parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileWriter.java
public void startBlock(long recordCount) throws IOException {
    state = state.startBlock();
    LOG.debug("{}: start block", out.getPos());
//    out.write(MAGIC); // TODO: add a magic delimiter

    alignment.alignForRowGroup(out);

    currentBlock = new BlockMetaData();
    currentRecordCount = recordCount;

    currentColumnIndexes = new ArrayList<>();
    currentOffsetIndexes = new ArrayList<>();
  }
public void startBlock(long recordCount) throws IOException {
    state = state.startBlock();
    LOG.debug("{}: start block", out.getPos());
//    out.write(MAGIC); // TODO: add a magic delimiter

    alignment.alignForRowGroup(out);

    currentBlock = new BlockMetaData();
    currentRecordCount = recordCount;

    currentColumnIndexes = new ArrayList<>();
    currentOffsetIndexes = new ArrayList<>();
  }
start a block
@param recordCount the record count in this block
@throws IOException if there is an error while writing