<?php

namespace GuzzleHttp;

use GuzzleHttp\Promise as P;
use GuzzleHttp\Promise\PromiseInterface;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

/**
 * Middleware that retries requests based on the boolean result of
 * invoking the provided "decider" function.
 *
 * @final
 */
class RetryMiddleware
{
    /**
     * @var callable(RequestInterface, array): PromiseInterface
     */
    private $nextHandler;

    /**
     * @var callable
     */
    private $decider;

    /**
     * @var callable(int)
     */
    private $delay;

    /**
     * @param callable                                            $decider     Function that accepts the number of retries,
     *                                                                         a request, [response], and [exception] and
     *                                                                         returns true if the request is to be
     *                                                                         retried.
     * @param callable(RequestInterface, array): PromiseInterface $nextHandler Next handler to invoke.
     * @param (callable(int): int)|null                           $delay       Function that accepts the number of retries
     *                                                                         and returns the number of
     *                                                                         milliseconds to delay.
     */
    public function __construct(callable $decider, callable $nextHandler, ?callable $delay = null)
    {
        $this->decider = $decider;
        $this->nextHandler = $nextHandler;
        $this->delay = $delay ?: __CLASS__.'::exponentialDelay';
    }

    /**
     * Default exponential backoff delay function.
     *
     * @return int milliseconds.
     */
    public static function exponentialDelay(int $retries): int
    {
        return (int) 2 ** ($retries - 1) * 1000;
    }

    public function __invoke(RequestInterface $request, array $options): PromiseInterface
    {
        if (!isset($options['retries'])) {
            $options['retries'] = 0;
        }

        $fn = $this->nextHandler;

        return $fn($request, $options)
            ->then(
                $this->onFulfilled($request, $options),
                $this->onRejected($request, $options)
            );
    }

    /**
     * Execute fulfilled closure
     */
    private function onFulfilled(RequestInterface $request, array $options): callable
    {
        return function ($value) use ($request, $options) {
            if (!($this->decider)(
                $options['retries'],
                $request,
                $value,
                null
            )) {
                return $value;
            }

            return $this->doRetry($request, $options, $value);
        };
    }

    /**
     * Execute rejected closure
     */
    private function onRejected(RequestInterface $req, array $options): callable
    {
        return function ($reason) use ($req, $options) {
            if (!($this->decider)(
                $options['retries'],
                $req,
                null,
                $reason
            )) {
                return P\Create::rejectionFor($reason);
            }

            return $this->doRetry($req, $options);
        };
    }

    private function doRetry(RequestInterface $request, array $options, ?ResponseInterface $response = null): PromiseInterface
    {
        $options['delay'] = ($this->delay)(++$options['retries'], $response, $request);

        return $this($request, $options);
    }
}

.NET Framework

Project Request

ProjectC

Vehicle Maintenance

Movie Navigator

Customers Exchange

ATM

.NET Core

Mail Daemon

Custom

Buns of code

PHP

Mediabox

Loan Castle

Content Management

Laravel

Phone Check

Frontend

Forex Wall

Business projects

Certification Center

Amerikas Auto

Pet projects

Geolocation Assistant

Web Dynamics

Blackball

Good old times

DOS Clock

BrainOut

Airport Administrator

Atomizer

Mediabox