解析php中memcache的应用

<?php
//连接
$mem = new Memcache;
$mem->connect("127.0.0.1", 11211);
//保存数据
$mem->set('key1', 'This is first value', 0, 60);
$val = $mem->get('key1');
echo "Get key1 value: " . $val ."<br />";
//替换数据
$mem->replace('key1', 'This is replace value', 0, 60);
$val = $mem->get('key1');
echo "Get key1 value: " . $val . "<br />";
//保存数组
$arr = array('aaa', 'bbb', 'ccc', 'ddd');
$mem->set('key2', $arr, 0, 60);
$val2 = $mem->get('key2');
echo "Get key2 value: ";
print_r($val2);
echo "<br />";
//删除数据
$mem->delete('key1');
$val = $mem->get('key1');
echo "Get key1 value: " . $val . "<br />";
//清除所有数据
$mem->flush();
$val2 = $mem->get('key2');
echo "Get key2 value: ";
print_r($val2);
echo "<br />";
//关闭连接
$mem->close();
$memcachehost = '192.168.10.1';
$memcacheport = 11211;
$memcachelife = 60;
$memcache = new Memcache;
$memcache->connect($memcachehost,$memcacheport) or die ("Could not connect");
$query="select * from user limit 10";
$key=md5($query);
if(!$memcache->get($key))
{
        $conn=mysql_connect("192.168.30.1","root","passwd");
        mysql_select_db(users);
        $result=mysql_query($query);
        while ($row=mysql_fetch_assoc($result))
        {
            $arr[]=$row;
        }
        $f = 'db';
        $memcache->add($key,serialize($arr),0,30);
        $data = $arr ;
}
else{
        $f = 'mem';
    $data_mem=$memcache->get($key);
    $data = unserialize($data_mem);
}
echo $f;
echo "";
//print_r($data);
foreach($data as $a)
{
        echo $a[user_id]._.$a[email];
        echo "";
}
?>

//==============memcache
$memcachehost = '127.0.0.1';
$memcacheport = 11211;
$memcachelife = 60;
$memcache = new Memcache;
$memcache->connect($memcachehost,$memcacheport) or die ("Could not connect");
//==============新闻
 $sql="SELECT id,title,left(title,16) as biaoti,date_time FROM `p_newsbase` where shenhe='1' order by id DESC limit 7 ";
 $query=$db->query($sql);
 $key=md5($query);
 while($row_news=$db->fetch_array($query)){
  $str=$row_news['biaoti'].$db->time_out($row_news['date_time']);
  $sm_news[]=array("name"=>$str,"title"=>$row_news['title'],"id"=>$row_news['id'],"date_time"=>$row_news['date_time']);
 }
 if(!$memcache->get($key)){
  $memcache->add($key,serialize($sm_news),0,$memcachelife);
 }else{
  $data_mem=$memcache->get($key);
    $sm_news = unserialize($data_mem);
 }
 $smarty->assign("sm_news",$sm_news);