25 lines
936 B
Lua
25 lines
936 B
Lua
-- A simple UUID function based on RFC 4122: http://www.ietf.org/rfc/rfc4122.txt
|
|
local unpack = unpack or table.unpack
|
|
local function uuid()
|
|
local r = math.random
|
|
-- Set all the other bits to randomly (or pseudo-randomly) chosen values.
|
|
local bytes = {
|
|
r(2^(4*8)), --time-low
|
|
r(2^(2*8)), --time-mid
|
|
r(2^(2*8-4)), --time-high-and-version
|
|
r(2^(1*8-2)), --clock-seq-and-reserved
|
|
r(2^(1*8)), --clock-seq-low
|
|
r(2^(3*8)), r(2^(3*8)), --node
|
|
}
|
|
-- Set the four most significant bits (bits 12 through 15) of the
|
|
-- time_hi_and_version field to the 4-bit version number from
|
|
-- Section 4.1.3.
|
|
bytes[3] = bytes[3] + 0x4000
|
|
-- Set the two most significant bits (bits 6 and 7) of the
|
|
-- clock_seq_hi_and_reserved to zero and one, respectively.
|
|
bytes[4] = bytes[4] + 0xC0
|
|
return ("%08x-%04x-%04x-%02x%02x-%6x%6x"):format(unpack(bytes))
|
|
end
|
|
|
|
return uuid
|