001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.transport;
018
019import java.io.IOException;
020import java.net.URI;
021import org.apache.activemq.Service;
022
023/**
024 * Represents the client side of a transport allowing messages to be sent
025 * synchronously, asynchronously and consumed.
026 * 
027 * 
028 */
029public interface Transport extends Service {
030
031    /**
032     * A one way asynchronous send
033     * 
034     * @param command
035     * @throws IOException
036     */
037    void oneway(Object command) throws IOException;
038
039    /**
040     * An asynchronous request response where the Receipt will be returned in
041     * the future. If responseCallback is not null, then it will be called when
042     * the response has been completed.
043     * 
044     * @param command
045     * @param responseCallback TODO
046     * @return the FutureResponse
047     * @throws IOException
048     */
049    FutureResponse asyncRequest(Object command, ResponseCallback responseCallback) throws IOException;
050
051    /**
052     * A synchronous request response
053     * 
054     * @param command
055     * @return the response
056     * @throws IOException
057     */
058    Object request(Object command) throws IOException;
059
060    /**
061     * A synchronous request response
062     * 
063     * @param command
064     * @param timeout
065     * @return the repsonse or null if timeout
066     * @throws IOException
067     */
068    Object request(Object command, int timeout) throws IOException;
069
070    // /**
071    // * A one way asynchronous send
072    // * @param command
073    // * @throws IOException
074    // */
075    // void oneway(Command command) throws IOException;
076    //
077    // /**
078    // * An asynchronous request response where the Receipt will be returned
079    // * in the future. If responseCallback is not null, then it will be called
080    // * when the response has been completed.
081    // *
082    // * @param command
083    // * @param responseCallback TODO
084    // * @return the FutureResponse
085    // * @throws IOException
086    // */
087    // FutureResponse asyncRequest(Command command, ResponseCallback
088    // responseCallback) throws IOException;
089    //    
090    // /**
091    // * A synchronous request response
092    // * @param command
093    // * @return the response
094    // * @throws IOException
095    // */
096    // Response request(Command command) throws IOException;
097    //
098    // /**
099    // * A synchronous request response
100    // * @param command
101    // * @param timeout
102    // * @return the repsonse or null if timeout
103    // * @throws IOException
104    // */
105    // Response request(Command command, int timeout) throws IOException;
106
107    /**
108     * Returns the current transport listener
109     * 
110     * @return
111     */
112    TransportListener getTransportListener();
113
114    /**
115     * Registers an inbound command listener
116     * 
117     * @param commandListener
118     */
119    void setTransportListener(TransportListener commandListener);
120
121    /**
122     * @param target
123     * @return the target
124     */
125    <T> T narrow(Class<T> target);
126
127    /**
128     * @return the remote address for this connection
129     */
130    String getRemoteAddress();
131
132    /**
133     * Indicates if the transport can handle faults
134     * 
135     * @return true if fault tolerant
136     */
137    boolean isFaultTolerant();
138    
139    /**
140     * @return true if the transport is disposed
141     */
142    boolean isDisposed();
143    
144    /**
145     * @return true if the transport is connected
146     */
147    boolean isConnected();
148    
149    /**
150     * @return true if reconnect is supported
151     */
152    boolean isReconnectSupported();
153    
154    /**
155     * @return true if updating uris is supported
156     */
157    boolean isUpdateURIsSupported();
158    /**
159     * reconnect to another location
160     * @param uri
161     * @throws IOException on failure of if not supported
162     */
163    void reconnect(URI uri) throws IOException;
164    
165    /**
166     * Provide a list of available alternative locations
167     * @param rebalance 
168     * @param uris
169     * @throws IOException
170     */
171    void updateURIs(boolean rebalance,URI[] uris) throws IOException;
172
173    /**
174     * Returns a counter which gets incremented as data is read from the transport.
175     * It should only be used to determine if there is progress being made in reading the next command from the transport.  
176     * The value may wrap into the negative numbers. 
177     * 
178     * @return a counter which gets incremented as data is read from the transport.
179     */
180    int getReceiveCounter();    
181}