PHPでmemcachedを使うとき

PdoDao.php

<?php
class PdoDao {

    const user = "hogehoge";
    const pass = "hogehoge";
    const memSec = 10;

    private $pdo;
    private $m;

    function __construct() {
        $this->pdo =
            new PDO('mysql:host=localhost;dbname=test', self::user, self::pass);

        $this->m = new Memcache;
        $this->m->connect('localhost', 11211);

    }

    function __destruct() {
        $this->pdo = null;
        $this->m = null;
    }

    /**
     * すべて検索
     */
    function findAll() {
        if($this->getMemcachedStatus()) {
            $data = $this->m->get("ArticleAll");
        }
        if(!$data) {
            echo "findAll:: Get Database.". PHP_EOL;
            $stmt = $this->pdo->prepare("select * from article;");
            $stmt->execute();
            $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

            if($this->getMemcachedStatus()) {
                echo "findAll:: Set Memcache.". PHP_EOL;
                $this->m->set("ArticleAll", $data, false, self::memSec);
            }
        }
        return $data;
    }

    /**
     * IDを指定して検索
     * @param id
     */
    function findId($id) {

        if($this->getMemcachedStatus()) {
            $data = $this->m->get($id);
        }
        if(!$data) {
            echo "findId:: Get Database.". PHP_EOL;
            $stmt = $this->pdo->prepare("select * from article where id = :id");
            $stmt->bindParam(":id", $id);
            $stmt->execute();
            $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

            if($this->getMemcachedStatus()) {
                echo "findId:: Set Memcache.". PHP_EOL;
                $this->m->set($id, $data, false, self::memSec);
            }
        }
        return $data;

    }

    /**
     * memcached が使用可能かどうかを返す
     */
    function getMemcachedStatus() {
        if (!is_null($this->m)) {
            return $this->m->getServerStatus("localhost", 11211) ? true : false;
        }
        return false;
    }

}

TestPdoDao.php

<?php

require_once('PdoDao.php');

$pdo = new PdoDao();

echo "## findId テスト". PHP_EOL;
$retVal = $pdo->findId(1);
foreach($retVal as $ret) {
    var_dump($ret);
}

echo "## findAll テスト". PHP_EOL;
$retVal = $pdo->findAll();
foreach($retVal as $ret) {
    var_dump($ret);
}

memcachedでDB問い合わせ結果をキャッシュ