Memcached::getMulti

(PECL memcached >= 0.1.0)

Memcached::getMulti — Retrieve multiple items

Description

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

Memcached::getMulti() is similar to Memcached::get(), but instead of a single key item, it retrieves multiple items the keys of which are specified in the keys array. If cas_tokens variable is provided, it is filled with the CAS token values for the found items.

Note:
Unlike Memcached::get() it is not possible to specify a read-through cache callback for Memcached::getMulti(), because the memcache protocol does not provide information on which keys were not found in the multi-key request.

The flags parameter can be used to specify additional options for Memcached::getMulti(). Currently, the only available option is Memcached::GET_PRESERVE_ORDER that ensures that the keys are returned in the same order as they were requested in.

Parameters

keys: Array of keys to retrieve.
cas_tokens: The variable to store the CAS tokens for the found items.
flags: The flags for the get operation.

Return Values

Returns the array of found items or FALSE on failure. Use Memcached::getResultCode() if necessary.

Examples

Example #1 Memcached::getMulti() example


<?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);
?>

The above example will output something similar to:

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

Example #2 Memcached::GET_PRESERVE_ORDER example


<?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";
}
?>

The above example will output something similar to:

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

User Contributed Notes

gabriel dot maybrun at demandmedia dot com

1 year ago


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'));
    }
}