Pool.php

<?php
namespace GuzzleHttp;
 
use GuzzleHttp\Promise\EachPromise;
use GuzzleHttp\Promise\PromiseInterface;
use GuzzleHttp\Promise\PromisorInterface;
use Psr\Http\Message\RequestInterface;
 
class Pool implements PromisorInterface
{
    private $each;
 
    public function __construct(
        ClientInterface $client,
        $requests,
        array $config = []
    ) {
        // Backwards compatibility.
        if (isset($config['pool_size'])) {
            $config['concurrency'] = $config['pool_size'];
        } elseif (!isset($config['concurrency'])) {
            $config['concurrency'] = 25;
        }
 
        if (isset($config['options'])) {
            $opts = $config['options'];
            unset($config['options']);
        } else {
            $opts = [];
        }
 
        $iterable = \GuzzleHttp\Promise\iter_for($requests);
        $requests = function () use ($iterable, $client, $opts) {
            foreach ($iterable as $key => $rfn) {
                if ($rfn instanceof RequestInterface) {
                    yield $key => $client->sendAsync($rfn, $opts);
                } elseif (is_callable($rfn)) {
                    yield $key => $rfn($opts);
                } else {
                    throw new \InvalidArgumentException('Each value yielded by '
                        . 'the iterator must be a Psr7\Http\Message\RequestInterface '
                        . 'or a callable that returns a promise that fulfills '
                        . 'with a Psr7\Message\Http\ResponseInterface object.');
                }
            }
        };
 
        $this->each = new EachPromise($requests(), $config);
    }
 
    public function promise()
    {
        return $this->each->promise();
    }
 
    public static function batch(
        ClientInterface $client,
        $requests,
        array $options = []
    ) {
        $res = [];
        self::cmpCallback($options, 'fulfilled', $res);
        self::cmpCallback($options, 'rejected', $res);
        $pool = new static($client, $requests, $options);
        $pool->promise()->wait();
        ksort($res);
 
        return $res;
    }
 
    private static function cmpCallback(array &$options, $name, array &$results)
    {
        if (!isset($options[$name])) {
            $options[$name] = function ($v, $k) use (&$results) {
                $results[$k] = $v;
            };
        } else {
            $currentFn = $options[$name];
            $options[$name] = function ($v, $k) use (&$results, $currentFn) {
                $currentFn($v, $k);
                $results[$k] = $v;
            };
        }
    }
}