Passed
Pull Request — master (#204)
by
unknown
02:33
created

RateLimiterMiddleware::addHeaders()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 6
Code Lines 4

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 1
eloc 4
nc 1
nop 2
dl 0
loc 6
rs 10
c 0
b 0
f 0
1
<?php
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declare(strict_types=1);
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namespace Yiisoft\Yii\Web\RateLimiter;
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use Psr\Http\Message\ResponseFactoryInterface;
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use Psr\Http\Message\ResponseInterface;
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use Psr\Http\Message\ServerRequestInterface;
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use Psr\Http\Server\MiddlewareInterface;
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use Psr\Http\Server\RequestHandlerInterface;
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/**
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 * RateLimiter limits the number of consequential requests ({@see CacheCounter::$period}) that could be processed per
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 * {@see CacheCounter::$limit}. If the number is reached, middleware responds with HTTP code 429, "Too Many Requests"
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 * until limit expires.
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 */
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final class RateLimiterMiddleware implements MiddlewareInterface
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{
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    private CacheCounter $counter;
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    private ResponseFactoryInterface $responseFactory;
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    private string $counterId;
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    /**
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     * @var callable
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     */
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    private $counterIdCallback;
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    public function __construct(CacheCounter $counter, ResponseFactoryInterface $responseFactory)
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    {
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        $this->counter = $counter;
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        $this->responseFactory = $responseFactory;
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    }
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    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
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    {
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        $this->counter->setId($this->generateId($request));
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        $result = $this->counter->incrementAndGetResult();
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        if ($result->remainingIsEmpty()) {
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            $response = $this->createErrorResponse();
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        } else {
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            $response = $handler->handle($request);
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        }
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        return $this->addHeaders($response, $result);
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    }
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    public function withCounterIdCallback(?callable $callback): self
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    {
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        $new = clone $this;
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        $new->counterIdCallback = $callback;
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        return $new;
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    }
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    public function withCounterId(string $id): self
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    {
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        $new = clone $this;
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        $new->counterId = $id;
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        return $new;
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    }
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    private function createErrorResponse(): ResponseInterface
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    {
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        $response = $this->responseFactory->createResponse(429);
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        $response->getBody()->write('Too Many Requests');
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        return $response;
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    }
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    private function generateId(ServerRequestInterface $request): string
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    {
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        if ($this->counterIdCallback !== null) {
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            return \call_user_func($this->counterIdCallback, $request);
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        }
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        return $this->counterId ?? $this->generateIdFromRequest($request);
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    }
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    private function generateIdFromRequest(ServerRequestInterface $request): string
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    {
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        return strtolower($request->getMethod() . '-' . $request->getUri()->getPath());
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    }
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    public function addHeaders(ResponseInterface $response, RateLimitResult $result): ResponseInterface
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    {
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        return $response
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            ->withHeader('X-Rate-Limit-Limit', $result->getLimit())
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            ->withHeader('X-Rate-Limit-Remaining', $result->getRemaining())
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            ->withHeader('X-Rate-Limit-Reset', $result->getReset());
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    }
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}
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