edge cases

Author: mutianf

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/RowSetUtil.java

@@ -184,9 +184,17 @@ private static List<RowRange> splitOnLargeRowKey(RowRange range, ByteString larg
     // if the end key is on the right of the large row key, set the start key to be large row key
     // open. Empty end key is unbounded so it's always on the right of the large key
     if (endKey.isEmpty() || ByteStringComparator.INSTANCE.compare(endKey, largeRowKey) > 0) {
-      RowRange afterSplit = range.toBuilder().setStartKeyOpen(largeRowKey).build();
-      rowRanges.add(afterSplit);
+      // handle the edge case where (key, key\0) is an empty range and should be excluded
+      ByteString nextKey = largeRowKey.concat(ByteString.copyFrom(new byte[] {0}));
+      EndPoint endPoint = EndPoint.extract(range);
+      boolean isEmptyRange = !endPoint.isClosed && endPoint.value.equals(nextKey);
+
+      if (!isEmptyRange) {
+        RowRange afterSplit = range.toBuilder().setStartKeyOpen(largeRowKey).build();
+        rowRanges.add(afterSplit);
+      }
     }
+
     return rowRanges;
   }
 

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/internal/RowSetUtilTest.java

@@ -331,6 +331,20 @@ public void multipleRangeBoundTest() {
     assertThat(actual).isEqualTo(ByteStringRange.create("a", "z"));
   }
 
+  @Test
+  public void eraseLargeRowEmptyRangeTest() {
+    ByteString key = ByteString.copyFromUtf8("a");
+    ByteString keyTrailer = key.concat(ByteString.copyFrom(new byte[] {0}));
+
+    RowSet rowSet =
+        RowSet.newBuilder()
+            .addRowRanges(
+                RowRange.newBuilder().setStartKeyClosed(key).setEndKeyOpen(keyTrailer).build())
+            .build();
+    RowSet actual = RowSetUtil.eraseLargeRow(rowSet, key);
+    assertThat(actual).isNull();
+  }
+
   // Helpers
   private static void verifyShard(RowSet input, SortedSet<ByteString> splits, RowSet... expected) {
     List<RowSet> actualWithNull = RowSetUtil.shard(input, splits);