util/uuid.lua
author Kim Alvefur <zash@zash.se>
Tue, 14 May 2024 17:07:47 +0200
changeset 13494 6f840763fc73
parent 13321 e6a5f196fc1f
permissions -rw-r--r--
net.server_epoll: Add support for systemd socket activation Allows creating listening sockets and accepting client connections before Prosody starts. This is unlike normal Prosody dynamic resource management, where ports may added and removed at any time, and the ports defined by the config. Weird things happen if these are closed (e.g. due to reload) so here we prevent closing and ensure sockets are reused when opened again.

-- 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;
};