[core] Fix offset bug of bitmap index (apache#3911)

herefree · Aug 6, 2024 · 1a3debc · 1a3debc
1 parent 84732cd
commit 1a3debc
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diff --git a/paimon-common/src/main/java/org/apache/paimon/fileindex/bitmap/BitmapFileIndex.java b/paimon-common/src/main/java/org/apache/paimon/fileindex/bitmap/BitmapFileIndex.java
@@ -116,7 +116,11 @@ public byte[] serializedBytes() {
                 // 2.build bitmap file index meta
                 LinkedHashMap<Object, Integer> bitmapOffsets = new LinkedHashMap<>();
                 LinkedList<byte[]> serializeBitmaps = new LinkedList<>();
-                int[] offsetRef = {nullBitmap.isEmpty() ? 0 : nullBitmapBytes.length};
+                int[] offsetRef = {
+                    nullBitmap.isEmpty() || nullBitmap.getCardinality() == 1
+                            ? 0
+                            : nullBitmapBytes.length
+                };
                 id2bitmap.forEach(
                         (k, v) -> {
                             if (v.getCardinality() == 1) {

diff --git a/paimon-common/src/test/java/org/apache/paimon/fileindex/bitmapindex/TestBitmapFileIndex.java b/paimon-common/src/test/java/org/apache/paimon/fileindex/bitmapindex/TestBitmapFileIndex.java
@@ -112,4 +112,30 @@ public void testBitmapIndex2() {
                 (BitmapIndexResultLazy) reader.visitNotIn(fieldRef, Arrays.asList(1, 0));
         assert result5.get().equals(RoaringBitmap32.bitmapOf(2));
     }
+
+    @Test
+    public void testBitmapIndex3() {
+
+        IntType intType = new IntType();
+        FieldRef fieldRef = new FieldRef(0, "", intType);
+        BitmapFileIndex bitmapFileIndex = new BitmapFileIndex(intType, null);
+        FileIndexWriter writer = bitmapFileIndex.createWriter();
+
+        // test only one null-value
+        Object[] arr = {1, 2, 1, 2, 1, 3, null};
+
+        for (Object o : arr) {
+            writer.write(o);
+        }
+        byte[] bytes = writer.serializedBytes();
+        ByteArraySeekableStream seekableStream = new ByteArraySeekableStream(bytes);
+        FileIndexReader reader = bitmapFileIndex.createReader(seekableStream, 0, bytes.length);
+
+        BitmapIndexResultLazy result1 = (BitmapIndexResultLazy) reader.visitEqual(fieldRef, 1);
+        assert result1.get().equals(RoaringBitmap32.bitmapOf(0, 2, 4));
+
+        // test read singleton bitmap
+        BitmapIndexResultLazy result2 = (BitmapIndexResultLazy) reader.visitIsNull(fieldRef);
+        assert result2.get().equals(RoaringBitmap32.bitmapOf(6));
+    }
 }