Developer
<?php
/*
* This file is part of the DebugBar package.
*
* (c) 2013 Maxime Bouroumeau-Fuseau
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace DebugBar\Storage;
use Memcached;
use ReflectionMethod;
/**
* Stores collected data into Memcache using the Memcached extension
*/
class MemcachedStorage implements StorageInterface
{
protected $memcached;
protected $keyNamespace;
protected $expiration;
protected $newGetMultiSignature;
/**
* @param Memcached $memcached
* @param string $keyNamespace Namespace for Memcached key names (to avoid conflict with other Memcached users).
* @param int $expiration Expiration for Memcached entries (see Expiration Times in Memcached documentation).
*/
public function __construct(Memcached $memcached, $keyNamespace = 'phpdebugbar', $expiration = 0)
{
$this->memcached = $memcached;
$this->keyNamespace = $keyNamespace;
$this->expiration = $expiration;
}
/**
* {@inheritdoc}
*/
public function save($id, $data)
{
$key = $this->createKey($id);
$this->memcached->set($key, $data, $this->expiration);
if (!$this->memcached->append($this->keyNamespace, "|$key")) {
$this->memcached->set($this->keyNamespace, $key, $this->expiration);
} else if ($this->expiration) {
// append doesn't support updating expiration, so do it here:
$this->memcached->touch($this->keyNamespace, $this->expiration);
}
}
/**
* {@inheritdoc}
*/
public function get($id)
{
return $this->memcached->get($this->createKey($id));
}
/**
* {@inheritdoc}
*/
public function find(array $filters = array(), $max = 20, $offset = 0)
{
if (!($keys = $this->memcached->get($this->keyNamespace))) {
return array();
}
$results = array();
$keys = array_reverse(explode('|', $keys)); // Reverse so newest comes first
$keyPosition = 0; // Index in $keys to try to get next items from
$remainingItems = $max + $offset; // Try to obtain this many remaining items
// Loop until we've found $remainingItems matching items or no more items may exist.
while ($remainingItems > 0 && $keyPosition < count($keys)) {
// Consume some keys from $keys:
$itemsToGet = array_slice($keys, $keyPosition, $remainingItems);
$keyPosition += $remainingItems;
// Try to get them, and filter them:
$newItems = $this->memcachedGetMulti($itemsToGet, Memcached::GET_PRESERVE_ORDER);
if ($newItems) {
foreach ($newItems as $data) {
$meta = $data['__meta'];
if ($this->filter($meta, $filters)) {
$remainingItems--;
// Keep the result only if we've discarded $offset items first
if ($offset <= 0) {
$results[] = $meta;
} else {
$offset--;
}
}
}
}
}
return $results;
}
/**
* Filter the metadata for matches.
*
* @param array $meta
* @param array $filters
* @return bool
*/
protected function filter($meta, $filters)
{
foreach ($filters as $key => $value) {
if (!isset($meta[$key]) || fnmatch($value, $meta[$key]) === false) {
return false;
}
}
return true;
}
/**
* {@inheritdoc}
*/
public function clear()
{
if (!($keys = $this->memcached->get($this->keyNamespace))) {
return;
}
$this->memcached->delete($this->keyNamespace);
$this->memcached->deleteMulti(explode('|', $keys));
}
/**
* @param string $id
* @return string
*/
protected function createKey($id)
{
return md5("{$this->keyNamespace}.$id");
}
/**
* The memcached getMulti function changed in version 3.0.0 to only have two parameters.
*
* @param array $keys
* @param int $flags
*/
protected function memcachedGetMulti($keys, $flags)
{
if ($this->newGetMultiSignature === null) {
$this->newGetMultiSignature = (new ReflectionMethod('Memcached', 'getMulti'))->getNumberOfParameters() === 2;
}
if ($this->newGetMultiSignature) {
return $this->memcached->getMulti($keys, $flags);
} else {
$null = null;
return $this->memcached->getMulti($keys, $null, $flags);
}
}
}
Developer
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