Author: sallen
Date: Tue Feb 5 20:49:11 2013
New Revision: 1442737
URL: http://svn.apache.org/viewvc?rev=1442737&view=rev
Log:
Add an example of a non-streaming UpdateEngine.
Added:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/modify/UpdateEngineNonStreaming.java
Added:
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/modify/UpdateEngineNonStreaming.java
URL:
http://svn.apache.org/viewvc/jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/modify/UpdateEngineNonStreaming.java?rev=1442737&view=auto
==============================================================================
---
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/modify/UpdateEngineNonStreaming.java
(added)
+++
jena/trunk/jena-arq/src/main/java/com/hp/hpl/jena/sparql/modify/UpdateEngineNonStreaming.java
Tue Feb 5 20:49:11 2013
@@ -0,0 +1,117 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hp.hpl.jena.sparql.modify;
+
+import com.hp.hpl.jena.sparql.engine.binding.Binding ;
+import com.hp.hpl.jena.sparql.modify.request.UpdateVisitor ;
+import com.hp.hpl.jena.sparql.util.Context ;
+import com.hp.hpl.jena.update.GraphStore ;
+import com.hp.hpl.jena.update.Update ;
+import com.hp.hpl.jena.update.UpdateRequest ;
+
+/**
+ * Default implementation of an update engine that does not stream data,
instead it will build it up into an
+ * in-memory UpdateRequest, and then traverse it after all update operations
have finished.
+ */
+public class UpdateEngineNonStreaming extends UpdateEngineBase
+{
+ protected final UpdateRequest request;
+
+ /**
+ * Creates a new Update Engine
+ * @param graphStore Graph Store the updates operate over
+ * @param initialBinding Initial Bindings
+ * @param context Execution Context
+ */
+ public UpdateEngineNonStreaming(GraphStore graphStore, Binding
initialBinding, Context context)
+ {
+ super(graphStore, initialBinding, context) ;
+ request = new UpdateRequest();
+ }
+
+ @Override
+ public void startRequest()
+ {
+ // Do nothing, we will call startRequest() on the graphstore in the
execute() method
+ }
+
+ @Override
+ public void finishRequest()
+ {
+ // Do nothing, we will call finishRequest() on the graphstore in the
execute() method
+ }
+
+ /**
+ * Creates an {@link UpdateSink} that adds all update operations into an
internal {@code UpdateRequest} object.
+ * After the last update operation has been added, the {@link #execute()}
method is called.
+ */
+ @Override
+ public UpdateSink getUpdateSink()
+ {
+ // Override the close() method to call execute() when we're done
accepting update operations
+ return new UpdateRequestSink(request)
+ {
+ @Override
+ public void close()
+ {
+ super.close();
+ execute();
+ }
+ };
+ }
+
+ /**
+ * Called after all of the update operations have been added to {@link
#request}.
+ */
+ protected void execute()
+ {
+ graphStore.startRequest() ;
+ UpdateVisitor worker = this.prepareWorker() ;
+ for ( Update up : request )
+ {
+ up.visit(worker) ;
+ }
+ graphStore.finishRequest();
+ }
+
+ /**
+ * Creates the {@link UpdateVisitor} which will do the work of applying
the updates
+ * @return The update visitor to be used to apply the updates
+ */
+ protected UpdateVisitor prepareWorker() {
+ return new UpdateEngineWorker(graphStore, startBinding, context) ;
+ }
+
+ private static UpdateEngineFactory factory = new UpdateEngineFactory()
+ {
+ @Override
+ public boolean accept(GraphStore graphStore, Context context)
+ {
+ return true ;
+ }
+
+ @Override
+ public UpdateEngine create(GraphStore graphStore, Binding
initialBinding, Context context)
+ {
+ return new UpdateEngineNonStreaming(graphStore, initialBinding,
context);
+ }
+ } ;
+
+ public static UpdateEngineFactory getFactory() { return factory ; }
+}
