File

util/uuid.lua @ 13262:9a86e7cbdd79

mod_storage_internal: Fix fast trimming of archive with exactly one item This method would previously never delete the first (and only) item since it works out which item should become the first item after the trim operation, which doesn't make sense when all should be removed. This also works as an optimization for when all the last item should be trimmed, thus items should be removed.
author Kim Alvefur <zash@zash.se>
date Sun, 24 Sep 2023 13:41:54 +0200
parent 12975:d10957394a3c
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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 "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;
};