From 3619de6000b340dbd71eb12849410cc9ffbbaa64 Mon Sep 17 00:00:00 2001 From: Kim Alvefur Date: Sun, 15 Aug 2021 14:44:21 +0200 Subject: util.uuid: Add UUIDv7 Allows sorting by id as a substitute for sorting by timestamp since it has the timestamp in the encoded in the first part, and only things that happen extremely close together may get out of order by such a sort, which might not matter. From draft-ietf-uuidrev-rfc4122bis formerly draft-peabody-dispatch-new-uuid-format --- util/uuid.lua | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'util') diff --git a/util/uuid.lua b/util/uuid.lua index 41c2e9cd..a70750bb 100644 --- a/util/uuid.lua +++ b/util/uuid.lua @@ -8,8 +8,10 @@ local random = require "prosody.util.random"; local random_bytes = random.bytes; +local time = require "prosody.util.time"; local hex = require "prosody.util.hex".encode; local m_ceil = math.ceil; +local m_floor = math.floor; local function get_nibbles(n) return hex(random_bytes(m_ceil(n/2))):sub(1, n); @@ -24,7 +26,22 @@ local function generate() return get_nibbles(8).."-"..get_nibbles(4).."-4"..get_nibbles(3).."-"..(get_twobits())..get_nibbles(3).."-"..get_nibbles(12); end +local function generate_v7() + -- Sortable based on time and random + -- https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-01#section-4.4 + local t = time.now(); + local unixts = m_floor(t); + local unixts_a = m_floor(unixts / 16); + local unixts_b = m_floor(unixts % 16); + local subsec = t % 1; + local subsec_a = m_floor(subsec * 0x1000); + local subsec_b = m_floor(subsec * 0x1000000) % 0x1000; + return ("%08x-%x%03x-7%03x-%4s-%12s"):format(unixts_a, unixts_b, subsec_a, subsec_b, get_twobits() .. get_nibbles(3), get_nibbles(12)); +end + return { + v4 = generate; + v7 = generate_v7; get_nibbles=get_nibbles; generate = generate ; -- COMPAT -- cgit v1.2.3