PHPOffice / PhpSpreadsheet

            $bbdBlocks = (self::BIG_BLOCK_SIZE - self::BIG_BLOCK_DEPOT_BLOCKS_POS) / 4;

        }

        for ($i = 0; $i < $bbdBlocks; ++$i) {

            $bigBlockDepotBlocks[$i] = self::getInt4d($this->data, $pos);

            $pos += 4;

        }

        for ($j = 0; $j < $this->numExtensionBlocks; ++$j) {

            $pos = ($this->extensionBlock + 1) * self::BIG_BLOCK_SIZE;

            $pos = ($this->extensionBlock + 1) * self::BIG_BLOCK_SIZE;

            $blocksToRead = min($this->numBigBlockDepotBlocks - $bbdBlocks, self::BIG_BLOCK_SIZE / 4 - 1);

            for ($i = $bbdBlocks; $i < $bbdBlocks + $blocksToRead; ++$i) {

                $bigBlockDepotBlocks[$i] = self::getInt4d($this->data, $pos);

                $pos += 4;

            }

            $bbdBlocks += $blocksToRead;

            if ($bbdBlocks < $this->numBigBlockDepotBlocks) {