From 4ee16e78eb4e74bd20062a19c331d70c87323712 Mon Sep 17 00:00:00 2001
From: Waqas Hussain <waqas20@gmail.com>
Date: Thu, 4 Jun 2009 18:04:26 +0500
Subject: util.uuid: Now generates RFC 4122 complaint UUIDs (version 4 -
 random)

---
 util/uuid.lua | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/util/uuid.lua b/util/uuid.lua
index e928259d..a6dc0a1e 100644
--- a/util/uuid.lua
+++ b/util/uuid.lua
@@ -27,8 +27,22 @@ local function new_random(x)
 	return sha1(x..os_clock()..tostring({}), true);
 end
 
+local buffer = new_random(uniq_time());
+local function get_nibbles(n)
+	if #buffer < n then
+		buffer = new_random(buffer..uniq_time());
+	end
+	local r = buffer:sub(0, n);
+	buffer = buffer:sub(n+1);
+	return r;
+end
+local function get_twobits()
+	return ("%x"):format(get_nibbles(1):byte() % 4 + 8);
+end
+
 function generate()
-	return new_random(uniq_time());
+	-- generate RFC 4122 complaint UUIDs (version 4 - random)
+	return get_nibbles(8).."-"..get_nibbles(4).."-4"..get_nibbles(3).."-"..(get_twobits())..get_nibbles(3).."-"..get_nibbles(12);
 end
 
 return _M;
-- 
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