view mod_throttle_presence/mod_throttle_presence.lua @ 5186:fa3059e653fa

mod_http_oauth2: Implement the Implicit flow Everyone says this is insecure and bad, but it's also the only thing that makes sense for e.g. pure JavaScript clients, but hey implement this even more complicated thing instead!
author Kim Alvefur <zash@zash.se>
date Thu, 02 Mar 2023 22:06:50 +0100
parents 552faee596b7
children
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local filters = require "util.filters";
local st = require "util.stanza";

module:depends("csi");

local function presence_filter(stanza, session)
	if getmetatable(stanza) ~= st.stanza_mt then
		return stanza; -- Things we don't want to touch
	end
	if stanza._flush then
		stanza._flush = nil;
		return stanza;
	end
	local buffer = session.presence_buffer;
	local from = stanza.attr.from;
	if stanza.name == "presence" and (stanza.attr.type == nil or stanza.attr.type == "unavailable") then
		module:log("debug", "Buffering presence stanza from %s to %s", stanza.attr.from, session.full_jid);
		buffer[stanza.attr.from] = st.clone(stanza);
		return nil; -- Drop this stanza (we've stored it for later)
	else
		local cached_presence = buffer[stanza.attr.from];
		if cached_presence then
			module:log("debug", "Important stanza for %s from %s, flushing presence", session.full_jid, from);
			stanza._flush = true;
			cached_presence._flush = true;
			session.send(cached_presence);
			buffer[stanza.attr.from] = nil;
		end
	end
	return stanza;
end

local function throttle_session(event)
	local session = event.origin;
	if session.presence_buffer then return; end
	module:log("debug", "Suppressing presence updates to %s", session.full_jid);
	session.presence_buffer = {};
	filters.add_filter(session, "stanzas/out", presence_filter);
end

local function restore_session(event)
	local session = event.origin;
	if not session.presence_buffer then return; end
	filters.remove_filter(session, "stanzas/out", presence_filter);
	module:log("debug", "Flushing buffer for %s", session.full_jid);
	for jid, presence in pairs(session.presence_buffer) do
		session.send(presence);
	end
	session.presence_buffer = nil;
end

module:hook("csi-client-inactive", throttle_session);
module:hook("csi-client-active", restore_session);