File

util/uuid.lua @ 12056:e62025f949f9

mod_smacks: Limit queue memory consumption using new util This brings back the queue size limit that was once added, then removed because destroying the session when reaching the limit was not great. Instead, the queue wraps and overwrites the oldest unacked stanza on the assumption that it will probably be acked anyway and thus does not need to be delivered. If those discarded stanzas turn out to be needed on resumption then the resumption fails.
author Kim Alvefur <zash@zash.se>
date Tue, 14 Dec 2021 20:00:45 +0100
parent 7078:ec17115e3721
child 12355:a0ff5c438e9d
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-- 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 "util.random";
local random_bytes = random.bytes;
local hex = require "util.hex".to;
local m_ceil = math.ceil;

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

return {
	get_nibbles=get_nibbles;
	generate = generate ;
	-- COMPAT
	seed = random.seed;
};