@Override
    public void beforeIndexLookup(Index index, int oper, Object key) {
      readLockCount = index.getStatistics().getReadLockCountLong();
    }
Test MapRenageIndex IndexStatistics for keys, values, updates and uses.
geode-core/src/integrationTest/java/org/apache/geode/cache/query/internal/index/IndexStatisticsJUnitTest.java