<?php

/*

* This file is part of the DebugBar package.

*

* (c) 2013 Maxime Bouroumeau-Fuseau

*

* For the full copyright and license information, please view the LICENSE

* file that was distributed with this source code.

*/

namespace DebugBar;

/**

* Basic request ID generator

*/

class RequestIdGenerator implements RequestIdGeneratorInterface

{

protected $index = 0;

/**

* @return string

*/

public function generate()

{

if (function_exists('random_bytes')) {

// PHP 7 only

return 'X' . bin2hex(random_bytes(16));

} else if (function_exists('openssl_random_pseudo_bytes')) {

// PHP >= 5.3.0, but OpenSSL may not always be available

return 'X' . bin2hex(openssl_random_pseudo_bytes(16));

} else {

// Fall back to a rudimentary ID generator:

// * $_SERVER array will make the ID unique to this request.

// * spl_object_hash($this) will make the ID unique to this object instance.

// (note that object hashes can be reused, but the other data here should prevent issues here).

// * uniqid('', true) will use the current microtime(), plus additional random data.

// * $this->index guarantees the uniqueness of IDs from the current object.

$this->index++;

$entropy = serialize($_SERVER) . uniqid('', true) . spl_object_hash($this) . $this->index;

return 'X' . md5($entropy);

}

}

}