PHP Memcached get()函数

Memcached::get()函数是PHP中 memcached 类的内置函数，用于获取存储在 memcache 服务器上的给定键下的值。

句法：

public Memcached::get( $key, 
    callable $cache_cb = ?,  $$flags = ?): mixed

参数：此函数接受三个参数，它们是：

• key：要检索的项目的键。
• cache_cb：通读缓存回调或null。
• flags：控制返回结果的标志。当给定 Memcached::GET_EXTENDED 时，该函数还将返回 CAS 令牌。

返回值：返回存储在缓存中的值，否则返回 false。如果标志设置为 Memcached::GET_EXTENDED，则返回包含值和 CAS 令牌的数组，而不仅仅是返回值。如果键不存在，Memcached::getResultCode() 将返回 Memcached::RES_NOTFOUND。

下面的程序说明了PHP中的 Memcached::set()函数：

示例 1：

PHP

";
  
// Server & port details
$server = '127.0.0.1';
$port = 11211;
  
// Initiate a new object of memcache
$memcacheD = new Memcached();
  
// Add server
if ($memcacheD->addServer($server, $port)) {
    echo "**  server added ** \n";
}
else {
    echo "** issue while creating a server **\n";
}
  
// Set key & value with TTL
$key = "GEEKSFORGEEKS";
$value = "computer science portal";
$ttl = 3600;
  
if ($memcacheD->add($key, $value, $ttl)) 
    echo "** added key-value (" . $key . ":" 
    . $value . ")to cache successfully!! **\n";
      
else 
    echo "** error while adding value to cache!! **\n";
  
// Get value of key
echo "****   FETCHED VALUE   FOR KEY :" 
    . $key . " ****\n";
      
$valD = $memcacheD->get($key);
var_dump($valD);
  
?>

输出：

**  server added **
** added key-value (GEEKSFORGEEKS:computer science portal)to cache successfully!! **
****   FETCHED VALUE   FOR KEY :GEEKSFORGEEKS ****
string(23) “computer science portal”

示例 2（已存储键值）：

PHP

";
  
// Server & port details
$server = '127.0.0.1';
$port = 11211;
  
// Initiate a new object of memcache
$memcacheD = new Memcached();
  
// Add server
if ($memcacheD->addServer($server, $port)) {
    echo "**  server added ** \n";
}
else {
    echo "** issue while creating a server **\n";
}
  
// Set key & value with TTL
$key = "GEEKSFORGEEKS";
$value = "computer science portal";
$ttl = 3600;
  
if ($memcacheD->add($key, $value, $ttl)) 
      echo "** added key-value (" . $key . ":" 
      . $value . ")to cache successfully!! **\n";
else 
      echo "** error while adding value to cache!! **\n";
  
// Get value of key
echo "****   FETCHED VALUE   FOR KEY :"
      . $key . " ****\n";
  
$valD = $memcacheD->get($key);
var_dump($valD);
  
?>

输出：

**  server added **
** error while adding value to cache!! :: MSG:: NOT STORED **
****   FETCHED VALUE   FOR KEY :geeksforgeeks ****
string(23) “computer science portal”

参考： https://www. PHP.net/manual/en/memcached.get。 PHP