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| # Licensed to the Apache Software Foundation (ASF) under one | |
| # or more contributor license agreements. See the NOTICE file | |
| # distributed with this work for additional information | |
| # regarding copyright ownership. The ASF licenses this file | |
| # to you under the Apache License, Version 2.0 (the | |
| # "License"); you may not use this file except in compliance | |
| # with the License. You may obtain a copy of the License at | |
| # | |
| # http://www.apache.org/licenses/LICENSE-2.0 | |
| # | |
| # Unless required by applicable law or agreed to in writing, | |
| # software distributed under the License is distributed on an | |
| # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| # KIND, either express or implied. See the License for the | |
| # specific language governing permissions and limitations | |
| # under the License. | |
| """An example Flight Python server.""" | |
| import argparse | |
| import ast | |
| import threading | |
| import time | |
| import pyarrow | |
| import pyarrow.flight | |
| class FlightServer(pyarrow.flight.FlightServerBase): | |
| def __init__(self, host="localhost", location=None, | |
| tls_certificates=None, verify_client=False, | |
| root_certificates=None, auth_handler=None): | |
| super(FlightServer, self).__init__( | |
| location, auth_handler, tls_certificates, verify_client, | |
| root_certificates) | |
| self.flights = {} | |
| self.host = host | |
| self.tls_certificates = tls_certificates | |
| def descriptor_to_key(self, descriptor): | |
| return (descriptor.descriptor_type.value, descriptor.command, | |
| tuple(descriptor.path or tuple())) | |
| def _make_flight_info(self, key, descriptor, table): | |
| if self.tls_certificates: | |
| location = pyarrow.flight.Location.for_grpc_tls( | |
| self.host, self.port) | |
| else: | |
| location = pyarrow.flight.Location.for_grpc_tcp( | |
| self.host, self.port) | |
| endpoints = [pyarrow.flight.FlightEndpoint(repr(key), [location]), ] | |
| mock_sink = pyarrow.MockOutputStream() | |
| stream_writer = pyarrow.RecordBatchStreamWriter( | |
| mock_sink, table.schema) | |
| stream_writer.write_table(table) | |
| stream_writer.close() | |
| data_size = mock_sink.size() | |
| return pyarrow.flight.FlightInfo(table.schema, | |
| descriptor, endpoints, | |
| table.num_rows, data_size) | |
| def list_flights(self, context, criteria): | |
| for key, table in self.flights.items(): | |
| if key[1] is not None: | |
| descriptor = \ | |
| pyarrow.flight.FlightDescriptor.for_command(key[1]) | |
| else: | |
| descriptor = pyarrow.flight.FlightDescriptor.for_path(*key[2]) | |
| yield self._make_flight_info(key, descriptor, table) | |
| def get_flight_info(self, context, descriptor): | |
| key = FlightServer.descriptor_to_key(descriptor) | |
| if key in self.flights: | |
| table = self.flights[key] | |
| return self._make_flight_info(key, descriptor, table) | |
| raise KeyError('Flight not found.') | |
| def do_put(self, context, descriptor, reader, writer): | |
| key = FlightServer.descriptor_to_key(descriptor) | |
| print(key) | |
| self.flights[key] = reader.read_all() | |
| print(self.flights[key]) | |
| def do_get(self, context, ticket): | |
| key = ast.literal_eval(ticket.ticket.decode()) | |
| if key not in self.flights: | |
| return None | |
| return pyarrow.flight.RecordBatchStream(self.flights[key]) | |
| def list_actions(self, context): | |
| return [ | |
| ("clear", "Clear the stored flights."), | |
| ("shutdown", "Shut down this server."), | |
| ] | |
| def do_action(self, context, action): | |
| if action.type == "clear": | |
| raise NotImplementedError( | |
| "{} is not implemented.".format(action.type)) | |
| elif action.type == "healthcheck": | |
| pass | |
| elif action.type == "shutdown": | |
| yield pyarrow.flight.Result(pyarrow.py_buffer(b'Shutdown!')) | |
| # Shut down on background thread to avoid blocking current | |
| # request | |
| threading.Thread(target=self._shutdown).start() | |
| else: | |
| raise KeyError("Unknown action {!r}".format(action.type)) | |
| def _shutdown(self): | |
| """Shut down after a delay.""" | |
| print("Server is shutting down...") | |
| time.sleep(2) | |
| self.shutdown() | |
| def main(): | |
| parser = argparse.ArgumentParser() | |
| parser.add_argument("--host", type=str, default="localhost", | |
| help="Address or hostname to listen on") | |
| parser.add_argument("--port", type=int, default=5005, | |
| help="Port number to listen on") | |
| parser.add_argument("--tls", nargs=2, default=None, | |
| metavar=('CERTFILE', 'KEYFILE'), | |
| help="Enable transport-level security") | |
| parser.add_argument("--verify_client", type=bool, default=False, | |
| help="enable mutual TLS and verify the client if True") | |
| args = parser.parse_args() | |
| tls_certificates = [] | |
| scheme = "grpc+tcp" | |
| if args.tls: | |
| scheme = "grpc+tls" | |
| with open(args.tls[0], "rb") as cert_file: | |
| tls_cert_chain = cert_file.read() | |
| with open(args.tls[1], "rb") as key_file: | |
| tls_private_key = key_file.read() | |
| tls_certificates.append((tls_cert_chain, tls_private_key)) | |
| location = "{}://{}:{}".format(scheme, args.host, args.port) | |
| server = FlightServer(args.host, location, | |
| tls_certificates=tls_certificates, | |
| verify_client=args.verify_client) | |
| print("Serving on", location) | |
| server.serve() | |
| if __name__ == '__main__': | |
| main() | |