def _setup_data_stream(self,log,callback,start,end,extended,meta=None): if meta is None: meta = {} stream = StreamingTupleWithCallback(callback,self._get_stream_length) stream.set_meta('begin',start) stream.set_meta('end',end) stream.set_meta('log', log) stream.set_meta('extended', extended) positive = {'index':0} negative = {'index':-1} positive['seek'] = start log.seek(end) line = _readline_backwards(log) negative['seek'] = log.tell() positive['last'] = None negative['last'] = None stream.set_meta('positive',positive) stream.set_meta('negative',negative) stream.get_meta().update(meta) try: callback(-1,stream) callback(0,stream) except IndexError: pass return stream
def get_slice(self,column,start,end): stream = StreamingTupleWithCallback(self._get_item_callback, self._get_length_callback) stream.set_meta('data',PeriodicLog.get_slice(self,column,start,end,1)) return stream