parquet-column/src/main/java/org/apache/parquet/internal/column/columnindex/OffsetIndexBuilder.java
public void add(int compressedPageSize, long rowCount) {
    add(previousOffset + previousPageSize, compressedPageSize, previousRowIndex + previousRowCount);
    previousRowCount = rowCount;
  }
public void add(int compressedPageSize, long rowCount) {
    add(previousOffset + previousPageSize, compressedPageSize, previousRowIndex + previousRowCount);
    previousRowCount = rowCount;
  }
Adds the specified parameters to this builder. Used by the writers to building up {@link OffsetIndex} objects to be
written to the Parquet file.

@param compressedPageSize
the size of the page (including header)
@param rowCount
the number of rows in the page