diff options
Diffstat (limited to 'vendor/react/socket/src/HappyEyeBallsConnectionBuilder.php')
| -rw-r--r-- | vendor/react/socket/src/HappyEyeBallsConnectionBuilder.php | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/vendor/react/socket/src/HappyEyeBallsConnectionBuilder.php b/vendor/react/socket/src/HappyEyeBallsConnectionBuilder.php new file mode 100644 index 0000000..6bd0716 --- /dev/null +++ b/vendor/react/socket/src/HappyEyeBallsConnectionBuilder.php @@ -0,0 +1,333 @@ +<?php + +namespace React\Socket; + +use React\Dns\Model\Message; +use React\Dns\Resolver\ResolverInterface; +use React\EventLoop\LoopInterface; +use React\EventLoop\TimerInterface; +use React\Promise; +use React\Promise\CancellablePromiseInterface; + +/** + * @internal + */ +final class HappyEyeBallsConnectionBuilder +{ + /** + * As long as we haven't connected yet keep popping an IP address of the connect queue until one of them + * succeeds or they all fail. We will wait 100ms between connection attempts as per RFC. + * + * @link https://tools.ietf.org/html/rfc8305#section-5 + */ + const CONNECTION_ATTEMPT_DELAY = 0.1; + + /** + * Delay `A` lookup by 50ms sending out connection to IPv4 addresses when IPv6 records haven't + * resolved yet as per RFC. + * + * @link https://tools.ietf.org/html/rfc8305#section-3 + */ + const RESOLUTION_DELAY = 0.05; + + public $loop; + public $connector; + public $resolver; + public $uri; + public $host; + public $resolved = array( + Message::TYPE_A => false, + Message::TYPE_AAAA => false, + ); + public $resolverPromises = array(); + public $connectionPromises = array(); + public $connectQueue = array(); + public $nextAttemptTimer; + public $parts; + public $ipsCount = 0; + public $failureCount = 0; + public $resolve; + public $reject; + + public $lastErrorFamily; + public $lastError6; + public $lastError4; + + public function __construct(LoopInterface $loop, ConnectorInterface $connector, ResolverInterface $resolver, $uri, $host, $parts) + { + $this->loop = $loop; + $this->connector = $connector; + $this->resolver = $resolver; + $this->uri = $uri; + $this->host = $host; + $this->parts = $parts; + } + + public function connect() + { + $timer = null; + $that = $this; + return new Promise\Promise(function ($resolve, $reject) use ($that, &$timer) { + $lookupResolve = function ($type) use ($that, $resolve, $reject) { + return function (array $ips) use ($that, $type, $resolve, $reject) { + unset($that->resolverPromises[$type]); + $that->resolved[$type] = true; + + $that->mixIpsIntoConnectQueue($ips); + + // start next connection attempt if not already awaiting next + if ($that->nextAttemptTimer === null && $that->connectQueue) { + $that->check($resolve, $reject); + } + }; + }; + + $that->resolverPromises[Message::TYPE_AAAA] = $that->resolve(Message::TYPE_AAAA, $reject)->then($lookupResolve(Message::TYPE_AAAA)); + $that->resolverPromises[Message::TYPE_A] = $that->resolve(Message::TYPE_A, $reject)->then(function (array $ips) use ($that, &$timer) { + // happy path: IPv6 has resolved already (or could not resolve), continue with IPv4 addresses + if ($that->resolved[Message::TYPE_AAAA] === true || !$ips) { + return $ips; + } + + // Otherwise delay processing IPv4 lookup until short timer passes or IPv6 resolves in the meantime + $deferred = new Promise\Deferred(); + $timer = $that->loop->addTimer($that::RESOLUTION_DELAY, function () use ($deferred, $ips) { + $deferred->resolve($ips); + }); + + $that->resolverPromises[Message::TYPE_AAAA]->then(function () use ($that, $timer, $deferred, $ips) { + $that->loop->cancelTimer($timer); + $deferred->resolve($ips); + }); + + return $deferred->promise(); + })->then($lookupResolve(Message::TYPE_A)); + }, function ($_, $reject) use ($that, &$timer) { + $reject(new \RuntimeException( + 'Connection to ' . $that->uri . ' cancelled' . (!$that->connectionPromises ? ' during DNS lookup' : '') . ' (ECONNABORTED)', + \defined('SOCKET_ECONNABORTED') ? \SOCKET_ECONNABORTED : 103 + )); + $_ = $reject = null; + + $that->cleanUp(); + if ($timer instanceof TimerInterface) { + $that->loop->cancelTimer($timer); + } + }); + } + + /** + * @internal + * @param int $type DNS query type + * @param callable $reject + * @return \React\Promise\PromiseInterface<string[]> Returns a promise that + * always resolves with a list of IP addresses on success or an empty + * list on error. + */ + public function resolve($type, $reject) + { + $that = $this; + return $that->resolver->resolveAll($that->host, $type)->then(null, function (\Exception $e) use ($type, $reject, $that) { + unset($that->resolverPromises[$type]); + $that->resolved[$type] = true; + + if ($type === Message::TYPE_A) { + $that->lastError4 = $e->getMessage(); + $that->lastErrorFamily = 4; + } else { + $that->lastError6 = $e->getMessage(); + $that->lastErrorFamily = 6; + } + + // cancel next attempt timer when there are no more IPs to connect to anymore + if ($that->nextAttemptTimer !== null && !$that->connectQueue) { + $that->loop->cancelTimer($that->nextAttemptTimer); + $that->nextAttemptTimer = null; + } + + if ($that->hasBeenResolved() && $that->ipsCount === 0) { + $reject(new \RuntimeException( + $that->error(), + 0, + $e + )); + } + + // Exception already handled above, so don't throw an unhandled rejection here + return array(); + }); + } + + /** + * @internal + */ + public function check($resolve, $reject) + { + $ip = \array_shift($this->connectQueue); + + // start connection attempt and remember array position to later unset again + $this->connectionPromises[] = $this->attemptConnection($ip); + \end($this->connectionPromises); + $index = \key($this->connectionPromises); + + $that = $this; + $that->connectionPromises[$index]->then(function ($connection) use ($that, $index, $resolve) { + unset($that->connectionPromises[$index]); + + $that->cleanUp(); + + $resolve($connection); + }, function (\Exception $e) use ($that, $index, $ip, $resolve, $reject) { + unset($that->connectionPromises[$index]); + + $that->failureCount++; + + $message = \preg_replace('/^(Connection to [^ ]+)[&?]hostname=[^ &]+/', '$1', $e->getMessage()); + if (\strpos($ip, ':') === false) { + $that->lastError4 = $message; + $that->lastErrorFamily = 4; + } else { + $that->lastError6 = $message; + $that->lastErrorFamily = 6; + } + + // start next connection attempt immediately on error + if ($that->connectQueue) { + if ($that->nextAttemptTimer !== null) { + $that->loop->cancelTimer($that->nextAttemptTimer); + $that->nextAttemptTimer = null; + } + + $that->check($resolve, $reject); + } + + if ($that->hasBeenResolved() === false) { + return; + } + + if ($that->ipsCount === $that->failureCount) { + $that->cleanUp(); + + $reject(new \RuntimeException( + $that->error(), + $e->getCode(), + $e + )); + } + }); + + // Allow next connection attempt in 100ms: https://tools.ietf.org/html/rfc8305#section-5 + // Only start timer when more IPs are queued or when DNS query is still pending (might add more IPs) + if ($this->nextAttemptTimer === null && (\count($this->connectQueue) > 0 || $this->resolved[Message::TYPE_A] === false || $this->resolved[Message::TYPE_AAAA] === false)) { + $this->nextAttemptTimer = $this->loop->addTimer(self::CONNECTION_ATTEMPT_DELAY, function () use ($that, $resolve, $reject) { + $that->nextAttemptTimer = null; + + if ($that->connectQueue) { + $that->check($resolve, $reject); + } + }); + } + } + + /** + * @internal + */ + public function attemptConnection($ip) + { + $uri = Connector::uri($this->parts, $this->host, $ip); + + return $this->connector->connect($uri); + } + + /** + * @internal + */ + public function cleanUp() + { + // clear list of outstanding IPs to avoid creating new connections + $this->connectQueue = array(); + + foreach ($this->connectionPromises as $connectionPromise) { + if ($connectionPromise instanceof CancellablePromiseInterface) { + $connectionPromise->cancel(); + } + } + + foreach ($this->resolverPromises as $resolverPromise) { + if ($resolverPromise instanceof CancellablePromiseInterface) { + $resolverPromise->cancel(); + } + } + + if ($this->nextAttemptTimer instanceof TimerInterface) { + $this->loop->cancelTimer($this->nextAttemptTimer); + $this->nextAttemptTimer = null; + } + } + + /** + * @internal + */ + public function hasBeenResolved() + { + foreach ($this->resolved as $typeHasBeenResolved) { + if ($typeHasBeenResolved === false) { + return false; + } + } + + return true; + } + + /** + * Mixes an array of IP addresses into the connect queue in such a way they alternate when attempting to connect. + * The goal behind it is first attempt to connect to IPv6, then to IPv4, then to IPv6 again until one of those + * attempts succeeds. + * + * @link https://tools.ietf.org/html/rfc8305#section-4 + * + * @internal + */ + public function mixIpsIntoConnectQueue(array $ips) + { + \shuffle($ips); + $this->ipsCount += \count($ips); + $connectQueueStash = $this->connectQueue; + $this->connectQueue = array(); + while (\count($connectQueueStash) > 0 || \count($ips) > 0) { + if (\count($ips) > 0) { + $this->connectQueue[] = \array_shift($ips); + } + if (\count($connectQueueStash) > 0) { + $this->connectQueue[] = \array_shift($connectQueueStash); + } + } + } + + /** + * @internal + * @return string + */ + public function error() + { + if ($this->lastError4 === $this->lastError6) { + $message = $this->lastError6; + } elseif ($this->lastErrorFamily === 6) { + $message = 'Last error for IPv6: ' . $this->lastError6 . '. Previous error for IPv4: ' . $this->lastError4; + } else { + $message = 'Last error for IPv4: ' . $this->lastError4 . '. Previous error for IPv6: ' . $this->lastError6; + } + + if ($this->hasBeenResolved() && $this->ipsCount === 0) { + if ($this->lastError6 === $this->lastError4) { + $message = ' during DNS lookup: ' . $this->lastError6; + } else { + $message = ' during DNS lookup. ' . $message; + } + } else { + $message = ': ' . $message; + } + + return 'Connection to ' . $this->uri . ' failed' . $message; + } +} |