Software / code / prosody
Diff
util/uuid.lua @ 13317:e6a5f196fc1f
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
| author | Kim Alvefur <zash@zash.se> |
|---|---|
| date | Sun, 15 Aug 2021 14:44:21 +0200 |
| parent | 12975:d10957394a3c |
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--- a/util/uuid.lua Sat Nov 11 21:33:53 2023 +0100 +++ b/util/uuid.lua Sun Aug 15 14:44:21 2021 +0200 @@ -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 @@ 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
