OPENDJ-1116 Introduce abstraction for the changelog DB

Jean-Noel Rouvignac

17.46.2013 cec016958f29b8849a1768e588e1d728d621af49

 opends/src/server/org/opends/server/replication/server/changelog/je/DraftCNDB.java

@@ -31,7 +31,6 @@
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.opends.messages.Message;
import org.opends.messages.MessageBuilder;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.replication.server.changelog.api.CNIndexRecord;
@@ -398,10 +397,12 @@
            // We could not move the cursor to the expected startChangeNumber
            if (localCursor.getSearchKeyRange(key, entry, DEFAULT) != SUCCESS)
            {
              // We could not even move the cursor close to it => failure
              throw new ChangelogException(
                  Message.raw("ChangeLog Change Number " + startChangeNumber
                      + " is not available"));
              // We could not even move the cursor close to it
              // => return an empty cursor
              isClosed = true;
              txn = null;
              cursor = null;
              return;
            }

            if (localCursor.getPrev(key, entry, LockMode.DEFAULT) != SUCCESS)