PhpOffice\PhpSpreadsheet\Shared\OLERead::read()

Complexity

Conditions	9
Paths	81

Size

Total Lines	87
Code Lines	45

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	37
CRAP Score	9.607

Importance

Changes

0

<?php
    public function read(string $filename): void
    {
        File::assertFile($filename);

        // Get the file identifier
        // Don't bother reading the whole file until we know it's a valid OLE file
        $this->data = (string) file_get_contents($filename, false, null, 0, 8);

        // Check OLE identifier
        $identifierOle = pack('CCCCCCCC', 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1);
        if ($this->data != $identifierOle) {
            throw new ReaderException('The filename ' . $filename . ' is not recognised as an OLE file');
        }

        // Get the file data
        $this->data = (string) file_get_contents($filename);

        // Total number of sectors used for the SAT
        $this->numBigBlockDepotBlocks = self::getInt4d($this->data, self::NUM_BIG_BLOCK_DEPOT_BLOCKS_POS);

        // SecID of the first sector of the directory stream
        $this->rootStartBlock = self::getInt4d($this->data, self::ROOT_START_BLOCK_POS);

        // SecID of the first sector of the SSAT (or -2 if not extant)
        $this->sbdStartBlock = self::getInt4d($this->data, self::SMALL_BLOCK_DEPOT_BLOCK_POS);

        // SecID of the first sector of the MSAT (or -2 if no additional sectors are used)
        $this->extensionBlock = self::getInt4d($this->data, self::EXTENSION_BLOCK_POS);

        // Total number of sectors used by MSAT
        $this->numExtensionBlocks = self::getInt4d($this->data, self::NUM_EXTENSION_BLOCK_POS);

        $bigBlockDepotBlocks = [];
        $pos = self::BIG_BLOCK_DEPOT_BLOCKS_POS;

        $bbdBlocks = $this->numBigBlockDepotBlocks;

        if ($this->numExtensionBlocks !== 0) {
            $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;
            $blocksToRead = min($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) {
                $this->extensionBlock = self::getInt4d($this->data, $pos);
            }
        }

        $pos = 0;
        $this->bigBlockChain = '';
        $bbs = self::BIG_BLOCK_SIZE / 4;
        for ($i = 0; $i < $this->numBigBlockDepotBlocks; ++$i) {
            $pos = ($bigBlockDepotBlocks[$i] + 1) * self::BIG_BLOCK_SIZE;

            $this->bigBlockChain .= substr($this->data, $pos, 4 * $bbs);
            $pos += 4 * $bbs;
        }

        $sbdBlock = $this->sbdStartBlock;
        $this->smallBlockChain = '';
        while ($sbdBlock != -2) {
            $pos = ($sbdBlock + 1) * self::BIG_BLOCK_SIZE;

            $this->smallBlockChain .= substr($this->data, $pos, 4 * $bbs);
            $pos += 4 * $bbs;

            $sbdBlock = self::getInt4d($this->bigBlockChain, $sbdBlock * 4);
        }

        // read the directory stream
        $block = $this->rootStartBlock;
        $this->entry = $this->readData($block);

        $this->readPropertySets();
    }