librenms-librenms/includes/object-cache.inc.php

<?php

/*
 * Copyright (C) 2015 Daniel Preussker <f0o@devilcode.org>
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Object-Cache
 * @author f0o <f0o@devilcode.org>
 * @copyright 2015 f0o, LibreNMS
 * @license GPL
 * @package LibreNMS
 * @subpackage Cache
 */

class ObjCache implements ArrayAccess {

    private $data = array();

    private $obj = '';


    /**
     * Initialize ObjCache
     * @param string $obj Name of Object
     * @return void
     */
    public function __construct($obj) {
        global $config;
        $this->obj = $obj;
        if (isset($GLOBALS['_ObjCache'][$obj])) {
            $this->data = $GLOBALS['_ObjCacheSkell'][$obj];
        }
        else {
            if (!is_array($GLOBALS['_ObjCacheSkell'])) {
                $GLOBALS['_ObjCacheSkell'] = array();
            }

            if (!is_array($GLOBALS['_ObjCache'])) {
                $GLOBALS['_ObjCache'] = array();
            }

            if (file_exists($config['install_dir'].'/includes/caches/'.$obj.'.inc.php')) {
                $data = array();
                include $config['install_dir'].'/includes/caches/'.$obj.'.inc.php';
                $this->data = $data;
                $GLOBALS['_ObjCacheSkell'][$obj] = $this->data;
                if (!is_array($GLOBALS['_ObjCache'][$obj])) {
                    $GLOBALS['_ObjCache'][$obj] = $this->data;
                }
            }
        }//end if

    }//end __construct()


    /**
     * Check if data exists
     * @param string $obj Name of Data-Object
     * @return boolean
     */
    public function offsetExists($obj) {
        if (isset($this->data[$obj])) {
            return true;
        }

        return false;

    }//end offsetExists()


    /**
     * Get Data-Object
     * @param string $obj Name of Data-Object
     * @return mixed
     */
    public function offsetGet($obj) {
        if (isset($this->data[$obj])) {
            if (isset($this->data[$obj]['value'])) {
                return $this->data[$obj]['value'];
            }
            else if (isset($GLOBALS['_ObjCache'][$this->obj][$obj]['value'])) {
                return $GLOBALS['_ObjCache'][$this->obj][$obj]['value'];
            }
            else {
                $GLOBALS['_ObjCache'][$this->obj][$obj]['value'] = dbFetchCell($this->data[$obj]['query'], $this->data[$obj]['params']);
                return $GLOBALS['_ObjCache'][$this->obj][$obj]['value'];
            }
        }

    }//end offsetGet()


    /**
     * Overrides internal Cache-Object
     * @param string $obj   Name of Data-Object
     * @param mixed  $value Value
     * @return boolean
     */
    public function offsetSet($obj, $value) {
        if (!is_array($this->data[$obj])) {
            $this->data[$obj] = array();
        }

        $this->data[$obj]['value'] = $value;
        return $this->data[$obj]['value'];

    }//end offsetSet()


    /**
     * Reset Data-Object
     * @param string $obj Name of Data-Object
     * @return mixed
     */
    public function offsetUnset($obj) {
        unset($this->data[$obj]['value']);
        return true;

    }//end offsetUnset()


}//end class