PHP+CI框架+Memcache集成

快来打我* 2023-08-17 17:27 147阅读 0赞

一、目录结构

![1509251-20190917162833340-1392841130.png][]

二、具体代码

MemcacheCluster.php

<?php
    
    /**
     * 一致性哈希memcache分布式，采用的是虚拟节点的方式解决分布均匀性问题,查找节点采用二分法快速查找
     */
    class MemcacheCluster
    {
        private $_node = array();
        private $_nodeData = array();
        private $_keyNode = 0;
        private $_memcache = null;
    
        //每个物理服务器生成虚拟节点个数 [注：节点数越多，cache分布的均匀性越好，同时set get操作时，也更耗资源，10台物理服务器，采用200较为合理]
        private $_virtualNodeNum = 2;
    
        private function __construct()
        {
            /* 放入配置文件 */
            $config = array(
                '127.0.0.1:11211',
            );
    
            if (!$config) throw new Exception('Cache config NULL');
            foreach ($config as $key => $value) {
                for ($i = 0; $i < $this->_virtualNodeNum; $i++) {
                    $this->_node[sprintf("%u", crc32($value . '_' . $i))] = $value . '_' . $i;
                }
            }
            ksort($this->_node);
        }
    
        private function __clone()
        {
        }
    
        /**
         * 单例，保证只有一个实例
         */
        static public function getInstance()
        {
            static $memcacheObj = null;
            if (!is_object($memcacheObj)) {
                $memcacheObj = new self();
            }
            return $memcacheObj;
        }
    
        /**
         * 根据key做一致性hash后连接到一台物理memcache服务器
         * @param string $key
         */
        private function _connectMemcache($key)
        {
            $this->_nodeData = array_keys($this->_node);
            $this->_keyNode = sprintf("%u", crc32($key));
            $nodeKey = $this->_findServerNode();
            //如果超出环，从头再用二分法查找一个最近的，然后环的头尾做判断，取最接近的节点
            if ($this->_keyNode > end($this->_nodeData)) {
                $this->_keyNode -= end($this->_nodeData);
                $nodeKey2 = $this->_findServerNode();
                if (abs($nodeKey2 - $this->_keyNode) < abs($nodeKey - $this->_keyNode)) $nodeKey = $nodeKey2;
            }
            //var_dump($this->_node[$nodeKey]); 127.0.0.1:11211_20
            list($config, $num) = explode('_', $this->_node[$nodeKey]);
            if (!$config) throw new Exception('Cache config Error');
            if (!isset($this->_memcache[$config])) {
                $this->_memcache[$config] = new Memcache;
                list($host, $port) = explode(':', $config);
                $this->_memcache[$config]->connect($host, $port);
            }
            return $this->_memcache[$config];
        }
    
        /**
         * 采用二分法从虚拟memcache节点中查找最近的节点
         * @param unknown_type $m
         * @param unknown_type $b
         */
        private function _findServerNode($m = 0, $b = 0)
        {
            $total = count($this->_nodeData);
            if ($total != 0 && $b == 0) $b = $total - 1;
            if ($m < $b) {
                $avg = intval(($m + $b) / 2);
                if ($this->_nodeData[$avg] == $this->_keyNode) return $this->_nodeData[$avg];
                elseif ($this->_keyNode < $this->_nodeData[$avg] && ($avg - 1 >= 0)) return $this->_findServerNode($m, $avg - 1);
                else return $this->_findServerNode($avg + 1, $b);
            }
            if (abs($this->_nodeData[$b] - $this->_keyNode) < abs($this->_nodeData[$m] - $this->_keyNode)) return $this->_nodeData[$b];
            else return $this->_nodeData[$m];
        }
    
        public function set($key, $value, $expire = 0)
        {
            return $this->_connectMemcache($key)->set($key, json_encode($value), 0, $expire);
        }
    
        public function add($key, $value, $expire = 0)
        {
            return $this->_connectMemcache($key)->add($key, json_encode($value), 0, $expire);
        }
    
        public function get($key)
        {
            return json_decode($this->_connectMemcache($key)->get($key), true);
        }
    
        public function delete($key)
        {
            return $this->_connectMemcache($key)->delete($key);
        }
    
    }

memcached.php

<?php
    /**
     * Created by PhpStorm.
     * User: 25754
     * Date: 2019/9/17
     * Time: 16:17
     */
    
    include_once APPPATH . "/third_party/MemcacheCluster.php";
    
    class Memcached
    {
        public function set($key, $value, $expire = 0)
        {
            return MemcacheCluster::getInstance()->set($key, $value, $expire);
        }
    
        public function add($key, $value, $expire = 0)
        {
            return MemcacheCluster::getInstance()->add($key, $value, $expire);
        }
    
        public function delete($key)
        {
            return MemcacheCluster::getInstance()->delete($key);
        }
    
        public function get($key)
        {
            return MemcacheCluster::getInstance()->get($key);
        }
    }

MY\_Controller.php

class Home_Controller extends CI_Controller
    {
        public function __construct()
        {
            parent::__construct();
            $this->load->library('memcached', null, 'memcache');
        }
    }

index.php

class Index extends Home_Controller
    {
        public function __construct()
        {
            parent::__construct();
            $this->load->set_home_view_dir();
        }
    
        public function index()
        {
            //要设置随机缓存时间，防止缓存失效，大的访问量造成数据库崩溃
            $time = rand(1, 10);
            $key = md5("yy");
            $cacheValue = $this->memcache->get($key);
            if (!$cacheValue) {
                //随机保存时间
                $flag = $this->memcache->set($key, "yang", $time);
                if ($flag) {
                    echo "缓存时间：".$time."秒";
                }
            }
            echo $cacheValue;
        }
    }

转载于:https://www.cnblogs.com/yang-2018/p/11535041.html

[1509251-20190917162833340-1392841130.png]: /images/20230808/82f271e607344ce79b4741cb496f323d.png