1<?php
2
3namespace React\Dns\Query;
4
5use React\Promise\CancellablePromiseInterface;
6use React\Promise\Deferred;
7use React\Promise\PromiseInterface;
8
9final class RetryExecutor implements ExecutorInterface
10{
11    private $executor;
12    private $retries;
13
14    public function __construct(ExecutorInterface $executor, $retries = 2)
15    {
16        $this->executor = $executor;
17        $this->retries = $retries;
18    }
19
20    public function query(Query $query)
21    {
22        return $this->tryQuery($query, $this->retries);
23    }
24
25    public function tryQuery(Query $query, $retries)
26    {
27        $deferred = new Deferred(function () use (&$promise) {
28            if ($promise instanceof CancellablePromiseInterface || (!\interface_exists('React\Promise\CancellablePromiseInterface') && \method_exists($promise, 'cancel'))) {
29                $promise->cancel();
30            }
31        });
32
33        $success = function ($value) use ($deferred, &$errorback) {
34            $errorback = null;
35            $deferred->resolve($value);
36        };
37
38        $executor = $this->executor;
39        $errorback = function ($e) use ($deferred, &$promise, $query, $success, &$errorback, &$retries, $executor) {
40            if (!$e instanceof TimeoutException) {
41                $errorback = null;
42                $deferred->reject($e);
43            } elseif ($retries <= 0) {
44                $errorback = null;
45                $deferred->reject($e = new \RuntimeException(
46                    'DNS query for ' . $query->describe() . ' failed: too many retries',
47                    0,
48                    $e
49                ));
50
51                // avoid garbage references by replacing all closures in call stack.
52                // what a lovely piece of code!
53                $r = new \ReflectionProperty('Exception', 'trace');
54                $r->setAccessible(true);
55                $trace = $r->getValue($e);
56
57                // Exception trace arguments are not available on some PHP 7.4 installs
58                // @codeCoverageIgnoreStart
59                foreach ($trace as &$one) {
60                    if (isset($one['args'])) {
61                        foreach ($one['args'] as &$arg) {
62                            if ($arg instanceof \Closure) {
63                                $arg = 'Object(' . \get_class($arg) . ')';
64                            }
65                        }
66                    }
67                }
68                // @codeCoverageIgnoreEnd
69                $r->setValue($e, $trace);
70            } else {
71                --$retries;
72                $promise = $executor->query($query)->then(
73                    $success,
74                    $errorback
75                );
76            }
77        };
78
79        $promise = $this->executor->query($query)->then(
80            $success,
81            $errorback
82        );
83
84        return $deferred->promise();
85    }
86}
87