/system/expressionengine/third_party/ce_cache/libraries/drivers/Ce_cache_driver.php

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



/**

 * CE Cache - Driver abstract class.

 *

 * @author		Aaron Waldon

 * @copyright	Copyright (c) 2013 Causing Effect

 * @license		http://www.causingeffect.com/software/expressionengine/ce-cache/license-agreement

 * @link		http://www.causingeffect.com

 */

abstract class Ce_cache_driver

{

	protected $debug = false;



	public function __construct()

	{

		$this->EE = get_instance();



		//if the template debugger is enabled, and a super admin user is logged in, enable debug mode

		$this->debug = false;

		if ( $this->EE->session->userdata['group_id'] == 1 && $this->EE->config->item('template_debugging') == 'y' )

		{

			$this->debug = true;

		}

	}



	/**

	 * Is the driver supported?

	 *

	 * @abstract

	 * @return bool

	 */

	abstract public function is_supported();



	/**

	 * The driver name.

	 *

	 * @abstract

	 * @return void

	 */

	abstract public function name();



	//------------------------------------ cache item methods ------------------------------------

	/**

	 * Stores a cache item.

	 *

	 * @abstract

	 * @param $id

	 * @param string $content

	 * @param string $seconds

	 * @return bool

	 */

	abstract public function set( $id, $content = '', $seconds = '' );



	/**

	 * Retrieve an item from the cache.

	 *

	 * @abstract

	 * @param $id

	 * @return mixed

	 */

	abstract public function get( $id );



	/**

	 * Remove an item from the cache.

	 *

	 * @abstract

	 * @param $id

	 * @return bool

	 */

	abstract public function delete( $id );



	/**

	 * Gives information about the item.

	 *

	 * @abstract

	 * @param $id

	 * @param bool $get_content Include the content in the return array?

	 * @return array|bool An array with the keys 'expiry', 'made', 'ttl', 'ttl_remaining', 'size', and 'size_raw' and 'content' (if $get_content is set to true) on success, or false on failure

	 */

	abstract public function meta( $id, $get_content = true );



	//------------------------------------ cache methods ------------------------------------

	/**

	 * Purges the entire cache.

	 *

	 * @abstract

	 * @return bool

	 */

	abstract public function clear();



	/**

	 * Retrieves all of the cached items at the specified relative path.

	 *

	 * @abstract

	 * @param $relative_path

	 * @return array

	 */

	abstract public function get_all( $relative_path );



	/**

	 * Retrieves all of the cached items (or folder paths) at the specified relative path for 1 level of depth.

	 *

	 * @param $relative_path

	 * @return array

	 */

	public function get_level( $relative_path )

	{

		$items = $this->get_all( $relative_path );



		if ( empty( $items ) )

		{

			return array();

		}



		$driver = $this->name();



		if (  $driver == 'db' || $driver == 'apc' ) //db and apc drivers

		{

			$files = array();

			$folders = array();



			foreach ( $items as $index => $item )

			{

				$slash_pos = strpos( $item['id'], '/' ); //is there a slash?



				if ( $slash_pos !== false ) //a directory (first segment of item path at a higher level)

				{

					$folders[] = substr( $item['id'], 0, $slash_pos + 1 );

				}

				else //an item at the current level

				{

					$files[$index] = $items[$index];

				}

			}

			$folders = array_unique( $folders );

			$dirs = array();

			foreach ( $folders as $folder )

			{

				$dirs[] = array( 'id' => $folder );

			}



			$items = array_merge( $dirs, $files );

			unset( $folders, $files, $dirs );



			return $items;

		}

		else //other drivers

		{

			foreach ( $items as $index => $item )

			{

				$slash_pos = strpos( $item, '/' );



				if ( $slash_pos !== false ) //a directory (first segment of item path at a higher level)

				{

					$items[ $index ] = substr( $item, 0, $slash_pos + 1 );

				}

			}



			return array_unique( $items );

		}

	}





	/**

	 * Retrieves basic info about the cache.

	 *

	 * @abstract

	 * @return array|bool

	 */

	abstract public function info();



	//------------------------------------ helpers ------------------------------------

	/**

	 * Removes double slashes, except when they are preceded by ':', so that 'http://', etc are preserved.

	 *

	 * @param string $str The string from which to remove the double slashes.

	 * @return string The string with double slashes removed.

	 */

	protected function remove_duplicate_slashes( $str )

	{

		return preg_replace( '#(?<!:)//+#', '/', $str );

	}



	/**

	 * Determines if an id is valid or if it contains invalid characters.

	 *

	 * @param $id

	 * @return bool

	 */

	protected function id_is_valid( $id )

	{

		$sanitized = $this->EE->security->sanitize_filename( $id, true );

		return ( $id === $sanitized );

	}



	/**

	 * Simple method to log a debug message to the EE Debug console.

	 *

	 * @param string $method

	 * @param string $message

	 * @return void

	 */

	protected function log_debug_message( $method = '', $message = '' )

	{

		$this->EE->TMPL->log_item( "&nbsp;&nbsp;***&nbsp;&nbsp;CE Cache - " . $this->name() . " - $method debug: " . $message );

	}



	/**

	 * Converts a file size from bytes to a human readable format.

	 *

	 * A method derived from a function originally posted by xelozz -at- gmail.com 18-Feb-2010 10:34 to http://us2.php.net/manual/en/function.memory-get-usage.php#96280

	 * Original code licensed under: http://creativecommons.org/licenses/by/3.0/legalcode

	 *

	 * @param int $size Bytes.

	 * @param int $precision

	 * @return string Human readable file size.

	 */

	public static function convert_size( $size, $precision = 2 )

	{

		if ( ! is_numeric( $size ) || $size <= 0 )

		{

			return '0 b';

		}



		if ( ! is_numeric( $precision ) || $precision < 0 )

		{

			$precision = 2;

		}



		$unit = array( 'b', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB' );



		$i = floor( log( $size, 1024 ) );



		if ( isset( $unit[$i] ) )

		{

			return @round( $size / pow( 1024, $i ), $precision ) . ' ' . $unit[$i];

		}

		else

		{

			return $size . ' ' . 'b';

		}

	}



	/**

	 * Get the file size of a string.

	 * @static

	 * @param $string

	 * @return int

	 */

	protected static function size( $string )

	{

		if ( function_exists( 'mb_strlen' ) )

		{

			return mb_strlen( $string, '8bit' );

		}

		else

		{

			return strlen( $string );

		}

	}

}