1 files changed, 62 insertions, 0 deletions
diff --git a/qpid/java/broker-core/src/main/java/org/apache/qpid/server/store/NonNullUpgrader.java b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/store/NonNullUpgrader.java
new file mode 100644
index 0000000000..a671e93b26
--- /dev/null
+++ b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/store/NonNullUpgrader.java
@@ -0,0 +1,62 @@
+/*
+ *
+ * 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.store;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public abstract class NonNullUpgrader implements DurableConfigurationStoreUpgrader
+{
+    private DurableConfigurationStoreUpgrader _nextUpgrader;
+    private final Map<UUID, ConfiguredObjectRecord> _updates = new HashMap<UUID, ConfiguredObjectRecord>();
+
+    public final void setNextUpgrader(final DurableConfigurationStoreUpgrader upgrader)
+    {
+        if(_nextUpgrader == null)
+        {
+            _nextUpgrader = upgrader;
+        }
+        else
+        {
+            _nextUpgrader.setNextUpgrader(upgrader);
+        }
+    }
+
+    protected DurableConfigurationStoreUpgrader getNextUpgrader()
+    {
+        return _nextUpgrader;
+    }
+
+    protected Map<UUID, ConfiguredObjectRecord> getUpdateMap()
+    {
+        return _updates;
+    }
+
+    @Override
+    public final Map<UUID, ConfiguredObjectRecord> getUpdatedRecords()
+    {
+        final Map<UUID, ConfiguredObjectRecord> updates = new HashMap<UUID, ConfiguredObjectRecord>(_updates);
+        updates.putAll(_nextUpgrader.getUpdatedRecords());
+        return updates;
+    }
+
+}