Skip to content

LimitHandlers Middleware #218

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
Closed
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
76 changes: 76 additions & 0 deletions src/Middleware/LimitHandlersMiddleware.php
Original file line number Diff line number Diff line change
@@ -0,0 +1,76 @@
<?php

namespace React\Http\Middleware;

use Psr\Http\Message\ServerRequestInterface;
use React\Promise\Deferred;
use React\Stream\ReadableStreamInterface;
use SplQueue;

final class LimitHandlersMiddleware
{
const DEFAULT_LIMIT = 10;

private $limit = self::DEFAULT_LIMIT;
private $pending = 0;
private $queued;

/**
* @param int $limit Maximum amount of concurrent requests handled.
*
* For example when $limit is set to 10, 10 requests will flow to $next
* while more incoming requests have to wait until one is done.
*/
public function __construct($limit = self::DEFAULT_LIMIT)
{
$this->limit = $limit;
$this->queued = new SplQueue();
}

public function __invoke(ServerRequestInterface $request, $next)
{
$body = $request->getBody();
if ($body instanceof ReadableStreamInterface) {
$body->pause();
}
$deferred = new Deferred();
$this->queued->enqueue($deferred);

$this->processQueue();

$that = $this;
$pending = &$this->pending;
return $deferred->promise()->then(function () use ($request, $next, &$pending) {
$pending++;
$body = $request->getBody();
if ($body instanceof ReadableStreamInterface) {
$body->resume();
}
return $next($request);
})->then(function ($response) use ($that, &$pending) {
$pending--;
$that->processQueue();
return $response;
}, function ($error) use ($that, &$pending) {
$pending--;
$that->processQueue();
return $error;
});
}

/**
* @internal
*/
public function processQueue()
{
if ($this->pending >= $this->limit) {
return;
}

if ($this->queued->count() === 0) {
return;
}

$this->queued->dequeue()->resolve();
}
}
54 changes: 52 additions & 2 deletions tests/FunctionalServerTest.php
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,9 @@

namespace React\Tests\Http;

use Psr\Http\Message\ServerRequestInterface;
use React\Http\Middleware\LimitHandlersMiddleware;
use React\Http\Middleware\RequestBodyBufferMiddleware;
use React\Http\MiddlewareRunner;
use React\Socket\Server as Socket;
use React\EventLoop\Factory;
Expand All @@ -13,7 +16,7 @@
use React\Http\Response;
use React\Socket\SecureServer;
use React\Stream\ReadableStreamInterface;
use React\Promise\Promise;
use React\Promise;
use React\Promise\PromiseInterface;
use React\Promise\Stream;
use React\Stream\ThroughStream;
Expand Down Expand Up @@ -614,7 +617,7 @@ public function testConnectWithThroughStreamReturnedFromPromiseReturnsDataAsGive
$stream->end();
});

return new Promise(function ($resolve) use ($loop, $stream) {
return new Promise\Promise(function ($resolve) use ($loop, $stream) {
$loop->addTimer(0.001, function () use ($resolve, $stream) {
$resolve(new Response(200, array(), $stream));
});
Expand Down Expand Up @@ -676,6 +679,53 @@ public function testConnectWithClosedThroughStreamReturnsNoData()

$socket->close();
}

public function testLimitHandlersMiddlewareRequestStreamPausing()
{
$loop = Factory::create();
$connector = new Connector($loop);

$server = new Server(new MiddlewareRunner(array(
new LimitHandlersMiddleware(5),
new RequestBodyBufferMiddleware(16 * 1024 * 1024), // 16 MiB
function (ServerRequestInterface $request, $next) use ($loop) {
return new Promise\Promise(function ($resolve) use ($request, $loop, $next) {
$loop->addTimer(0.1, function () use ($request, $resolve, $next) {
$resolve($next($request));
});
});
},
function (ServerRequestInterface $request) {
return new Response(200, array(), (string)strlen((string)$request->getBody()));
}
)));

$socket = new Socket(0, $loop);
$server->listen($socket);

$result = array();
for ($i = 0; $i < 6; $i++) {
$result[] = $connector->connect($socket->getAddress())->then(function (ConnectionInterface $conn) {
$conn->write(
"GET / HTTP/1.0\r\nContent-Length: 1024\r\nHost: " . noScheme($conn->getRemoteAddress()) . "\r\n\r\n" .
str_repeat('a', 1024) .
"\r\n\r\n"
);

return Stream\buffer($conn);
});
}

$responses = Block\await(Promise\all($result), $loop, 1.0);

foreach ($responses as $response) {
$this->assertContains("HTTP/1.0 200 OK", $response, $response);
$this->assertTrue(substr($response, -4) == 1024, $response);
}

$socket->close();
}

}

function noScheme($uri)
Expand Down
100 changes: 100 additions & 0 deletions tests/Middleware/LimitHandlersMiddlewareTest.php
Original file line number Diff line number Diff line change
@@ -0,0 +1,100 @@
<?php

namespace React\Tests\Http\Middleware;

use React\Http\Middleware\LimitHandlersMiddleware;
use React\Http\ServerRequest;
use React\Promise\Deferred;
use React\Tests\Http\TestCase;

final class LimitHandlersMiddlewareTest extends TestCase
{
public function testLimitOneRequestConcurrently()
{
/**
* The first request
*/
$requestA = new ServerRequest('GET', 'https://example.com/');
$deferredA = new Deferred();
$calledA = false;
$nextA = function () use (&$calledA, $deferredA) {
$calledA = true;
return $deferredA->promise();
};

/**
* The second request
*/
$requestB = new ServerRequest('GET', 'https://www.example.com/');
$deferredB = new Deferred();
$calledB = false;
$nextB = function () use (&$calledB, $deferredB) {
$calledB = true;
return $deferredB->promise();
};

/**
* The third request
*/
$requestC = new ServerRequest('GET', 'https://www.example.com/');
$calledC = false;
$nextC = function () use (&$calledC) {
$calledC = true;
};

/**
* The handler
*
*/
$limitHandlers = new LimitHandlersMiddleware(1);

$this->assertFalse($calledA);
$this->assertFalse($calledB);
$this->assertFalse($calledC);

$limitHandlers($requestA, $nextA);

$this->assertTrue($calledA);
$this->assertFalse($calledB);
$this->assertFalse($calledC);

$limitHandlers($requestB, $nextB);

$this->assertTrue($calledA);
$this->assertFalse($calledB);
$this->assertFalse($calledC);

$limitHandlers($requestC, $nextC);

$this->assertTrue($calledA);
$this->assertFalse($calledB);
$this->assertFalse($calledC);

/**
* Ensure resolve frees up a slot
*/
$deferredA->resolve();

$this->assertTrue($calledA);
$this->assertTrue($calledB);
$this->assertFalse($calledC);

/**
* Ensure reject also frees up a slot
*/
$deferredB->reject();

$this->assertTrue($calledA);
$this->assertTrue($calledB);
$this->assertTrue($calledC);
}

public function testStreamPauseAndResume()
{
$body = $this->getMockBuilder('React\Http\HttpBodyStream')->disableOriginalConstructor()->getMock();
$body->expects($this->once())->method('pause');
$body->expects($this->once())->method('resume');
$limitHandlers = new LimitHandlersMiddleware(1);
$limitHandlers(new ServerRequest('GET', 'https://example.com/', array(), $body), function () {});
}
}