TEIID-2731 adding a stable sort option

teiid · Nov 8, 2013 · de9eccd · de9eccd
1 parent a4ebf9b
commit de9eccd
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Showing 2 changed files with 34 additions and 1 deletion.
diff --git a/engine/src/main/java/org/teiid/query/processor/relational/SortUtility.java b/engine/src/main/java/org/teiid/query/processor/relational/SortUtility.java
@@ -39,6 +39,7 @@
 import org.teiid.core.TeiidComponentException;
 import org.teiid.core.TeiidProcessingException;
 import org.teiid.core.util.Assertion;
+import org.teiid.core.util.PropertiesUtils;
 import org.teiid.language.SortSpecification.NullOrdering;
 import org.teiid.logging.LogConstants;
 import org.teiid.logging.LogManager;
@@ -114,6 +115,10 @@ public String toString() {
 	private TupleBuffer workingBuffer;
 	private long[] attempts = new long[2];
 	private boolean nonBlocking;
+
+	private static boolean STABLE_SORT = PropertiesUtils.getBooleanProperty(System.getProperties(), "org.teiid.requireStableSort", false); //$NON-NLS-1$
+
+	private boolean stableSort = STABLE_SORT;
 
     public SortUtility(TupleSource sourceID, List<OrderByItem> items, Mode mode, BufferManager bufferMgr,
                         String groupName, List<? extends Expression> schema) {
@@ -325,7 +330,7 @@ protected void initialSort(boolean onePass) throws TeiidComponentException, Teii
 				}
 			}
 			TupleBufferTupleSource ts = workingBuffer.createIndexedTupleSource(source != null);
-			ts.setReverse(workingBuffer.getRowCount() > this.batchSize);
+			ts.setReverse((!stableSort || mode == Mode.DUP_REMOVE) && workingBuffer.getRowCount() > this.batchSize);
 			processed+=this.workingBuffer.getRowCount();
 			maxRows = Math.max(1, (totalReservedBuffers/schemaSize))*batchSize;
             if (mode == Mode.SORT) {
@@ -560,5 +565,13 @@ public void remove() {
 	public void setNonBlocking(boolean b) {
 		this.nonBlocking = b;
 	}
+
+	public void setStableSort(boolean stableSort) {
+		this.stableSort = stableSort;
+	}
+
+	void setBatchSize(int batchSize) {
+		this.batchSize = batchSize;
+	}
 
 }
diff --git a/engine/src/test/java/org/teiid/query/processor/relational/TestSortNode.java b/engine/src/test/java/org/teiid/query/processor/relational/TestSortNode.java
@@ -384,5 +384,25 @@ private void helpTestAllSorts(int batches) throws Exception {
         FakeDataStore.sampleData1(dataMgr, RealMetadataFactory.example1Cached());
         TestProcessor.helpProcess(plan, dataMgr, new List[]{Collections.singletonList(null)});
     }
+
+    @Test public void testStableSort() throws Exception {
+    	ElementSymbol es1 = new ElementSymbol("e1"); //$NON-NLS-1$
+        es1.setType(DataTypeManager.DefaultDataClasses.INTEGER);
+        BufferManager bm = BufferManagerFactory.getStandaloneBufferManager();
+        TupleBuffer tsid = bm.createTupleBuffer(Arrays.asList(es1, es1), "test", TupleSourceType.PROCESSOR); //$NON-NLS-1$
+        tsid.addTuple(Arrays.asList(1, 1));
+    	tsid.addTuple(Arrays.asList(1, 2));
+    	tsid.addTuple(Arrays.asList(1, 3));
+    	tsid.close();
+    	SortUtility su = new SortUtility(tsid.createIndexedTupleSource(), Arrays.asList(es1), Arrays.asList(Boolean.TRUE), Mode.SORT, bm, "test", tsid.getSchema()); //$NON-NLS-1$
+    	su.setBatchSize(1);
+    	su.setStableSort(true);
+    	TupleBuffer out = su.sort();
+    	TupleSource ts = out.createIndexedTupleSource();
+    	assertEquals(Arrays.asList(1,1), ts.nextTuple());
+    	assertEquals(Arrays.asList(1,2), ts.nextTuple());
+    	assertEquals(Arrays.asList(1,3), ts.nextTuple());
+    	assertNull(ts.nextTuple());
+    }
 
 }