Fix Extraction Filter cast problems for empty results

processing/src/main/java/io/druid/segment/filter/ExtractionFilter.java

@@ -19,7 +19,7 @@ package io.druid.segment.filter;
 
 import com.google.common.collect.Lists;
 import com.metamx.collections.bitmap.ImmutableBitmap;
-import com.metamx.collections.bitmap.WrappedConciseBitmap;
+import com.metamx.collections.bitmap.WrappedImmutableConciseBitmap;
 import io.druid.query.extraction.ExtractionFn;
 import io.druid.query.filter.BitmapIndexSelector;
 import io.druid.query.filter.Filter;
@@ -27,6 +27,7 @@ import io.druid.query.filter.ValueMatcher;
 import io.druid.query.filter.ValueMatcherFactory;
 import io.druid.segment.ColumnSelectorFactory;
 import io.druid.segment.data.Indexed;
+import it.uniroma3.mat.extendedset.intset.ImmutableConciseSet;
 
 import java.util.List;
 
@@ -65,12 +66,14 @@ public class ExtractionFilter implements Filter
     return filters;
   }
 
+  private static final WrappedImmutableConciseBitmap ZERO_LENGTH_SET = new WrappedImmutableConciseBitmap(new ImmutableConciseSet());
+
   @Override
   public ImmutableBitmap getBitmapIndex(BitmapIndexSelector selector)
   {
     final List<Filter> filters = makeFilters(selector);
     if (filters.isEmpty()) {
-      return new WrappedConciseBitmap();
+      return ZERO_LENGTH_SET;
     }
     return new OrFilter(makeFilters(selector)).getBitmapIndex(selector);
   }

processing/src/test/java/io/druid/segment/filter/ExtractionDimFilterTest.java

@@ -22,6 +22,7 @@ import com.metamx.collections.bitmap.BitmapFactory;
 import com.metamx.collections.bitmap.ConciseBitmapFactory;
 import com.metamx.collections.bitmap.ImmutableBitmap;
 import com.metamx.collections.bitmap.WrappedConciseBitmap;
+import com.metamx.collections.bitmap.WrappedImmutableConciseBitmap;
 import com.metamx.collections.spatial.ImmutableRTree;
 import io.druid.query.extraction.DimExtractionFn;
 import io.druid.query.extraction.ExtractionFn;
@@ -31,6 +32,7 @@ import io.druid.query.filter.ExtractionDimFilter;
 import io.druid.segment.data.ArrayIndexed;
 import io.druid.segment.data.Indexed;
 import it.uniroma3.mat.extendedset.intset.ConciseSet;
+import it.uniroma3.mat.extendedset.intset.ImmutableConciseSet;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -59,11 +61,12 @@ public class ExtractionDimFilterTest
   {
     final ConciseSet conciseSet = new ConciseSet();
     conciseSet.add(1);
-    foo1BitMap = new WrappedConciseBitmap(conciseSet);
+    foo1BitMap = new WrappedImmutableConciseBitmap(ImmutableConciseSet.newImmutableFromMutable(conciseSet));
   }
 
   private static final BitmapIndexSelector BITMAP_INDEX_SELECTOR = new BitmapIndexSelector()
   {
+    private final ConciseBitmapFactory factory = new ConciseBitmapFactory();
     @Override
     public Indexed<String> getDimensionValues(String dimension)
     {
@@ -80,7 +83,7 @@ public class ExtractionDimFilterTest
     @Override
     public BitmapFactory getBitmapFactory()
     {
-      return new ConciseBitmapFactory();
+      return factory;
     }
 
     @Override
@@ -183,4 +186,72 @@ public class ExtractionDimFilterTest
         ).getBitmapIndex(BITMAP_INDEX_SELECTOR).size()
     );
   }
+
+  @Test
+  public void testAnd()
+  {
+    Assert.assertEquals(
+        1, Filters.convertDimensionFilters(
+            DimFilters.or(
+                new ExtractionDimFilter(
+                    "foo",
+                    "extractDimVal",
+                    DIM_EXTRACTION_FN,
+                    null
+                )
+            )
+        ).getBitmapIndex(BITMAP_INDEX_SELECTOR).size()
+    );
+
+    Assert.assertEquals(
+        1,
+        Filters.convertDimensionFilters(
+            DimFilters.and(
+                new ExtractionDimFilter(
+                    "foo",
+                    "extractDimVal",
+                    DIM_EXTRACTION_FN,
+                    null
+                ),
+                new ExtractionDimFilter(
+                    "foo",
+                    "extractDimVal",
+                    DIM_EXTRACTION_FN,
+                    null
+                )
+            )
+        ).getBitmapIndex(BITMAP_INDEX_SELECTOR).size()
+    );
+  }
+
+  @Test
+  public void testNot(){
+
+    Assert.assertEquals(
+        1, Filters.convertDimensionFilters(
+            DimFilters.or(
+                new ExtractionDimFilter(
+                    "foo",
+                    "extractDimVal",
+                    DIM_EXTRACTION_FN,
+                    null
+                )
+            )
+        ).getBitmapIndex(BITMAP_INDEX_SELECTOR).size()
+    );
+
+    Assert.assertEquals(
+        1,
+        Filters.convertDimensionFilters(
+            DimFilters.not(
+                new ExtractionDimFilter(
+                    "foo",
+                    "DOES NOT EXIST",
+                    DIM_EXTRACTION_FN,
+                    null
+                )
+            )
+        ).getBitmapIndex(BITMAP_INDEX_SELECTOR).size()
+    );
+  }
 }