+
−"""provide an abstract class for external sources using a sqlite database helper
+
−
+
−:organization: Logilab
+
−:copyright: 2007-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
+
−:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
+
−:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
+
−"""
+
−__docformat__ = "restructuredtext en"
+
−
+
−
+
−from os.path import join, exists
+
−
+
−from cubicweb import server
+
−from cubicweb.server.sqlutils import SQL_PREFIX, SQLAdapterMixIn, sqlexec
+
−from cubicweb.server.sources import native, rql2sql
+
−from cubicweb.server.sources import AbstractSource, dbg_st_search, dbg_results
+
−
+
−class ConnectionWrapper(object):
+
−    def __init__(self, source=None):
+
−        self.source = source
+
−        self._cnx = None
+
−
+
−    @property
+
−    def logged_user(self):
+
−        if self._cnx is None:
+
−            self._cnx = self.source._sqlcnx
+
−        return self._cnx.logged_user
+
−
+
−    def cursor(self):
+
−        if self._cnx is None:
+
−            self._cnx = self.source._sqlcnx
+
−            if server.DEBUG & server.DBG_SQL:
+
−                print 'sql cnx OPEN', self._cnx
+
−        return self._cnx.cursor()
+
−
+
−    def commit(self):
+
−        if self._cnx is not None:
+
−            if server.DEBUG & (server.DBG_SQL | server.DBG_RQL):
+
−                print 'sql cnx COMMIT', self._cnx
+
−            self._cnx.commit()
+
−
+
−    def rollback(self):
+
−        if self._cnx is not None:
+
−            if server.DEBUG & (server.DBG_SQL | server.DBG_RQL):
+
−                print 'sql cnx ROLLBACK', self._cnx
+
−            self._cnx.rollback()
+
−
+
−    def close(self):
+
−        if self._cnx is not None:
+
−            if server.DEBUG & server.DBG_SQL:
+
−                print 'sql cnx CLOSE', self._cnx
+
−            self._cnx.close()
+
−            self._cnx = None
+
−
+
−
+
−class SQLiteAbstractSource(AbstractSource):
+
−    """an abstract class for external sources using a sqlite database helper
+
−    """
+
−    sqlgen_class = rql2sql.SQLGenerator
+
−    @classmethod
+
−    def set_nonsystem_types(cls):
+
−        # those entities are only in this source, we don't want them in the
+
−        # system source
+
−        for etype in cls.support_entities:
+
−            native.NONSYSTEM_ETYPES.add(etype)
+
−        for rtype in cls.support_relations:
+
−            native.NONSYSTEM_RELATIONS.add(rtype)
+
−
+
−    options = (
+
−        ('helper-db-path',
+
−         {'type' : 'string',
+
−          'default': None,
+
−          'help': 'path to the sqlite database file used to do queries on the \
+
−repository.',
+
−          'inputlevel': 2,
+
−          }),
+
−    )
+
−
+
−    def __init__(self, repo, appschema, source_config, *args, **kwargs):
+
−        # the helper db is used to easy querying and will store everything but
+
−        # actual file content
+
−        dbpath = source_config.get('helper-db-path')
+
−        if dbpath is None:
+
−            dbpath = join(repo.config.appdatahome,
+
−                          '%(uri)s.sqlite' % source_config)
+
−        self.dbpath = dbpath
+
−        self.sqladapter = SQLAdapterMixIn({'db-driver': 'sqlite',
+
−                                           'db-name': dbpath})
+
−        # those attributes have to be initialized before ancestor's __init__
+
−        # which will call set_schema
+
−        self._need_sql_create = not exists(dbpath)
+
−        self._need_full_import = self._need_sql_create
+
−        AbstractSource.__init__(self, repo, appschema, source_config,
+
−                                *args, **kwargs)
+
−
+
−    def backup(self, backupfile):
+
−        """method called to create a backup of the source's data"""
+
−        self.close_pool_connections()
+
−        try:
+
−            self.sqladapter.backup_to_file(backupfile)
+
−        finally:
+
−            self.open_pool_connections()
+
−
+
−    def restore(self, backupfile, confirm, drop):
+
−        """method called to restore a backup of source's data"""
+
−        self.close_pool_connections()
+
−        try:
+
−            self.sqladapter.restore_from_file(backupfile, confirm, drop)
+
−        finally:
+
−            self.open_pool_connections()
+
−
+
−    @property
+
−    def _sqlcnx(self):
+
−        # XXX: sqlite connections can only be used in the same thread, so
+
−        #      create a new one each time necessary. If it appears to be time
+
−        #      consuming, find another way
+
−        return self.sqladapter.get_connection()
+
−
+
−    def _is_schema_complete(self):
+
−        for etype in self.support_entities:
+
−            if not etype in self.schema:
+
−                self.warning('not ready to generate %s database, %s support missing from schema',
+
−                             self.uri, etype)
+
−                return False
+
−        for rtype in self.support_relations:
+
−            if not rtype in self.schema:
+
−                self.warning('not ready to generate %s database, %s support missing from schema',
+
−                             self.uri, rtype)
+
−                return False
+
−        return True
+
−
+
−    def _create_database(self):
+
−        from yams.schema2sql import eschema2sql, rschema2sql
+
−        from cubicweb.toolsutils import restrict_perms_to_user
+
−        self.warning('initializing sqlite database for %s source' % self.uri)
+
−        cnx = self._sqlcnx
+
−        cu = cnx.cursor()
+
−        schema = self.schema
+
−        for etype in self.support_entities:
+
−            eschema = schema.eschema(etype)
+
−            createsqls = eschema2sql(self.sqladapter.dbhelper, eschema,
+
−                                     skip_relations=('data',), prefix=SQL_PREFIX)
+
−            sqlexec(createsqls, cu, withpb=False)
+
−        for rtype in self.support_relations:
+
−            rschema = schema.rschema(rtype)
+
−            if not rschema.inlined:
+
−                sqlexec(rschema2sql(rschema), cu, withpb=False)
+
−        cnx.commit()
+
−        cnx.close()
+
−        self._need_sql_create = False
+
−        if self.repo.config['uid']:
+
−            from logilab.common.shellutils import chown
+
−            # database file must be owned by the uid of the server process
+
−            self.warning('set %s as owner of the database file',
+
−                         self.repo.config['uid'])
+
−            chown(self.dbpath, self.repo.config['uid'])
+
−        restrict_perms_to_user(self.dbpath, self.info)
+
−
+
−    def set_schema(self, schema):
+
−        super(SQLiteAbstractSource, self).set_schema(schema)
+
−        if self._need_sql_create and self._is_schema_complete() and self.dbpath:
+
−            self._create_database()
+
−        self.rqlsqlgen = self.sqlgen_class(schema, self.sqladapter.dbhelper)
+
−
+
−    def get_connection(self):
+
−        return ConnectionWrapper(self)
+
−
+
−    def check_connection(self, cnx):
+
−        """check connection validity, return None if the connection is still valid
+
−        else a new connection (called when the pool using the given connection is
+
−        being attached to a session)
+
−
+
−        always return the connection to reset eventually cached cursor
+
−        """
+
−        return cnx
+
−
+
−    def pool_reset(self, cnx):
+
−        """the pool using the given connection is being reseted from its current
+
−        attached session: release the connection lock if the connection wrapper
+
−        has a connection set
+
−        """
+
−        # reset _cnx to ensure next thread using cnx will get a new
+
−        # connection
+
−        cnx.close()
+
−
+
−    def syntax_tree_search(self, session, union, args=None, cachekey=None,
+
−                           varmap=None):
+
−        """return result from this source for a rql query (actually from a rql
+
−        syntax tree and a solution dictionary mapping each used variable to a
+
−        possible type). If cachekey is given, the query necessary to fetch the
+
−        results (but not the results themselves) may be cached using this key.
+
−        """
+
−        if self._need_sql_create:
+
−            return []
+
−        assert dbg_st_search(self.uri, union, varmap, args, cachekey)
+
−        sql, query_args = self.rqlsqlgen.generate(union, args)
+
−        args = self.sqladapter.merge_args(args, query_args)
+
−        results = self.sqladapter.process_result(self.doexec(session, sql, args))
+
−        assert dbg_results(results)
+
−        return results
+
−
+
−    def local_add_entity(self, session, entity):
+
−        """insert the entity in the local database.
+
−
+
−        This is not provided as add_entity implementation since usually source
+
−        don't want to simply do this, so let raise NotImplementedError and the
+
−        source implementor may use this method if necessary
+
−        """
+
−        attrs = self.sqladapter.preprocess_entity(entity)
+
−        sql = self.sqladapter.sqlgen.insert(SQL_PREFIX + str(entity.e_schema), attrs)
+
−        self.doexec(session, sql, attrs)
+
−
+
−    def add_entity(self, session, entity):
+
−        """add a new entity to the source"""
+
−        raise NotImplementedError()
+
−
+
−    def local_update_entity(self, session, entity, attrs=None):
+
−        """update an entity in the source
+
−
+
−        This is not provided as update_entity implementation since usually
+
−        source don't want to simply do this, so let raise NotImplementedError
+
−        and the source implementor may use this method if necessary
+
−        """
+
−        if attrs is None:
+
−            attrs = self.sqladapter.preprocess_entity(entity)
+
−        sql = self.sqladapter.sqlgen.update(SQL_PREFIX + str(entity.e_schema),
+
−                                            attrs, [SQL_PREFIX + 'eid'])
+
−        self.doexec(session, sql, attrs)
+
−
+
−    def update_entity(self, session, entity):
+
−        """update an entity in the source"""
+
−        raise NotImplementedError()
+
−
+
−    def delete_entity(self, session, etype, eid):
+
−        """delete an entity from the source
+
−
+
−        this is not deleting a file in the svn but deleting entities from the
+
−        source. Main usage is to delete repository content when a Repository
+
−        entity is deleted.
+
−        """
+
−        attrs = {SQL_PREFIX + 'eid': eid}
+
−        sql = self.sqladapter.sqlgen.delete(SQL_PREFIX + etype, attrs)
+
−        self.doexec(session, sql, attrs)
+
−
+
−    def local_add_relation(self, session, subject, rtype, object):
+
−        """add a relation to the source
+
−
+
−        This is not provided as add_relation implementation since usually
+
−        source don't want to simply do this, so let raise NotImplementedError
+
−        and the source implementor may use this method if necessary
+
−        """
+
−        attrs = {'eid_from': subject, 'eid_to': object}
+
−        sql = self.sqladapter.sqlgen.insert('%s_relation' % rtype, attrs)
+
−        self.doexec(session, sql, attrs)
+
−
+
−    def add_relation(self, session, subject, rtype, object):
+
−        """add a relation to the source"""
+
−        raise NotImplementedError()
+
−
+
−    def delete_relation(self, session, subject, rtype, object):
+
−        """delete a relation from the source"""
+
−        rschema = self.schema.rschema(rtype)
+
−        if rschema.inlined:
+
−            if subject in session.transaction_data.get('pendingeids', ()):
+
−                return
+
−            table = SQL_PREFIX + session.describe(subject)[0]
+
−            column = SQL_PREFIX + rtype
+
−            sql = 'UPDATE %s SET %s=NULL WHERE %seid=%%(eid)s' % (table, column, SQL_PREFIX)
+
−            attrs = {'eid' : subject}
+
−        else:
+
−            attrs = {'eid_from': subject, 'eid_to': object}
+
−            sql = self.sqladapter.sqlgen.delete('%s_relation' % rtype, attrs)
+
−        self.doexec(session, sql, attrs)
+
−
+
−    def doexec(self, session, query, args=None):
+
−        """Execute a query.
+
−        it's a function just so that it shows up in profiling
+
−        """
+
−        if server.DEBUG:
+
−            print 'exec', query, args
+
−        cursor = session.pool[self.uri]
+
−        try:
+
−            # str(query) to avoid error if it's an unicode string
+
−            cursor.execute(str(query), args)
+
−        except Exception, ex:
+
−            self.critical("sql: %r\n args: %s\ndbms message: %r",
+
−                          query, args, ex.args[0])
+
−            try:
+
−                session.pool.connection(self.uri).rollback()
+
−                self.critical('transaction has been rollbacked')
+
−            except:
+
−                pass
+
−            raise
+
−        return cursor