php shmop 内存读写操作

shmop php在linux上操作共享内存的函数

关于php操作内存,我选择了shmop扩展,其方法只有6个:

• shmop_open 打开内存块.
• shmop_write 向内存块中写入数据
• shmop_size 获得内存块大小
• shmop_read 读取内存块数据
• shmop_delete 删除内存块数据
• shmop_close 关闭内存块                                               

<?php

class shared {

    private $shm_id;
    private $shm_key = 0xff3;
    private $shm_size = 1024;

    function __construct() {
        $this->shm_id = shmop_open($this->shm_key, "c", 0644, $this->shm_size) or die('申请失败');
    }

    function __get($name) {
        $buf = shmop_read($this->shm_id, 0, $this->shm_size);
        $buf = unserialize(trim($buf));
        if ($name == '_all')
            return $buf;
        return isset($buf[$name]) ? $buf[$name] : false;
    }

    function __set($name, $value) {
        $buf = shmop_read($this->shm_id, 0, $this->shm_size);
        $buf = unserialize(trim($buf));
        $buf[$name] = $value;
        $buf = serialize($buf);
        if (strlen($buf) >= $this->shm_size)
            die('空间不足');
        shmop_write($this->shm_id, $buf, 0) or die('写入失败');
    }

    function del() {
        shmop_delete($this->shm_id);
    }

}

$shmopobj = new shared();

if (isset($shmopobj->database) || $shmopobj->database == null) {
    echo "input memory";
    echo "</br>";
    $shmopobj->database = "localhost";
} else {
    echo "get data";
    echo "</br>";
    echo $shmopobj->database;
}
//$shmopobj->del();
?>

第一次刷新页面，输出

input memory

第二次刷新页面，输出

get data
localhost

然后可以调用

$shmopobj->del();删除该内存数据