Cache_File_Cleaner_Generic.php

<?php
namespace W3TC;

/**
 * Generic file cache cleaner class
 */
class Cache_File_Cleaner_Generic extends Cache_File_Cleaner {
	/**
	 * Number of items processed
	 *
	 * @var integer
	 */
	var $processed_count = 0;
	/**
	 * Cache expire time
	 *
	 * @var int
	 */
	var $_expire = 0;

	/**
	 * PHP5-style constructor
	 *
	 * @param array   $config
	 */
	function __construct( $config = array() ) {
		parent::__construct( $config );

		$this->_expire = ( isset( $config['expire'] ) ? (int) $config['expire'] : 0 );

		if ( !$this->_expire || $this->_expire > W3TC_CACHE_FILE_EXPIRE_MAX ) {
			$this->_expire = 0;
		}
	}

	function _clean( $path, $remove = false ) {
		$dir = false;
		if ( is_dir( $path ) ) {
			$dir = @opendir( $path );
		}

		if ( $dir ) {
			while ( ( $entry = @readdir( $dir ) ) !== false ) {
				if ( $entry == '.' || $entry == '..' ) {
					continue;
				}

				$full_path = $path . DIRECTORY_SEPARATOR . $entry;

				if ( substr( $entry, -4 ) === '_old' && !$this->is_old_file_expired( $full_path ) ) {
					continue;
				}

				foreach ( $this->_exclude as $mask ) {
					if ( fnmatch( $mask, basename( $entry ) ) ) {
						continue 2;
					}
				}


				if ( @is_dir( $full_path ) ) {
					$this->_clean( $full_path );
				} elseif ( substr( $entry, -4 ) === '_old' ) {
					$this->processed_count++;
					@unlink( $full_path );
				} elseif ( !$this->is_valid( $full_path ) ) {
					$old_entry_path = $full_path . '_old';
					$this->processed_count++;
					if ( !@rename( $full_path, $old_entry_path ) ) {
						// if we can delete old entry - do second attempt to store in old-entry file
						if ( @unlink( $old_entry_path ) ) {
							@rename( $full_path, $old_entry_path );
						}
					}
				}
			}

			@closedir( $dir );
			if ( $this->is_empty_dir( $path ) )
				@rmdir( $path );
		}
	}

	/**
	 * Checks if file is valid
	 *
	 * @param string  $file
	 * @return bool
	 */
	function is_valid( $file ) {
		if ( $this->_expire <= 0 )
			return false;

		if ( file_exists( $file ) ) {
			$ftime = @filemtime( $file );

			if ( $ftime && $ftime > ( time() - $this->_expire ) ) {
				return true;
			}
		}

		return false;
	}

	function is_old_file_expired( $file ) {
		$ftime = @filemtime( $file );
		$expire = $this->_expire ? $this->_expire * 5 : W3TC_CACHE_FILE_EXPIRE_MAX;
		if ( $ftime && $ftime < ( time() - $expire ) ) {
			return true;
		}

		return false;
	}
	function is_empty_dir( $dir ) {
		return ( $files = @scandir( $dir ) ) && count( $files ) <= 2;
	}
}