util/uuid.lua
author Kim Alvefur <zash@zash.se>
Sat, 02 Mar 2024 13:23:24 +0100
changeset 13456 69faf3552d52
parent 13321 e6a5f196fc1f
permissions -rw-r--r--
mod_posix: Move POSIX signal handling into util.startup to avoid race When libunbound is initialized, it spawns a thread to work in. In case a module initializes libunbound, e.g. by triggering a s2s connection, Prosody would not handle signals, instead immediately quit on e.g. the reload (SIGHUP) signal. Likely because the libunbound thread would not have inherited the signal mask from the main Prosody thread. Thanks Menel, riau and franck-x for reporting and help narrowing down

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

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);
end

local function get_twobits()
	return ("%x"):format(random_bytes(1):byte() % 4 + 8);
end

local function generate()
	-- 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

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
	seed = random.seed;
};