[李景山php]thinkphp核心源码注释|Shomp.class.php

<?php// +----------------------------------------------------------------------// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]// +----------------------------------------------------------------------// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.// +----------------------------------------------------------------------// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )// +----------------------------------------------------------------------// | Author: liu21st <[e-mail]>// +----------------------------------------------------------------------namespace Think\Cache\Driver;use Think\Cache;defined('THINK_PATH') or exit();/** * Shmop缓存驱动 * 共享 内存 控制 */class Shmop extends Cache {    /**     * 架构函数     * @param array $options 缓存参数     * @access public     */    public function __construct($options=array()) {        if ( !extension_loaded('shmop') ) {            E(L('_NOT_SUPPORT_').':shmop');        }        if(!empty($options)){            $options = array(                'size'      => C('SHARE_MEM_SIZE'),                'temp'      => TEMP_PATH,                'project'   => 's',                'length'    =>  0,                );        }        $this->options = $options;        $this->options['prefix'] =  isset($options['prefix'])?  $options['prefix']  :   C('DATA_CACHE_PREFIX');                $this->options['length'] =  isset($options['length'])?  $options['length']  :   0;                $this->handler = $this->_ftok($this->options['project']);    }    /**     * 读取缓存     * @access public     * @param string $name 缓存变量名     * @return mixed     */    public function get($name = false) {        N('cache_read',1); // 记录        $id = shmop_open($this->handler, 'c', 0600, 0);// 打开连接 ，获取资源        if ($id !== false) {            $ret = unserialize(shmop_read($id, 0, shmop_size($id)));            shmop_close($id);// 关闭资料            if ($name === false) {                return $ret;            }            $name   =   $this->options['prefix'].$name; // 规划名字            if(isset($ret[$name])) { // key values                $content   =  $ret[$name];                if(C('DATA_CACHE_COMPRESS') && function_exists('gzcompress')) {                    //启用数据压缩                    $content   =   gzuncompress($content); // 启动数据压缩                }                return $content;            }else {                return null;            }        }else {            return false;        }    }    /**     * 写入缓存     * @access public     * @param string $name 缓存变量名     * @param mixed $value  存储数据     * @return boolean     */    public function set($name, $value) {        N('cache_write',1);        $lh = $this->_lock();        $val = $this->get();        if (!is_array($val)) $val = array();        if( C('DATA_CACHE_COMPRESS') && function_exists('gzcompress')) {            //数据压缩            $value   =   gzcompress($value,3);        }        $name   =   $this->options['prefix'].$name;        $val[$name] = $value;        $val = serialize($val);        if($this->_write($val, $lh)) {            if($this->options['length']>0) {                // 记录缓存队列                $this->queue($name);            }            return true;        }        return false;    }    /**     * 删除缓存     * @access public     * @param string $name 缓存变量名     * @return boolean     */    public function rm($name) {        $lh = $this->_lock();        $val = $this->get();        if (!is_array($val)) $val = array();        $name   =   $this->options['prefix'].$name;        unset($val[$name]);        $val = serialize($val);        return $this->_write($val, $lh);    }    /**     * 生成IPC key     * @access private     * @param string $project 项目标识名     * @return integer     */    private function _ftok($project) {        if (function_exists('ftok'))   return ftok(__FILE__, $project);        if(strtoupper(PHP_OS) == 'WINNT'){            $s = stat(__FILE__);            return sprintf("%u", (($s['ino'] & 0xffff) | (($s['dev'] & 0xff) << 16) |            (($project & 0xff) << 24)));        }else {            $filename = __FILE__ . (string) $project;            for($key = array(); sizeof($key) < strlen($filename); $key[] = ord(substr($filename, sizeof($key), 1)));            return dechex(array_sum($key));        }    }    /**     * 写入操作     * @access private     * @param string $name 缓存变量名     * @return integer|boolean     * 内部写入操作     */    private function _write(&$val, &$lh) {        $id  = shmop_open($this->handler, 'c', 0600, $this->options['size']);        if ($id) {           $ret = shmop_write($id, $val, 0) == strlen($val);           shmop_close($id);           $this->_unlock($lh);           return $ret;        }        $this->_unlock($lh);        return false;    }    /**     * 共享锁定     * @access private     * @param string $name 缓存变量名     * @return boolean     * 加锁     */    private function _lock() {        if (function_exists('sem_get')) {            $fp = sem_get($this->handler, 1, 0600, 1);            sem_acquire ($fp);        } else {            $fp = fopen($this->options['temp'].$this->options['prefix'].md5($this->handler), 'w');            flock($fp, LOCK_EX);        }        return $fp;    }    /**     * 解除共享锁定     * @access private     * @param string $name 缓存变量名     * @return boolean     * 解除共享锁     */    private function _unlock(&$fp) {        if (function_exists('sem_release')) {            sem_release($fp);        } else {            fclose($fp);        }    }}// 总结，更多的作为一个函数的 封装，模块调用。