THRIFT-1899 Delphi: Support for Multiplexing Services on any Transport, Protocol and Server
Patch: Jens Geyer
diff --git a/lib/delphi/src/Thrift.Protocol.Multiplex.pas b/lib/delphi/src/Thrift.Protocol.Multiplex.pas
new file mode 100644
index 0000000..2cd2401
--- /dev/null
+++ b/lib/delphi/src/Thrift.Protocol.Multiplex.pas
@@ -0,0 +1,107 @@
+(*
+ * 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.
+ *)
+
+unit Thrift.Protocol.Multiplex;
+
+interface
+
+uses Thrift.Protocol;
+
+{ TMultiplexedProtocol is a protocol-independent concrete decorator
+ that allows a Thrift client to communicate with a multiplexing Thrift server,
+ by prepending the service name to the function name during function calls.
+
+ NOTE: THIS IS NOT USED BY SERVERS.
+ On the server, use TMultiplexedProcessor to handle requests from a multiplexing client.
+
+ This example uses a single socket transport to invoke two services:
+
+ TSocket transport = new TSocket("localhost", 9090);
+ transport.open();
+
+ TBinaryProtocol protocol = new TBinaryProtocol(transport);
+
+ TMultiplexedProtocol mp = new TMultiplexedProtocol(protocol, "Calculator");
+ Calculator.Client service = new Calculator.Client(mp);
+
+ TMultiplexedProtocol mp2 = new TMultiplexedProtocol(protocol, "WeatherReport");
+ WeatherReport.Client service2 = new WeatherReport.Client(mp2);
+
+ System.out.println(service.add(2,2));
+ System.out.println(service2.getTemperature());
+
+}
+
+type
+ TMultiplexedProtocol = class( TProtocolDecorator)
+ public const
+ { Used to delimit the service name from the function name }
+ SEPARATOR = ':';
+
+ private
+ FServiceName : String;
+
+ public
+ { Wrap the specified protocol, allowing it to be used to communicate with a multiplexing server.
+ The serviceName is required as it is prepended to the message header so that the multiplexing
+ server can broker the function call to the proper service.
+
+ Args:
+ protocol ....... Your communication protocol of choice, e.g. TBinaryProtocol.
+ serviceName .... The service name of the service communicating via this protocol.
+ }
+ constructor Create( const aProtocol : IProtocol; const aServiceName : string);
+
+ { Prepends the service name to the function name, separated by SEPARATOR.
+ Args: The original message.
+ }
+ procedure WriteMessageBegin( const msg: IMessage); override;
+ end;
+
+
+implementation
+
+
+constructor TMultiplexedProtocol.Create(const aProtocol: IProtocol; const aServiceName: string);
+begin
+ ASSERT( aServiceName <> '');
+ inherited Create(aProtocol);
+ FServiceName := aServiceName;
+end;
+
+
+procedure TMultiplexedProtocol.WriteMessageBegin( const msg: IMessage);
+// Prepends the service name to the function name, separated by TMultiplexedProtocol.SEPARATOR.
+var newMsg : IMessage;
+begin
+ case msg.Type_ of
+ TMessageType.Call,
+ TMessageType.Oneway : begin
+ newMsg := TMessageImpl.Create( FServiceName + SEPARATOR + msg.Name, msg.Type_, msg.SeqID);
+ inherited WriteMessageBegin( newMsg);
+ end;
+
+ else
+ inherited WriteMessageBegin( msg);
+ end;
+end;
+
+
+end.
+