@Override
  public Chunk loadChunk(ChunkMetadata chunkMetaData) throws IOException {
    return ChunkCache.getInstance()
        .get(
            new ChunkCache.ChunkCacheKey(
                resource.getTsFilePath(),
                resource.getTsFileID(),
                chunkMetaData.getOffsetOfChunkHeader(),
                resource.isClosed()),
            chunkMetaData.getDeleteIntervalList(),
            chunkMetaData.getStatistics(),
            context);
  }
To read one chunk from disk, and only used in iotdb server module.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/read/reader/chunk/DiskChunkLoader.java