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administrator/components/com_akeebabackup/engine/Archiver/BaseFileManagement.php

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+<?php
+/**
+ * Akeeba Engine
+ *
+ * @package   akeebaengine
+ * @copyright Copyright (c)2006-2022 Nicholas K. Dionysopoulos / Akeeba Ltd
+ * @license   GNU General Public License version 3, or later
+ */
+
+namespace Akeeba\Engine\Archiver;
+
+defined('AKEEBAENGINE') || die();
+
+use Akeeba\Engine\Base\Exceptions\ErrorException;
+use Akeeba\Engine\Factory;
+
+if (!function_exists('akstrlen'))
+{
+	/**
+	 * Attempt to use mbstring for calculating the binary string length.
+	 *
+	 * @param $string
+	 *
+	 * @return int
+	 */
+	function akstrlen($string)
+	{
+		return function_exists('mb_strlen') ? mb_strlen($string, '8bit') : strlen($string);
+	}
+}
+
+/**
+ * Abstract class for an archiver using managed file pointers
+ */
+abstract class BaseFileManagement extends Base
+{
+	/** @var resource File pointer to the archive's central directory file (for ZIP) */
+	protected $cdfp = null;
+
+	/** @var resource File pointer to the archive being currently written to */
+	protected $fp = null;
+
+	/** @var   array  An array of the last open files for writing and their last written to offsets */
+	private $fileOffsets = [];
+
+	/** @var   array  An array of open file pointers */
+	private $filePointers = [];
+
+	/** @var   null|string  The last filename fwrite() wrote to */
+	private $lastFileName = null;
+
+	/** @var   null|resource  The last file pointer fwrite() wrote to */
+	private $lastFilePointer = null;
+
+	/**
+	 * Release file pointers when the object is being destroyed
+	 *
+	 * @codeCoverageIgnore
+	 *
+	 * @return  void
+	 */
+	public function __destruct()
+	{
+		$this->_closeAllFiles();
+
+		$this->fp   = null;
+		$this->cdfp = null;
+	}
+
+	/**
+	 * Release file pointers when the object is being serialized
+	 *
+	 * @codeCoverageIgnore
+	 *
+	 * @return  void
+	 */
+	public function _onSerialize()
+	{
+		$this->_closeAllFiles();
+
+		$this->fp   = null;
+		$this->cdfp = null;
+	}
+
+	/**
+	 * Closes all open files known to this archiver object
+	 *
+	 * @return  void
+	 */
+	protected function _closeAllFiles()
+	{
+		if (!empty($this->filePointers))
+		{
+			foreach ($this->filePointers as $file => $fp)
+			{
+				$this->conditionalFileClose($fp);
+
+				unset($this->filePointers[$file]);
+			}
+		}
+	}
+
+	/**
+	 * Closes an already open file
+	 *
+	 * @param   resource  $fp  The file pointer to close
+	 *
+	 * @return  boolean
+	 */
+	protected function fclose(&$fp)
+	{
+		$result = true;
+
+		$offset = array_search($fp, $this->filePointers, true);
+
+		if (!is_null($fp) && is_resource($fp))
+		{
+			$result = $this->conditionalFileClose($fp);
+		}
+
+		if ($offset !== false)
+		{
+			unset($this->filePointers[$offset]);
+		}
+
+		$fp = null;
+
+		return $result;
+	}
+
+	protected function fcloseByName($file)
+	{
+		if (!array_key_exists($file, $this->filePointers))
+		{
+			return true;
+		}
+
+		$ret = $this->fclose($this->filePointers[$file]);
+
+		if (array_key_exists($file, $this->filePointers))
+		{
+			unset($this->filePointers[$file]);
+		}
+
+		return $ret;
+	}
+
+	/**
+	 * Opens a file, if it's not already open, or returns its cached file pointer if it's already open
+	 *
+	 * @param   string  $file  The filename to open
+	 * @param   string  $mode  File open mode, defaults to binary write
+	 *
+	 * @return  resource
+	 */
+	protected function fopen($file, $mode = 'w')
+	{
+		if (!array_key_exists($file, $this->filePointers))
+		{
+			//Factory::getLog()->debug("Opening backup archive $file with mode $mode");
+			$this->filePointers[$file] = @fopen($file, $mode);
+
+			// If we open a file for append we have to seek to the correct offset
+			if (substr($mode, 0, 1) == 'a')
+			{
+				if (isset($this->fileOffsets[$file]))
+				{
+					Factory::getLog()->debug("Truncating backup archive file $file to " . $this->fileOffsets[$file] . " bytes");
+					@ftruncate($this->filePointers[$file], $this->fileOffsets[$file]);
+				}
+
+				fseek($this->filePointers[$file], 0, SEEK_END);
+			}
+		}
+
+		return $this->filePointers[$file];
+	}
+
+	/**
+	 * Write to file, defeating magic_quotes_runtime settings (pure binary write)
+	 *
+	 * @param   resource  $fp     Handle to a file
+	 * @param   string    $data   The data to write to the file
+	 * @param   integer   $p_len  Maximum length of data to write
+	 *
+	 * @return  int  The number of bytes written
+	 *
+	 * @throws  ErrorException  When writing to the file is not possible
+	 */
+	protected function fwrite($fp, $data, $p_len = null)
+	{
+		if ($fp !== $this->lastFilePointer)
+		{
+			$this->lastFilePointer = $fp;
+			$this->lastFileName    = array_search($fp, $this->filePointers, true);
+		}
+
+		$len = is_null($p_len) ? (akstrlen($data)) : $p_len;
+		$ret = fwrite($fp, $data, $len);
+
+		if (($ret === false) || (abs(($ret - $len)) >= 1))
+		{
+			// Log debug information about the archive file's existence and current size. This helps us figure out if
+			// there is a server-imposed maximum file size limit.
+			clearstatcache();
+			$fileExists  = @file_exists($this->lastFileName) ? 'exists' : 'does NOT exist';
+			$currentSize = @filesize($this->lastFileName);
+
+			Factory::getLog()->debug(sprintf("%s::_fwrite() ERROR!! Cannot write to archive file %s. The file %s. File size %s bytes after writing %s of %d bytes. Please check the output directory permissions and make sure you have enough disk space available. If this does not help, please set up a Part Size for Split Archives LOWER than this size and retry backing up.", __CLASS__, $this->lastFileName, $fileExists, $currentSize, $ret, $len));
+
+			throw new ErrorException(sprintf("Couldn\'t write to the archive file; check the output directory permissions and make sure you have enough disk space available. [len=%s / %s]", $ret, $len));
+		}
+
+		if ($this->lastFileName !== false)
+		{
+			$this->fileOffsets[$this->lastFileName] = @ftell($fp);
+		}
+
+		return $ret;
+	}
+
+	/**
+	 * Removes a file path from the list of resumable offsets
+	 *
+	 * @param $filename
+	 */
+	protected function removeFromOffsetsList($filename)
+	{
+		if (isset($this->fileOffsets[$filename]))
+		{
+			unset($this->fileOffsets[$filename]);
+		}
+	}
+
+}