1 # Copyright 2019 the gRPC authors. 2 # 3 # Licensed under the Apache License, Version 2.0 (the "License"); 4 # you may not use this file except in compliance with the License. 5 # You may obtain a copy of the License at 6 # 7 # http://www.apache.org/licenses/LICENSE-2.0 8 # 9 # Unless required by applicable law or agreed to in writing, software 10 # distributed under the License is distributed on an "AS IS" BASIS, 11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 # See the License for the specific language governing permissions and 13 # limitations under the License. 14 """An example of cancelling requests in gRPC.""" 15 16 from __future__ import absolute_import 17 from __future__ import division 18 from __future__ import print_function 19 20 import argparse 21 import logging 22 import signal 23 import sys 24 25 import grpc 26 27 from examples.python.cancellation import hash_name_pb2 28 from examples.python.cancellation import hash_name_pb2_grpc 29 30 _DESCRIPTION = "A client for finding hashes similar to names." 31 _LOGGER = logging.getLogger(__name__) 32 33 34 def run_unary_client(server_target, name, ideal_distance): 35 with grpc.insecure_channel(server_target) as channel: 36 stub = hash_name_pb2_grpc.HashFinderStub(channel) 37 future = stub.Find.future( 38 hash_name_pb2.HashNameRequest( 39 desired_name=name, ideal_hamming_distance=ideal_distance 40 ), 41 wait_for_ready=True, 42 ) 43 44 def cancel_request(unused_signum, unused_frame): 45 future.cancel() 46 sys.exit(0) 47 48 signal.signal(signal.SIGINT, cancel_request) 49 result = future.result() 50 print(result) 51 52 53 def run_streaming_client( 54 server_target, name, ideal_distance, interesting_distance 55 ): 56 with grpc.insecure_channel(server_target) as channel: 57 stub = hash_name_pb2_grpc.HashFinderStub(channel) 58 result_generator = stub.FindRange( 59 hash_name_pb2.HashNameRequest( 60 desired_name=name, 61 ideal_hamming_distance=ideal_distance, 62 interesting_hamming_distance=interesting_distance, 63 ), 64 wait_for_ready=True, 65 ) 66 67 def cancel_request(unused_signum, unused_frame): 68 result_generator.cancel() 69 sys.exit(0) 70 71 signal.signal(signal.SIGINT, cancel_request) 72 for result in result_generator: 73 print(result) 74 75 76 def main(): 77 parser = argparse.ArgumentParser(description=_DESCRIPTION) 78 parser.add_argument("name", type=str, help="The desired name.") 79 parser.add_argument( 80 "--ideal-distance", 81 default=0, 82 nargs="?", 83 type=int, 84 help="The desired Hamming distance.", 85 ) 86 parser.add_argument( 87 "--server", 88 default="localhost:50051", 89 type=str, 90 nargs="?", 91 help="The host-port pair at which to reach the server.", 92 ) 93 parser.add_argument( 94 "--show-inferior", 95 default=None, 96 type=int, 97 nargs="?", 98 help=( 99 "Also show candidates with a Hamming distance less than this value." 100 ), 101 ) 102 103 args = parser.parse_args() 104 if args.show_inferior is not None: 105 run_streaming_client( 106 args.server, args.name, args.ideal_distance, args.show_inferior 107 ) 108 else: 109 run_unary_client(args.server, args.name, args.ideal_distance) 110 111 112 if __name__ == "__main__": 113 logging.basicConfig() 114 main() 115