public function Php::generate

Implements Drupal\Component\Uuid\UuidInterface::generate().

Overrides UuidInterface::generate

File

drupal/core/lib/Drupal/Component/Uuid/Php.php, line 22

Definition of Drupal\Component\Uuid\Php.

Class

Php

Generates a UUID v4 using PHP code.

Namespace

Code

public function generate() {
  $hex = substr(hash('sha256', drupal_random_bytes(16)), 0, 32);

  // The field names refer to RFC 4122 section 4.1.2.
  $time_low = substr($hex, 0, 8);
  $time_mid = substr($hex, 8, 4);
  $time_hi_and_version = base_convert(substr($hex, 12, 4), 16, 10);
  $time_hi_and_version &= 0xfff;
  $time_hi_and_version |= 4 << 12;
  $clock_seq_hi_and_reserved = base_convert(substr($hex, 16, 4), 16, 10);
  $clock_seq_hi_and_reserved &= 0x3f;
  $clock_seq_hi_and_reserved |= 0x80;
  $clock_seq_low = substr($hex, 20, 2);
  $nodes = substr($hex, 20);
  $uuid = sprintf('%s-%s-%04x-%02x%02x-%s', $time_low, $time_mid, $time_hi_and_version, $clock_seq_hi_and_reserved, $clock_seq_low, $nodes);
  return $uuid;
}