prosody
c48ae06e24d6
util/uuid.lua

Find changesets by keywords by author, files, the commit message, revision number or hash, or revset expression.

Software / code / prosody

File

util/uuid.lua @ 13182:c48ae06e24d6

util.datamanager: Fix indexing first item if not at the very start If the first item does not start at position 0 then the index function produces a phantom first entry covering position zero until where the real first item starts. When using the index, this would make it either appear as the first item was missing or cause an off-by-one issue with remaining items.
author Kim Alvefur <zash@zash.se>
date Mon, 10 Jul 2023 17:19:05 +0200
parent 12975:d10957394a3c
child 13317:e6a5f196fc1f
line wrap: on
line source

-- 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 hex = require "prosody.util.hex".encode;
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;
};