public int numCompactableOplogs() {
    CompactableOplog[] oplogs = getOplogsToBeCompacted(true);
    if (oplogs == null) {
      return 0;
    } else {
      return oplogs.length;
    }

  }
Test hook to see how many oplogs are available for compaction
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreImpl.java