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| 1 | +<?php |
| 2 | +/* |
| 3 | + * |
| 4 | + * Copyright 2020 gRPC authors. |
| 5 | + * |
| 6 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | + * you may not use this file except in compliance with the License. |
| 8 | + * You may obtain a copy of the License at |
| 9 | + * |
| 10 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | + * |
| 12 | + * Unless required by applicable law or agreed to in writing, software |
| 13 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | + * See the License for the specific language governing permissions and |
| 16 | + * limitations under the License. |
| 17 | + * |
| 18 | + */ |
| 19 | + |
| 20 | +namespace Grpc; |
| 21 | + |
| 22 | +/** |
| 23 | + * This is an experimental and incomplete implementation of gRPC server |
| 24 | + * for PHP. APIs are _definitely_ going to be changed. |
| 25 | + * |
| 26 | + * DO NOT USE in production. |
| 27 | + */ |
| 28 | + |
| 29 | +/** |
| 30 | + * Class RpcServer |
| 31 | + * @package Grpc |
| 32 | + */ |
| 33 | +class RpcServer extends Server |
| 34 | +{ |
| 35 | + protected $call; |
| 36 | + // [ <String method_full_path> => [ |
| 37 | + // 'service' => <Object service>, |
| 38 | + // 'method' => <String method_name>, |
| 39 | + // 'request' => <Object request>, |
| 40 | + // ] ] |
| 41 | + protected $paths_map; |
| 42 | + |
| 43 | + private function waitForNextEvent() { |
| 44 | + return $this->requestCall(); |
| 45 | + } |
| 46 | + |
| 47 | + private function loadRequest($request) { |
| 48 | + if (!$this->call) { |
| 49 | + throw new Exception("serverCall is not ready"); |
| 50 | + } |
| 51 | + $event = $this->call->startBatch([ |
| 52 | + OP_RECV_MESSAGE => true, |
| 53 | + ]); |
| 54 | + if (!$event->message) { |
| 55 | + throw new Exception("Did not receive a proper message"); |
| 56 | + } |
| 57 | + $request->mergeFromString($event->message); |
| 58 | + return $request; |
| 59 | + } |
| 60 | + |
| 61 | + protected function sendOkResponse($response) { |
| 62 | + if (!$this->call) { |
| 63 | + throw new Exception("serverCall is not ready"); |
| 64 | + } |
| 65 | + $this->call->startBatch([ |
| 66 | + OP_SEND_INITIAL_METADATA => [], |
| 67 | + OP_SEND_MESSAGE => ['message' => |
| 68 | + $response->serializeToString()], |
| 69 | + OP_SEND_STATUS_FROM_SERVER => [ |
| 70 | + 'metadata' => [], |
| 71 | + 'code' => STATUS_OK, |
| 72 | + 'details' => 'OK', |
| 73 | + ], |
| 74 | + OP_RECV_CLOSE_ON_SERVER => true, |
| 75 | + ]); |
| 76 | + } |
| 77 | + |
| 78 | + /** |
| 79 | + * Add a service to this server |
| 80 | + * |
| 81 | + * @param Object $service The service to be added |
| 82 | + */ |
| 83 | + public function handle($service) { |
| 84 | + $rf = new \ReflectionClass($service); |
| 85 | + |
| 86 | + // If input does not have a parent class, which should be the |
| 87 | + // generated stub, don't proceeed. This might change in the |
| 88 | + // future. |
| 89 | + if (!$rf->getParentClass()) return; |
| 90 | + |
| 91 | + // The input class name needs to match the service name |
| 92 | + $service_name = $rf->getName(); |
| 93 | + $namespace = $rf->getParentClass()->getNamespaceName(); |
| 94 | + $prefix = ""; |
| 95 | + if ($namespace) { |
| 96 | + $parts = explode("\\", $namespace); |
| 97 | + foreach ($parts as $part) { |
| 98 | + $prefix .= lcfirst($part) . "."; |
| 99 | + } |
| 100 | + } |
| 101 | + $base_path = "/" . $prefix . $service_name; |
| 102 | + |
| 103 | + // Right now, assume all the methods in the class are RPC method |
| 104 | + // implementations. Might change in the future. |
| 105 | + $methods = $rf->getMethods(); |
| 106 | + foreach ($methods as $method) { |
| 107 | + $method_name = $method->getName(); |
| 108 | + $full_path = $base_path . "/" . ucfirst($method_name); |
| 109 | + |
| 110 | + $method_params = $method->getParameters(); |
| 111 | + // RPC should have exactly 1 request param |
| 112 | + if (count($method_params) != 1) continue; |
| 113 | + $request_param = $method_params[0]; |
| 114 | + // Method implementation must have type hint for request param |
| 115 | + if (!$request_param->getType()) continue; |
| 116 | + $request_type = $request_param->getType()->getName(); |
| 117 | + |
| 118 | + // $full_path needs to match the incoming event->method |
| 119 | + // from requestCall() for us to know how to handle the request |
| 120 | + $this->paths_map[$full_path] = [ |
| 121 | + 'service' => $service, |
| 122 | + 'method' => $method_name, |
| 123 | + 'request' => new $request_type(), |
| 124 | + ]; |
| 125 | + } |
| 126 | + } |
| 127 | + |
| 128 | + public function run() { |
| 129 | + $this->start(); |
| 130 | + while (true) { |
| 131 | + // This blocks until the server receives a request |
| 132 | + $event = $this->waitForNextEvent(); |
| 133 | + if (!$event) { |
| 134 | + throw new Exception( |
| 135 | + "Unexpected error: server->waitForNextEvent delivers" |
| 136 | + . " an empty event"); |
| 137 | + } |
| 138 | + if (!$event->call) { |
| 139 | + throw new Exception( |
| 140 | + "Unexpected error: server->waitForNextEvent delivers" |
| 141 | + . " an event without a call"); |
| 142 | + } |
| 143 | + $this->call = $event->call; |
| 144 | + $full_path = $event->method; |
| 145 | + |
| 146 | + // TODO: Can send a proper UNIMPLEMENTED response in the future |
| 147 | + if (!array_key_exists($full_path, $this->paths_map)) continue; |
| 148 | + |
| 149 | + $service = $this->paths_map[$full_path]['service']; |
| 150 | + $method = $this->paths_map[$full_path]['method']; |
| 151 | + $request = $this->paths_map[$full_path]['request']; |
| 152 | + |
| 153 | + $request = $this->loadRequest($request); |
| 154 | + if (!$request) { |
| 155 | + throw new Exception("Unexpected error: fail to parse request"); |
| 156 | + } |
| 157 | + if (!method_exists($service, $method)) { |
| 158 | + // TODO: Can send a proper UNIMPLEMENTED response in the future |
| 159 | + throw new Exception("Method not implemented"); |
| 160 | + } |
| 161 | + |
| 162 | + // Dispatch to actual server logic |
| 163 | + $response = $service->$method($request); |
| 164 | + $this->sendOkResponse($response); |
| 165 | + $this->call = null; |
| 166 | + } |
| 167 | + } |
| 168 | +} |
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