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-rw-r--r--util/uuid.lua37
1 files changed, 34 insertions, 3 deletions
diff --git a/util/uuid.lua b/util/uuid.lua
index fd21dfcc..eca35134 100644
--- a/util/uuid.lua
+++ b/util/uuid.lua
@@ -7,13 +7,44 @@
--
-
local m_random = math.random;
local tostring = tostring;
+local os_time = os.time;
+local os_clock = os.clock;
+local sha1 = require "util.hashes".sha1;
+
module "uuid"
+local last_uniq_time = 0;
+local function uniq_time()
+ local new_uniq_time = os_time();
+ if last_uniq_time >= new_uniq_time then new_uniq_time = last_uniq_time + 1; end
+ last_uniq_time = new_uniq_time;
+ return new_uniq_time;
+end
+
+local function new_random(x)
+ return sha1(x..os_clock()..tostring({}), true);
+end
+
+local buffer = new_random(uniq_time());
+local function _seed(x)
+ buffer = new_random(buffer..x);
+end
+local function get_nibbles(n)
+ if #buffer < n then seed(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 tostring(m_random(0, 99999999));
+ -- 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
+seed = _seed;
-return _M; \ No newline at end of file
+return _M;