diff core/lib/Drupal/Component/Uuid/Php.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/lib/Drupal/Component/Uuid/Php.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,56 @@
+<?php
+
+namespace Drupal\Component\Uuid;
+
+use Drupal\Component\Utility\Crypt;
+
+/**
+ * Generates a UUID v4 (RFC 4122 section 4.4) using PHP code.
+ *
+ * @see http://www.rfc-editor.org/rfc/rfc4122.txt
+ * @see http://www.rfc-editor.org/errata_search.php?rfc=4122&eid=3546
+ */
+class Php implements UuidInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function generate() {
+    // Obtain a random string of 32 hex characters.
+    $hex = bin2hex(Crypt::randomBytes(16));
+
+    // The variable names $time_low, $time_mid, $time_hi_and_version,
+    // $clock_seq_hi_and_reserved, $clock_seq_low, and $node correlate to
+    // the fields defined in RFC 4122 section 4.1.2.
+    //
+    // Use characters 0-11 to generate 32-bit $time_low and 16-bit $time_mid.
+    $time_low = substr($hex, 0, 8);
+    $time_mid = substr($hex, 8, 4);
+
+    // Use characters 12-15 to generate 16-bit $time_hi_and_version.
+    // The 4 most significant bits are the version number (0100 == 0x4).
+    // We simply skip character 12 from $hex, and concatenate the strings.
+    $time_hi_and_version = '4' . substr($hex, 13, 3);
+
+    // Use characters 16-17 to generate 8-bit $clock_seq_hi_and_reserved.
+    // The 2 most significant bits are set to one and zero respectively.
+    $clock_seq_hi_and_reserved = base_convert(substr($hex, 16, 2), 16, 10);
+    $clock_seq_hi_and_reserved &= 0b00111111;
+    $clock_seq_hi_and_reserved |= 0b10000000;
+
+    // Use characters 18-19 to generate 8-bit $clock_seq_low.
+    $clock_seq_low = substr($hex, 18, 2);
+    // Use characters 20-31 to generate 48-bit $node.
+    $node = substr($hex, 20);
+
+    // Re-combine as a UUID. $clock_seq_hi_and_reserved is still an integer.
+    $uuid = sprintf('%s-%s-%s-%02x%s-%s',
+      $time_low, $time_mid, $time_hi_and_version,
+      $clock_seq_hi_and_reserved, $clock_seq_low,
+      $node
+    );
+
+    return $uuid;
+  }
+
+}