File

util/presence.lua @ 10571:cfeb0077c9e9

net.server_epoll: Avoid concatenating buffer with single item Saves creating a string that'll be identical to buffer[1] anyways, as well as a C function call. Depending on Lua version and length of the string, this could be reusing an interned string, but a longer one would probably be duplicated for no reason. Having exactly one item in the buffer seems like it would be fairly common, but I have not done an extensive study. If opportunistic writes are enabled then it will be even more likely. This special case could be optimized like this in table.concat but it does not look like it is.
author Kim Alvefur <zash@zash.se>
date Sat, 28 Dec 2019 06:18:58 +0100
parent 8885:d4f5d47f874d
line wrap: on
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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 t_insert = table.insert;

local function select_top_resources(user)
	local priority = 0;
	local recipients = {};
	for _, session in pairs(user.sessions) do -- find resource with greatest priority
		if session.presence then
			local p = session.priority;
			if p > priority then
				priority = p;
				recipients = {session};
			elseif p == priority then
				t_insert(recipients, session);
			end
		end
	end
	return recipients;
end
local function recalc_resource_map(user)
	if user then
		user.top_resources = select_top_resources(user);
		if #user.top_resources == 0 then user.top_resources = nil; end
	end
end

return {
	select_top_resources = select_top_resources;
	recalc_resource_map = recalc_resource_map;
}