protected function lock(Request $request, Response $entry)
    {
        // try to acquire a lock to call the backend
        $lock = $this->store->lock($request);

        if (true === $lock) {
            // we have the lock, call the backend
            return false;
        }

        // there is already another process calling the backend

        // May we serve a stale response?
        if ($this->mayServeStaleWhileRevalidate($entry)) {
            $this->record($request, 'stale-while-revalidate');

            return true;
        }

        // wait for the lock to be released
        if ($this->waitForLock($request)) {
            // replace the current entry with the fresh one
            $new = $this->lookup($request);
            $entry->headers = $new->headers;
            $entry->setContent($new->getContent());
            $entry->setStatusCode($new->getStatusCode());
            $entry->setProtocolVersion($new->getProtocolVersion());
            foreach ($new->headers->getCookies() as $cookie) {
                $entry->headers->setCookie($cookie);
            }
        } else {
            // backend is slow as hell, send a 503 response (to avoid the dog pile effect)
            $entry->setStatusCode(503);
            $entry->setContent('503 Service Unavailable');
            $entry->headers->set('Retry-After', 10);
        }

        return true;
    }
protected function lock(Request $request, Response $entry)
    {
        // try to acquire a lock to call the backend
        $lock = $this->store->lock($request);

        if (true === $lock) {
            // we have the lock, call the backend
            return false;
        }

        // there is already another process calling the backend

        // May we serve a stale response?
        if ($this->mayServeStaleWhileRevalidate($entry)) {
            $this->record($request, 'stale-while-revalidate');

            return true;
        }

        // wait for the lock to be released
        if ($this->waitForLock($request)) {
            // replace the current entry with the fresh one
            $new = $this->lookup($request);
            $entry->headers = $new->headers;
            $entry->setContent($new->getContent());
            $entry->setStatusCode($new->getStatusCode());
            $entry->setProtocolVersion($new->getProtocolVersion());
            foreach ($new->headers->getCookies() as $cookie) {
                $entry->headers->setCookie($cookie);
            }
        } else {
            // backend is slow as hell, send a 503 response (to avoid the dog pile effect)
            $entry->setStatusCode(503);
            $entry->setContent('503 Service Unavailable');
            $entry->headers->set('Retry-After', 10);
        }

        return true;
    }
protected function lock ( Request $ request , Response $ entry ) { // try to acquire a lock to call the backend $ lock = $ this -> store -> lock ( $ request ) ; if ( true === $ lock ) { // we have the lock, call the backend return false ; } // there is already another process calling the backend // May we serve a stale response? if ( $ this -> mayServeStaleWhileRevalidate ( $ entry ) ) { $ this -> record ( $ request , 'stale-while-revalidate' ) ; return true ; } // wait for the lock to be released if ( $ this -> waitForLock ( $ request ) ) { // replace the current entry with the fresh one $ new = $ this -> lookup ( $ request ) ; $ entry -> headers = $ new -> headers ; $ entry -> setContent ( $ new -> getContent ( ) ) ; $ entry -> setStatusCode ( $ new -> getStatusCode ( ) ) ; $ entry -> setProtocolVersion ( $ new -> getProtocolVersion ( ) ) ; foreach ( $ new -> headers -> getCookies ( ) as $ cookie ) { $ entry -> headers -> setCookie ( $ cookie ) ; } } else { // backend is slow as hell, send a 503 response (to avoid the dog pile effect) $ entry -> setStatusCode ( 503 ) ; $ entry -> setContent ( '503 Service Unavailable' ) ; $ entry -> headers -> set ( 'Retry-After' , 10 ) ; } return true ; }
Locks a Request during the call to the backend.

@return bool true if the cache entry can be returned even if it is staled, false otherwise
Locks a Request during the call to the backend .