ovidiul / XCloner-Wordpress

includes/class-xcloner-archive.php

<?php
/**
 * XCloner - Backup and Restore backup plugin for Wordpress
 *
 * class-xcloner-archive.php
 * @author Liuta Ovidiu <info@thinkovi.com>
 *
 *        This program is free software; you can redistribute it and/or modify
 *        it under the terms of the GNU General Public License as published by
 *        the Free Software Foundation; either version 2 of the License, or
 *        (at your option) any later version.
 *
 *        This program is distributed in the hope that it will be useful,
 *        but WITHOUT ANY WARRANTY; without even the implied warranty of
 *        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *        GNU General Public License for more details.
 *
 *        You should have received a copy of the GNU General Public License
 *        along with this program; if not, write to the Free Software
 *        Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *        MA 02110-1301, USA.
 *
 * @link https://github.com/ovidiul/XCloner-Wordpress
 *
 * @modified 7/31/18 3:10 PM
 *
 */

use splitbrain\PHPArchive\Tar;
use splitbrain\PHPArchive\Archive;
use splitbrain\PHPArchive\FileInfo;

/**
 * Class responsible for adding files to Tar
 * Class Xcloner_Archive
 */
class Xcloner_Archive extends Tar
{
	/**
	 * Process file size per API request
	 * @var float|int
	 */
	private $file_size_per_request_limit = 52428800; //50MB = 52428800; 1MB = 1048576
	/**
	 * Files count to process per API request
	 * @var int
	 */
	private $files_to_process_per_request = 250; //block of 512 bytes
	/**
	 * Compression level, 0-uncompressed, 9-maximum compression
	 * @var int
	 */
	private $compression_level = 0; //0-9 , 0 uncompressed
	/**
	 * Split backup size limit
	 * Create a new backup archive file once the set size is reached
	 * @var float|int
	 */
	private $xcloner_split_backup_limit = 2048; //2048MB
	/**
	 * Number of processed bytes
	 * @var int
	 */
	private $processed_size_bytes = 0;

    /**
     * The backup name encryption suffix
     * @var string
     */
	private $encrypt_suffix = "-enc";

	/**
	 * Archive name
	 * @var string
	 */
	private $archive_name;
	/**
	 * @var Tar
	 */
	private $backup_archive;
	/**
	 * @var Xcloner_File_System
	 */
	private $filesystem;
	/**
	 * @var Xcloner_Logger
	 */
	private $logger;
	/**
	 * @var Xcloner_Settings
	 */
	private $xcloner_settings;

	/**
	 * [__construct description]
	 * @param Xcloner $xcloner_container XCloner Container
	 * @param string $archive_name Achive Name
	 */
	public function __construct(Xcloner $xcloner_container, $archive_name = "")
	{
		$this->filesystem = $xcloner_container->get_xcloner_filesystem();
		$this->logger = $xcloner_container->get_xcloner_logger()->withName("xcloner_archive");
		$this->xcloner_settings = $xcloner_container->get_xcloner_settings();

		if ($value = $this->xcloner_settings->get_xcloner_option('xcloner_size_limit_per_request')) {

The method get_xcloner_option() does not exist on null.

			$this->file_size_per_request_limit = $value * 1024 * 1024;
		} //MB

		if ($value = $this->xcloner_settings->get_xcloner_option('xcloner_files_to_process_per_request')) {
			$this->files_to_process_per_request = $value;
		}

		if ($value = get_option('xcloner_backup_compression_level')) {
			$this->compression_level = $value;
		}

		if ($value = get_option('xcloner_split_backup_limit')) {
			$this->xcloner_split_backup_limit = $value;
		}

		$this->xcloner_split_backup_limit = $this->xcloner_split_backup_limit * 1024 * 1024; //transform to bytes

		if (isset($archive_name) && $archive_name) {
			$this->set_archive_name($archive_name);
		}
	}

	/*
     * Rename backup archive
     *
     * @param string $old_name
     * @param string $new_name
     *
     */
	public function rename_archive($old_name, $new_name)
	{
		$this->logger->info(sprintf("Renaming backup archive %s to %s", $old_name, $new_name));
		$storage_filesystem = $this->filesystem->get_storage_filesystem();
		$storage_filesystem->rename($old_name, $new_name);
	}

	/*
     *
     * Set the backup archive name
     *
     */
	public function set_archive_name($name = "", $part = 0, $encrypt_prefix = false)
	{

		$this->archive_name = $this->filesystem->process_backup_name($name);

		if($encrypt_prefix) {
		    $this->archive_name .= $this->encrypt_suffix;
        }

		if ($diff_timestamp_start = $this->filesystem->get_diff_timestamp_start()) {
			//$this->archive_name = $this->archive_name."-diff-".date("Y-m-d_H-i",$diff_timestamp_start);
			$new_name = $this->archive_name;

			if (!stristr($new_name, "-diff")) {
				$new_name = $this->archive_name."-diff".date("Y-m-d_H-i", $diff_timestamp_start);

$diff_timestamp_start of type string is incompatible with the type integer expected by parameter $timestamp of date().

			}

			$this->archive_name = $new_name;

		}

		if (isset($part) and $part) {
			$new_name = preg_replace('/-part(\d*)/', "-part".$part, $this->archive_name);
			if (!stristr($new_name, "-part")) {
				$new_name = $this->archive_name."-part".$part;
			}

			$this->archive_name = $new_name;
		}

		return $this;
	}

	/*
     *
     * Returns the backup archive name
     *
     * @return string archive name
     */
	public function get_archive_name()
	{
		return $this->archive_name;
	}

	/*
     *
     * Returns the multipart naming for the backup archive
     *
     * @return string multi-part backup name
     */
	public function get_archive_name_multipart()
	{
		$new_name = preg_replace('/-part(\d*)/', "", $this->archive_name);
		return $new_name."-multipart".$this->xcloner_settings->get_backup_extension_name(".csv");
	}

	/*
     *
     * Returns the full backup name including extension
     *
     */
	public function get_archive_name_with_extension()
	{
		return $this->archive_name.$this->xcloner_settings->get_backup_extension_name();
	}

	/*
     *
     * Send notification error by E-Mail
     *
     * @param $to
     * @param $from
     * @param $subject
     * @param $backup_name
     * @param $params
     * @param $error_message
     *
     * @return bool
     */

	/**
	 * @param string $error_message
	 */
	public function send_notification_error($to, $from, $subject, $backup_name, $params, $error_message)

The parameter $backup_name is not used and could be removed.

The parameter $params is not used and could be removed.

	{

		$body = "";
		$body .= sprintf(__("Backup Site Url: %s"), get_site_url());
		$body .= "<br /><>";

		$body .= sprintf(__("Error Message: %s"), $error_message);

		$this->logger->info(sprintf("Sending backup error notification to %s", $to));

		$admin_email = get_option("admin_email");

		$headers = array('Content-Type: text/html; charset=UTF-8');

		if ($admin_email and $from) {
			$headers[] = 'From: '.$from.' <'.$admin_email.'>';
		}

		$return = wp_mail($to, $subject, $body, $headers);

		return $return;
	}

	/*
     *
     * Send backup archive notfication by E-Mail
     *
     * @param $to
     * @param $from
     * @param $subject
     * @param $backup_name
     * @param $params
     * @param string $error_message
     * @param array $additional
     *
     * @return bool
     */
	public function send_notification(
		$to,
		$from,
		$subject,
		$backup_name,
		$params,
		$error_message = "",
		$additional = array()
	) {
		if (!$from) {
			$from = "XCloner Backup";
		}

		if (($error_message)) {
			return $this->send_notification_error($to, $from, $subject, $backup_name, $params, $error_message);
		}

		$params = (array)$params;

		if (!$subject) {
			$subject = sprintf(__("New backup generated %s"), $backup_name);
		}

		$body = sprintf(__("Generated Backup Size: %s"), size_format($this->filesystem->get_backup_size($backup_name)));

It seems like size_format($this->filesystem->get_backup_size($backup_name)) can also be of type false; however, parameter $args of sprintf() does only seem to accept string, maybe add an additional type check?

		$body .= "<br /><br />";

		if (isset($additional['lines_total'])) {
			$body .= sprintf(__("Total files added: %s"), $additional['lines_total']);
			$body .= "<br /><br />";
		}

		$backup_parts = $this->filesystem->get_multipart_files($backup_name);

		if (!$backups_counter = sizeof($backup_parts)) {
			$backups_counter = 1;
		}

		$body .= sprintf(__("Backup Parts: %s"), $backups_counter);
		$body .= "<br />";

		if (sizeof($backup_parts)) {
			$body .= implode("<br />", $backup_parts);
			$body .= "<br />";
		}

		$body .= "<br />";

		$body .= sprintf(__("Backup Site Url: %s"), get_site_url());
		$body .= "<br />";

		if (isset($params['backup_params']->backup_comments)) {
			$body .= __("Backup Comments: ").$params['backup_params']->backup_comments;
			$body .= "<br /><br />";
		}

		if ($this->xcloner_settings->get_xcloner_option('xcloner_enable_log')) {
			$body .= __("Latest 50 Log Lines: ")."<br />".implode("<br />\n",
																		$this->logger->getLastDebugLines(50));

It seems like $this->logger->getLastDebugLines(50) can also be of type false; however, parameter $pieces of implode() does only seem to accept array, maybe add an additional type check?

		}

		$attachments = $this->filesystem->get_backup_attachments();

		$attachments_archive = $this->xcloner_settings->get_xcloner_tmp_path().DS."info.tgz";

		$tar = new Tar();
		$tar->create($attachments_archive);

		foreach ($attachments as $key => $file) {
			$tar->addFile($file, basename($file));
		}
		$tar->close();

		$this->logger->info(sprintf("Sending backup notification to %s", $to));

		$admin_email = get_option("admin_email");

		$headers = array('Content-Type: text/html; charset=UTF-8', 'From: '.$from.' <'.$admin_email.'>');

Are you sure $admin_email of type false|mixed can be used in concatenation?

		$return = wp_mail($to, $subject, $body, $headers, array($attachments_archive));

		return $return;
	}

	/*
     *
     * Incremental Backup method
     *
     */
	public function start_incremental_backup($backup_params, $extra_params, $init)
	{
		$return = array();

		if (!isset($extra_params['backup_part'])) {
			$extra_params['backup_part'] = 0;
		}

		$return['extra']['backup_part'] = $extra_params['backup_part'];

		if (isset($extra_params['backup_archive_name'])) {
			$this->set_archive_name($extra_params['backup_archive_name'], $return['extra']['backup_part']);
		} else {
		    $encrypt = false;
            if(isset($backup_params['backup_encrypt']) && $backup_params['backup_encrypt']) {
                $encrypt = true;
            }
			$this->set_archive_name($backup_params['backup_name'], 0, $encrypt);
		}

		if (!$this->get_archive_name()) {
			$this->set_archive_name();
		}

		$this->backup_archive = new Tar();
		$this->backup_archive->setCompression($this->compression_level);

		$archive_info = $this->filesystem->get_storage_path_file_info($this->get_archive_name_with_extension());

		if ($init) {
			$this->logger->info(sprintf(__("Initializing the backup archive %s"), $this->get_archive_name()));

			$this->backup_archive->create($archive_info->getPath().DS.$archive_info->getFilename());

			$return['extra']['backup_init'] = 1;

		} else {
			$this->logger->info(sprintf(__("Opening for append the backup archive %s"), $this->get_archive_name()));

			$this->backup_archive->openForAppend($archive_info->getPath().DS.$archive_info->getFilename());

			$return['extra']['backup_init'] = 0;

		}

		$return['extra']['backup_archive_name'] = $this->get_archive_name();
		$return['extra']['backup_archive_name_full'] = $this->get_archive_name_with_extension();

		if (!isset($extra_params['start_at_line'])) {
			$extra_params['start_at_line'] = 0;
		}

		if (!isset($extra_params['start_at_byte'])) {
			$extra_params['start_at_byte'] = 0;
		}

		if (!$this->filesystem->get_tmp_filesystem()->has($this->filesystem->get_included_files_handler())) {
			$this->logger->error(sprintf("Missing the includes file handler %s, aborting...",
				$this->filesystem->get_included_files_handler()));

			$return['finished'] = 1;
			return $return;
		}

		$included_files_handler = $this->filesystem->get_included_files_handler(1);

		$file = new SplFileObject($included_files_handler);

		$file->seek(PHP_INT_MAX);

		$return['extra']['lines_total'] = ($file->key() - 1);

		//we skip the first CSV line with headers
		if (!$extra_params['start_at_line']) {
			$file->seek(1);
		} else {
			$file->seek($extra_params['start_at_line'] + 1);
		}

		$this->processed_size_bytes = 0;

		$counter = 0;

		$start_byte = $extra_params['start_at_byte'];

		$byte_limit = 0;

The assignment to $byte_limit is dead and can be removed.

		while (!$file->eof() and $counter <= $this->files_to_process_per_request) {
			$current_line_str = $file->current();

			$line = str_getcsv($current_line_str);

It seems like $current_line_str can also be of type array; however, parameter $input of str_getcsv() does only seem to accept string, maybe add an additional type check?

			$relative_path = stripslashes($line[0]);

			$start_filesystem = "start_filesystem";

			if (isset($line[4])) {
				$start_filesystem = $line[4];
			}

			//$adapter = $this->filesystem->get_adapter($start_filesystem);

			if (!$relative_path || !$this->filesystem->get_filesystem($start_filesystem)->has($relative_path)) {
				if ($relative_path != "") {
					$this->logger->error(sprintf("Could not add file %b to backup archive, file not found",
						$relative_path));
				}

				$extra_params['start_at_line']++;
				$file->next();
				continue;
			}

			$file_info = $this->filesystem->get_filesystem($start_filesystem)->getMetadata($relative_path);

			if (!isset($file_info['size'])) {
				$file_info['size'] = 0;
			}

			if ($start_filesystem == "tmp_filesystem") {
				$file_info['archive_prefix_path'] = $this->xcloner_settings->get_xcloner_tmp_path_suffix();
			}

			$byte_limit = (int)$this->file_size_per_request_limit / 512;

			$append = 0;

			if ($file_info['size'] > $byte_limit * 512 or $start_byte) {
				$append = 1;
			}

			if (!isset($return['extra']['backup_size'])) {
				$return['extra']['backup_size'] = 0;
			}

			$return['extra']['backup_size'] = $archive_info->getSize();

			$estimated_new_size = $return['extra']['backup_size'] + $file_info['size'];

			//we create a new backup part if we reach the Split Achive Limit
			if ($this->xcloner_split_backup_limit and ($estimated_new_size > $this->xcloner_split_backup_limit) and (!$start_byte)) {
				$this->logger->info(sprintf("Backup size limit %s bytes reached, file add estimate %s, attempt to create a new archive ",
					$this->xcloner_split_backup_limit, $estimated_new_size));
				list($archive_info, $return['extra']['backup_part']) = $this->create_new_backup_part($return['extra']['backup_part']);

				if ($file_info['size'] > $this->xcloner_split_backup_limit) {
					$this->logger->info(sprintf("Excluding %s file as it's size(%s) is bigger than the backup split limit of %s and it won't fit a single backup file",
						$file_info['path'], $file_info['size'], $this->xcloner_split_backup_limit));
					$extra_params['start_at_line']++;
				}

				$return['extra']['start_at_line'] = $extra_params['start_at_line'];
				$return['extra']['start_at_byte'] = 0;

				$return['finished'] = 0;

				return $return;
			}

			list($bytes_wrote, $last_position) = $this->add_file_to_archive($file_info, $start_byte, $byte_limit,
				$append, $start_filesystem);
			$this->processed_size_bytes += $bytes_wrote;

			//echo" - processed ".$this->processed_size_bytes." bytes ".$this->file_size_per_request_limit." last_position:".$last_position." \n";
			$return['extra']['processed_file'] = $file_info['path'];
			$return['extra']['processed_file_size'] = $file_info['size'];
			$return['extra']['backup_size'] = $archive_info->getSize();

			if ($last_position > 0) {
				$start_byte = $last_position;
			} else {
				$extra_params['start_at_line']++;
				$file->next();
				$start_byte = 0;
				$counter++;
			}

			if ($this->processed_size_bytes >= $this->file_size_per_request_limit) {
				clearstatcache();
				$return['extra']['backup_size'] = $archive_info->getSize();

				$return['finished'] = 0;
				$return['extra']['start_at_line'] = $extra_params['start_at_line'];
				$return['extra']['start_at_byte'] = $last_position;
				$this->logger->info(sprintf("Reached the maximum %s request data limit, returning response",
					$this->file_size_per_request_limit));
				return $return;
			}
		}

		if (!$file->eof()) {
			clearstatcache();
			$return['extra']['backup_size'] = $archive_info->getSize();

			$return['finished'] = 0;
			$return['extra']['start_at_line'] = $extra_params['start_at_line'];
			$return['extra']['start_at_byte'] = $last_position;

The variable $last_position does not seem to be defined for all execution paths leading up to this point.

			$this->logger->info(sprintf("We have reached the maximum files to process per request limit of %s, returning response",
				$this->files_to_process_per_request));

			return $return;
		}

		//close the backup archive by adding 2*512 blocks of zero bytes
		$this->logger->info(sprintf("Closing the backup archive %s with 2*512 zero bytes blocks.",
			$this->get_archive_name_with_extension()));
		$this->backup_archive->close();

		/**
		 * XCloner HOOK backup_archive_finished.
		 *
		 * This will get triggered when a backup archive is finished writing.
		 */
		//do_action('backup_archive_finished', $this->backup_archive, $this);

		//updating archive_info
		$archive_info = $this->filesystem->get_storage_path_file_info($this->get_archive_name_with_extension());

		if ($return['extra']['backup_part']) {
			$this->write_multipart_file($this->get_archive_name_with_extension());
		}

		$return['extra']['start_at_line'] = $extra_params['start_at_line'] - 1;

		if (isset($file_info)) {
			$return['extra']['processed_file'] = $file_info['path'];
			$return['extra']['processed_file_size'] = $file_info['size'];
		}

		clearstatcache();
		$return['extra']['backup_size'] = $archive_info->getSize();

		$return['finished'] = 1;
		return $return;
	}

	/*
     *
     * Write multipart file components
     *
     */
	private function write_multipart_file($path = "")
	{
		if (!$path) {
			$path = $this->get_archive_name_with_extension();
		}

		$file = $this->filesystem->get_filesystem("storage_filesystem_append")->getMetadata($path);
		//print_r($file_info);
		$line = '"'.$file['path'].'","'.$file['timestamp'].'","'.$file['size'].'"'.PHP_EOL;


		$this->filesystem->get_filesystem("storage_filesystem_append")
			->write($this->get_archive_name_multipart(), $line);
	}

	/*
     *
     * Create a new backup part
     *
     */
	private function create_new_backup_part($part = 0)
	{
		//close the backup archive by adding 2*512 blocks of zero bytes
		$this->logger->info(sprintf("Closing the backup archive %s with 2*512 zero bytes blocks.",
			$this->get_archive_name_with_extension()));
		$this->backup_archive->close();

		if (!$part) {
			$old_name = $this->get_archive_name_with_extension();
			$this->set_archive_name($this->get_archive_name(), ++$part);
			$this->rename_archive($old_name, $this->get_archive_name_with_extension());

			if ($this->filesystem->get_storage_filesystem()->has($this->get_archive_name_multipart())) {
				$this->filesystem->get_storage_filesystem()->delete($this->get_archive_name_multipart());
			}

			$this->write_multipart_file($this->get_archive_name_with_extension());

		} else {
			$this->logger->info(sprintf("Creating new multipart info file %s",
				$this->get_archive_name_with_extension()));
			$this->write_multipart_file($this->get_archive_name_with_extension());
		}

		$this->set_archive_name($this->get_archive_name(), ++$part);

		$this->logger->info(sprintf("Creating new backup archive part %s", $this->get_archive_name_with_extension()));

		$this->backup_archive = new Tar();
		$this->backup_archive->setCompression($this->compression_level);
		$archive_info = $this->filesystem->get_storage_path_file_info($this->get_archive_name_with_extension());
		$this->backup_archive->create($archive_info->getPath().DS.$archive_info->getFilename());

		return array($archive_info, $part);

	}

	/*
     *
     * Add file to archive
     *
     */

	/**
	 * @param integer $append
	 */
	public function add_file_to_archive($file_info, $start_at_byte, $byte_limit = 0, $append, $filesystem)
	{

		$start_adapter = $this->filesystem->get_adapter($filesystem);
		$start_filesystem = $this->filesystem->get_adapter($filesystem);

		if (!$file_info['path']) {
			return;
		}

		if (isset($file_info['archive_prefix_path'])) {
			$file_info['target_path'] = $file_info['archive_prefix_path']."/".$file_info['path'];
		} else {
			$file_info['target_path'] = $file_info['path'];
		}

		$last_position = $start_at_byte;

		//$start_adapter = $this->filesystem->get_start_adapter();

		if (!$append) {
			$bytes_wrote = $file_info['size'];
			$this->logger->info(sprintf("Adding %s bytes of file %s to archive %s ", $bytes_wrote,
				$file_info['target_path'], $this->get_archive_name_with_extension()));
			$this->backup_archive->addFile($start_adapter->applyPathPrefix($file_info['path']),
				$file_info['target_path']);
		} else {
			$tmp_file = md5($file_info['path']);

			//we isolate file to tmp if we are at byte 0, the starting point of file reading
			if (!$start_at_byte) {
				$this->logger->info(sprintf("Copying %s file to tmp filesystem file %s to prevent reading changes",
					$file_info['path'], $tmp_file));
				$file_stream = $start_filesystem->readStream($file_info['path']);

				if (is_resource($file_stream['stream'])) {
					$this->filesystem->get_tmp_filesystem()->writeStream($tmp_file, $file_stream['stream']);
				}
			}

			if ($this->filesystem->get_tmp_filesystem()->has($tmp_file)) {
				$is_tmp = 1;
				$last_position = $this->backup_archive->appendFileData($this->filesystem->get_tmp_filesystem_adapter()

Are you sure the assignment to $last_position is correct as $this->backup_archive->appendFileData($this->filesystem->get_tmp_filesystem_adapter()->applyPathPrefix($tmp_file), $file_info['target_path'], $start_at_byte, $byte_limit) targeting splitbrain\PHPArchive\Tar::appendFileData() seems to always return null.

														->applyPathPrefix($tmp_file),
					$file_info['target_path'], $start_at_byte, $byte_limit);
			} else {
				$is_tmp = 0;
				$last_position = $this->backup_archive->appendFileData($start_adapter->applyPathPrefix($file_info['path']),

Are you sure the assignment to $last_position is correct as $this->backup_archive->appendFileData($start_adapter->applyPathPrefix($file_info['path']), $file_info['target_path'], $start_at_byte, $byte_limit) targeting splitbrain\PHPArchive\Tar::appendFileData() seems to always return null.

					$file_info['target_path'], $start_at_byte, $byte_limit);
			}


			if ($last_position == -1) {
				$bytes_wrote = $file_info['size'] - $start_at_byte;
			} else {
				$bytes_wrote = $last_position - $start_at_byte;
			}


			if ($is_tmp) {
				$this->logger->info(sprintf("Appended %s bytes, starting position %s, of tmp file %s (%s) to archive %s ",
					$bytes_wrote, $start_at_byte, $tmp_file, $file_info['target_path'], $this->get_archive_name()));
			} else {
				$this->logger->info(sprintf("Appended %s bytes, starting position %s, of original file %s to archive %s ",
					$bytes_wrote, $start_at_byte, $file_info['target_path'], $tmp_file, $this->get_archive_name()));
			}

			//we delete here the isolated tmp file
			if ($last_position == -1) {
				if ($this->filesystem->get_tmp_filesystem_adapter()->has($tmp_file)) {
					$this->logger->info(sprintf("Deleting %s from the tmp filesystem", $tmp_file));
					$this->filesystem->get_tmp_filesystem_adapter()->delete($tmp_file);
				}
			}

		}

		return array($bytes_wrote, $last_position);
	}

	/**
	 * Open a TAR archive and put the file cursor at the end for data appending
	 *
	 * If $file is empty, the tar file will be created in memory
	 *
	 * @param string $file
	 * @throws ArchiveIOException
	 */
	/*
    public function openForAppend($file = '')
    {
        $this->file   = $file;
        $this->memory = '';
        $this->fh     = 0;

        if ($this->file) {
            // determine compression
            if ($this->comptype == Archive::COMPRESS_AUTO) {
                $this->setCompression($this->complevel, $this->filetype($file));
            }

            if ($this->comptype === Archive::COMPRESS_GZIP) {
                $this->fh = @gzopen($this->file, 'ab'.$this->complevel);
            } elseif ($this->comptype === Archive::COMPRESS_BZIP) {
                $this->fh = @bzopen($this->file, 'a');
            } else {
                $this->fh = @fopen($this->file, 'ab');
            }

            if (!$this->fh) {
                throw new ArchiveIOException('Could not open file for writing: '.$this->file);
            }
        }
        $this->backup_archive->writeaccess = true;
        $this->backup_archive->closed      = false;
    }
    */

	/**
	 * Append data to a file to the current TAR archive using an existing file in the filesystem
	 *
	 * @param string $file path to the original file
	 * @param int $start starting reading position in file
	 * @param int $end end position in reading multiple with 512
	 * @param string|FileInfo $fileinfo either the name to us in archive (string) or a FileInfo oject with
	 * all meta data, empty to take from original
	 * @throws ArchiveIOException
	 */
	/*
     * public function appendFileData($file, $fileinfo = '', $start = 0, $limit = 0)
    {
		$end = $start+($limit*512);

		//check to see if we are at the begining of writing the file
		if(!$start)
		{
	        if (is_string($fileinfo)) {
				$fileinfo = FileInfo::fromPath($file, $fileinfo);
	        }
		}

        if ($this->closed) {
            throw new ArchiveIOException('Archive has been closed, files can no longer be added');
        }

        $fp = fopen($file, 'rb');

        fseek($fp, $start);

        if (!$fp) {
            throw new ArchiveIOException('Could not open file for reading: '.$file);
        }

        // create file header
		if(!$start)
			$this->backup_archive->writeFileHeader($fileinfo);

		$bytes = 0;
        // write data
        while ($end >=ftell($fp) and !feof($fp) ) {
            $data = fread($fp, 512);
            if ($data === false) {
                break;
            }
            if ($data === '') {
                break;
            }
            $packed = pack("a512", $data);
            $bytes += $this->backup_archive->writebytes($packed);
        }



        //if we are not at the end of file, we return the current position for incremental writing
        if(!feof($fp))
			$last_position = ftell($fp);
		else
			$last_position = -1;

        fclose($fp);

        return $last_position;
    }*/

	/**
	 * Adds a file to a TAR archive by appending it's data
	 *
	 * @param string $archive name of the archive file
	 * @param string $file name of the file to read data from
	 * @param string $start start position from where to start reading data
	 * @throws ArchiveIOException
	 */
	/*public function addFileToArchive($archive, $file, $start = 0)
    {
        $this->openForAppend($archive);
        return $start = $this->appendFileData($file, $start, $this->file_size_per_request_limit);
    }
    */

}