File

util/filters.lua @ 12462:11765f0605ec

mod_s2s: Store real stanzas in session.sendq, rather than strings This is the "right" thing to do. Strings were more memory-efficient, but e.g. bypassed stanza filters at reconnection time. Also not being stanzas prevents us from potential future work, such as merging sendq with mod_smacks. Regarding performance: we should counter the probable negative effect of this change with other positive changes that are desired anyway - e.g. a limit on the size of the sendq, improved in-memory representation of stanzas, s2s backoff (e.g. if a remote server is persistently unreachable, cache this failure for a while and don't just keep forever queuing stanzas for it).
author Matthew Wild <mwild1@gmail.com>
date Wed, 23 Mar 2022 15:25:22 +0000
parent 8555:4f0f5b49bb03
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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, t_remove = table.insert, table.remove;

local _ENV = nil;
-- luacheck: std none

local new_filter_hooks = {};

local function initialize(session)
	if not session.filters then
		local filters = {};
		session.filters = filters;

		function session.filter(type, data)
			local filter_list = filters[type];
			if filter_list then
				for i = 1, #filter_list do
					data = filter_list[i](data, session);
					if data == nil then break; end
				end
			end
			return data;
		end
	end

	for i=1,#new_filter_hooks do
		new_filter_hooks[i](session);
	end

	return session.filter;
end

local function add_filter(session, type, callback, priority)
	if not session.filters then
		initialize(session);
	end

	local filter_list = session.filters[type];
	if not filter_list then
		filter_list = {};
		session.filters[type] = filter_list;
	elseif filter_list[callback] then
		return; -- Filter already added
	end

	priority = priority or 0;

	local i = 0;
	repeat
		i = i + 1;
	until not filter_list[i] or filter_list[filter_list[i]] < priority;

	t_insert(filter_list, i, callback);
	filter_list[callback] = priority;
end

local function remove_filter(session, type, callback)
	if not session.filters then return; end
	local filter_list = session.filters[type];
	if filter_list and filter_list[callback] then
		for i=1, #filter_list do
			if filter_list[i] == callback then
				t_remove(filter_list, i);
				filter_list[callback] = nil;
				return true;
			end
		end
	end
end

local function add_filter_hook(callback)
	t_insert(new_filter_hooks, callback);
end

local function remove_filter_hook(callback)
	for i=1,#new_filter_hooks do
		if new_filter_hooks[i] == callback then
			t_remove(new_filter_hooks, i);
		end
	end
end

return {
	initialize = initialize;
	add_filter = add_filter;
	remove_filter = remove_filter;
	add_filter_hook = add_filter_hook;
	remove_filter_hook = remove_filter_hook;
};