1<?php
2/**
3 * Elasticsearch PHP client
4 *
5 * @link      https://github.com/elastic/elasticsearch-php/
6 * @copyright Copyright (c) Elasticsearch B.V (https://www.elastic.co)
7 * @license   http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
8 * @license   https://www.gnu.org/licenses/lgpl-2.1.html GNU Lesser General Public License, Version 2.1
9 *
10 * Licensed to Elasticsearch B.V under one or more agreements.
11 * Elasticsearch B.V licenses this file to you under the Apache 2.0 License or
12 * the GNU Lesser General Public License, Version 2.1, at your option.
13 * See the LICENSE file in the project root for more information.
14 */
15
16
17declare(strict_types = 1);
18
19namespace Elasticsearch\ConnectionPool\Selectors;
20
21use Elasticsearch\Connections\ConnectionInterface;
22
23class StickyRoundRobinSelector implements SelectorInterface
24{
25    /**
26     * @var int
27     */
28    private $current = 0;
29
30    /**
31     * @var int
32     */
33    private $currentCounter = 0;
34
35    /**
36     * Use current connection unless it is dead, otherwise round-robin
37     *
38     * @param ConnectionInterface[] $connections Array of connections to choose from
39     */
40    public function select(array $connections): ConnectionInterface
41    {
42        /**
43 * @var ConnectionInterface[] $connections
44*/
45        if ($connections[$this->current]->isAlive()) {
46            return $connections[$this->current];
47        }
48
49        $this->currentCounter += 1;
50        $this->current = $this->currentCounter % count($connections);
51
52        return $connections[$this->current];
53    }
54}
55