<?php

if (!defined('BASEPATH'))
    exit('No direct script access allowed');

class MY_Output extends CI_Output
{
	
	// --------------------------------------------------------------------

	/**
	 * Write a Cache File
	 *
	 * @access	public
	 * @param 	string
	 * @return	void
	 */
	function _write_cache($output)
	{


		$cache_path = APPPATH.'cache/static_html';
		
		if ( ! is_dir($cache_path) OR ! is_really_writable($cache_path))
		{
			log_message('error', "Unable to write cache file: ".$cache_path);
			return;
		}

		///////改成按照URL保存缓存
		//优先使用提交过来的static_html_url做文件名，这是主动生成静态文件用的参数
		if(empty($_GET['static_html_url']))
		{
			return FALSE;
		}
		$cache_path=$cache_path.$_GET['static_html_url'];
		if(mb_substr($cache_path,-1,1)=='/')
		{
			$cache_path.='index.htm';
		}

		$this->create_folder_by_path(dirname($cache_path));

		//如果文件存在，先判断是否为缓存文件，防止覆盖原始程序文件
		if (@file_exists($cache_path))
		{
			if ( ! $fp_read = @fopen($cache_path, FOPEN_READ))
			{
				return FALSE;
			}

			flock($fp_read, LOCK_SH);

			$cache = '';
			if (filesize($cache_path) > 0)
			{
				$cache = fread($fp_read, filesize($cache_path));
			}

			flock($fp_read, LOCK_UN);
			fclose($fp_read);
			if(strpos($cache,'<!-- Generated by ')===false)
			{
				log_message('error', "is not cache file.".$cache_path);
				return FALSE;
			}
		}
		
		///////

		if ( ! $fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE))
		{
			log_message('error', "Unable to write cache file: ".$cache_path);
			return;
		}

		if (flock($fp, LOCK_EX))
		{
			fwrite($fp, $output.'<!-- Generated by '.$_SERVER['HTTP_HOST'].' ('.date('c').') -->');
			flock($fp, LOCK_UN);
		}
		else
		{
			log_message('error', "Unable to secure a file lock for file at: ".$cache_path);
			return;
		}
		fclose($fp);
		@chmod($cache_path, FILE_WRITE_MODE);

		log_message('debug', "Cache file written: ".$cache_path);
	}

	// --------------------------------------------------------------------

/*
* 递归创建文件夹
*/
function create_folder_by_path($dir, $mode = 0777)
{
    if (!is_dir($dir))
    {
        return @mkdir($dir, $mode, true);
    }
    return;
}

}