<?php
/**
 * Piwik - Open source web analytics
 * 
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 * @category Piwik
 * @package Piwik
 */

/**
 * Unzip implementation for .gz files.
 * 
 * @package Piwik
 * @subpackage Piwik_Unzip
 */
class Piwik_Unzip_Gzip implements Piwik_Unzip_Interface
{
	/**
	 * Name of .gz file.
	 * 
	 * @var string
	 */
	private $filename = null;
	
	/**
	 * Error string.
	 * 
	 * @var string
	 */
	private $error = null;
	
	/**
	 * Constructor.
	 * 
	 * @param string $filename Name of .gz file.
	 */
	public function __construct($filename)
	{
		$this->filename = $filename;
	}
	
	/**
	 * Extracts the contents of the .gz file to $pathExtracted.
	 * 
	 * @param string $pathExtracted Must be file, not directory.
	 * @return bool true if successful, false if otherwise.
	 */
	public function extract($pathExtracted)
	{
		$file = gzopen($this->filename, 'r');
		if ($file === false)
		{
			$this->error = "gzopen failed";
			return false;
		}
		
		$output = fopen($pathExtracted, 'w');
		while (!feof($file))
		{
			fwrite($output, fread($file, 1024*1024));
		}
		fclose($output);
		
		$success = gzclose($file);
		if ($success === false)
		{
			$this->error = "gzclose failed";
			return false;
		}
		
		return true;
	}

	/**
	 * Get error status string for the latest error.
	 *
	 * @return string
	 */
	public function errorInfo()
	{
		return $this->error;
	}
}

