@Override
  public boolean needsCompaction(List<HStoreFile> filesCompacting) {
    return compactionPolicy.needsCompaction(this.storeFileManager.getStoreFiles(), filesCompacting);
  }
Default StoreEngine creates the default compactor, policy, and store file manager, or their
derivatives.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/DefaultStoreEngine.java