<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Cache\Traits;
use Psr\Cache\CacheItemInterface;
use Psr\Log\LoggerAwareTrait;
use Symfony\Component\Cache\CacheItem;
use Symfony\Component\Cache\Exception\InvalidArgumentException;
/**
* @author Nicolas Grekas <p@tchwork.com>
*
* @internal
*/
trait AbstractAdapterTrait
{
use LoggerAwareTrait;
/**
* @var \Closure needs to be set by class, signature is function(string <key>, mixed <value>, bool <isHit>)
*/
private static $createCacheItem;
/**
* @var \Closure needs to be set by class, signature is function(array <deferred>, string <namespace>, array <&expiredIds>)
*/
private static $mergeByLifetime;
private $namespace = '';
private $defaultLifetime;
private $namespaceVersion = '';
private $versioningIsEnabled = false;
private $deferred = [];
private $ids = [];
/**
* @var int|null The maximum length to enforce for identifiers or null when no limit applies
*/
protected $maxIdLength;
/**
* Fetches several cache items.
*
* @param array $ids The cache identifiers to fetch
*
* @return array|\Traversable
*/
abstract protected function doFetch(array $ids);
/**
* Confirms if the cache contains specified cache item.
*
* @param string $id The identifier for which to check existence
*
* @return bool
*/
abstract protected function doHave(string $id);
/**
* Deletes all items in the pool.
*
* @param string $namespace The prefix used for all identifiers managed by this pool
*
* @return bool
*/
abstract protected function doClear(string $namespace);
/**
* Removes multiple items from the pool.
*
* @param array $ids An array of identifiers that should be removed from the pool
*
* @return bool
*/
abstract protected function doDelete(array $ids);
/**
* Persists several cache items immediately.
*
* @param array $values The values to cache, indexed by their cache identifier
* @param int $lifetime The lifetime of the cached values, 0 for persisting until manual cleaning
*
* @return array|bool The identifiers that failed to be cached or a boolean stating if caching succeeded or not
*/
abstract protected function doSave(array $values, int $lifetime);
/**
* {@inheritdoc}
*
* @return bool
*/
public function hasItem($key)
{
$id = $this->getId($key);
if (isset($this->deferred[$key])) {
$this->commit();
}
try {
return $this->doHave($id);
} catch (\Exception $e) {
CacheItem::log($this->logger, 'Failed to check if key "{key}" is cached: '.$e->getMessage(), ['key' => $key, 'exception' => $e, 'cache-adapter' => get_debug_type($this)]);
return false;
}
}
/**
* {@inheritdoc}
*
* @return bool
*/
public function clear(string $prefix = '')
{
$this->deferred = [];
if ($cleared = $this->versioningIsEnabled) {
if ('' === $namespaceVersionToClear = $this->namespaceVersion) {
foreach ($this->doFetch([static::NS_SEPARATOR.$this->namespace]) as $v) {
$namespaceVersionToClear = $v;
}
}
$namespaceToClear = $this->namespace.$namespaceVersionToClear;
$namespaceVersion = self::formatNamespaceVersion(mt_rand());
try {
$e = $this->doSave([static::NS_SEPARATOR.$this->namespace => $namespaceVersion], 0);
} catch (\Exception $e) {
}
if (true !== $e && [] !== $e) {
$cleared = false;
$message = 'Failed to save the new namespace'.($e instanceof \Exception ? ': '.$e->getMessage() : '.');
CacheItem::log($this->logger, $message, ['exception' => $e instanceof \Exception ? $e : null, 'cache-adapter' => get_debug_type($this)]);
} else {
$this->namespaceVersion = $namespaceVersion;
$this->ids = [];
}
} else {
$namespaceToClear = $this->namespace.$prefix;
}
try {
return $this->doClear($namespaceToClear) || $cleared;
} catch (\Exception $e) {
CacheItem::log($this->logger, 'Failed to clear the cache: '.$e->getMessage(), ['exception' => $e, 'cache-adapter' => get_debug_type($this)]);
return false;
}
}
/**
* {@inheritdoc}
*
* @return bool
*/
public function deleteItem($key)
{
return $this->deleteItems([$key]);
}
/**
* {@inheritdoc}
*
* @return bool
*/
public function deleteItems(array $keys)
{
$ids = [];
foreach ($keys as $key) {
$ids[$key] = $this->getId($key);
unset($this->deferred[$key]);
}
try {
if ($this->doDelete($ids)) {
return true;
}
} catch (\Exception $e) {
}
$ok = true;
// When bulk-delete failed, retry each item individually
foreach ($ids as $key => $id) {
try {
$e = null;
if ($this->doDelete([$id])) {
continue;
}
} catch (\Exception $e) {
}
$message = 'Failed to delete key "{key}"'.($e instanceof \Exception ? ': '.$e->getMessage() : '.');
CacheItem::log($this->logger, $message, ['key' => $key, 'exception' => $e, 'cache-adapter' => get_debug_type($this)]);
$ok = false;
}
return $ok;
}
/**
* {@inheritdoc}
*/
public function getItem($key)
{
$id = $this->getId($key);
if (isset($this->deferred[$key])) {
$this->commit();
}
$isHit = false;
$value = null;
try {
foreach ($this->doFetch([$id]) as $value) {
$isHit = true;
}
return (self::$createCacheItem)($key, $value, $isHit);
} catch (\Exception $e) {
CacheItem::log($this->logger, 'Failed to fetch key "{key}": '.$e->getMessage(), ['key' => $key, 'exception' => $e, 'cache-adapter' => get_debug_type($this)]);
}
return (self::$createCacheItem)($key, null, false);
}
/**
* {@inheritdoc}
*/
public function getItems(array $keys = [])
{
$ids = [];
$commit = false;
foreach ($keys as $key) {
$ids[] = $this->getId($key);
$commit = $commit || isset($this->deferred[$key]);
}
if ($commit) {
$this->commit();
}
try {
$items = $this->doFetch($ids);
} catch (\Exception $e) {
CacheItem::log($this->logger, 'Failed to fetch items: '.$e->getMessage(), ['keys' => $keys, 'exception' => $e, 'cache-adapter' => get_debug_type($this)]);
$items = [];
}
$ids = array_combine($ids, $keys);
return $this->generateItems($items, $ids);
}
/**
* {@inheritdoc}
*
* @return bool
*/
public function save(CacheItemInterface $item)
{
if (!$item instanceof CacheItem) {
return false;
}
$this->deferred[$item->getKey()] = $item;
return $this->commit();
}
/**
* {@inheritdoc}
*
* @return bool
*/
public function saveDeferred(CacheItemInterface $item)
{
if (!$item instanceof CacheItem) {
return false;
}
$this->deferred[$item->getKey()] = $item;
return true;
}
/**
* Enables/disables versioning of items.
*
* When versioning is enabled, clearing the cache is atomic and doesn't require listing existing keys to proceed,
* but old keys may need garbage collection and extra round-trips to the back-end are required.
*
* Calling this method also clears the memoized namespace version and thus forces a resynchronization of it.
*
* @return bool the previous state of versioning
*/
public function enableVersioning(bool $enable = true)
{
$wasEnabled = $this->versioningIsEnabled;
$this->versioningIsEnabled = $enable;
$this->namespaceVersion = '';
$this->ids = [];
return $wasEnabled;
}
/**
* {@inheritdoc}
*/
public function reset()
{
if ($this->deferred) {
$this->commit();
}
$this->namespaceVersion = '';
$this->ids = [];
}
/**
* @return array
*/
public function __sleep()
{
throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
}
public function __wakeup()
{
throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
}
public function __destruct()
{
if ($this->deferred) {
$this->commit();
}
}
private function generateItems(iterable $items, array &$keys): \Generator
{
$f = self::$createCacheItem;
try {
foreach ($items as $id => $value) {
if (!isset($keys[$id])) {
throw new InvalidArgumentException(sprintf('Could not match value id "%s" to keys "%s".', $id, implode('", "', $keys)));
}
$key = $keys[$id];
unset($keys[$id]);
yield $key => $f($key, $value, true);
}
} catch (\Exception $e) {
CacheItem::log($this->logger, 'Failed to fetch items: '.$e->getMessage(), ['keys' => array_values($keys), 'exception' => $e, 'cache-adapter' => get_debug_type($this)]);
}
foreach ($keys as $key) {
yield $key => $f($key, null, false);
}
}
/**
* @internal
*/
protected function getId($key)
{
if ($this->versioningIsEnabled && '' === $this->namespaceVersion) {
$this->ids = [];
$this->namespaceVersion = '1'.static::NS_SEPARATOR;
try {
foreach ($this->doFetch([static::NS_SEPARATOR.$this->namespace]) as $v) {
$this->namespaceVersion = $v;
}
$e = true;
if ('1'.static::NS_SEPARATOR === $this->namespaceVersion) {
$this->namespaceVersion = self::formatNamespaceVersion(time());
$e = $this->doSave([static::NS_SEPARATOR.$this->namespace => $this->namespaceVersion], 0);
}
} catch (\Exception $e) {
}
if (true !== $e && [] !== $e) {
$message = 'Failed to save the new namespace'.($e instanceof \Exception ? ': '.$e->getMessage() : '.');
CacheItem::log($this->logger, $message, ['exception' => $e instanceof \Exception ? $e : null, 'cache-adapter' => get_debug_type($this)]);
}
}
if (\is_string($key) && isset($this->ids[$key])) {
return $this->namespace.$this->namespaceVersion.$this->ids[$key];
}
\assert('' !== CacheItem::validateKey($key));
$this->ids[$key] = $key;
if (\count($this->ids) > 1000) {
$this->ids = \array_slice($this->ids, 500, null, true); // stop memory leak if there are many keys
}
if (null === $this->maxIdLength) {
return $this->namespace.$this->namespaceVersion.$key;
}
if (\strlen($id = $this->namespace.$this->namespaceVersion.$key) > $this->maxIdLength) {
// Use MD5 to favor speed over security, which is not an issue here
$this->ids[$key] = $id = substr_replace(base64_encode(hash('md5', $key, true)), static::NS_SEPARATOR, -(\strlen($this->namespaceVersion) + 2));
$id = $this->namespace.$this->namespaceVersion.$id;
}
return $id;
}
/**
* @internal
*/
public static function handleUnserializeCallback(string $class)
{
throw new \DomainException('Class not found: '.$class);
}
private static function formatNamespaceVersion(int $value): string
{
return strtr(substr_replace(base64_encode(pack('V', $value)), static::NS_SEPARATOR, 5), '/', '_');
}
}