zeroc ICE 使用案例

此處案例將ICE接口當做單servant使用（ICE自帶端口復用的多servant，過於復雜，此處不討論）

使用ICE較為方便的地方時 可以編寫 ice中間代碼，然后由官方工具轉換為目標平台代碼（通過語句自動生成），生產的代碼結構比較復雜，不贅述，此處需要注意一點，自動生成的文件夾路徑不要包含特殊字符。

ICE的使用概念與傳統的RPC框架沒有差異。過程如下：

1、由某一方建立監聽，作為通訊宿主（習慣稱之為服務器）

2、由另外一方建立鏈接到服務器（習慣稱之為客戶端）

3、客戶端向服務器注冊自己的信息（可能會有多個客戶端，意味着可以注冊多個客戶，服務器需要存儲）

4、雙向自由互調。

其中雙向互調過程中，主動發起調用方名義上都叫做 client ，提供服務方 都叫做 servant。

雙方需要有一個約定，即上面提到的自動生成的 <interface>Disp_ 抽象類，作為雙方統一接口。雙方均需要定義自己的服務去實現該抽象類（client/servant 作用不同，實現的方式自然不同）。

為了滿足多個不同端口不通服務使用，筆者對客戶端和服務器進行了簡單封裝，如下

需要改進重連機制

public class ICEClient<T,TPrx>
    {
        public TPrx Server { get; private set; }

        public bool Online { get; private set; }

        ILog _Logger = Spv2LoggerFactory.GetLoggerByName("RPC");

        string _IPAddress;
        int _Port;
        int connectTimeout = 60000;
        int idleTimeout = -1;  //no limit

        public ICEClient(string ip, int port)
        {
            _IPAddress = ip;
            _Port = port;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="Servant"> 作為服務端接收指令響應</param>
        public void Connect(T Servant=default(T))
        {
            if (Online)
            {
                _Logger.InfoFormat("Initializing,  Online!");
                return;
            }
            try
            {
                _Logger.InfoFormat("Initializing ICE Comm using Host: {0}, Port: {1}, connectTimeout: {2}, idleTimeout: {3}",
                    _IPAddress, _Port, connectTimeout, idleTimeout);

                // TODO figure out how to use properties.
                Ice.InitializationData id = new Ice.InitializationData();
                id.properties = Ice.Util.createProperties();
                id.properties.setProperty("Ice.Default.ConnectTimeout", connectTimeout.ToString());
                id.properties.setProperty("Ice.Default.Timeout", idleTimeout.ToString()); // 5 min?
                id.properties.setProperty("Ice.Warn.UnusedProperties", "1");
                id.properties.setProperty("Ice.Warn.Host", _IPAddress);

                var _ICEComm = Ice.Util.initialize(id);

                string connectString = String.Format("{0}:tcp -p {1} -h {2}", typeof(T).Name, _Port, _IPAddress);
                ObjectPrx iceProxy = _ICEComm.stringToProxy(connectString);

                Server = CreateServerProxy(iceProxy);

                _Logger.InfoFormat("ICE check proxy cast finished. {0}", _IPAddress);
                if (Server == null)
                {
                    _ICEComm.destroy();
                    _ICEComm = null;
                    id = null;
                    GC.Collect();
                    throw new System.Exception("Invalid proxy");
                }

                if(Servant!=null)
                {
                    Ice.ObjectAdapter iceAdapter = _ICEComm.createObjectAdapter("");
                    iceAdapter.add((Ice.Object)Servant, iceProxy.ice_getIdentity());
                    iceProxy.ice_getConnection().setAdapter(iceAdapter);
                    iceAdapter.activate();
                }
            }
            catch (System.Exception ex)
            {
                Online = false;
                GC.Collect();
                string errorMsg = String.Format("System Exception {0} caught.", ex.Message);
                _Logger.Error(errorMsg);
                throw;
            }
            Online = true;
        }


        private TPrx CreateServerProxy(ObjectPrx iceProxy)
        {
            //TestICEPrxHelper
            var str = typeof(TPrx).FullName + "Helper";
            var type = Type.GetType(str);
            var serverproxy = Activator.CreateInstance(type);

            //static method
            var method = type.GetRuntimeMethod("uncheckedCast", new Type[] { typeof(ObjectPrx) });


            return (TPrx)method.Invoke(type, new[] { iceProxy });
        }
    }

public class ICEServer<T,TPrx>
    {
        ILog _Logger = Spv2LoggerFactory.GetLoggerByName("RPC");

        /// <summary>
        /// 客戶端的集合
        /// </summary>
        public Dictionary<string,TPrx> Clients { get; set; } = new Dictionary<string, TPrx>();

        string _IPAddress;
        int _Port;


        public ICEServer(string ip, int port)
        {
            _IPAddress = ip;
            _Port = port;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="Servant"> 作為服務端接收指令響應</param>
        public void StartUp(T Servant)
        {
            try
            {
                _Logger.InfoFormat("Initializing ICE Comm using Host: {0}, Port: {1}",_IPAddress, _Port);

                var _ICEComm = Ice.Util.initialize();
                Ice.Communicator iceComm = Ice.Util.initialize();
                // Create adaptor for commands and requests from client

                Ice.ObjectAdapter iceAdapter = iceComm.createObjectAdapterWithEndpoints(typeof(T).Name, $"tcp -p {_Port} -h {_IPAddress}");
                iceAdapter.add((Ice.Object)Servant, iceComm.stringToIdentity(typeof(T).Name));
                iceAdapter.activate();
            }
            catch (System.Exception ex)
            {
                GC.Collect();
                string errorMsg = String.Format("System Exception {0} caught.", ex.Message);
                _Logger.Error(errorMsg);
                throw;
            }
        }
    }

 

以下為測試代碼

// Copyright 2016 Complete Genomics, Inc.  All Rights Reserved.
// Confidential and proprietary works of Complete Genomics, Inc.

module My {
    module RPC {
            interface TestICE
            {
            void AddClient(string name);

            string ClientCallServer(int i);

            void ServerCallClient(int i);
            };
    };
};

 

    internal class TestICEServer : TestICEDisp_
    {
        ICEServer<TestICE, TestICEPrx> server;
        internal TestICEServer()
        {
            server = new ICEServer<TestICE, TestICEPrx>("172.16.35.66", 11106);
            server.StartUp(this);
        }
        public override void AddClient(string name, Current current__)
        {
            Ice.ObjectPrx @base = current__.con.createProxy(current__.id);
            var client = TestICEPrxHelper.checkedCast(@base);
            server.Clients.Add(name, client);
        }

        public override string ClientCallServer(int i, Current current__)
        {
            return (++i).ToString();
        }

        public override void ServerCallClient(int i, Current current__)
        {
            foreach (var client in server.Clients.Values)
            {
                client.ServerCallClient(i);
            }
        }
    }

    public class TestServerService : TestICEOperationsNC_
    {
        TestICEServer server;
        public TestServerService()
        {
            server = new TestICEServer();
        }

        public void AddClient(string name)
        {
            server.AddClient(name);
        }

        public string ClientCallServer(int i)
        {
            return server.ClientCallServer(i);
        }

        public void ServerCallClient(int i)
        {
            server.ServerCallClient(i);
        }
    }

    internal class TestICEClient : TestICEDisp_
    {
        ICEClient<TestICE, TestICEPrx> client;
        internal TestICEClient()
        {
            client = new ICEClient<TestICE, TestICEPrx>("172.16.35.66", 11106);
            client.Connect(this);
        }
        public override void AddClient(string name, Current current__)
        {
            client.Server.AddClient(name);
        }

        public override string ClientCallServer(int i, Current current__)
        {
           var r= client.Server.ClientCallServer(i);
            return r;
        }

        public override void ServerCallClient(int i, Current current__)
        {
            var r = i;
        }
    }

    public class TestICEClientService : TestICEOperationsNC_
    {
        TestICEClient server;
        public TestICEClientService()
        {
            server = new TestICEClient();
        }

        public void AddClient(string name)
        {
            server.AddClient(name);
        }

        public string ClientCallServer(int i)
        {
            return server.ClientCallServer(i);
        }

        public void ServerCallClient(int i)
        {
            server.ServerCallClient(i);
        }
    }