<?php
/**
* Copyright 2015 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace Google\Cloud\Core;
use Google\Auth\FetchAuthTokenInterface;
use Google\Auth\GetQuotaProjectInterface;
use Google\Auth\HttpHandler\Guzzle5HttpHandler;
use Google\Auth\HttpHandler\Guzzle6HttpHandler;
use Google\Auth\HttpHandler\HttpHandlerFactory;
use Google\Cloud\Core\RequestWrapperTrait;
use GuzzleHttp\Exception\RequestException;
use GuzzleHttp\Promise\PromiseInterface;
use GuzzleHttp\Psr7\Utils;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\StreamInterface;
/**
* The RequestWrapper is responsible for delivering and signing requests.
*/
class RequestWrapper
{
use RequestWrapperTrait;
use RetryDeciderTrait;
/**
* @var string|null The current version of the component from which the request
* originated.
*/
private $componentVersion;
/**
* @var string|null Access token used to sign requests.
*/
private $accessToken;
/**
* @var callable A handler used to deliver PSR-7 requests specifically for
* authentication.
*/
private $authHttpHandler;
/**
* @var callable A handler used to deliver PSR-7 requests.
*/
private $httpHandler;
/**
* @var callable A handler used to deliver PSR-7 requests asynchronously.
*/
private $asyncHttpHandler;
/**
* @var array HTTP client specific configuration options.
*/
private $restOptions;
/**
* @var bool Whether to enable request signing.
*/
private $shouldSignRequest;
/**
* @var callable Sets the conditions for whether or not a
* request should attempt to retry.
*/
private $retryFunction;
/**
* @var callable Executes a delay.
*/
private $delayFunction;
/**
* @var callable|null Sets the conditions for determining how long to wait
* between attempts to retry.
*/
private $calcDelayFunction;
/**
* @param array $config [optional] {
* Configuration options. Please see
* {@see Google\Cloud\Core\RequestWrapperTrait::setCommonDefaults()} for
* the other available options.
*
* @type string $componentVersion The current version of the component from
* which the request originated.
* @type string $accessToken Access token used to sign requests.
* @type callable $asyncHttpHandler *Experimental* A handler used to
* deliver PSR-7 requests asynchronously. Function signature should match:
* `function (RequestInterface $request, array $options = []) : PromiseInterface<ResponseInterface>`.
* @type callable $authHttpHandler A handler used to deliver PSR-7
* requests specifically for authentication. Function signature
* should match:
* `function (RequestInterface $request, array $options = []) : ResponseInterface`.
* @type callable $httpHandler A handler used to deliver PSR-7 requests.
* Function signature should match:
* `function (RequestInterface $request, array $options = []) : ResponseInterface`.
* @type array $restOptions HTTP client specific configuration options.
* @type bool $shouldSignRequest Whether to enable request signing.
* @type callable $restRetryFunction Sets the conditions for whether or
* not a request should attempt to retry. Function signature should
* match: `function (\Exception $ex) : bool`.
* @type callable $restDelayFunction Executes a delay, defaults to
* utilizing `usleep`. Function signature should match:
* `function (int $delay) : void`.
* @type callable $restCalcDelayFunction Sets the conditions for
* determining how long to wait between attempts to retry. Function
* signature should match: `function (int $attempt) : int`.
* }
*/
public function __construct(array $config = [])
{
$this->setCommonDefaults($config);
$config += [
'accessToken' => null,
'asyncHttpHandler' => null,
'authHttpHandler' => null,
'httpHandler' => null,
'restOptions' => [],
'shouldSignRequest' => true,
'componentVersion' => null,
'restRetryFunction' => null,
'restDelayFunction' => null,
'restCalcDelayFunction' => null
];
$this->componentVersion = $config['componentVersion'];
$this->accessToken = $config['accessToken'];
$this->restOptions = $config['restOptions'];
$this->shouldSignRequest = $config['shouldSignRequest'];
$this->retryFunction = $config['restRetryFunction'] ?: $this->getRetryFunction();
$this->delayFunction = $config['restDelayFunction'] ?: function ($delay) {
usleep($delay);
};
$this->calcDelayFunction = $config['restCalcDelayFunction'];
$this->httpHandler = $config['httpHandler'] ?: HttpHandlerFactory::build();
$this->authHttpHandler = $config['authHttpHandler'] ?: $this->httpHandler;
$this->asyncHttpHandler = $config['asyncHttpHandler'] ?: $this->buildDefaultAsyncHandler();
if ($this->credentialsFetcher instanceof AnonymousCredentials) {
$this->shouldSignRequest = false;
}
}
/**
* Deliver the request.
*
* @param RequestInterface $request A PSR-7 request.
* @param array $options [optional] {
* Request options.
*
* @type float $requestTimeout Seconds to wait before timing out the
* request. **Defaults to** `0`.
* @type int $retries Number of retries for a failed request.
* **Defaults to** `3`.
* @type callable $restRetryFunction Sets the conditions for whether or
* not a request should attempt to retry. Function signature should
* match: `function (\Exception $ex) : bool`.
* @type callable $restDelayFunction Executes a delay, defaults to
* utilizing `usleep`. Function signature should match:
* `function (int $delay) : void`.
* @type callable $restCalcDelayFunction Sets the conditions for
* determining how long to wait between attempts to retry. Function
* signature should match: `function (int $attempt) : int`.
* @type array $restOptions HTTP client specific configuration options.
* }
* @return ResponseInterface
*/
public function send(RequestInterface $request, array $options = [])
{
$retryOptions = $this->getRetryOptions($options);
$backoff = new ExponentialBackoff(
$retryOptions['retries'],
$retryOptions['retryFunction']
);
if ($retryOptions['delayFunction']) {
$backoff->setDelayFunction($retryOptions['delayFunction']);
}
if ($retryOptions['calcDelayFunction']) {
$backoff->setCalcDelayFunction($retryOptions['calcDelayFunction']);
}
try {
return $backoff->execute($this->httpHandler, [
$this->applyHeaders($request),
$this->getRequestOptions($options)
]);
} catch (\Exception $ex) {
throw $this->convertToGoogleException($ex);
}
}
/**
* Deliver the request asynchronously.
*
* @param RequestInterface $request A PSR-7 request.
* @param array $options [optional] {
* Request options.
*
* @type float $requestTimeout Seconds to wait before timing out the
* request. **Defaults to** `0`.
* @type int $retries Number of retries for a failed request.
* **Defaults to** `3`.
* @type callable $restRetryFunction Sets the conditions for whether or
* not a request should attempt to retry. Function signature should
* match: `function (\Exception $ex, int $retryAttempt) : bool`.
* @type callable $restDelayFunction Executes a delay, defaults to
* utilizing `usleep`. Function signature should match:
* `function (int $delay) : void`.
* @type callable $restCalcDelayFunction Sets the conditions for
* determining how long to wait between attempts to retry. Function
* signature should match: `function (int $attempt) : int`.
* @type array $restOptions HTTP client specific configuration options.
* }
* @return PromiseInterface<ResponseInterface>
* @experimental The experimental flag means that while we believe this method
* or class is ready for use, it may change before release in backwards-
* incompatible ways. Please use with caution, and test thoroughly when
* upgrading.
*/
public function sendAsync(RequestInterface $request, array $options = [])
{
// Unfortunately, the current ExponentialBackoff implementation doesn't
// play nicely with promises.
$retryAttempt = 0;
$fn = function ($retryAttempt) use (&$fn, $request, $options) {
$asyncHttpHandler = $this->asyncHttpHandler;
$retryOptions = $this->getRetryOptions($options);
if (!$retryOptions['calcDelayFunction']) {
$retryOptions['calcDelayFunction'] = [ExponentialBackoff::class, 'calculateDelay'];
}
return $asyncHttpHandler(
$this->applyHeaders($request),
$this->getRequestOptions($options)
)->then(null, function (\Exception $ex) use ($fn, $retryAttempt, $retryOptions) {
$shouldRetry = $retryOptions['retryFunction']($ex, $retryAttempt);
if ($shouldRetry === false || $retryAttempt >= $retryOptions['retries']) {
throw $this->convertToGoogleException($ex);
}
$delay = $retryOptions['calcDelayFunction']($retryAttempt);
$retryOptions['delayFunction']($delay);
$retryAttempt++;
return $fn($retryAttempt);
});
};
return $fn($retryAttempt);
}
/**
* Applies headers to the request.
*
* @param RequestInterface $request A PSR-7 request.
* @return RequestInterface
*/
private function applyHeaders(RequestInterface $request)
{
$headers = [
'User-Agent' => 'gcloud-php/' . $this->componentVersion,
'x-goog-api-client' => 'gl-php/' . PHP_VERSION . ' gccl/' . $this->componentVersion,
];
if ($this->shouldSignRequest) {
$quotaProject = $this->quotaProject;
$token = null;
if ($this->accessToken) {
$token = $this->accessToken;
} else {
$credentialsFetcher = $this->getCredentialsFetcher();
$token = $this->fetchCredentials($credentialsFetcher)['access_token'];
if ($credentialsFetcher instanceof GetQuotaProjectInterface) {
$quotaProject = $credentialsFetcher->getQuotaProject();
}
}
$headers['Authorization'] = 'Bearer ' . $token;
if ($quotaProject) {
$headers['X-Goog-User-Project'] = [$quotaProject];
}
}
return Utils::modifyRequest($request, ['set_headers' => $headers]);
}
/**
* Fetches credentials.
*
* @param FetchAuthTokenInterface $credentialsFetcher
* @return array
*/
private function fetchCredentials(FetchAuthTokenInterface $credentialsFetcher)
{
$backoff = new ExponentialBackoff($this->retries, $this->getRetryFunction());
try {
return $backoff->execute(
function () use ($credentialsFetcher) {
if ($token = $credentialsFetcher->fetchAuthToken($this->authHttpHandler)) {
return $token;
}
// As we do not know the reason the credentials fetcher could not fetch the
// token, we should not retry.
throw new \RuntimeException('Unable to fetch token');
}
);
} catch (\Exception $ex) {
throw $this->convertToGoogleException($ex);
}
}
/**
* Convert any exception to a Google Exception.
*
* @param \Exception $ex
* @return Exception\ServiceException
*/
private function convertToGoogleException(\Exception $ex)
{
switch ($ex->getCode()) {
case 400:
$exception = Exception\BadRequestException::class;
break;
case 404:
$exception = Exception\NotFoundException::class;
break;
case 409:
$exception = Exception\ConflictException::class;
break;
case 412:
$exception = Exception\FailedPreconditionException::class;
break;
case 500:
$exception = Exception\ServerException::class;
break;
case 504:
$exception = Exception\DeadlineExceededException::class;
break;
default:
$exception = Exception\ServiceException::class;
break;
}
return new $exception($this->getExceptionMessage($ex), $ex->getCode(), $ex);
}
/**
* Gets the exception message.
*
* @access private
* @param \Exception $ex
* @return string
*/
private function getExceptionMessage(\Exception $ex)
{
if ($ex instanceof RequestException && $ex->hasResponse()) {
return (string) $ex->getResponse()->getBody();
}
return $ex->getMessage();
}
/**
* Gets a set of request options.
*
* @param array $options
* @return array
*/
private function getRequestOptions(array $options)
{
$restOptions = isset($options['restOptions'])
? $options['restOptions']
: $this->restOptions;
$timeout = isset($options['requestTimeout'])
? $options['requestTimeout']
: $this->requestTimeout;
if ($timeout && !array_key_exists('timeout', $restOptions)) {
$restOptions['timeout'] = $timeout;
}
return $restOptions;
}
/**
* Gets a set of retry options.
*
* @param array $options
* @return array
*/
private function getRetryOptions(array $options)
{
return [
'retries' => isset($options['retries'])
? $options['retries']
: $this->retries,
'retryFunction' => isset($options['restRetryFunction'])
? $options['restRetryFunction']
: $this->retryFunction,
'delayFunction' => isset($options['restDelayFunction'])
? $options['restDelayFunction']
: $this->delayFunction,
'calcDelayFunction' => isset($options['restCalcDelayFunction'])
? $options['restCalcDelayFunction']
: $this->calcDelayFunction
];
}
/**
* Builds the default async HTTP handler.
*
* @return callable
*/
private function buildDefaultAsyncHandler()
{
$isGuzzleHandler = $this->httpHandler instanceof Guzzle6HttpHandler
|| $this->httpHandler instanceof Guzzle5HttpHandler;
return $isGuzzleHandler
? [$this->httpHandler, 'async']
: [HttpHandlerFactory::build(), 'async'];
}
}