1 files changed, 109 insertions, 0 deletions
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/txn/TxnBuffer.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/txn/TxnBuffer.java
new file mode 100644
index 0000000000..46a68b6a23
--- /dev/null
+++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/txn/TxnBuffer.java
@@ -0,0 +1,109 @@
+/*
+ *
+ * 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 org.apache.qpid.server.txn;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.log4j.Logger;
+import org.apache.qpid.AMQException;
+import org.apache.qpid.server.store.StoreContext;
+
+/** Holds a list of TxnOp instance representing transactional operations. */
+public class TxnBuffer
+{
+    private final List<TxnOp> _ops = new ArrayList<TxnOp>();
+    private static final Logger _log = Logger.getLogger(TxnBuffer.class);
+
+    public TxnBuffer()
+    {
+    }
+
+    public void commit(StoreContext context) throws AMQException
+    {
+        if (_log.isDebugEnabled())
+        {
+            _log.debug("Committing " + _ops.size() + " ops to commit.:" + _ops);
+        }
+
+        if (prepare(context))
+        {
+            for (TxnOp op : _ops)
+            {
+                op.commit(context);
+            }
+        }
+        _ops.clear();
+    }
+
+    private boolean prepare(StoreContext context) throws AMQException
+    {
+        for (int i = 0; i < _ops.size(); i++)
+        {
+            TxnOp op = _ops.get(i);
+            try
+            {
+                op.prepare(context);
+            }
+            catch (AMQException e)
+            {
+                undoPrepare(i);
+                throw e;
+            }
+            catch (RuntimeException e)
+            {
+                undoPrepare(i);
+                throw e;
+            }
+        }
+        return true;
+    }
+
+    private void undoPrepare(int lastPrepared)
+    {
+        //compensate previously prepared ops
+        for (int j = 0; j < lastPrepared; j++)
+        {
+            _ops.get(j).undoPrepare();
+        }
+    }
+
+	
+	
+    public void rollback(StoreContext context) throws AMQException
+    {
+        for (TxnOp op : _ops)
+        {
+            op.rollback(context);
+        }
+        _ops.clear();
+    }
+
+    public void enlist(TxnOp op)
+    {
+        _ops.add(op);
+    }
+
+    public void cancel(TxnOp op)
+    {
+        _ops.remove(op);
+    }
+}