public function __construct(FileInterface $file, ColumnSchema $columnPage)
{
$this->file = $file;
$this->columnSchema = $columnPage;
$cellSize = $columnPage->getCellSize();
if ($cellSize <= 1) {
$this->cellLengthSize = 1;
} else {
$this->cellLengthSize = ceil(log($columnPage->getCellSize(), 256));
}
assert($this->file->getLength() % $this->getPageSize() === 0);
}