QPID-3888: ensure the SQEL iterator uses the getNextValidEntry() method to advance, simplifying its implementation and aiding queue cleanup by releasing deleted entries from the data structure. In doing so ensure that it ignores a deleted node at the end of the list, returning that it is atTail and cannot advance. Add unit test highlighting the issue and confirming its resolution.
git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1297794 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/queue/SimpleQueueEntryList.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/queue/SimpleQueueEntryList.java
index e573901..c82d1b9 100644
--- a/qpid/java/broker/src/main/java/org/apache/qpid/server/queue/SimpleQueueEntryList.java
+++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/queue/SimpleQueueEntryList.java
@@ -116,7 +116,6 @@
public static class QueueEntryIteratorImpl implements QueueEntryIterator<SimpleQueueEntryImpl>
{
-
private SimpleQueueEntryImpl _lastNode;
QueueEntryIteratorImpl(SimpleQueueEntryImpl startNode)
@@ -124,10 +123,9 @@
_lastNode = startNode;
}
-
public boolean atTail()
{
- return _lastNode.getNextNode() == null;
+ return _lastNode.getNextValidEntry() == null;
}
public SimpleQueueEntryImpl getNode()
@@ -137,28 +135,17 @@
public boolean advance()
{
+ SimpleQueueEntryImpl nextValidNode = _lastNode.getNextValidEntry();
- if(!atTail())
+ if(nextValidNode != null)
{
- SimpleQueueEntryImpl nextNode = _lastNode.getNextNode();
- while(nextNode.isDispensed() && nextNode.getNextNode() != null)
- {
- nextNode = nextNode.getNextNode();
- }
- _lastNode = nextNode;
- return true;
-
- }
- else
- {
- return false;
+ _lastNode = nextValidNode;
}
+ return nextValidNode != null;
}
-
}
-
public QueueEntryIteratorImpl iterator()
{
return new QueueEntryIteratorImpl(_head);
diff --git a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/QueueEntryListTestBase.java b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/QueueEntryListTestBase.java
index 7f81aae..4b40c3b 100644
--- a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/QueueEntryListTestBase.java
+++ b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/QueueEntryListTestBase.java
@@ -31,6 +31,7 @@
{
protected static final AMQQueue _testQueue = new MockAMQQueue("test");
public abstract QueueEntryList<QueueEntry> getTestList();
+ public abstract QueueEntryList<QueueEntry> getTestList(boolean newList);
public abstract long getExpectedFirstMsgId();
public abstract int getExpectedListLength();
public abstract ServerMessage getTestMessageToAdd() throws AMQException;
@@ -188,4 +189,36 @@
.getMessage().getMessageNumber(), third.getMessage().getMessageNumber());
}
+ /**
+ * Tests that after the last node of the list is marked deleted but has not yet been removed,
+ * the iterator still ignores it and returns that it is 'atTail()' and can't 'advance()'
+ *
+ * @see QueueEntryListTestBase#getTestList()
+ * @see QueueEntryListTestBase#getExpectedListLength()
+ */
+ public void testIteratorIgnoresDeletedFinalNode() throws Exception
+ {
+ QueueEntryList<QueueEntry> list = getTestList(true);
+ int i = 0;
+
+ QueueEntry queueEntry1 = list.add(new MockAMQMessage(i++));
+ QueueEntry queueEntry2 = list.add(new MockAMQMessage(i++));
+
+ assertSame(queueEntry2, list.next(queueEntry1));
+ assertNull(list.next(queueEntry2));
+
+ //'delete' the 2nd QueueEntry
+ assertTrue("Deleting node should have succeeded", queueEntry2.delete());
+
+ QueueEntryIterator<QueueEntry> iter = list.iterator();
+
+ //verify the iterator isn't 'atTail', can advance, and returns the 1st QueueEntry
+ assertFalse("Iterator should not have been 'atTail'", iter.atTail());
+ assertTrue("Iterator should have been able to advance", iter.advance());
+ assertSame("Iterator returned unexpected QueueEntry", queueEntry1, iter.getNode());
+
+ //verify the iterator is atTail() and can't advance
+ assertTrue("Iterator should have been 'atTail'", iter.atTail());
+ assertFalse("Iterator should not have been able to advance", iter.advance());
+ }
}
diff --git a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SimpleQueueEntryListTest.java b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SimpleQueueEntryListTest.java
index 55c6143..caf1eea 100644
--- a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SimpleQueueEntryListTest.java
+++ b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SimpleQueueEntryListTest.java
@@ -23,6 +23,7 @@
import org.apache.qpid.AMQException;
import org.apache.qpid.server.message.AMQMessage;
import org.apache.qpid.server.message.ServerMessage;
+import org.apache.qpid.server.queue.SimpleQueueEntryList.QueueEntryIteratorImpl;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
@@ -59,11 +60,24 @@
System.clearProperty(SCAVENGE_PROP);
}
}
-
+
@Override
public QueueEntryList getTestList()
{
- return _sqel;
+ return getTestList(false);
+ }
+
+ @Override
+ public QueueEntryList getTestList(boolean newList)
+ {
+ if(newList)
+ {
+ return new SimpleQueueEntryList(_testQueue);
+ }
+ else
+ {
+ return _sqel;
+ }
}
@Override
@@ -216,5 +230,4 @@
next = next.getNextValidEntry();
assertNull("The next entry after the last should be null", next);
}
-
}
diff --git a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SortedQueueEntryListTest.java b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SortedQueueEntryListTest.java
index 794888f..38b12f8 100644
--- a/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SortedQueueEntryListTest.java
+++ b/qpid/java/broker/src/test/java/org/apache/qpid/server/queue/SortedQueueEntryListTest.java
@@ -77,9 +77,23 @@
}
+ @Override
public QueueEntryList getTestList()
{
- return _sqel;
+ return getTestList(false);
+ }
+
+ @Override
+ public QueueEntryList getTestList(boolean newList)
+ {
+ if(newList)
+ {
+ return new SelfValidatingSortedQueueEntryList(_testQueue, "KEY");
+ }
+ else
+ {
+ return _sqel;
+ }
}
public int getExpectedListLength()
