File

plugins/muc/occupant.lib.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 7086:6cc7c9da29ed
child 12977:74b9e05af71e
line wrap: on
line source

local pairs = pairs;
local setmetatable = setmetatable;
local st = require "util.stanza";
local util = module:require "muc/util";

local function get_filtered_presence(stanza)
	return util.filter_muc_x(st.clone(stanza));
end

local occupant_mt = {};
occupant_mt.__index = occupant_mt;

local function new_occupant(bare_real_jid, nick)
	return setmetatable({
		bare_jid = bare_real_jid;
		nick = nick; -- in-room jid
		sessions = {}; -- hash from real_jid to presence stanzas. stanzas should not be modified
		role = nil;
		jid = nil; -- Primary session
	}, occupant_mt);
end

-- Deep copy an occupant
local function copy_occupant(occupant)
	local sessions = {};
	for full_jid, presence_stanza in pairs(occupant.sessions) do
		-- Don't keep unavailable presences, as they'll accumulate; unless they're the primary session
		if presence_stanza.attr.type ~= "unavailable" or full_jid == occupant.jid then
			sessions[full_jid] = presence_stanza;
		end
	end
	return setmetatable({
		bare_jid = occupant.bare_jid;
		nick = occupant.nick;
		sessions = sessions;
		role = occupant.role;
		jid = occupant.jid;
	}, occupant_mt);
end

-- finds another session to be the primary (there might not be one)
function occupant_mt:choose_new_primary()
	for jid, pr in self:each_session() do
		if pr.attr.type == nil then
			return jid;
		end
	end
	return nil;
end

function occupant_mt:set_session(real_jid, presence_stanza, replace_primary)
	local pr = get_filtered_presence(presence_stanza);
	pr.attr.from = self.nick;
	pr.attr.to = real_jid;

	self.sessions[real_jid] = pr;
	if replace_primary then
		self.jid = real_jid;
	elseif self.jid == nil or (pr.attr.type == "unavailable" and self.jid == real_jid) then
		-- Only leave an unavailable presence as primary when there are no other options
		self.jid = self:choose_new_primary() or real_jid;
	end
end

function occupant_mt:remove_session(real_jid)
	-- Delete original session
	self.sessions[real_jid] = nil;
	if self.jid == real_jid then
		self.jid = self:choose_new_primary();
	end
end

function occupant_mt:each_session()
	return pairs(self.sessions)
end

function occupant_mt:get_presence(real_jid)
	return self.sessions[real_jid or self.jid]
end

return {
	new = new_occupant;
	copy = copy_occupant;
	mt = occupant_mt;
}