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/** Notice of modification as required by the LGPL
* This file was modified by Gemstone Systems Inc. on
* $Date$
**/
// $Id: RouterStub.java,v 1.15 2005/12/08 09:34:47 belaban Exp $
package com.gemstone.org.jgroups.stack;
import com.gemstone.org.jgroups.util.GemFireTracer;
import com.gemstone.org.jgroups.Address;
import com.gemstone.org.jgroups.Message;
import com.gemstone.org.jgroups.protocols.TunnelHeader;
import com.gemstone.org.jgroups.util.Buffer;
import com.gemstone.org.jgroups.util.ExposedByteArrayOutputStream;
import com.gemstone.org.jgroups.util.ExternalStrings;
import com.gemstone.org.jgroups.util.List;
import com.gemstone.org.jgroups.util.Util;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.ByteArrayInputStream;
import java.net.Socket;
public class RouterStub {
String router_host=null; // name of the router host
int router_port=0; // port on which router listens on router_host
Socket sock=null; // socket connecting to the router
final ExposedByteArrayOutputStream out_stream=new ExposedByteArrayOutputStream(512);
DataOutputStream output=null; // output stream associated with sock
DataInputStream input=null; // input stream associated with sock
Address local_addr=null; // addr of group mbr. Once assigned, remains the same
static final long RECONNECT_TIMEOUT=5000; // msecs to wait until next connection retry attempt
private volatile boolean connected=false;
private volatile boolean reconnect=false; // controls reconnect() loop
protected static final GemFireTracer log=GemFireTracer.getLog(RouterStub.class);
/**
Creates a stub for a remote Router object.
@param router_host The name of the router's host
@param router_port The router's port
*/
public RouterStub(String router_host, int router_port) {
this.router_host=router_host != null? router_host : "localhost";
this.router_port=router_port;
}
public boolean isConnected() {
return connected;
}
/**
* Establishes a connection to the router. The router will send my address (its peer address) back
* as an Address, which is subsequently returned to the caller. The reason for not using
* InetAddress.getLocalHost() or sock.getLocalAddress() is that this may not be permitted
* with certain security managers (e.g if this code runs in an applet). Also, some network
* address translation (NAT) (e.g IP Masquerading) may return the wrong address.
*/
public synchronized Address connect() throws Exception {
Address ret=null;
int len=0;
byte[] buf;
try {
sock=new Socket(router_host, router_port);
sock.setSoLinger(true, 500);
// Retrieve our own address by reading it from the socket
input=new DataInputStream(sock.getInputStream());
len=input.readInt();
buf=new byte[len];
input.readFully(buf);
ret=(Address)Util.objectFromByteBuffer(buf);
output=new DataOutputStream(sock.getOutputStream());
connected=true;
}
catch(Exception e) {
connected=false;
if(sock != null)
sock.close();
throw e;
}
// IpAddress uses InetAddress.getLocalHost() to find the host. May not be permitted in applets !
if(ret == null && sock != null)
ret=new com.gemstone.org.jgroups.stack.IpAddress(sock.getLocalPort());
// set local address; this is the one that we will use from now on !
if(local_addr == null)
local_addr=ret;
return ret;
}
/** Closes the socket and the input and output streams associated with it */
public synchronized void disconnect() {
if(output != null) {
try {
output.close();
output=null;
}
catch(Exception e) {
}
}
if(input != null) {
try {
input.close();
input=null;
}
catch(Exception e) {
}
}
if(sock != null) {
try {
sock.close();
sock=null;
}
catch(Exception e) {
}
}
connected=false;
// stop the TUNNEL receiver thread
reconnect=false;
}
/**
Register this process with the router under groupname.
@param groupname The name of the group under which to register
@return boolean False if connection down, true if registration successful.
*/
public boolean register(String groupname) {
byte[] buf=null;
if(sock == null || output == null || input == null) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_NO_CONNECTION_TO_ROUTER_GROUPNAME_0, groupname);
connected=false;
return false;
}
if(groupname == null || groupname.length() == 0) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_GROUPNAME_IS_NULL);
return false;
}
if(local_addr == null) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_LOCAL_ADDR_IS_NULL);
return false;
}
try {
buf=Util.objectToByteBuffer(local_addr);
output.writeInt(Router.REGISTER);
output.writeUTF(groupname);
output.writeInt(buf.length);
output.write(buf, 0, buf.length); // local_addr
output.flush();
}
catch(Exception e) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_FAILURE__0, Util.getStackTrace(e));
connected=false;
return false;
}
return true;
}
/**
Retrieves the membership (list of Addresses) for a given group. This is mainly used by the PING
protocol to obtain its initial membership. This is used infrequently, so don't maintain socket
for the entire time, but create/delete it on demand.
*/
public List get(String groupname) {
List ret=null;
Socket tmpsock=null;
DataOutputStream tmpOutput=null;
DataInputStream tmpInput=null;
int len;
byte[] buf;
if(groupname == null || groupname.length() == 0) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_GROUPNAME_IS_NULL);
return null;
}
try {
tmpsock=new Socket(router_host, router_port);
tmpsock.setSoLinger(true, 500);
tmpInput=new DataInputStream(tmpsock.getInputStream());
len=tmpInput.readInt(); // discard my own address
buf=new byte[len]; // (first thing returned by router on acept())
tmpInput.readFully(buf);
tmpOutput=new DataOutputStream(tmpsock.getOutputStream());
// request membership for groupname
tmpOutput.writeInt(Router.GET);
tmpOutput.writeUTF(groupname);
// wait for response (List)
len=tmpInput.readInt();
if(len == 0)
return null;
buf=new byte[len];
tmpInput.readFully(buf);
ret=(List)Util.objectFromByteBuffer(buf);
}
catch(Exception e) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_EXCEPTION_0, e);
}
finally {
try {
if(tmpOutput != null) tmpOutput.close();
}
catch(Exception e) {
}
try {
if(tmpInput != null) tmpInput.close();
}
catch(Exception e) {
}
try {
if(tmpsock != null) tmpsock.close();
}
catch(Exception e) {
}
}
return ret;
}
/** Sends a message to the router. Returns false if message cannot be sent (e.g. no connection to
router, true otherwise. */
public boolean send(Message msg, String groupname) {
Address dst_addr=null;
if(sock == null || output == null || input == null) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_NO_CONNECTION_TO_ROUTER_GROUPNAME_0, groupname);
connected=false;
return false;
}
if(msg == null) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_MESSAGE_IS_NULL);
return false;
}
try {
dst_addr=msg.getDest(); // could be null in case of mcast
out_stream.reset();
DataOutputStream tmp=new DataOutputStream(out_stream);
msg.writeTo(tmp);
tmp.close();
Buffer buf=new Buffer(out_stream.getRawBuffer(), 0, out_stream.size());
// 1. Group name
output.writeUTF(groupname);
// 2. Destination address
Util.writeAddress(dst_addr, output);
// 3. Length of byte buffer
output.writeInt(buf.getLength());
// 4. Byte buffer
output.write(buf.getBuf(), 0, buf.getLength());
}
catch(Exception e) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_FAILED_SENDING_MESSAGE_TO__0, dst_addr, e);
connected=false;
return false;
}
return true;
}
/** Receives a message from the router (blocking mode). If the connection is down,
false is returned, otherwise true */
public Message receive() {
Message ret=null;
byte[] buf=null;
int len;
if(sock == null || output == null || input == null) {
if(log.isErrorEnabled()) log.error(ExternalStrings.RouterStub_NO_CONNECTION_TO_ROUTER);
connected=false;
return null;
}
Address dest;
try {
dest=Util.readAddress(input);
len=input.readInt();
if(len == 0) {
// ret=null; GemStoneAddition (redundant assignment)
}
else {
buf=new byte[len];
input.readFully(buf, 0, len);
ret=new Message(false);
ByteArrayInputStream tmp=new ByteArrayInputStream(buf);
DataInputStream in=new DataInputStream(tmp);
ret.readFrom(in);
ret.setDest(dest);
in.close();
}
}
catch(Exception e) {
if (connected) {
if(log.isTraceEnabled()) log.trace("failed receiving message", e);
}
connected=false;
return null;
}
if(log.isTraceEnabled()) log.trace("received "+ret);
return ret;
}
/** Tries to establish connection to router. Tries until router is up again. */
public boolean reconnect(int max_attempts) {
Address new_addr=null;
int num_atttempts=0;
if(connected) return false;
disconnect();
reconnect=true;
while(reconnect && (num_atttempts++ < max_attempts || max_attempts == -1)) {
try {
if((new_addr=connect()) != null)
break;
}
catch(Exception ex) { // this is a normal case
if(log.isTraceEnabled()) log.trace("failed reconnecting", ex);
}
if(max_attempts == -1) {
try { // GemStoneAddition
Util.sleep(RECONNECT_TIMEOUT);
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
return false; // treat like we ran out of attempts
}
}
}
if(new_addr == null) {
return false;
}
if(log.isTraceEnabled()) log.trace("client reconnected, new address is " + new_addr);
return true;
}
public boolean reconnect() {
return reconnect(-1);
}
// public static void main(String[] args) {
// if(args.length != 2) {
// System.out.println("RouterStub ");
// return;
// }
// RouterStub stub=new RouterStub(args[0], Integer.parseInt(args[1]));
// Address my_addr;
// boolean rc;
// final String groupname="BelaGroup";
// Message msg;
// List mbrs;
//
// try {
// my_addr=stub.connect();
// System.out.println("My address is " + my_addr);
//
// System.out.println("Registering under " + groupname);
// rc=stub.register(groupname);
// System.out.println("Done, rc=" + rc);
//
//
// System.out.println("Getting members of " + groupname + ": ");
// mbrs=stub.get(groupname);
// System.out.println("Done, mbrs are " + mbrs);
//
//
// for(int i=0; i < 10; i++) {
// msg=new Message(null, my_addr, "Bela #" + i);
// msg.putHeader("TUNNEL", new TunnelHeader(groupname));
// rc=stub.send(msg, groupname);
// System.out.println("Sent msg, rc=" + rc);
// }
//
// for(int i=0; i < 10; i++) {
// System.out.println("stub.receive():");
// msg=stub.receive();
// System.out.println("Received msg");
// }
//
// }
// catch(Exception ex) {
// log.error(ex);
// }
// finally {
// stub.disconnect();
// }
// }
}