@Override
    public void afterHavingCompacted() {
      try {
        putsCompleted.await(10, TimeUnit.SECONDS);
      } catch (InterruptedException e) {
        exceptionOccurred.set(true);
        throw new RuntimeException(e);
      }
      cache.getLogger().info("afterHavingCompacted");
      if (spaceUsageBefore > -1) {
        hasCompacted.set(true);
        long after = dh.getDirStatsDiskSpaceUsage();
        // after compaction, in _2.crf, key3 is an create-entry,
        // key1 and key2 are tombstones.
        // _2.drf contained a rvvgc with drMap.size()==1
        int expectedDrfSize = Oplog.OPLOG_DISK_STORE_REC_SIZE + Oplog.OPLOG_MAGIC_SEQ_REC_SIZE
            + Oplog.OPLOG_GEMFIRE_VERSION_REC_SIZE
            + CompactOfflineDiskStoreJUnitTest.getRVVSize(1, new int[] {0}, true);
        int expectedCrfSize = Oplog.OPLOG_DISK_STORE_REC_SIZE + Oplog.OPLOG_MAGIC_SEQ_REC_SIZE
            + Oplog.OPLOG_GEMFIRE_VERSION_REC_SIZE
            + CompactOfflineDiskStoreJUnitTest.getRVVSize(1, new int[] {1}, false)
            + Oplog.OPLOG_NEW_ENTRY_BASE_REC_SIZE + key3Size + tombstoneKey1 + tombstoneKey2;
        int oplog2Size = expectedDrfSize + expectedCrfSize;
        if (after != oplog2Size) {
          cache.getLogger().info("test failed before=" + spaceUsageBefore + " after=" + after
              + " expected=" + oplog2Size);
          exceptionOccurred.set(true);
        } else {
          exceptionOccurred.set(false);
        }
        LocalRegion.ISSUE_CALLBACKS_TO_CACHE_OBSERVER = false;
      }
    }
Tests if without rolling the region size before close is same as after recreation
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/OplogJUnitTest.java