public Object get(long id) {
      Object result;
      if (id >= 0 && id <= 0x00000000FFFFFFFFL) {
        result = ints.get((int) id);
      } else {
        result = longs.get(id);
      }
      return result;
    }
Mpa of OplogEntryIds (longs). Memory is optimized by using an int[] for ids in the unsigned int
range.
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java