commit e51f379e39e0fcb8b68ff2633f58f6616dc6e8bd
Author: OnkelTem <OnkelTem@239962.no-reply.drupal.org>
Date:   Mon Mar 25 14:01:08 2013 +0400

    Introduce UUIDs onto panes & displays for better exportability & features compatibility

diff --git a/ctools.module b/ctools.module
index f014e74..e61e380 100644
--- a/ctools.module
+++ b/ctools.module
@@ -368,6 +368,71 @@ function ctools_set_no_blocks($blocks = FALSE) {
 }
 
 /**
+ * Generates a Universally Unique IDentifier, version 4.
+ * @see http://php.net/uniqid#65879
+ *
+ * RFC 4122 (http://www.ietf.org/rfc/rfc4122.txt) defines a special type of
+ * Globally Unique IDentifiers (GUID), as well as several methods for
+ * producing them. One such method, described in section 4.4, is based on
+ * truly random or pseudo-random number generators, and is therefore
+ * implementable in a language like PHP.
+ *
+ * We choose to produce pseudo-random numbers with the Mersenne Twister, and
+ * to always limit single generated numbers to 16 bits (ie. the decimal value
+ * 65535). That is because, even on 32-bit systems, PHP's RAND_MAX will often
+ * be the maximum *signed* value, with only the equivalent of 31 significant
+ * bits. Producing two 16-bit random numbers to make up a 32-bit one is less
+ * efficient, but guarantees that all 32 bits are random.
+ *
+ * The algorithm for version 4 UUIDs (ie. those based on random number
+ * generators) states that all 128 bits separated into the various fields (32
+ * bits, 16 bits, 16 bits, 8 bits and 8 bits, 48 bits) should be random,
+ * except: (a) the version number should be the last 4 bits in the 3rd field,
+ * and (b) bits 6 and 7 of the 4th field should be 01. We try to conform to
+ * that definition as efficiently as possible, generating smaller values where
+ * possible, and minimizing the number of base conversions.
+ *
+ * @copyright   Copyright (c) CFD Labs, 2006. This function may be used freely
+ *              for any purpose ; it is distributed without any form of
+ *              warranty whatsoever.
+ * @author      David Holmes <dholmes@cfdsoftware.net>
+ *
+ * @return string
+ *   A UUID, made up of 32 hex digits and 4 hyphens.
+ */
+function ctools_uuid_generate() {
+  // The field names refer to RFC 4122 section 4.1.2
+  return sprintf('%04x%04x-%04x-%03x4-%04x-%04x%04x%04x',
+    // 32 bits for "time_low":
+    mt_rand(0, 65535), mt_rand(0, 65535),
+    // 16 bits for "time_mid":
+    mt_rand(0, 65535),
+    // 12 bits before the 0100 of (version) 4 for "time_hi_and_version":
+    mt_rand(0, 4095),
+    // 8 bits, the last two of which (positions 6 and 7) are 01, for
+    // "clk_seq_hi_res" (hence, the 2nd hex digit after the 3rd hyphen can
+    // only be 1, 5, 9 or d) 8 bits for "clk_seq_low":
+    bindec(substr_replace(sprintf('%016b', mt_rand(0, 65535)), '01', 6, 2)),
+    // 48 bits for "node":
+    mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(0, 65535)
+  );
+}
+
+/**
+ * Check that a string appears to be in the format of a UUID.
+ * @see http://drupal.org/project/uuid
+ *
+ * @param $uuid
+ *   The string to test.
+ *
+ * @return
+ *   TRUE if the string is well formed.
+ */
+function ctools_uuid_is_valid($uuid) {
+  return preg_match("/^[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}$/", $uuid);
+}
+
+/**
  * Add an array of classes to the body.
  *
  * @param mixed $classes