| import logging |
| import messages_pb2 |
| import struct |
| |
| import h2 |
| import h2.connection |
| import twisted |
| import twisted.internet |
| import twisted.internet.protocol |
| |
| _READ_CHUNK_SIZE = 16384 |
| _GRPC_HEADER_SIZE = 5 |
| |
| class H2ProtocolBaseServer(twisted.internet.protocol.Protocol): |
| def __init__(self): |
| self._conn = h2.connection.H2Connection(client_side=False) |
| self._recv_buffer = {} |
| self._handlers = {} |
| self._handlers['ConnectionMade'] = self.on_connection_made_default |
| self._handlers['DataReceived'] = self.on_data_received_default |
| self._handlers['WindowUpdated'] = self.on_window_update_default |
| self._handlers['RequestReceived'] = self.on_request_received_default |
| self._handlers['SendDone'] = self.on_send_done_default |
| self._handlers['ConnectionLost'] = self.on_connection_lost |
| self._handlers['PingAcknowledged'] = self.on_ping_acknowledged_default |
| self._stream_status = {} |
| self._send_remaining = {} |
| self._outstanding_pings = 0 |
| |
| def set_handlers(self, handlers): |
| self._handlers = handlers |
| |
| def connectionMade(self): |
| self._handlers['ConnectionMade']() |
| |
| def connectionLost(self, reason): |
| self._handlers['ConnectionLost'](reason) |
| |
| def on_connection_made_default(self): |
| logging.info('Connection Made') |
| self._conn.initiate_connection() |
| self.transport.setTcpNoDelay(True) |
| self.transport.write(self._conn.data_to_send()) |
| |
| def on_connection_lost(self, reason): |
| logging.info('Disconnected %s' % reason) |
| twisted.internet.reactor.callFromThread(twisted.internet.reactor.stop) |
| |
| def dataReceived(self, data): |
| try: |
| events = self._conn.receive_data(data) |
| except h2.exceptions.ProtocolError: |
| # this try/except block catches exceptions due to race between sending |
| # GOAWAY and processing a response in flight. |
| return |
| if self._conn.data_to_send: |
| self.transport.write(self._conn.data_to_send()) |
| for event in events: |
| if isinstance(event, h2.events.RequestReceived) and self._handlers.has_key('RequestReceived'): |
| logging.info('RequestReceived Event for stream: %d' % event.stream_id) |
| self._handlers['RequestReceived'](event) |
| elif isinstance(event, h2.events.DataReceived) and self._handlers.has_key('DataReceived'): |
| logging.info('DataReceived Event for stream: %d' % event.stream_id) |
| self._handlers['DataReceived'](event) |
| elif isinstance(event, h2.events.WindowUpdated) and self._handlers.has_key('WindowUpdated'): |
| logging.info('WindowUpdated Event for stream: %d' % event.stream_id) |
| self._handlers['WindowUpdated'](event) |
| elif isinstance(event, h2.events.PingAcknowledged) and self._handlers.has_key('PingAcknowledged'): |
| logging.info('PingAcknowledged Event') |
| self._handlers['PingAcknowledged'](event) |
| self.transport.write(self._conn.data_to_send()) |
| |
| def on_ping_acknowledged_default(self, event): |
| logging.info('ping acknowledged') |
| self._outstanding_pings -= 1 |
| |
| def on_data_received_default(self, event): |
| self._conn.acknowledge_received_data(len(event.data), event.stream_id) |
| self._recv_buffer[event.stream_id] += event.data |
| |
| def on_request_received_default(self, event): |
| self._recv_buffer[event.stream_id] = '' |
| self._stream_id = event.stream_id |
| self._stream_status[event.stream_id] = True |
| self._conn.send_headers( |
| stream_id=event.stream_id, |
| headers=[ |
| (':status', '200'), |
| ('content-type', 'application/grpc'), |
| ('grpc-encoding', 'identity'), |
| ('grpc-accept-encoding', 'identity,deflate,gzip'), |
| ], |
| ) |
| self.transport.write(self._conn.data_to_send()) |
| |
| def on_window_update_default(self, event): |
| # send pending data, if any |
| self.default_send(event.stream_id) |
| |
| def send_reset_stream(self): |
| self._conn.reset_stream(self._stream_id) |
| self.transport.write(self._conn.data_to_send()) |
| |
| def setup_send(self, data_to_send, stream_id): |
| logging.info('Setting up data to send for stream_id: %d' % stream_id) |
| self._send_remaining[stream_id] = len(data_to_send) |
| self._send_offset = 0 |
| self._data_to_send = data_to_send |
| self.default_send(stream_id) |
| |
| def default_send(self, stream_id): |
| if not self._send_remaining.has_key(stream_id): |
| # not setup to send data yet |
| return |
| |
| while self._send_remaining[stream_id] > 0: |
| lfcw = self._conn.local_flow_control_window(stream_id) |
| if lfcw == 0: |
| break |
| chunk_size = min(lfcw, _READ_CHUNK_SIZE) |
| bytes_to_send = min(chunk_size, self._send_remaining[stream_id]) |
| logging.info('flow_control_window = %d. sending [%d:%d] stream_id %d' % |
| (lfcw, self._send_offset, self._send_offset + bytes_to_send, |
| stream_id)) |
| data = self._data_to_send[self._send_offset : self._send_offset + bytes_to_send] |
| try: |
| self._conn.send_data(stream_id, data, False) |
| except h2.exceptions.ProtocolError: |
| logging.info('Stream %d is closed' % stream_id) |
| break |
| self._send_remaining[stream_id] -= bytes_to_send |
| self._send_offset += bytes_to_send |
| if self._send_remaining[stream_id] == 0: |
| self._handlers['SendDone'](stream_id) |
| |
| def default_ping(self): |
| logging.info('sending ping') |
| self._outstanding_pings += 1 |
| self._conn.ping(b'\x00'*8) |
| self.transport.write(self._conn.data_to_send()) |
| |
| def on_send_done_default(self, stream_id): |
| if self._stream_status[stream_id]: |
| self._stream_status[stream_id] = False |
| self.default_send_trailer(stream_id) |
| else: |
| logging.error('Stream %d is already closed' % stream_id) |
| |
| def default_send_trailer(self, stream_id): |
| logging.info('Sending trailer for stream id %d' % stream_id) |
| self._conn.send_headers(stream_id, |
| headers=[ ('grpc-status', '0') ], |
| end_stream=True |
| ) |
| self.transport.write(self._conn.data_to_send()) |
| |
| @staticmethod |
| def default_response_data(response_size): |
| sresp = messages_pb2.SimpleResponse() |
| sresp.payload.body = b'\x00'*response_size |
| serialized_resp_proto = sresp.SerializeToString() |
| response_data = b'\x00' + struct.pack('i', len(serialized_resp_proto))[::-1] + serialized_resp_proto |
| return response_data |
| |
| def parse_received_data(self, stream_id): |
| """ returns a grpc framed string of bytes containing response proto of the size |
| asked in request """ |
| recv_buffer = self._recv_buffer[stream_id] |
| grpc_msg_size = struct.unpack('i',recv_buffer[1:5][::-1])[0] |
| if len(recv_buffer) != _GRPC_HEADER_SIZE + grpc_msg_size: |
| return None |
| req_proto_str = recv_buffer[5:5+grpc_msg_size] |
| sr = messages_pb2.SimpleRequest() |
| sr.ParseFromString(req_proto_str) |
| logging.info('Parsed request for stream %d: response_size=%s' % (stream_id, sr.response_size)) |
| return sr |