bencodetorrent.class.php

<?

/**
 * Torrent class that contains some convenient functions related to torrent meta data
 */
class BencodeTorrent extends BencodeDecode {
    private $PathKey = 'path';
    public $Files = array();
    public $Size = 0;

    /**
     * Create a list of the files in the torrent and their sizes as well as the total torrent size
     *
     * @return array with a list of files and file sizes
     */
    public function file_list() {
        if (empty($this->Dec)) {
            return false;
        }
        $InfoDict = &$this->Dec['info'];
        if (!isset($InfoDict['files'])) {
            // Single-file torrent
            $this->Size = (Int64::is_int($InfoDict['length'])
                ? Int64::get($InfoDict['length'])
                : $InfoDict['length']);
            $Name = (isset($InfoDict['name.utf-8'])
                ? $InfoDict['name.utf-8']
                : $InfoDict['name']);
            $this->Files[] = array($this->Size, $Name);
        } else {
            if (isset($InfoDict['path.utf-8']['files'][0])) {
                $this->PathKey = 'path.utf-8';
            }
            foreach ($InfoDict['files'] as $File) {
                $TmpPath = array();
                foreach ($File[$this->PathKey] as $SubPath) {
                    $TmpPath[] = $SubPath;
                }
                $CurSize = (Int64::is_int($File['length'])
                    ? Int64::get($File['length'])
                    : $File['length']);
                $this->Files[] = array($CurSize, implode('/', $TmpPath));
                $this->Size += $CurSize;
            }
            uasort($this->Files, function ($a, $b) {
                return strnatcasecmp($a[1], $b[1]);
            });
        }
        return array($this->Size, $this->Files);
    }

    /**
     * Find out the name of the torrent
     *
     * @return string torrent name
     */
    public function get_name() {
        if (empty($this->Dec)) {
            return false;
        }
        if (isset($this->Dec['info']['name.utf-8'])) {
            return $this->Dec['info']['name.utf-8'];
        }
        return $this->Dec['info']['name'];
    }

    /**
     * Find out the total size of the torrent
     *
     * @return string torrent size
     */
    public function get_size() {
        if (empty($this->Files)) {
            if (empty($this->Dec)) {
                return false;
            }
            $FileList = $this->file_list();
        }
        return $FileList[0];
    }

    /**
     * Checks if the "private" flag is present in the torrent
     *
     * @return true if the "private" flag is set
     */
    public function is_private() {
        if (empty($this->Dec)) {
            return false;
        }
        return isset($this->Dec['info']['private']) && Int64::get($this->Dec['info']['private']) == 1;
    }
    /**
     * Add the "private" flag to the torrent
     *
     * @return true if a change was required
     */
    public function make_private() {
        if (empty($this->Dec)) {
            return false;
        }
        if ($this->is_private()) {
            return false;
        }
        $this->Dec['info']['private'] = Int64::make(1);
        ksort($this->Dec['info']);
        return true;
    }

    /**
     * Adds thet "source" flag to the torrent to allow for easier cross-seeding
     *
     * @return bool false if the source flag was already set to GreatPosterWall, else true
     */
    function set_source() {
        if (empty($this->Dec)) {
            return false;
        }

        if (isset($this->Dec['info']['source']) && $this->Dec['info']['source'] === TORRENT_SOURCE) {
            return false;
        }

        $this->Dec['info']['source'] = TORRENT_SOURCE;
        ksort($this->Dec['info']);
        return true;
    }

    /**
     * Calculate the torrent's info hash
     *
     * @return info hash in hexadecimal form
     */
    public function info_hash() {
        if (empty($this->Dec) || !isset($this->Dec['info'])) {
            return false;
        }
        return sha1($this->encode(false, 'info'));
    }

    /**
     * Add the announce URL to a torrent
     */
    public static function add_announce_url($Data, $Url) {
        return 'd8:announce' . strlen($Url) . ':' . $Url . substr($Data, 1);
    }
}