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<?php
namespace Drupal\Core\Flood;
use Drupal\Component\Datetime\TimeInterface;
use Drupal\Core\Database\Connection;
use Drupal\Core\Database\DatabaseException;
use Symfony\Component\HttpFoundation\RequestStack;
/**
* Defines the database flood backend. This is the default Drupal backend.
*/
class DatabaseBackend implements FloodInterface, PrefixFloodInterface {
/**
* The database table name.
*/
const TABLE_NAME = 'flood';
/**
* Construct the DatabaseBackend.
*
* @param \Drupal\Core\Database\Connection $connection
* The database connection which will be used to store the flood event
* information.
* @param \Symfony\Component\HttpFoundation\RequestStack $requestStack
* The request stack used to retrieve the current request.
* @param \Drupal\Component\Datetime\TimeInterface $time
* The time service.
*/
public function __construct(
protected Connection $connection,
protected RequestStack $requestStack,
protected TimeInterface $time,
) {
}
/**
* {@inheritdoc}
*/
public function register($name, $window = 3600, $identifier = NULL) {
if (!isset($identifier)) {
$identifier = $this->requestStack->getCurrentRequest()->getClientIp();
}
$try_again = FALSE;
try {
$this->doInsert($name, $window, $identifier);
}
catch (\Exception $e) {
$try_again = $this->ensureTableExists();
if (!$try_again) {
throw $e;
}
}
if ($try_again) {
$this->doInsert($name, $window, $identifier);
}
}
/**
* Inserts an event into the flood table.
*
* @param string $name
* The name of an event.
* @param int $window
* Number of seconds before this event expires.
* @param string $identifier
* Unique identifier of the current user.
*
* @see \Drupal\Core\Flood\DatabaseBackend::register
*/
protected function doInsert($name, $window, $identifier) {
$this->connection->insert(static::TABLE_NAME)
->fields([
'event' => $name,
'identifier' => $identifier,
'timestamp' => $this->time->getRequestTime(),
'expiration' => $this->time->getRequestTime() + $window,
])
->execute();
}
/**
* {@inheritdoc}
*/
public function clear($name, $identifier = NULL) {
if (!isset($identifier)) {
$identifier = $this->requestStack->getCurrentRequest()->getClientIp();
}
try {
$this->connection->delete(static::TABLE_NAME)
->condition('event', $name)
->condition('identifier', $identifier)
->execute();
}
catch (\Exception $e) {
$this->catchException($e);
}
}
/**
* {@inheritdoc}
*/
public function clearByPrefix(string $name, string $prefix): void {
try {
$this->connection->delete(static::TABLE_NAME)
->condition('event', $name)
->condition('identifier', $prefix . '-%', 'LIKE')
->execute();
}
catch (\Exception $e) {
$this->catchException($e);
}
}
/**
* {@inheritdoc}
*/
public function isAllowed($name, $threshold, $window = 3600, $identifier = NULL) {
if (!isset($identifier)) {
$identifier = $this->requestStack->getCurrentRequest()->getClientIp();
}
try {
$number = $this->connection->select(static::TABLE_NAME, 'f')
->condition('event', $name)
->condition('identifier', $identifier)
->condition('timestamp', $this->time->getRequestTime() - $window, '>')
->countQuery()
->execute()
->fetchField();
return ($number < $threshold);
}
catch (\Exception $e) {
if (!$this->ensureTableExists()) {
throw $e;
}
return TRUE;
}
}
/**
* {@inheritdoc}
*/
public function garbageCollection() {
try {
$this->connection->delete(static::TABLE_NAME)
->condition('expiration', $this->time->getRequestTime(), '<')
->execute();
}
catch (\Exception $e) {
$this->catchException($e);
}
}
/**
* Check if the flood table exists and create it if not.
*/
protected function ensureTableExists() {
try {
$database_schema = $this->connection->schema();
$schema_definition = $this->schemaDefinition();
$database_schema->createTable(static::TABLE_NAME, $schema_definition);
}
// If another process has already created the table, attempting to create
// it will throw an exception. In this case just catch the exception and do
// nothing.
catch (DatabaseException) {
}
catch (\Exception) {
return FALSE;
}
return TRUE;
}
/**
* Act on an exception when flood might be stale.
*
* If the table does not yet exist, that's fine, but if the table exists and
* yet the query failed, then the flood is stale and the exception needs to
* propagate.
*
* @param \Exception $e
* The exception.
*
* @throws \Exception
*/
protected function catchException(\Exception $e) {
if ($this->connection->schema()->tableExists(static::TABLE_NAME)) {
throw $e;
}
}
/**
* Defines the schema for the flood table.
*
* @internal
*/
public function schemaDefinition() {
return [
'description' => 'Flood controls the threshold of events, such as the number of contact attempts.',
'fields' => [
'fid' => [
'description' => 'Unique flood event ID.',
'type' => 'serial',
'not null' => TRUE,
],
'event' => [
'description' => 'Name of event (e.g. contact).',
'type' => 'varchar_ascii',
'length' => 64,
'not null' => TRUE,
'default' => '',
],
'identifier' => [
'description' => 'Identifier of the visitor, such as an IP address or hostname.',
'type' => 'varchar_ascii',
'length' => 128,
'not null' => TRUE,
'default' => '',
],
'timestamp' => [
'description' => 'Timestamp of the event.',
'type' => 'int',
'not null' => TRUE,
'default' => 0,
'size' => 'big',
],
'expiration' => [
'description' => 'Expiration timestamp. Expired events are purged on cron run.',
'type' => 'int',
'not null' => TRUE,
'default' => 0,
'size' => 'big',
],
],
'primary key' => ['fid'],
'indexes' => [
'allow' => ['event', 'identifier', 'timestamp'],
'purge' => ['expiration'],
],
];
}
}
|
