diff options
Diffstat (limited to 'util/uuid.lua')
| -rw-r--r-- | util/uuid.lua | 37 |
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; |