Symfony Profiler

<?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\RateLimiter\Policy;
use Symfony\Component\Lock\LockInterface;
use Symfony\Component\Lock\NoLock;
use Symfony\Component\RateLimiter\Exception\MaxWaitDurationExceededException;
use Symfony\Component\RateLimiter\LimiterInterface;
use Symfony\Component\RateLimiter\RateLimit;
use Symfony\Component\RateLimiter\Reservation;
use Symfony\Component\RateLimiter\Storage\StorageInterface;
/**
* @author Wouter de Jong <wouter@wouterj.nl>
*
* @experimental in 5.3
*/
final class TokenBucketLimiter implements LimiterInterface
{
use ResetLimiterTrait;
private $maxBurst;
private $rate;
public function __construct(string $id, int $maxBurst, Rate $rate, StorageInterface $storage, LockInterface $lock = null)
{
$this->id = $id;
$this->maxBurst = $maxBurst;
$this->rate = $rate;
$this->storage = $storage;
$this->lock = $lock ?? new NoLock();
}
/**
* Waits until the required number of tokens is available.
*
* The reserved tokens will be taken into account when calculating
* future token consumptions. Do not use this method if you intend
* to skip this process.
*
* @param int $tokens the number of tokens required
* @param float $maxTime maximum accepted waiting time in seconds
*
* @throws MaxWaitDurationExceededException if $maxTime is set and the process needs to wait longer than its value (in seconds)
* @throws \InvalidArgumentException if $tokens is larger than the maximum burst size
*/
public function reserve(int $tokens = 1, float $maxTime = null): Reservation
{
if ($tokens > $this->maxBurst) {
throw new \InvalidArgumentException(sprintf('Cannot reserve more tokens (%d) than the burst size of the rate limiter (%d).', $tokens, $this->maxBurst));
}
$this->lock->acquire(true);
try {
$bucket = $this->storage->fetch($this->id);
if (!$bucket instanceof TokenBucket) {
$bucket = new TokenBucket($this->id, $this->maxBurst, $this->rate);
}
$now = microtime(true);
$availableTokens = $bucket->getAvailableTokens($now);
if ($availableTokens >= $tokens) {
// tokens are now available, update bucket
$bucket->setTokens($availableTokens - $tokens);
$bucket->setTimer($now);
$reservation = new Reservation($now, new RateLimit($bucket->getAvailableTokens($now), \DateTimeImmutable::createFromFormat('U', floor($now)), true, $this->maxBurst));
} else {
$remainingTokens = $tokens - $availableTokens;
$waitDuration = $this->rate->calculateTimeForTokens($remainingTokens);
if (null !== $maxTime && $waitDuration > $maxTime) {
// process needs to wait longer than set interval
$rateLimit = new RateLimit($availableTokens, \DateTimeImmutable::createFromFormat('U', floor($now + $waitDuration)), false, $this->maxBurst);
throw new MaxWaitDurationExceededException(sprintf('The rate limiter wait time ("%d" seconds) is longer than the provided maximum time ("%d" seconds).', $waitDuration, $maxTime), $rateLimit);
}
// at $now + $waitDuration all tokens will be reserved for this process,
// so no tokens are left for other processes.
$bucket->setTokens($availableTokens - $tokens);
$bucket->setTimer($now);
$reservation = new Reservation($now + $waitDuration, new RateLimit(0, \DateTimeImmutable::createFromFormat('U', floor($now + $waitDuration)), false, $this->maxBurst));
}
$this->storage->save($bucket);
} finally {
$this->lock->release();
}
return $reservation;
}
/**
* {@inheritdoc}
*/
public function consume(int $tokens = 1): RateLimit
{
try {
return $this->reserve($tokens, 0)->getRateLimit();
} catch (MaxWaitDurationExceededException $e) {
return $e->getRateLimit();
}
}
}

vendor/symfony/rate-limiter/Policy/TokenBucketLimiter.php line 56