Memcached::getMulti

(PECL memcached >= 0.1.0)

Memcached::getMulti — 检索多个元素

说明

public mixed Memcached::getMulti ( array $keys [, array &$cas_tokens [, int $flags ]] )

Memcached::getMulti() 与 Memcached::get() 类似，但是这个方法用来检索 keys数组指定的多个key对应的元素。如果提供了参数cas_tokens，对于检索到的元素会为其添加CAS标记值。

Note:

与 Memcached::get() 不同的是，不能为 Memcached::getMulti() 指定通读回调函数，因为memcache协议不能提供多个key检索时没有查找到的key的信息。

flags参数可以用做指定 Memcached::getMulti() 的附加选项。当前，仅可以指定为 Memcached::GET_PRESERVE_ORDER 以保证返回的key的顺序和请求时一致。

参数

keys: 要检索的key的数组。
cas_tokens: 用来存储检索到的元素的CAS标记。
flags: get操作的附加选项。

返回值

返回检索到的元素的数组或者在失败时返回 FALSE . 如需要则使用 Memcached::getResultCode() 。

范例

Example #1 Memcached::getMulti() 示例

  <?php
$m  = new  Memcached ();
 $m -> addServer ( 'localhost' ,  11211 );

 $items  = array(
     'key1'  =>  'value1' ,
     'key2'  =>  'value2' ,
     'key3'  =>  'value3'
 );
 $m -> setMulti ( $items );
 $result  =  $m -> getMulti (array( 'key1' ,  'key3' ,  'badkey' ),  $cas );
 var_dump ( $result ,  $cas );
 ?>

以上例程的输出类似于：

array(2) {
  ["key1"]=>
  string(6) "value1"
  ["key3"]=>
  string(6) "value3"
}
array(2) {
  ["key1"]=>
  float(2360)
  ["key3"]=>
  float(2362)
}

Example #2 Memcached::GET_PRESERVE_ORDER 示例

  <?php
$m  = new  Memcached ();
 $m -> addServer ( 'localhost' ,  11211 );

 $data  = array(
     'foo'  =>  'foo-data' ,
     'bar'  =>  'bar-data' ,
     'baz'  =>  'baz-data' ,
     'lol'  =>  'lol-data' ,
     'kek'  =>  'kek-data' ,
);

 $m -> setMulti ( $data ,  3600 );

 $null  =  null ;
 $keys  =  array_keys ( $data );
 $keys [] =  'zoo' ;
 $got  =  $m -> getMulti ( $keys ,  $null ,  Memcached :: GET_PRESERVE_ORDER );

foreach ( $got  as  $k  =>  $v ) {
    echo  " $k   $v \n" ;
}
 ?>

以上例程的输出类似于：

foo foo-data
bar bar-data
baz baz-data
lol lol-data
kek kek-data
zoo

参见

Memcached::getMultiByKey() - 从特定服务器检索多个元素
Memcached::get() - 检索一个元素
Memcached::getDelayed() - 请求多个元素

用户评论:

[#1] gabriel dot maybrun at demandmedia dot com [2014-09-04 23:58:03]

GOTCHA: Recently I was tasked with moving from PECL memcache to PECL memcached and ran into a major problem -- memcache and memcached serialize data differently, meaning that data written with one library can't necessarily be read with the other library.

For example, If you write an object or an array with memcache, it's interpreted as an integer by memcached.  If you write it with memcached, it's interpreted as a string by memcache.

tl;dr - You can't safely switch between memcache and memcached without a either a cache flush or isolated cache environments.

<?php
$memcache = new Memcache;
$memcacheD = new Memcached;
$memcache->addServer($host);
$memcacheD->addServers($servers);

$checks = array(
    123,
    4542.32,
    'a string',
    true,
    array(123, 'string'),
    (object)array('key1' => 'value1'),
);
foreach ($checks as $i => $value) {
    print "Checking WRITE with Memcache\n";
    $key = 'cachetest' . $i;
    $memcache->set($key, $value);
    usleep(100);
    $val = $memcache->get($key);
    $valD = $memcacheD->get($key);
    if ($val !== $valD) {
        print "Not compatible!";
        var_dump(compact('val', 'valD'));
    }

    print "Checking WRITE with MemcacheD\n";
    $key = 'cachetest' . $i;
    $memcacheD->set($key, $value);
    usleep(100);
    $val = $memcache->get($key);
    $valD = $memcacheD->get($key);
    if ($val !== $valD) {
        print "Not compatible!";
        var_dump(compact('val', 'valD'));
    }
}