File

mod_presence_dedup/mod_presence_dedup.lua @ 5170:4d6af8950016

mod_muc_moderation: Derive role from reserved nickname if occupant When using a different client to moderate than the one used to participate in the chat, e.g. a command line tool like clix, there's no occupant and no role to use in the permission check. Previously the default role based on affiliation was used. Now if you are present in the room using your reserved nick, the role you have there is used in the permission check instead of the default affiliation-derived role.
author Kim Alvefur <zash@zash.se>
date Sun, 19 Feb 2023 18:17:37 +0100
parent 3445:19924a2c4a48
line wrap: on
line source

local st = require "util.stanza";
local cache = require "util.cache";
local add_filter = require "util.filters".add_filter;

local cache_size = module:get_option_number("presence_dedup_cache_size", 100);

-- stanza equality tests
local function attr_eq(a, b)
	if a == b then return true; end -- unlikely but not impossible
	for k,v in pairs(a) do if b[k] ~= v then return false; end end
	for k,v in pairs(b) do if a[k] ~= v then return false; end end
	return true;
end

local function st_eq(a, b)
	if a == b then return true; end
	if type(b) ~= "table" then return false; end
	if getmetatable(b) ~= st.stanza_mt then return false; end
	if a.name ~= b.name then return false; end
	if #a ~= #b then return false; end
	if not attr_eq(a.attr, b.attr) then return false; end
	for i = 1, #a do if not st_eq(a[i], b[i]) then return false; end end
	return true;
end

local function dedup_presence(stanza, session)
	if session.presence_cache and session.presence
	and getmetatable(stanza) == st.stanza_mt and stanza.name == "presence"
	and stanza.attr.xmlns == nil and stanza.attr.from then
		local cached = session.presence_cache:get(stanza.attr.from);
		if st_eq(stanza, cached) then
			return nil;
		else
			session.presence_cache:set(stanza.attr.from, st.clone(stanza));
		end
	end
	return stanza;
end

module:hook("presence/initial",	function (event)
	local session = event.origin;
	session.presence_cache = cache.new(cache_size);
	add_filter(session, "stanzas/out", dedup_presence, 90);
end);