parquet-column/src/main/java/org/apache/parquet/internal/column/columnindex/OffsetIndexBuilder.java
public void add(long offset, int compressedPageSize, long firstRowIndex) {
    previousOffset = offset;
    offsets.add(offset);
    previousPageSize = compressedPageSize;
    compressedPageSizes.add(compressedPageSize);
    previousRowIndex = firstRowIndex;
    firstRowIndexes.add(firstRowIndex);
  }
public void add(long offset, int compressedPageSize, long firstRowIndex) {
    previousOffset = offset;
    offsets.add(offset);
    previousPageSize = compressedPageSize;
    compressedPageSizes.add(compressedPageSize);
    previousRowIndex = firstRowIndex;
    firstRowIndexes.add(firstRowIndex);
  }
Adds the specified parameters to this builder. Used by the metadata converter to building up {@link OffsetIndex}
objects read from the Parquet file.

@param offset
the offset of the page in the file
@param compressedPageSize
the size of the page (including header)
@param firstRowIndex
the index of the first row in the page (within the row group)