[203511] Provide vetoable transaction hooks

https://bugs.eclipse.org/bugs/show_bug.cgi?id=203511

5 files changed, 143 insertions, 37 deletions

diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransaction.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransaction.java
index ad068b0ea0..ac74b4d6a4 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransaction.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransaction.java
@@ -11,12 +11,17 @@
 package org.eclipse.emf.cdo;
 
 import org.eclipse.emf.cdo.eresource.CDOResource;
+import org.eclipse.emf.cdo.protocol.CDOID;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
+import org.eclipse.emf.cdo.protocol.model.CDOPackage;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 
+import java.util.List;
+import java.util.Map;
+
 /**
  * @author Eike Stepper
  */
@@ -40,4 +45,18 @@ public interface CDOTransaction extends CDOView
    * @see CDOTransaction#rollback()
    */
   public void rollback();
+
+  public void addHandler(CDOTransactionHandler handler);
+
+  public void removeHandler(CDOTransactionHandler handler);
+
+  public CDOTransactionHandler[] getHandlers();
+
+  public List<CDOPackage> getNewPackages();
+
+  public Map<CDOID, CDOResource> getNewResources();
+
+  public Map<CDOID, CDOObject> getNewObjects();
+
+  public Map<CDOID, CDOObject> getDirtyObjects();
 }
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransactionHandler.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransactionHandler.java
new file mode 100644
index 0000000000..8769fa518e
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/cdo/CDOTransactionHandler.java
@@ -0,0 +1,38 @@
+/***************************************************************************
+ * Copyright (c) 2004 - 2007 Eike Stepper, Germany.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *    Eike Stepper - initial API and implementation
+ **************************************************************************/
+package org.eclipse.emf.cdo;
+
+/**
+ * @author Eike Stepper
+ */
+public interface CDOTransactionHandler
+{
+  /**
+   * Called by a <code>CDOTransaction</code> <b>before</b> an object is added. The implementor of this method is
+   * allowed to throw an unchecked exception that will propagate up to the operation that is about to add the object.
+   */
+  public void addingObject(CDOTransaction transaction, CDOObject object);
+
+  /**
+   * Called by a <code>CDOTransaction</code> <b>before</b> an object is modified. The implementor of this method is
+   * allowed to throw an unchecked exception that will propagate up to the operation that is about to modify the object.
+   * <p>
+   * Note: This method will be called at most once per object until the associated transaction is committed.
+   */
+  public void modifyingObject(CDOTransaction transaction, CDOObject object);
+
+  /**
+   * Called by a <code>CDOTransaction</code> <b>before</b> it is being committed. The implementor of this method is
+   * allowed to throw an unchecked exception that will propagate up to the operation that is about to commit the
+   * transaction.
+   */
+  public void committingTransaction(CDOTransaction transaction);
+}
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOTransactionImpl.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOTransactionImpl.java
index ef26efc19b..03fb795b15 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOTransactionImpl.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/CDOTransactionImpl.java
@@ -10,13 +10,17 @@
  **************************************************************************/
 package org.eclipse.emf.internal.cdo;
 
+import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.CDOTransaction;
 import org.eclipse.emf.cdo.CDOTransactionCommittedEvent;
 import org.eclipse.emf.cdo.CDOTransactionDirtyEvent;
+import org.eclipse.emf.cdo.CDOTransactionHandler;
+import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.eresource.impl.CDOResourceImpl;
 import org.eclipse.emf.cdo.internal.protocol.CDOIDImpl;
 import org.eclipse.emf.cdo.internal.protocol.model.CDOPackageImpl;
 import org.eclipse.emf.cdo.protocol.CDOID;
+import org.eclipse.emf.cdo.protocol.model.CDOPackage;
 import org.eclipse.emf.cdo.protocol.util.TransportException;
 
 import org.eclipse.emf.ecore.EPackage;
@@ -27,6 +31,7 @@ import org.eclipse.emf.internal.cdo.util.EMFPackageClosure;
 import org.eclipse.emf.internal.cdo.util.ModelUtil;
 
 import org.eclipse.net4j.IChannel;
+import org.eclipse.net4j.internal.util.event.Notifier;
 import org.eclipse.net4j.internal.util.om.trace.ContextTracer;
 import org.eclipse.net4j.signal.IFailOverStrategy;
 import org.eclipse.net4j.util.ImplementationError;
@@ -50,13 +55,18 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
 
   private transient long nextTemporaryID = INITIAL_TEMPORARY_ID;
 
-  private List<CDOPackageImpl> newPackages;
+  /**
+   * TODO Optimize by storing an array. See {@link Notifier}.
+   */
+  private List<CDOTransactionHandler> handlers = new ArrayList<CDOTransactionHandler>(0);
+
+  private List<CDOPackage> newPackages;
 
-  private Map<CDOID, CDOResourceImpl> newResources = new HashMap<CDOID, CDOResourceImpl>();
+  private Map<CDOID, CDOResource> newResources = new HashMap<CDOID, CDOResource>();
 
-  private Map<CDOID, InternalCDOObject> newObjects = new HashMap<CDOID, InternalCDOObject>();
+  private Map<CDOID, CDOObject> newObjects = new HashMap<CDOID, CDOObject>();
 
-  private Map<CDOID, InternalCDOObject> dirtyObjects = new HashMap<CDOID, InternalCDOObject>();
+  private Map<CDOID, CDOObject> dirtyObjects = new HashMap<CDOID, CDOObject>();
 
   private boolean dirty;
 
@@ -71,28 +81,52 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
     return Type.TRANSACTION;
   }
 
+  public void addHandler(CDOTransactionHandler handler)
+  {
+    synchronized (handlers)
+    {
+      handlers.add(handler);
+    }
+  }
+
+  public void removeHandler(CDOTransactionHandler handler)
+  {
+    synchronized (handlers)
+    {
+      handlers.remove(handler);
+    }
+  }
+
+  public CDOTransactionHandler[] getHandlers()
+  {
+    synchronized (handlers)
+    {
+      return handlers.toArray(new CDOTransactionHandler[handlers.size()]);
+    }
+  }
+
   @Override
   public boolean isDirty()
   {
     return dirty;
   }
 
-  public List<CDOPackageImpl> getNewPackages()
+  public List<CDOPackage> getNewPackages()
   {
     return newPackages;
   }
 
-  public Map<CDOID, CDOResourceImpl> getNewResources()
+  public Map<CDOID, CDOResource> getNewResources()
   {
     return newResources;
   }
 
-  public Map<CDOID, InternalCDOObject> getNewObjects()
+  public Map<CDOID, CDOObject> getNewObjects()
   {
     return newObjects;
   }
 
-  public Map<CDOID, InternalCDOObject> getDirtyObjects()
+  public Map<CDOID, CDOObject> getDirtyObjects()
   {
     return dirtyObjects;
   }
@@ -115,6 +149,11 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
         TRACER.trace("commit()");
       }
 
+      for (CDOTransactionHandler handler : getHandlers())
+      {
+        handler.committingTransaction(this);
+      }
+
       try
       {
         CDOSessionImpl session = getSession();
@@ -138,9 +177,9 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
           session.notifyInvalidation(result.getTimeStamp(), dirtyObjects.keySet(), this);
         }
 
-        for (CDOPackageImpl newPackage : newPackages)
+        for (CDOPackage newPackage : newPackages)
         {
-          newPackage.setPersistent(true);
+          ((CDOPackageImpl)newPackage).setPersistent(true);
         }
 
         newPackages = null;
@@ -191,22 +230,22 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
 
   public void registerNew(InternalCDOObject object)
   {
-    if (object instanceof CDOResourceImpl)
+    if (TRACER.isEnabled())
     {
-      if (TRACER.isEnabled())
-      {
-        TRACER.format("Registering new resource {0}", object);
-      }
+      TRACER.format("Registering new object {0}", object);
+    }
+
+    for (CDOTransactionHandler handler : getHandlers())
+    {
+      handler.addingObject(this, object);
+    }
 
+    if (object instanceof CDOResourceImpl)
+    {
       register(newResources, object);
     }
     else
     {
-      if (TRACER.isEnabled())
-      {
-        TRACER.format("Registering new object {0}", object);
-      }
-
       register(newObjects, object);
     }
   }
@@ -218,6 +257,11 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
       TRACER.format("Registering dirty object {0}", object);
     }
 
+    for (CDOTransactionHandler handler : getHandlers())
+    {
+      handler.modifyingObject(this, object);
+    }
+
     register(dirtyObjects, object);
   }
 
@@ -237,10 +281,10 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
     }
   }
 
-  private List<CDOPackageImpl> analyzeNewPackages(CDOSessionImpl session)
+  private List<CDOPackage> analyzeNewPackages(CDOSessionImpl session)
   {
     Set<EPackage> ePackages = new HashSet<EPackage>();
-    for (InternalCDOObject object : newObjects.values())
+    for (CDOObject object : newObjects.values())
     {
       ePackages.add(object.eClass().getEPackage());
     }
@@ -249,7 +293,7 @@ public class CDOTransactionImpl extends CDOViewImpl implements CDOTransaction
     ePackages = new EMFPackageClosure().calculate(ePackages);
 
     CDOSessionPackageManager packageManager = session.getPackageManager();
-    List<CDOPackageImpl> cdoPackages = new ArrayList<CDOPackageImpl>();
+    List<CDOPackage> cdoPackages = new ArrayList<CDOPackage>();
     for (EPackage ePackage : ePackages)
     {
       CDOPackageImpl cdoPackage = ModelUtil.getCDOPackage(ePackage, packageManager);
diff --git a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/protocol/CommitTransactionRequest.java b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/protocol/CommitTransactionRequest.java
index 0e140d9fb0..3ce55f051c 100644
--- a/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/protocol/CommitTransactionRequest.java
+++ b/plugins/org.eclipse.emf.cdo/src/org/eclipse/emf/internal/cdo/protocol/CommitTransactionRequest.java
@@ -10,7 +10,8 @@
  **************************************************************************/
 package org.eclipse.emf.internal.cdo.protocol;
 
-import org.eclipse.emf.cdo.eresource.impl.CDOResourceImpl;
+import org.eclipse.emf.cdo.CDOObject;
+import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.internal.protocol.CDOIDImpl;
 import org.eclipse.emf.cdo.internal.protocol.CDOIDRangeImpl;
 import org.eclipse.emf.cdo.internal.protocol.model.CDOPackageImpl;
@@ -18,17 +19,18 @@ import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
 import org.eclipse.emf.cdo.protocol.CDOID;
 import org.eclipse.emf.cdo.protocol.CDOIDRange;
 import org.eclipse.emf.cdo.protocol.CDOProtocolConstants;
+import org.eclipse.emf.cdo.protocol.model.CDOPackage;
 import org.eclipse.emf.cdo.protocol.revision.CDORevision;
 
+import org.eclipse.emf.internal.cdo.CDOTransactionImpl;
+import org.eclipse.emf.internal.cdo.InternalCDOObject;
+import org.eclipse.emf.internal.cdo.bundle.OM;
+
 import org.eclipse.net4j.IChannel;
 import org.eclipse.net4j.internal.util.om.trace.ContextTracer;
 import org.eclipse.net4j.util.io.ExtendedDataInputStream;
 import org.eclipse.net4j.util.io.ExtendedDataOutputStream;
 
-import org.eclipse.emf.internal.cdo.CDOTransactionImpl;
-import org.eclipse.emf.internal.cdo.InternalCDOObject;
-import org.eclipse.emf.internal.cdo.bundle.OM;
-
 import java.io.IOException;
 import java.util.Collection;
 import java.util.Iterator;
@@ -67,22 +69,22 @@ public class CommitTransactionRequest extends CDOClientRequest<CommitTransaction
 
   private void writeNewPackages(ExtendedDataOutputStream out) throws IOException
   {
-    List<CDOPackageImpl> newPackages = transaction.getNewPackages();
+    List<CDOPackage> newPackages = transaction.getNewPackages();
     if (PROTOCOL.isEnabled())
     {
       PROTOCOL.format("Writing {0} new packages", newPackages.size());
     }
 
     out.writeInt(newPackages.size());
-    for (CDOPackageImpl newPackage : newPackages)
+    for (CDOPackage newPackage : newPackages)
     {
-      newPackage.write(out);
+      ((CDOPackageImpl)newPackage).write(out);
     }
   }
 
   private void writeNewResources(ExtendedDataOutputStream out) throws IOException
   {
-    Collection<CDOResourceImpl> newResources = transaction.getNewResources().values();
+    Collection<CDOResource> newResources = transaction.getNewResources().values();
     if (PROTOCOL.isEnabled())
     {
       PROTOCOL.format("Writing {0} new resources", newResources.size());
@@ -93,7 +95,7 @@ public class CommitTransactionRequest extends CDOClientRequest<CommitTransaction
 
   private void writeNewObjects(ExtendedDataOutputStream out) throws IOException
   {
-    Collection<InternalCDOObject> newObjects = transaction.getNewObjects().values();
+    Collection<CDOObject> newObjects = transaction.getNewObjects().values();
     if (PROTOCOL.isEnabled())
     {
       PROTOCOL.format("Writing {0} new objects", newObjects.size());
@@ -104,7 +106,7 @@ public class CommitTransactionRequest extends CDOClientRequest<CommitTransaction
 
   private void writeDirtyObjects(ExtendedDataOutputStream out) throws IOException
   {
-    Collection<InternalCDOObject> dirtyObjects = transaction.getDirtyObjects().values();
+    Collection<CDOObject> dirtyObjects = transaction.getDirtyObjects().values();
     if (PROTOCOL.isEnabled())
     {
       PROTOCOL.format("Writing {0} dirty objects", dirtyObjects.size());
@@ -130,12 +132,12 @@ public class CommitTransactionRequest extends CDOClientRequest<CommitTransaction
     long timeStamp = in.readLong();
     CommitTransactionResult result = new CommitTransactionResult(timeStamp);
 
-    List<CDOPackageImpl> newPackages = transaction.getNewPackages();
-    for (CDOPackageImpl newPackage : newPackages)
+    List<CDOPackage> newPackages = transaction.getNewPackages();
+    for (CDOPackage newPackage : newPackages)
     {
       CDOIDRange oldRange = newPackage.getMetaIDRange();
       CDOIDRange newRange = CDOIDRangeImpl.read(in);
-      newPackage.setMetaIDRange(newRange);
+      ((CDOPackageImpl)newPackage).setMetaIDRange(newRange);
       for (long i = 0; i < oldRange.getCount(); i++)
       {
         CDOID oldID = oldRange.get(i);
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/internal/util/event/Notifier.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/internal/util/event/Notifier.java
index c6bb4fa188..1f43034c39 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/internal/util/event/Notifier.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/internal/util/event/Notifier.java
@@ -23,6 +23,9 @@ import java.util.List;
  */
 public class Notifier implements INotifier.Introspection
 {
+  /**
+   * TODO Optimize by storing an array
+   */
   private List<IListener> listeners = new ArrayList<IListener>(0);
 
   public Notifier()