PHP Classes

File: application/modules/extensions/aws/Aws/RetryMiddleware.php

Recommend this page to a friend!
  Classes of Tran Tuan   Pretty PHP S3 Files Manager   application/modules/extensions/aws/Aws/RetryMiddleware.php   Download  
File: application/modules/extensions/aws/Aws/RetryMiddleware.php
Role: Application script
Content type: text/plain
Description: Initial
Class: Pretty PHP S3 Files Manager
Web based interface to manage files in Amazon S3
Author: By
Last change:
Date: 8 years ago
Size: 3,684 bytes
 

Contents

Class file image Download
<?php
namespace Aws;

use
Aws\Exception\AwsException;
use
Psr\Http\Message\RequestInterface;
use
GuzzleHttp\Promise\PromiseInterface;
use
GuzzleHttp\Psr7;

/**
 * @internal Middleware that retries failures.
 */
class RetryMiddleware
{
    private static
$retryStatusCodes = [
       
500 => true,
       
503 => true
   
];

    private static
$retryCodes = [
       
'RequestLimitExceeded' => true,
       
'Throttling' => true,
       
'ThrottlingException' => true,
       
'ProvisionedThroughputExceededException' => true,
       
'RequestThrottled' => true,
    ];

    private
$decider;
    private
$delay;
    private
$nextHandler;

    public function
__construct(
        callable
$decider,
        callable
$delay,
        callable
$nextHandler
   
) {
       
$this->decider = $decider;
       
$this->delay = $delay;
       
$this->nextHandler = $nextHandler;
    }

   
/**
     * Creates a default AWS retry decider function.
     *
     * @param int $maxRetries
     *
     * @return callable
     */
   
public static function createDefaultDecider($maxRetries = 3)
    {
        return function (
           
$retries,
           
CommandInterface $command,
           
RequestInterface $request,
           
ResultInterface $result = null,
           
$error = null
       
) use ($maxRetries) {
           
// Allow command-level options to override this value
           
$maxRetries = null !== $command['@retries'] ?
               
$command['@retries']
                :
$maxRetries;

            if (
$retries >= $maxRetries) {
                return
false;
            } elseif (!
$error) {
                return isset(
self::$retryStatusCodes[$result['@metadata']['statusCode']]);
            } elseif (!(
$error instanceof AwsException)) {
                return
false;
            } elseif (
$error->isConnectionError()) {
                return
true;
            } elseif (isset(
self::$retryCodes[$error->getAwsErrorCode()])) {
                return
true;
            } elseif (isset(
self::$retryStatusCodes[$error->getStatusCode()])) {
                return
true;
            } else {
                return
false;
            }
        };
    }

   
/**
     * Delay function that calculates an exponential delay.
     *
     * @param $retries
     *
     * @return int
     */
   
public static function exponentialDelay($retries)
    {
        return
mt_rand(0, (int) pow(2, $retries - 1) * 100);
    }

   
/**
     * @param CommandInterface $command
     * @param RequestInterface $request
     *
     * @return PromiseInterface
     */
   
public function __invoke(
       
CommandInterface $command,
       
RequestInterface $request = null
   
) {
       
$retries = 0;
       
$handler = $this->nextHandler;
       
$decider = $this->decider;
       
$delay = $this->delay;

       
$g = function ($value) use ($handler, $decider, $delay, $command, $request, &$retries, &$g) {
            if (
$value instanceof \Exception) {
                if (!
$decider($retries, $command, $request, null, $value)) {
                    return \
GuzzleHttp\Promise\rejection_for($value);
                }
            } elseif (
$value instanceof ResultInterface
               
&& !$decider($retries, $command, $request, $value, null)
            ) {
                return
$value;
            }

           
// Delay fn is called with 0, 1, ... so increment after the call.
           
$command['@http']['delay'] = $delay($retries++);
            return
$handler($command, $request)->then($g, $g);
        };

        return
$handler($command, $request)->then($g, $g);
    }
}