thrift/protocol/TMultiplexedProtocol.h

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one
0003  * or more contributor license agreements. See the NOTICE file
0004  * distributed with this work for additional information
0005  * regarding copyright ownership. The ASF licenses this file
0006  * to you under the Apache License, Version 2.0 (the
0007  * "License"); you may not use this file except in compliance
0008  * with the License. You may obtain a copy of the License at
0009  *
0010  *   http://www.apache.org/licenses/LICENSE-2.0
0011  *
0012  * Unless required by applicable law or agreed to in writing,
0013  * software distributed under the License is distributed on an
0014  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
0015  * KIND, either express or implied. See the License for the
0016  * specific language governing permissions and limitations
0017  * under the License.
0018  */
0019
0020 #ifndef THRIFT_TMULTIPLEXEDPROTOCOL_H_
0021 #define THRIFT_TMULTIPLEXEDPROTOCOL_H_ 1
0022
0023 #include <thrift/protocol/TProtocolDecorator.h>
0024
0025 namespace apache {
0026 namespace thrift {
0027 namespace protocol {
0028 using std::shared_ptr;
0029
0030 /**
0031  * <code>TMultiplexedProtocol</code> is a protocol-independent concrete decorator
0032  * that allows a Thrift client to communicate with a multiplexing Thrift server,
0033  * by prepending the service name to the function name during function calls.
0034  *
0035  * \note THIS IS NOT USED BY SERVERS.  On the server, use
0036  * {@link apache::thrift::TMultiplexedProcessor TMultiplexedProcessor} to handle requests
0037  * from a multiplexing client.
0038  *
0039  * This example uses a single socket transport to invoke two services:
0040  *
0041  * <blockquote><code>
0042  *     shared_ptr<TSocket> transport(new TSocket("localhost", 9090));
0043  *     transport->open();
0044  *
0045  *     shared_ptr<TBinaryProtocol> protocol(new TBinaryProtocol(transport));
0046  *
0047  *     shared_ptr<TMultiplexedProtocol> mp1(new TMultiplexedProtocol(protocol, "Calculator"));
0048  *     shared_ptr<CalculatorClient> service1(new CalculatorClient(mp1));
0049  *
0050  *     shared_ptr<TMultiplexedProtocol> mp2(new TMultiplexedProtocol(protocol, "WeatherReport"));
0051  *     shared_ptr<WeatherReportClient> service2(new WeatherReportClient(mp2));
0052  *
0053  *     service1->add(2,2);
0054  *     int temp = service2->getTemperature();
0055  * </code></blockquote>
0056  *
0057  * @see apache::thrift::protocol::TProtocolDecorator
0058  */
0059 class TMultiplexedProtocol : public TProtocolDecorator {
0060 public:
0061   /**
0062    * Wrap the specified protocol, allowing it to be used to communicate with a
0063    * multiplexing server.  The <code>serviceName</code> is required as it is
0064    * prepended to the message header so that the multiplexing server can broker
0065    * the function call to the proper service.
0066    *
0067    * \param _protocol    Your communication protocol of choice, e.g. <code>TBinaryProtocol</code>.
0068    * \param _serviceName The service name of the service communicating via this protocol.
0069    */
0070   TMultiplexedProtocol(shared_ptr<TProtocol> _protocol, const std::string& _serviceName)
0071     : TProtocolDecorator(_protocol), serviceName(_serviceName), separator(":") {}
0072   ~TMultiplexedProtocol() override = default;
0073
0074   /**
0075    * Prepends the service name to the function name, separated by TMultiplexedProtocol::SEPARATOR.
0076    *
0077    * \param [in] _name   The name of the method to be called in the service.
0078    * \param [in] _type   The type of message
0079    * \param [in] _name   The sequential id of the message
0080    *
0081    * \throws TException  Passed through from wrapped <code>TProtocol</code> instance.
0082    */
0083   uint32_t writeMessageBegin_virt(const std::string& _name,
0084                                   const TMessageType _type,
0085                                   const int32_t _seqid) override;
0086
0087 private:
0088   const std::string serviceName;
0089   const std::string separator;
0090 };
0091 }
0092 }
0093 }
0094
0095 #endif // THRIFT_TMULTIPLEXEDPROTOCOL_H_