Proyectos de Subversion Moodle

<?php

namespace Aws\ClientSideMonitoring;

use Aws\CommandInterface;

use Aws\Exception\AwsException;

use Aws\MonitoringEventsInterface;

use Aws\ResponseContainerInterface;

use Aws\ResultInterface;

use GuzzleHttp\Promise;

use Psr\Http\Message\RequestInterface;

use Psr\Http\Message\ResponseInterface;

/**

 * @internal

 */

abstract class AbstractMonitoringMiddleware

    implements MonitoringMiddlewareInterface

{

    private static $socket;

    private $nextHandler;

    private $options;

    protected $credentialProvider;

    protected $region;

    protected $service;

    protected static function getAwsExceptionHeader(AwsException $e, $headerName)

    {

        $response = $e->getResponse();

        if ($response !== null) {

            $header = $response->getHeader($headerName);

            if (!empty($header[0])) {

                return $header[0];

            }

        }

        return null;

    }

    protected static function getResultHeader(ResultInterface $result, $headerName)

    {

        if (isset($result['@metadata']['headers'][$headerName])) {

            return $result['@metadata']['headers'][$headerName];

        }

        return null;

    }

    protected static function getExceptionHeader(\Exception $e, $headerName)

    {

        if ($e instanceof ResponseContainerInterface) {

            $response = $e->getResponse();

            if ($response instanceof ResponseInterface) {

                $header = $response->getHeader($headerName);

                if (!empty($header[0])) {

                    return $header[0];

                }

            }

        }

        return null;

    }

    /**

     * Constructor stores the passed in handler and options.

     *

     * @param callable $handler

     * @param callable $credentialProvider

     * @param $options

     * @param $region

     * @param $service

     */

    public function __construct(

        callable $handler,

        callable $credentialProvider,

        $options,

        $region,

        $service

    ) {

        $this->nextHandler = $handler;

        $this->credentialProvider = $credentialProvider;

        $this->options = $options;

        $this->region = $region;

        $this->service = $service;

    }

    /**

     * Standard invoke pattern for middleware execution to be implemented by

     * child classes.

     *

     * @param  CommandInterface $cmd

     * @param  RequestInterface $request

     * @return Promise\PromiseInterface

     */

    public function __invoke(CommandInterface $cmd, RequestInterface $request)

    {

        $handler = $this->nextHandler;

        $eventData = null;

        $enabled = $this->isEnabled();

        if ($enabled) {

            $cmd['@http']['collect_stats'] = true;

            $eventData = $this->populateRequestEventData(

                $cmd,

                $request,

                $this->getNewEvent($cmd, $request)

            );

        }

        $g = function ($value) use ($eventData, $enabled) {

            if ($enabled) {

                $eventData = $this->populateResultEventData(

                    $value,

                    $eventData

                );

                $this->sendEventData($eventData);

                if ($value instanceof MonitoringEventsInterface) {

                    $value->appendMonitoringEvent($eventData);

                }

            }

            if ($value instanceof \Exception || $value instanceof \Throwable) {

                return Promise\Create::rejectionFor($value);

            }

            return $value;

        };

        return Promise\Create::promiseFor($handler($cmd, $request))->then($g, $g);

    }

    private function getClientId()

    {

        return $this->unwrappedOptions()->getClientId();

    }

    private function getNewEvent(

        CommandInterface $cmd,

        RequestInterface $request

    ) {

        $event = [

            'Api' => $cmd->getName(),

            'ClientId' => $this->getClientId(),

            'Region' => $this->getRegion(),

            'Service' => $this->getService(),

            'Timestamp' => (int) floor(microtime(true) * 1000),

            'UserAgent' => substr(

                $request->getHeaderLine('User-Agent') . ' ' . \Aws\default_user_agent(),

                0,

                256

            ),

            'Version' => 1

        ];

        return $event;

    }

    private function getHost()

    {

        return $this->unwrappedOptions()->getHost();

    }

    private function getPort()

    {

        return $this->unwrappedOptions()->getPort();

    }

    private function getRegion()

    {

        return $this->region;

    }

    private function getService()

    {

        return $this->service;

    }

    /**

     * Returns enabled flag from options, unwrapping options if necessary.

     *

     * @return bool

     */

    private function isEnabled()

    {

        return $this->unwrappedOptions()->isEnabled();

    }

    /**

     * Returns $eventData array with information from the request and command.

     *

     * @param CommandInterface $cmd

     * @param RequestInterface $request

     * @param array $event

     * @return array

     */

    protected function populateRequestEventData(

        CommandInterface $cmd,

        RequestInterface $request,

        array $event

    ) {

        $dataFormat = static::getRequestData($request);

        foreach ($dataFormat as $eventKey => $value) {

            if ($value !== null) {

                $event[$eventKey] = $value;

            }

        }

        return $event;

    }

    /**

     * Returns $eventData array with information from the response, including

     * the calculation for attempt latency.

     *

     * @param ResultInterface|\Exception $result

     * @param array $event

     * @return array

     */

    protected function populateResultEventData(

        $result,

        array $event

    ) {

        $dataFormat = static::getResponseData($result);

        foreach ($dataFormat as $eventKey => $value) {

            if ($value !== null) {

                $event[$eventKey] = $value;

            }

        }

        return $event;

    }

    /**

     * Creates a UDP socket resource and stores it with the class, or retrieves

     * it if already instantiated and connected. Handles error-checking and

     * re-connecting if necessary. If $forceNewConnection is set to true, a new

     * socket will be created.

     *

     * @param bool $forceNewConnection

     * @return Resource

     */

    private function prepareSocket($forceNewConnection = false)

    {

        if (!is_resource(self::$socket)

            || $forceNewConnection

            || socket_last_error(self::$socket)

        ) {

            self::$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);

            socket_clear_error(self::$socket);

            socket_connect(self::$socket, $this->getHost(), $this->getPort());

        }

        return self::$socket;

    }

    /**

     * Sends formatted monitoring event data via the UDP socket connection to

     * the CSM agent endpoint.

     *

     * @param array $eventData

     * @return int

     */

    private function sendEventData(array $eventData)

    {

        $socket = $this->prepareSocket();

        $datagram = json_encode($eventData);

        $result = socket_write($socket, $datagram, strlen($datagram));

        if ($result === false) {

            $this->prepareSocket(true);

        }

        return $result;

    }

    /**

     * Unwraps options, if needed, and returns them.

     *

     * @return ConfigurationInterface

     */

    private function unwrappedOptions()

    {

        if (!($this->options instanceof ConfigurationInterface)) {

            try {

                $this->options = ConfigurationProvider::unwrap($this->options);

            } catch (\Exception $e) {

                // Errors unwrapping CSM config defaults to disabling it

                $this->options = new Configuration(

                    false,

                    ConfigurationProvider::DEFAULT_HOST,

                    ConfigurationProvider::DEFAULT_PORT

                );

            }

        }

        return $this->options;

    }

}