| ################################################################################ |
| # 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. |
| ################################################################################ |
| from messages_pb2 import SeenCount, GreetRequest, GreetResponse |
| |
| from statefun import StatefulFunctions |
| from statefun import RequestReplyHandler |
| from statefun import kafka_egress_record |
| |
| functions = StatefulFunctions() |
| |
| |
| @functions.bind("example/greeter") |
| def greet(context, greet_request: GreetRequest): |
| state = context.state('seen_count').unpack(SeenCount) |
| if not state: |
| state = SeenCount() |
| state.seen = 1 |
| else: |
| state.seen += 1 |
| context.state('seen_count').pack(state) |
| |
| response = compute_greeting(greet_request.name, state.seen) |
| |
| egress_message = kafka_egress_record(topic="greetings", key=greet_request.name, value=response) |
| context.pack_and_send_egress("example/greets", egress_message) |
| |
| |
| def compute_greeting(name, seen): |
| """ |
| Compute a personalized greeting, based on the number of times this @name had been seen before. |
| """ |
| templates = ["", "Welcome %s", "Nice to see you again %s", "Third time is a charm %s"] |
| if seen < len(templates): |
| greeting = templates[seen] % name |
| else: |
| greeting = "Nice to see you at the %d-nth time %s!" % (seen, name) |
| |
| response = GreetResponse() |
| response.name = name |
| response.greeting = greeting |
| |
| return response |
| |
| |
| handler = RequestReplyHandler(functions) |
| |
| # |
| # Serve the endpoint |
| # |
| |
| from flask import request |
| from flask import make_response |
| from flask import Flask |
| |
| app = Flask(__name__) |
| |
| |
| @app.route('/statefun', methods=['POST']) |
| def handle(): |
| response_data = handler(request.data) |
| response = make_response(response_data) |
| response.headers.set('Content-Type', 'application/octet-stream') |
| return response |
| |
| |
| if __name__ == "__main__": |
| app.run() |