基于memcache接口的统一存储工具类设计

lrx182125

　　刚开始处理的时候，临时想做一个统一接口的key-value数据的存储方式。然后我模拟memcached接口，写了个简单的k-v数据存储的工具类。
临时想到，暂且记下。

1. 接口类 /**

* 存储工具抽象接口类

*

*/

abstract class StoreTool

{

abstract public function set($key, $val);

abstract public function get($key);

abstract public function replace($key, $val);

abstract public function delete($key);

abstract public function flush();

abstract public function increment($key, $val=1);

abstract public function add($key, $val);

}



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2. memcached和mysql处理 （mysql用的heap engine） /**

* mysql heap engin 存储工具类

*

*/

class DbStoreTool extends StoreTool

{

static private $_instance;

private $_dbh;

private $_tablename = 'mmouc_memory_kv';



static public function getInstance($config) {

  if (self::$_instance == null) {

   self::$_instance = new self($config);

  }

  return self::$_instance;

}



private function __construct($config) {

  $conn = $config['persistency'] ? mysql_pconnect($config['host'].':'.$config['port'], $config['user'], $config['password'])

     : mysql_connect($config['host'].':'.$config['port'], $config['user'], $config['password']);



  if($conn) {

   if($config['charset']) mysql_query("SET NAMES '" . $config['charset'] . "'", $conn);



   if(!empty($config['database'])) {

    $dbselect = mysql_select_db($config['database'], $conn);

    if(!$dbselect) {

     mysql_close($conn);

     $conn = $dbselect;

    }

   }



   $this->_dbh = $conn;

   $this->_tablename = $config['tablename'];

  }

}



/**

  * Store data at the server

  * stores an item var with key on the memcached server

  *

  * @param unknown_type $key

  * @param unknown_type $val

  * @return unknown

  */

public function set($key, $val) {

  $res = $this->update($key, $val);

  if (0 === $res) {

   return $this->add($key, $val);

  }

  return true;

}



/**

  *  Replace value of the existing item

  *  should be used to replace value of existing item with key.

  *  In case if item with such key doesn't exists, This function returns FALSE

  *

  * @param unknown_type $key

  * @param unknown_type $val

  * @return unknown

  */

public function replace($key, $val) {

  $res = $this->update($key, $val);

  if (0 === $res) {

   return false;

  }

  return true;

}



public function get($key) {

  if (is_array($key)) {

   $in_keys = "'" . implode("','", $key) . "'";

   $sql = "

    SELECT `k`, `v` FROM `" . $this->_tablename . "`

    WHERE `k` IN ({$in_keys})

   ";

   $res = mysql_query($sql, $this->_dbh);



   if (empty($res)) {

    return MMO_STORE_OP_ERROR;

   }



   $_arr_res = array();

   while ($row = mysql_fetch_assoc($res)) {

    $row['v'] = unserialize($row['v']);

    $_arr_res[$row['k']] = $row;    

   }



   $out = array();

   foreach ($key as $_k) {

    $out[] = $_arr_res[$_k]['v'];

   }

   return $out;



  } else if (is_string($key)) {



   $sql = "

    SELECT `v` FROM `" . $this->_tablename . "`

    WHERE `k`='{$key}'

   ";

   $res = mysql_query($sql, $this->_dbh);



   if (empty($res)) {

    return -1;

   }

   $row = mysql_fetch_assoc($res);

   if (empty($row)) {

    return MMO_STORE_ITEM_NOT_EXIST;

   }

   return unserialize($row['v']);

  } else {



   return false;

  }



}



public function delete($key) {

  $sql = "

   DELETE FROM `" . $this->_tablename . "`

   WHERE `k`='$key'   

   ";

  $res = mysql_query($sql, $this->_dbh);

  if (!$res) {

   return MMO_STORE_OP_ERROR;

  }

  return mysql_affected_rows($this->_dbh);

}



public function flush() {

  $sql = " TRUNCATE TABLE `" . $this->_tablename . "` ";

  $res = mysql_query($sql, $this->_dbh);

  return $res ? true : false;

}



/**

  *

  * TODO:

  * 修改这里的并发访问问题

  *

  * @param unknown_type $key

  * @param unknown_type $val

  * @return unknown

  */

public function increment($key, $val=1) {

  $_db_val = $this->get($key);

  if (MMO_STORE_ITEM_NOT_EXIST == $_db_val) {

   //不存在

   return false;  

  }



  $val = intval($_db_val) + intval($val);

  $this->update($key, $val);

  return $val;

}



/**

  * Add an item to the server

  *

  * stores variable var with key only if such key doesn't exist at the server yet

  *

  * @param unknown_type $key

  * @param unknown_type $val

  * @return unknown

  */

public function add($key, $val) {

  if (!$this->_isExist($key)) {

   $val = serialize($val);

   $time = time();

   $sql = "

    INSERT INTO `" . $this->_tablename . "`

    SET `k`='{$key}',

        `v`='{$val}',

        `t`='{$time}'

   ";

   $res = mysql_query($sql, $this->_dbh);

   return $res ? true : MMO_STORE_OP_ERROR;



  } else {

   return false;

  }

}





private function _isExist($key, $val='') {

  $sql = "

   SELECT COUNT(`k`) as 'num'

   FROM `" . $this->_tablename . "`

   WHERE `k`='{$key}'

  ";

  !empty($val) && $sql .= ", `v`='" . serialize($val) . "'";

  $res = mysql_query($sql, $this->_dbh);

  if (empty($res)) {

   return -1;

  }

  $row = mysql_fetch_assoc($res);

  return $row['num'] ? true : false;

}



private function update($key, $val) {

  $val = serialize($val);

  $time = time();

  $sql = "

   UPDATE `" . $this->_tablename . "`

   SET `v`='{$val}',

       `t`='{$time}'

   WHERE `k`='$key'   

   ";

  $res = mysql_query($sql, $this->_dbh);

  if (!$res) {

   return MMO_STORE_OP_ERROR;

  }

  return mysql_affected_rows($this->_dbh);

}

}



class FileStoreTool

{



}



class MemcacheStoreTool extends StoreTool

{

static private $_instance;

private $_memcacheHandler;



static public function getInstance($config) {

  if (self::$_instance == null) {

   self::$_instance = new self($config);

  }

  return self::$_instance;

}



private function __construct($config) {

  $this->_memServers = $config;

  $this->_initMemcacheObj();

}



public function set($key, $val) {

  return $this->_memcacheHandler->set($key, $val);

}

public function get($key) {

  return $this->_memcacheHandler->get($key);

}



public function replace($key, $val) {

  return $this->_memcacheHandler->replace($key, $val);

}



public function delete($key) {

  return $this->_memcacheHandler->delete($key);

}

public function flush() {

  return $this->_memcacheHandler->flush();

}

public function increment($key, $val=1) {

  return $this->_memcacheHandler->increment($key, $val);

}



public function add($key, $val) {

  return $this->_memcacheHandler->add($key, $val);

}



/**

    * 检查保存Session数据的路径是否存在

    *

    * @return bool 成功返回true

    */

   private function _initMemcacheObj(){

       if (!class_exists('Memcache') || !function_exists('memcache_connect')){

           die('Failed: Memcache extension not install, please from http://pecl.php.net download and install');

       }       

       if ($this->_memcacheHandler && is_object($this->_memcacheHandler)){

           return true;

       }

       $this->_memcacheHandler = new Memcache;

       if (!empty($this->_memServers)) {

          foreach ($this->_memServers as $_host => $_port) {

            $this->_memcacheHandler->addServer($_host, $_port);

        }

       }



       return true;

   }

}



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3. mysql和file相关

mysql 记录方式，对应表 建表语句如下：
CREATE TABLE IF NOT EXISTS `mmouc_memory_kv` (
`k` varchar(40) NOT NULL COMMENT '键名',
`v` varchar(2048) NOT NULL COMMENT '键值的serialize值',
`t` int(10) NOT NULL DEFAULT '0' COMMENT '更新时间',
PRIMARY KEY (`k`)
) ENGINE=MEMORY DEFAULT CHARSET=utf8 COMMENT='代替memcache数据记录表';
对于file，暂未处理，以后补上。


4. todo:

a. 对于memcached数据的遍历方式策略，需要做一个完备而统一接口的策略算法处理类，可以在多种分级存储模式，和存储策略间任意切换；
b. file存储工具类补上