Aerys\Router::do PHP Method

    public function do(InternalRequest $ireq)
    {
        $toMatch = "{$ireq->method}{$ireq->uriPath}";
        if (isset($this->cache[$toMatch])) {
            list($args, $routeArgs) = $cache = $this->cache[$toMatch];
            list($action, $middlewares) = $args;
            $ireq->locals["aerys.routeArgs"] = $routeArgs;
            // Keep the most recently used entry at the back of the LRU cache
            unset($this->cache[$toMatch]);
            $this->cache[$toMatch] = $cache;
            $ireq->locals["aerys.routed"] = [$isMethodAllowed = true, $action];
            if (!empty($middlewares)) {
                try {
                    return yield from responseFilter($middlewares, $ireq);
                } catch (FilterException $e) {
                    end($ireq->badFilterKeys);
                    unset($ireq->badFilterKeys[key($ireq->badFilterKeys)]);
                    $ireq->filterErrorFlag = false;
                    throw $e->getPrevious();
                }
            }
            return;
        }
        $match = $this->routeDispatcher->dispatch($ireq->method, $ireq->uriPath);
        switch ($match[0]) {
            case Dispatcher::FOUND:
                list(, $args, $routeArgs) = $match;
                list($action, $middlewares) = $args;
                $ireq->locals["aerys.routeArgs"] = $routeArgs;
                if ($this->maxCacheEntries > 0) {
                    $this->cacheDispatchResult($toMatch, $routeArgs, $args);
                }
                $ireq->locals["aerys.routed"] = [$isMethodAllowed = true, $action];
                if (!empty($middlewares)) {
                    try {
                        return yield from responseFilter($middlewares, $ireq);
                    } catch (FilterException $e) {
                        end($ireq->badFilterKeys);
                        unset($ireq->badFilterKeys[key($ireq->badFilterKeys)]);
                        $ireq->filterErrorFlag = false;
                        throw $e->getPrevious();
                    }
                }
                break;
            case Dispatcher::NOT_FOUND:
                // Do nothing; allow actions further down the chain a chance to respond.
                // If no other registered host actions respond the server will send a
                // 404 automatically anyway.
                return;
            case Dispatcher::METHOD_NOT_ALLOWED:
                $allowedMethods = $match[1];
                $ireq->locals["aerys.routed"] = [$isMethodAllowed = false, $allowedMethods];
                break;
            default:
                throw new \UnexpectedValueException("Encountered unexpected Dispatcher code");
        }
    }