cells: Let CellPath#revert return a copy

CellPath#revert reverts the path inline. In almost all
cases this means one should clone the CellPath object
before reverting it.

This patch updates revert to return a reverted copy of
the path rather than modifying the path itself. This
protects against accidentally modifying shared cell
path.

The patch also modifies CellMessage to clone the injected
CellPath. This too is to avoid that shared CellPath objects
get modified.

Targe: trunk
Require-book: no
Require-notes: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5393/

Author: gbehrmann

modules/cells/src/main/java/dmg/cells/network/LocationMgrTunnel.java

@@ -133,8 +133,7 @@ private void returnToSender(CellMessage msg, NoRouteToCellException e)
     {
         try {
             if (!(msg instanceof CellExceptionMessage)) {
-                CellPath retAddr = (CellPath)msg.getSourcePath().clone();
-                retAddr.revert();
+                CellPath retAddr = msg.getSourcePath().revert();
                 CellExceptionMessage ret = new CellExceptionMessage(retAddr, e);
                 ret.setLastUOID(msg.getUOID());
                 _nucleus.sendMessage(ret);

modules/cells/src/main/java/dmg/cells/nucleus/CellGlue.java

@@ -676,8 +676,7 @@ private void sendException( CellNucleus nucleus ,
                               destination ,
                               "Tunnel cell >"+routeTarget+
                               "< not found at >"+_cellDomainName+"<" ) ;
-            CellPath retAddr = (CellPath)msg.getSourcePath().clone() ;
-            retAddr.revert() ;
+            CellPath retAddr = msg.getSourcePath().revert();
             CellExceptionMessage ret =
                  new CellExceptionMessage( retAddr , exception )  ;
             LOGGER.warn("Sending CellException to {}", retAddr);

modules/cells/src/main/java/dmg/cells/nucleus/CellMessage.java

@@ -37,7 +37,7 @@ public class CellMessage implements Cloneable , Serializable {
 
   public CellMessage( CellPath addr , Serializable msg ){
 
-     _destination  = addr ;
+     _destination  = (CellPath) addr.clone();
      _message      = msg ;
      _source       = new CellPath() ;
      _creationTime = System.currentTimeMillis() ;
@@ -102,8 +102,7 @@ public void        setLastUOID( UOID lastUOID ) {
   public Serializable getMessageObject(){ return (Serializable) _message  ; }
   public void        setMessageObject( Serializable obj ){ _message = obj ; }
   public void        revertDirection(){
-     _destination = _source ;
-     _destination.revert() ;
+     _destination = _source.revert();
      _source      = new CellPath() ;
      _lastUmid    = _umid ;
      _isPersistent = true;

modules/cells/src/main/java/dmg/cells/nucleus/CellPath.java

@@ -1,5 +1,7 @@
 package dmg.cells.nucleus ;
 
+import com.google.common.collect.Lists;
+
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -138,14 +140,13 @@ public synchronized boolean next(){
       _position++ ;
       return true;
    }
-   public synchronized void toFirstDestination(){
-      _position = _list.size() == 0 ? -1 : 0 ;
-   }
-   public synchronized void revert(){
 
-	 Collections.reverse(_list);
-     toFirstDestination() ;
-   }
+    public synchronized CellPath revert(){
+        CellPath copy = new CellPath();
+        copy._list = Lists.newArrayList(Lists.reverse(_list));
+        copy._position = copy._list.size() == 0 ? -1 : 0 ;
+        return copy;
+    }
    public synchronized boolean isFinalDestination(){
       return _position >= ( _list.size() - 1 ) ;
    }

modules/cells/src/main/java/dmg/cells/services/multicaster/BroadcastCell.java

@@ -349,8 +349,7 @@ private void handleBroadcastCommandMessage( CellMessage msg , BroadcastCommandMe
             String eventClass = event.getEventClass() ;
             CellPath target   = event.getTarget() ;
             if( target == null ){
-                target = (CellPath)msg.getSourcePath().clone() ;
-                target.revert() ;
+                target = msg.getSourcePath().revert();
             }
             if( event instanceof BroadcastRegisterMessage ){
                 BroadcastRegisterMessage reg = (BroadcastRegisterMessage)event ;

modules/cells/src/main/java/dmg/cells/services/multicaster/MulticastCell.java

@@ -219,8 +219,7 @@ private void registerArrived( MulticastRegister register , CellPath path )
            throw new
                    NoSuchElementException("Not found : " + eventClass + ":" + eventName);
        }
-       path.revert() ;
-       entry.addClient(new Client(path)) ;
+       entry.addClient(new Client(path.revert())) ;
        register.setServerInfo( entry.getServerDetail() , entry.getServerState() ) ;
    }
    private void unregisterArrived( MulticastUnregister register , CellPath path )
@@ -231,8 +230,7 @@ private void unregisterArrived( MulticastUnregister register , CellPath path )
        if( entry == null ) {
            return;
        }
-       path.revert() ;
-       entry.removeClient(path) ;
+       entry.removeClient(path.revert()) ;
    }
    private void registerMessageArrived(
                   MulticastMessage message ,
@@ -271,8 +269,7 @@ private void registerMessageArrived(
            }
        }else{
           _log.info( "Message from client "+path ) ;
-          serverPath = (CellPath)serverPath.clone() ;
-          serverPath.revert() ;
+          serverPath = serverPath.revert();
           originalMessage.getDestinationPath().add( serverPath ) ;
           originalMessage.nextDestination() ;
           try{

modules/cells/src/main/java/dmg/cells/services/multicaster/MulticastCommander.java

@@ -37,9 +37,8 @@ public void messageToForward( CellMessage msg ){
         }catch( NoRouteToCellException nrtc ){
            _log.warn( "NoRouteToCell in messageToForward : "+nrtc ) ;
            _log.warn( "Sending NoRouteToCellt to : "+source ) ;
-           source.revert() ;
            try{
-              sendMessage( new CellMessage( source , nrtc ) ) ;
+              sendMessage( new CellMessage( source.revert() , nrtc ) ) ;
            }catch(Exception ee ){
               _log.warn( "can't return NoRouteToCell to : "+source ) ;
            }

modules/dcache-jms/src/main/java/org/dcache/cells/JMSTunnel.java

@@ -240,8 +240,7 @@ private void returnToSender(CellMessage msg, NoRouteToCellException e)
             if (!(msg instanceof CellExceptionMessage)) {
                 _log.info("Cannot deliver {}", msg);
 
-                CellPath retAddr = (CellPath)msg.getSourcePath().clone();
-                retAddr.revert();
+                CellPath retAddr = msg.getSourcePath().revert();
                 CellExceptionMessage ret = new CellExceptionMessage(retAddr, e);
                 ret.setLastUOID(msg.getUOID());
                 sendMessage(ret);

modules/dcache/src/main/java/diskCacheV111/namespace/PnfsManagerV3.java

@@ -1420,8 +1420,7 @@ private void listDirectory(CellMessage envelope, PnfsListDirectoryMessage msg)
                 (delay == Long.MAX_VALUE)
                 ? Long.MAX_VALUE
                 : delay - envelope.getLocalAge();
-            CellPath source = (CellPath)envelope.getSourcePath().clone();
-            source.revert();
+            CellPath source = envelope.getSourcePath().revert();
             ListHandler handler =
                 new ListHandlerImpl(source, envelope.getUOID(),
                                     msg, initialDelay, delay);

modules/dcache/src/main/java/org/dcache/pool/classic/PoolV4.java

@@ -706,21 +706,18 @@ private void ioFile(CellMessage envelope, PoolIoFileMessage message)
             String initiator = message.getInitiator();
             String pool = message.getPoolName();
             String queueName = message.getIoQueueName();
-            CellPath source = (CellPath)envelope.getSourcePath().clone();
+            CellPath source = envelope.getSourcePath().revert();
             Set<Repository.OpenFlags> openFlags =
                     (Set<Repository.OpenFlags>) (
                         message.isPool2Pool() ? Collections.emptySet() :
                             Collections.singleton(Repository.OpenFlags.NOATIME)
                     );
 
-            String door =
-                source.getCellName() + "@" + source.getCellDomainName();
-
             /* Eliminate duplicate requests.
              */
             if (!(message instanceof PoolAcceptFileMessage)
                 && !message.isPool2Pool()) {
-
+                String door = source.getDestinationAddress().toString();
                 JobInfo job = _ioQueue.findJob(door, id);
                 if (job != null) {
                     switch (_dupRequest) {
@@ -752,8 +749,6 @@ private void ioFile(CellMessage envelope, PoolIoFileMessage message)
                                 pi);
             }
 
-            source.revert();
-
             String protocolName = protocolNameOf(pi);
             MoverExecutorService moverExecutorService = _moverExecutorServices.getExecutorService(protocolName);
             PostTransferExecutionService postExecutorService =