vr-shopxo-source/thinkphp/library/think/cache/Driver.php

<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think\cache;

use think\Container;

/**
 * 缓存基础类
 */
abstract class Driver
{
    /**
     * 驱动句柄
     * @var object
     */
    protected $handler = null;

    /**
     * 缓存读取次数
     * @var integer
     */
    protected $readTimes = 0;

    /**
     * 缓存写入次数
     * @var integer
     */
    protected $writeTimes = 0;

    /**
     * 缓存参数
     * @var array
     */
    protected $options = [];

    /**
     * 缓存标签
     * @var string
     */
    protected $tag;

    /**
     * 序列化方法
     * @var array
     */
    protected static $serialize = ['serialize', 'unserialize', 'think_serialize:', 16];

    /**
     * 判断缓存是否存在
     * @access public
     * @param  string $name 缓存变量名
     * @return bool
     */
    abstract public function has($name);

    /**
     * 读取缓存
     * @access public
     * @param  string $name 缓存变量名
     * @param  mixed  $default 默认值
     * @return mixed
     */
    abstract public function get($name, $default = false);

    /**
     * 写入缓存
     * @access public
     * @param  string    $name 缓存变量名
     * @param  mixed     $value  存储数据
     * @param  int       $expire  有效时间 0为永久
     * @return boolean
     */
    abstract public function set($name, $value, $expire = null);

    /**
     * 自增缓存（针对数值缓存）
     * @access public
     * @param  string    $name 缓存变量名
     * @param  int       $step 步长
     * @return false|int
     */
    abstract public function inc($name, $step = 1);

    /**
     * 自减缓存（针对数值缓存）
     * @access public
     * @param  string    $name 缓存变量名
     * @param  int       $step 步长
     * @return false|int
     */
    abstract public function dec($name, $step = 1);

    /**
     * 删除缓存
     * @access public
     * @param  string $name 缓存变量名
     * @return boolean
     */
    abstract public function rm($name);

    /**
     * 清除缓存
     * @access public
     * @param  string $tag 标签名
     * @return boolean
     */
    abstract public function clear($tag = null);

    /**
     * 获取有效期
     * @access protected
     * @param  integer|\DateTime $expire 有效期
     * @return integer
     */
    protected function getExpireTime($expire)
    {
        if ($expire instanceof \DateTime) {
            $expire = $expire->getTimestamp() - time();
        }

        return $expire;
    }

    /**
     * 获取实际的缓存标识
     * @access protected
     * @param  string $name 缓存名
     * @return string
     */
    protected function getCacheKey($name)
    {
        return $this->options['prefix'] . $name;
    }

    /**
     * 读取缓存并删除
     * @access public
     * @param  string $name 缓存变量名
     * @return mixed
     */
    public function pull($name)
    {
        $result = $this->get($name, false);

        if ($result) {
            $this->rm($name);
            return $result;
        } else {
            return;
        }
    }

    /**
     * 如果不存在则写入缓存
     * @access public
     * @param  string    $name 缓存变量名
     * @param  mixed     $value  存储数据
     * @param  int       $expire  有效时间 0为永久
     * @return mixed
     */
    public function remember($name, $value, $expire = null)
    {
        if (!$this->has($name)) {
            $time = time();
            while ($time + 5 > time() && $this->has($name . '_lock')) {
                // 存在锁定则等待
                usleep(200000);
            }

            try {
                // 锁定
                $this->set($name . '_lock', true);

                if ($value instanceof \Closure) {
                    // 获取缓存数据
                    $value = Container::getInstance()->invokeFunction($value);
                }