FORGE-801: Initial implementation

resources/api/src/main/java/org/jboss/forge/resource/transaction/ChangeSet.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.resource.transaction;
+
+import java.util.Set;
+
+import org.jboss.forge.resource.Resource;
+
+/**
+ * A {@link ChangeSet} object contains the modified resources of a specific transaction
+ *
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ *
+ */
+public interface ChangeSet
+{
+   /**
+    * @return a set of the modified resources
+    */
+   Set<Resource<?>> getModifiedResources();
+}

resources/api/src/main/java/org/jboss/forge/resource/transaction/ResourceTransaction.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.resource.transaction;
+
+import org.jboss.forge.resource.ResourceException;
+
+/**
+ * The ResourceTransaction interface allows operations to be performed on transactions
+ *
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ *
+ */
+public interface ResourceTransaction
+{
+   /**
+    * Attempt to commit this transaction, discarding the current {@link ChangeSet}.
+    *
+    * @throws ResourceException if any operation fails
+    */
+   void commit() throws ResourceException;
+
+   /**
+    * Rolls back this transaction. This transaction should not be used again
+    *
+    * This also discards the current {@link ChangeSet}
+    *
+    * @throws ResourceException
+    */
+   void rollback() throws ResourceException;
+
+   /**
+    * @return A {@link ChangeSet} object containing which resources were modified during this transaction
+    */
+   ChangeSet getChangeSet();
+
+}

resources/api/src/main/java/org/jboss/forge/resource/transaction/ResourceTransactionManager.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.resource.transaction;
+
+import org.jboss.forge.container.services.Exported;
+import org.jboss.forge.resource.ResourceException;
+
+/**
+ * The ResourceTransactionManager interface allows
+ *
+ * <ul>
+ * <li>Starting a {@link ResourceTransaction}</li>
+ * <li>Getting the current {@link ResourceTransaction}</li>
+ * </ul>
+ *
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ *
+ */
+@Exported
+public interface ResourceTransactionManager
+{
+   /**
+    * Start a new transaction.
+    *
+    * If a transaction was already started, a {@link ResourceException} will be thrown
+    *
+    * @return a new {@link ResourceTransaction} instance
+    * @throws ResourceException if a transaction was already started
+    */
+   ResourceTransaction startTransaction() throws ResourceException;
+
+   /**
+    * @return The current transaction or null if {@link ResourceTransactionManager#startTransaction()} was not
+    *         previously called
+    */
+   ResourceTransaction getCurrentTransaction();
+}

resources/impl/src/main/java/org/jboss/forge/resource/ChangeSetImpl.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.resource;
+
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.jboss.forge.resource.transaction.ChangeSet;
+
+public class ChangeSetImpl implements ChangeSet
+{
+   private Set<Resource<?>> changeSet = new TreeSet<Resource<?>>();
+
+   public ChangeSetImpl()
+   {
+   }
+
+   public void addResource(Resource<?> resource)
+   {
+      changeSet.add(resource);
+   }
+
+   public void removeResource(Resource<?> resource)
+   {
+      changeSet.remove(resource);
+   }
+
+   @Override
+   public Set<Resource<?>> getModifiedResources()
+   {
+      return changeSet;
+   }
+
+}

resources/impl/src/main/java/org/jboss/forge/resource/ResourceFactoryImpl.java

@@ -15,24 +15,26 @@
 import javax.inject.Singleton;
 
 import org.jboss.forge.container.AddonRegistry;
-import org.jboss.forge.container.services.Exported;
 import org.jboss.forge.container.services.ExportedInstance;
 import org.jboss.forge.resource.events.ResourceEvent;
+import org.jboss.forge.resource.transaction.ResourceTransaction;
+import org.jboss.forge.resource.transaction.ResourceTransactionManager;
 
 /**
  * @author <a href="http://community.jboss.org/people/kenfinni">Ken Finnigan</a>
  * @author Mike Brock <cbrock@redhat.com>
  */
-@Exported
 @Singleton
-public class ResourceFactoryImpl implements ResourceFactory
+public class ResourceFactoryImpl implements ResourceFactory, ResourceTransactionManager
 {
    @Inject
    private BeanManager manager;
 
    @Inject
    private AddonRegistry registry;
 
+   private ResourceTransactionImpl transaction;
+
    @Override
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public <E, T extends Resource<E>> T create(final Class<T> type, final E underlyingResource)
@@ -79,7 +81,8 @@ public <E> Resource<E> create(E underlyingResource)
             ResourceGenerator generator = instance.get();
             if (generator.handles(Resource.class, underlyingResource))
             {
-               generated.add(generator.getResource(this, Resource.class, underlyingResource));
+               Resource resource = generator.getResource(this, Resource.class, underlyingResource);
+               generated.add(resource);
             }
             instance.release(generator);
          }
@@ -90,9 +93,17 @@ public <E> Resource<E> create(E underlyingResource)
          for (Resource<?> resource : generated)
          {
             if (result == null || result.getClass().isAssignableFrom(resource.getClass()))
+            {
                result = (Resource<E>) resource;
+            }
          }
       }
+      // Transaction Hook
+      if (result != null && transaction != null)
+      {
+         result = transaction.decorateResource(result);
+      }
+
       return result;
    }
 
@@ -109,4 +120,26 @@ public ResourceFactory fireEvent(ResourceEvent event)
       return this;
    }
 
+   @Override
+   public ResourceTransaction getCurrentTransaction()
+   {
+      return transaction;
+   }
+
+   @Override
+   public ResourceTransaction startTransaction() throws ResourceException
+   {
+      if (transaction != null)
+      {
+         throw new ResourceException("Transaction already exists!");
+      }
+      transaction = new ResourceTransactionImpl(this);
+      return transaction;
+   }
+
+   void unsetTransaction()
+   {
+      transaction = null;
+   }
+
 }

resources/impl/src/main/java/org/jboss/forge/resource/ResourceTransactionImpl.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.resource;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.jboss.forge.resource.transaction.ChangeSet;
+import org.jboss.forge.resource.transaction.ResourceTransaction;
+
+public class ResourceTransactionImpl implements ResourceTransaction
+{
+   private File tempWorkspace;
+
+   private ChangeSetImpl changeSet = new ChangeSetImpl();
+   private ResourceFactoryImpl factoryImpl;
+
+   public ResourceTransactionImpl(ResourceFactoryImpl factoryImpl) throws ResourceException
+   {
+      try
+      {
+         tempWorkspace = File.createTempFile("Forge_RT", null);
+      }
+      catch (IOException io)
+      {
+         throw new ResourceException(io);
+      }
+      tempWorkspace.delete();
+      tempWorkspace.mkdir();
+      this.factoryImpl = factoryImpl;
+   }
+
+   @Override
+   public void commit() throws ResourceException
+   {
+      factoryImpl.unsetTransaction();
+   }
+
+   @Override
+   public void rollback() throws ResourceException
+   {
+      factoryImpl.unsetTransaction();
+   }
+
+   /**
+    * Decorates a Resource
+    *
+    * @param resource
+    * @return
+    */
+   public <TYPE> Resource<TYPE> decorateResource(Resource<TYPE> resource)
+   {
+      changeSet.addResource(resource);
+      // TODO: Create a proxy to the FileResource
+      return resource;
+   }
+
+   @Override
+   public ChangeSet getChangeSet()
+   {
+      return changeSet;
+   }
+
+}