/**
* Define Predis base path if not already set, and if we need to set the
* autoloader by ourself. This will ensure no crash. Best way would have
* been that Drupal ships a PSR-0 autoloader, in which we could manually
* add our library path.
*
* We cannot do that in the file header, PHP class_exists() function wont
* see classes being loaded during the autoloading because this file is
* loaded by another autoloader: attempting the class_exists() during a
* pending autoloading would cause PHP to crash and ignore the rest of the
* file silentely (WTF!?). By delaying this at the getClient() call we
* ensure we are not in the class loading process anymore.
*/
public static function setPredisAutoload()
{
if (self::$autoloaderRegistered) {
return;
} else {
self::$autoloaderRegistered = true;
}
// If you attempt to set Drupal's bin cache_bootstrap using Redis, you
// will experience an infinite loop (breaking by itself the second time
// it passes by): the following call will wake up autoloaders (and we
// want that to work since user may have set its own autoloader) but
// will wake up Drupal's one too, and because Drupal core caches its
// file map, this will trigger this method to be called a second time
// and boom! Adios bye bye. That's why this will be called early in the
// 'redis.autoload.inc' file instead.
if (!class_exists('Predis\\Client')) {
if (!defined('PREDIS_BASE_PATH')) {
$search = DRUPAL_ROOT . '/sites/all/libraries/predis/lib/';
if (is_dir($search)) {
define('PREDIS_BASE_PATH', $search);
} else {
throw new Exception("PREDIS_BASE_PATH constant must be set, Predis library must live in sites/all/libraries/predis.");
}
}
if (class_exists('AutoloadEarly')) {
AutoloadEarly::getInstance()->registerNamespace('Predis', PREDIS_BASE_PATH);
} else {
// Register a simple autoloader for Predis library. Since the Predis
// library is PHP 5.3 only, we can afford doing closures safely.
spl_autoload_register(function ($classname) {
if (0 === strpos($classname, 'Predis\\')) {
$filename = PREDIS_BASE_PATH . str_replace('\\', '/', $classname) . '.php';
return (bool) (require_once $filename);
}
return false;
});
}
}
}
/**
* Define Predis base path if not already set, and if we need to set the
* autoloader by ourself. This will ensure no crash. Best way would have
* been that Drupal ships a PSR-0 autoloader, in which we could manually
* add our library path.
*
* We cannot do that in the file header, PHP class_exists() function wont
* see classes being loaded during the autoloading because this file is
* loaded by another autoloader: attempting the class_exists() during a
* pending autoloading would cause PHP to crash and ignore the rest of the
* file silentely (WTF!?). By delaying this at the getClient() call we
* ensure we are not in the class loading process anymore.
*/
public static function setPredisAutoload()
{
if (self::$autoloaderRegistered) {
return;
}
self::$stupidCoreWorkaround++;
// If you attempt to set Drupal's bin cache_bootstrap using Redis, you
// will experience an infinite loop (breaking by itself the second time
// it passes by): the following call will wake up autoloaders (and we
// want that to work since user may have set its own autoloader) but
// will wake up Drupal's one too, and because Drupal core caches its
// file map, this will trigger this method to be called a second time
// and boom! Adios bye bye. That's why this will be called early in the
// 'redis.autoload.inc' file instead.
if (1 < self::$stupidCoreWorkaround || !class_exists('Predis\\Client')) {
if (!defined('PREDIS_BASE_PATH')) {
$search = DRUPAL_ROOT . '/sites/all/libraries/predis';
define('PREDIS_BASE_PATH', $search);
} else {
$search = PREDIS_BASE_PATH;
}
if (is_dir($search . '/src')) {
// Predis v1.x
define('PREDIS_VERSION_MAJOR', 1);
} else {
if (is_dir($search . '/lib')) {
// Predis v0.x
define('PREDIS_VERSION_MAJOR', 0);
} else {
throw new Exception("PREDIS_BASE_PATH constant must be set, Predis library must live in sites/all/libraries/predis.");
}
}
// Register a simple autoloader for Predis library. Since the Predis
// library is PHP 5.3 only, we can afford doing closures safely.
switch (PREDIS_VERSION_MAJOR) {
case 0:
$autoload = function ($classname) {
// PSR-0 autoloader.
if (0 === strpos($classname, 'Predis\\')) {
$filename = PREDIS_BASE_PATH . '/lib/' . str_replace('\\', '/', $classname) . '.php';
return (bool) (require_once $filename);
}
return false;
};
break;
case 1:
// Register a simple autoloader for Predis library. Since the Predis
// library is PHP 5.3 only, we can afford doing closures safely.
$autoload = function ($classname) {
// PSR-4 autoloader
if (0 === strpos($classname, 'Predis\\')) {
$filename = PREDIS_BASE_PATH . '/src/' . str_replace('\\', '/', substr($classname, 7)) . '.php';
return (bool) (require_once $filename);
}
return false;
};
break;
}
if ($autoload) {
spl_autoload_register($autoload);
}
// Same reason why we have the stupid core workaround, if this happens
// during a second autoload call, PHP won't call the newly registered
// autoloader function, so just load the file.
if (1 < self::$stupidCoreWorkaround) {
call_user_func($autoload, 'Predis\\Client');
}
}
self::$autoloaderRegistered = true;
}
public function lockAcquire($name, $timeout = 30.0)
{
$client = Redis_Client::getClient();
$key = $this->getKey($name);
$id = $this->getLockId();
// Insure that the timeout is at least 1 second, we cannot do otherwise with
// Redis, this is a minor change to the function signature, but in real life
// nobody will notice with so short duration.
$timeout = ceil(max($timeout, 1));
// If we already have the lock, check for his owner and attempt a new EXPIRE
// command on it.
if (isset($this->_locks[$name])) {
// Create a new transaction, for atomicity.
$client->watch($key);
// Global tells us we are the owner, but in real life it could have expired
// and another process could have taken it, check that.
if ($client->get($key) != $id) {
$client->unwatch($key);
unset($this->_locks[$name]);
return FALSE;
}
switch (Redis_Client_Predis::getPredisVersionMajor()) {
case 0:
$replies = $client->pipeline(function ($pipe) use($key, $timeout, $id) {
$pipe->multi();
$pipe->setex($key, $timeout, $id);
$pipe->exec();
});
break;
default:
$replies = $client->transaction(function ($pipe) use($key, $timeout, $id) {
$pipe->setex($key, $timeout, $id);
});
break;
}
$execReply = array_pop($replies);
if (FALSE === $execReply[0]) {
unset($this->_locks[$name]);
return FALSE;
}
return TRUE;
} else {
$client->watch($key);
$owner = $client->get($key);
if (!empty($owner) && $owner != $id) {
$client->unwatch();
unset($this->_locks[$name]);
return FALSE;
}
$replies = $client->pipeline(function ($pipe) use($key, $timeout, $id) {
$pipe->multi();
$pipe->setex($key, $timeout, $id);
$pipe->exec();
});
$execReply = array_pop($replies);
// If another client modified the $key value, transaction will be discarded
// $result will be set to FALSE. This means atomicity have been broken and
// the other client took the lock instead of us.
// EXPIRE and SETEX won't return something here, EXEC return is index 0
// This was determined debugging, seems to be Predis specific.
if (FALSE === $execReply[0]) {
return FALSE;
}
// Register the lock and return.
return $this->_locks[$name] = TRUE;
}
return FALSE;
}
