init__(self, repo, source_config, eid)
+
−        self.update_config(None, self.check_conf_dict(eid, source_config,
+
−                                                      fail_if_unknown=False))
+
−
+
−    def check_config(self, source_entity):
+
−        """check configuration of source entity"""
+
−        typedconfig = super(DataFeedSource, self).check_config(source_entity)
+
−        if typedconfig['synchronization-interval'] < 60:
+
−            _ = source_entity._cw._
+
−            msg = _('synchronization-interval must be greater than 1 minute')
+
−            raise ValidationError(source_entity.eid, {'config': msg})
+
−        return typedconfig
+
−
+
−    def _entity_update(self, source_entity):
+
−        source_entity.complete()
+
−        self.parser_id = source_entity.parser
+
−        self.latest_retrieval = source_entity.latest_retrieval
+
−        self.urls = [url.strip() for url in source_entity.url.splitlines()
+
−                     if url.strip()]
+
−
+
−    def update_config(self, source_entity, typedconfig):
+
−        """update configuration from source entity. `typedconfig` is config
+
−        properly typed with defaults set
+
−        """
+
−        self.synchro_interval = timedelta(seconds=typedconfig['synchronization-interval'])
+
−        if source_entity is not None:
+
−            self._entity_update(source_entity)
+
−        self.config = typedconfig
+
−
+
−    def init(self, activated, source_entity):
+
−        if activated:
+
−            self._entity_update(source_entity)
+
−        self.parser_id = source_entity.parser
+
−        self.load_mapping(source_entity._cw)
+
−
+
−    def _get_parser(self, session, **kwargs):
+
−        return self.repo.vreg['parsers'].select(
+
−            self.parser_id, session, source=self, **kwargs)
+
−
+
−    def load_mapping(self, session):
+
−        self.mapping = {}
+
−        self.mapping_idx = {}
+
−        try:
+
−            parser = self._get_parser(session)
+
−        except (RegistryNotFound, ObjectNotFound):
+
−            return # no parser yet, don't go further
+
−        self._load_mapping(session, parser=parser)
+
−
+
−    def add_schema_config(self, schemacfg, checkonly=False, parser=None):
+
−        """added CWSourceSchemaConfig, modify mapping accordingly"""
+
−        if parser is None:
+
−            parser = self._get_parser(schemacfg._cw)
+
−        parser.add_schema_config(schemacfg, checkonly)
+
−
+
−    def del_schema_config(self, schemacfg, checkonly=False, parser=None):
+
−        """deleted CWSourceSchemaConfig, modify mapping accordingly"""
+
−        if parser is None:
+
−            parser = self._get_parser(schemacfg._cw)
+
−        parser.del_schema_config(schemacfg, checkonly)
+
−
+
−    def fresh(self):
+
−        if self.latest_retrieval is None:
+
−            return False
+
−        return datetime.utcnow() < (self.latest_retrieval + self.synchro_interval)
+
−
+
−    def update_latest_retrieval(self, session):
+
−        self.latest_retrieval = datetime.utcnow()
+
−        session.execute('SET X latest_retrieval %(date)s WHERE X eid %(x)s',
+
−                        {'x': self.eid, 'date': self.latest_retrieval})
+
−
+
−    def acquire_synchronization_lock(self, session):
+
−        # XXX race condition until WHERE of SET queries is executed using
+
−        # 'SELECT FOR UPDATE'
+
−        if not session.execute('SET X synchronizing TRUE WHERE X eid %(x)s, X synchronizing FALSE',
+
−                               {'x': self.eid}):
+
−            self.error('concurrent synchronization detected, skip pull')
+
−            session.commit(free_cnxset=False)
+
−            return False
+
−        session.commit(free_cnxset=False)
+
−        return True
+
−
+
−    def release_synchronization_lock(self, session):
+
−        session.set_cnxset()
+
−        session.execute('SET X synchronizing FALSE WHERE X eid %(x)s',
+
−                        {'x': self.eid})
+
−        session.commit()
+
−
+
−    def pull_data(self, session, force=False, raise_on_error=False):
+
−        """Launch synchronization of the source if needed.
+
−
+
−        This method is responsible to handle commit/rollback on the given
+
−        session.
+
−        """
+
−        if not force and self.fresh():
+
−            return {}
+
−        if not self.acquire_synchronization_lock(session):
+
−            return {}
+
−        try:
+
−            with session.transaction(free_cnxset=False):
+
−                return self._pull_data(session, force, raise_on_error)
+
−        finally:
+
−            self.release_synchronization_lock(session)
+
−
+
−    def _pull_data(self, session, force=False, raise_on_error=False):
+
−        if self.config['delete-entities']:
+
−            myuris = self.source_cwuris(session)
+
−        else:
+
−            myuris = None
+
−        parser = self._get_parser(session, sourceuris=myuris)
+
−        if self.process_urls(parser, self.urls, raise_on_error):
+
−            self.warning("some error occured, don't attempt to delete entities")
+
−        elif self.config['delete-entities'] and myuris:
+
−            byetype = {}
+
−            for eid, etype in myuris.values():
+
−                byetype.setdefault(etype, []).append(str(eid))
+
−            self.error('delete %s entities %s', self.uri, byetype)
+
−            for etype, eids in byetype.iteritems():
+
−                session.execute('DELETE %s X WHERE X eid IN (%s)'
+
−                                % (etype, ','.join(eids)))
+
−        self.update_latest_retrieval(session)
+
−        return parser.stats
+
−
+
−    def process_urls(self, parser, urls, raise_on_error=False):
+
−        error = False
+
−        for url in urls:
+
−            self.info('pulling data from %s', url)
+
−            try:
+
−                if parser.process(url, raise_on_error):
+
−                    error = True
+
−            except IOError, exc:
+
−                if raise_on_error:
+
−                    raise
+
−                self.error('could not pull data while processing %s: %s',
+
−                           url, exc)
+
−                error = True
+
−            except Exception, exc:
+
−                if raise_on_error:
+
−                    raise
+
−                self.exception('error while processing %s: %s',
+
−                               url, exc)
+
−                error = True
+
−        return error
+
−
+
−    def before_entity_insertion(self, session, lid, etype, eid, sourceparams):
+
−        """called by the repository when an eid has been attributed for an
+
−        entity stored here but the entity has not been inserted in the system
+
−        table yet.
+
−
+
−        This method must return the an Entity instance representation of this
+
−        entity.
+
−        """
+
−        entity = super(DataFeedSource, self).before_entity_insertion(
+
−            session, lid, etype, eid, sourceparams)
+
−        entity.cw_edited['cwuri'] = lid.decode('utf-8')
+
−        entity.cw_edited.set_defaults()
+
−        sourceparams['parser'].before_entity_copy(entity, sourceparams)
+
−        return entity
+
−
+
−    def after_entity_insertion(self, session, lid, entity, sourceparams):
+
−        """called by the repository after an entity stored here has been
+
−        inserted in the system table.
+
−        """
+
−        if session.is_hook_category_activated('integrity'):
+
−            entity.cw_edited.check(creation=True)
+
−        self.repo.system_source.add_entity(session, entity)
+
−        entity.cw_edited.saved = entity._cw_is_saved = True
+
−        sourceparams['parser'].after_entity_copy(entity, sourceparams)
+
−
+
−    def source_cwuris(self, session):
+
−        sql = ('SELECT extid, eid, type FROM entities, cw_source_relation '
+
−               'WHERE entities.eid=cw_source_relation.eid_from '
+
−               'AND cw_source_relation.eid_to=%s' % self.eid)
+
−        return dict((b64decode(uri), (eid, type))
+
−                    for uri, eid, type in session.system_sql(sql))
+
−
+
−
+
−class DataFeedParser(AppObject):
+
−    __registry__ = 'parsers'
+
−
+
−    def __init__(self, session, source, sourceuris=None, **kwargs):
+
−        super(DataFeedParser, self).__init__(session, **kwargs)
+
−        self.source = source
+
−        self.sourceuris = sourceuris
+
−        self.stats = {'created': set(),
+
−                      'updated': set()}
+
−
+
−    def add_schema_config(self, schemacfg, checkonly=False):
+
−        """added CWSourceSchemaConfig, modify mapping accordingly"""
+
−        msg = schemacfg._cw._("this parser doesn't use a mapping")
+
−        raise ValidationError(schemacfg.eid, {None: msg})
+
−
+
−    def del_schema_config(self, schemacfg, checkonly=False):
+
−        """deleted CWSourceSchemaConfig, modify mapping accordingly"""
+
−        msg = schemacfg._cw._("this parser doesn't use a mapping")
+
−        raise ValidationError(schemacfg.eid, {None: msg})
+
−
+
−    def extid2entity(self, uri, etype, **sourceparams):
+
−        """return an entity for the given uri. May return None if it should be
+
−        skipped
+
−        """
+
−        session = self._cw
+
−        # if cwsource is specified and repository has a source with the same
+
−        # name, call extid2eid on that source so entity will be properly seen as
+
−        # coming from this source
+
−        source_uri = sourceparams.pop('cwsource', None)
+
−        if source_uri is not None and source_uri != 'system':
+
−            source = session.repo.sources_by_uri.get(source_uri, self.source)
+
−        else:
+
−            source = self.source
+
−        sourceparams['parser'] = self
+
−        if isinstance(uri, unicode):
+
−            uri = uri.encode('utf-8')
+
−        try:
+
−            eid = session.repo.extid2eid(source, str(uri), etype, session,
+
−                                         complete=False, commit=False,
+
−                                         sourceparams=sourceparams)
+
−        except ValidationError, ex:
+
−            self.source.error('error while creating %s: %s', etype, ex)
+
−            return None
+
−        if eid < 0:
+
−            # entity has been moved away from its original source
+
−            #
+
−            # Don't give etype to entity_from_eid so we get UnknownEid if the
+
−            # entity has been removed
+
−            try:
+
−                entity = session.entity_from_eid(-eid)
+
−            except UnknownEid:
+
−                return None
+
−            self.notify_updated(entity) # avoid later update from the source's data
+
−            return entity
+
−        if self.sourceuris is not None:
+
−            self.sourceuris.pop(str(uri), None)
+
−        return session.entity_from_eid(eid, etype)
+
−
+
−    def process(self, url, partialcommit=True):
+
−        """main callback: process the url"""
+
−        raise NotImplementedError
+
−
+
−    def before_entity_copy(self, entity, sourceparams):
+
−        raise NotImplementedError
+
−
+
−    def after_entity_copy(self, entity, sourceparams):
+
−        self.stats['created'].add(entity.eid)
+
−
+
−    def created_during_pull(self, entity):
+
−        return entity.eid in self.stats['created']
+
−
+
−    def updated_during_pull(self, entity):
+
−        return entity.eid in self.stats['updated']
+
−
+
−    def notify_updated(self, entity):
+
−        return self.stats['updated'].add(entity.eid)
+
−
+
−
+
−class DataFeedXMLParser(DataFeedParser):
+
−
+
−    def process(self, url, raise_on_error=False, partialcommit=True):
+
−        """IDataFeedParser main entry point"""
+
−        try:
+
−            parsed = self.parse(url)
+
−        except Exception, ex:
+
−            if raise_on_error:
+
−                raise
+
−            self.source.error(str(ex))
+
−            return True
+
−        error = False
+
−        for args in parsed:
+
−            try:
+
−                self.process_item(*args)
+
−                if partialcommit:
+
−                    # commit+set_cnxset instead of commit(free_cnxset=False) to let
+
−                    # other a chance to get our connections set
+
−                    self._cw.commit()
+
−                    self._cw.set_cnxset()
+
−            except ValidationError, exc:
+
−                if raise_on_error:
+
−                    raise
+
−                if partialcommit:
+
−                    self.source.error('Skipping %s because of validation error %s' % (args, exc))
+
−                    self._cw.rollback()
+
−                    self._cw.set_cnxset()
+
−                    error = True
+
−                else:
+
−                    raise
+
−        return error
+
−
+
−    def parse(self, url):
+
−        if url.startswith('http'):
+
−            from cubicweb.sobjects.parsers import URL_MAPPING
+
−            for mappedurl in URL_MAPPING:
+
−                if url.startswith(mappedurl):
+
−                    url = url.replace(mappedurl, URL_MAPPING[mappedurl], 1)
+
−                    break
+
−            self.source.info('GET %s', url)
+
−            stream = _OPENER.open(url)
+
−        elif url.startswith('file://'):
+
−            stream = open(url[7:])
+
−        else:
+
−            stream = StringIO.StringIO(url)
+
−        return self.parse_etree(etree.parse(stream).getroot())
+
−
+
−    def parse_etree(self, document):
+
−        return [(document,)]
+
−
+
−    def process_item(self, *args):
+
−        raise NotImplementedError
+
−
+
−# use a cookie enabled opener to use session cookie if any
+
−_OPENER = urllib2.build_opener()
+
−try:
+
−    from logilab.common import urllib2ext
+
−    _OPENER.add_handler(urllib2ext.HTTPGssapiAuthHandler())
+
−except ImportError: # python-kerberos not available
+
−    pass
+
−_OPENER.add_handler(urllib2.HTTPCookieProcessor(CookieJar()))