view mod_presence_cache/mod_presence_cache.lua @ 5271:3a1df3adad0c

mod_http_oauth2: Allow user to decide which requested scopes to grant These should at the very least be shown to the user, so they can decide whether to grant them. Considered whether to filter the requested scopes down to actually understood scopes that would be granted, but decided that this was a bit complex for a first step, since role role selection and other kinds of scopes are mixed into the same field here.
author Kim Alvefur <zash@zash.se>
date Thu, 23 Mar 2023 16:28:08 +0100
parents 830a01443a2f
children
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-- XEP-0280: Message Carbons implementation for Prosody
-- Copyright (C) 2015-2016 Kim Alvefur
--
-- This file is MIT/X11 licensed.

local is_contact_subscribed = require"core.rostermanager".is_contact_subscribed;
local jid_split = require"util.jid".split;
local jid_bare = require"util.jid".bare;
local jid_host = require"util.jid".host;
local st = require"util.stanza";
local datetime = require"util.datetime";
local cache = require "util.cache";

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

local bare_cache = {}; -- [username NUL bare_jid] = { [full_jid] = { timestamp, ... } }

local function on_evict(cache_key)
	local bare_cache_key = cache_key:match("^%Z+%z[^/]+");
	local full_jid = cache_key:match("%z(.*)$");
	local jids = bare_cache[bare_cache_key];

	if jids then
		jids[full_jid] = nil;
		if next(jids) == nil then
			bare_cache[bare_cache_key] = nil;
		end
	end
end

-- used indirectly for the on_evict callback
local presence_cache = cache.new(cache_size, on_evict);

local function cache_hook(event)
	local origin, stanza = event.origin, event.stanza;
	local typ = stanza.attr.type;
	module:log("debug", "Cache hook, got %s from a %s", stanza:top_tag(), origin.type);
	if origin.type == "s2sin" and ( typ == nil or typ == "unavailable" ) then

		local contact_full = stanza.attr.from;
		local contact_bare = jid_bare(contact_full);
		local username, host = jid_split(stanza.attr.to);

		if not is_contact_subscribed(username, host, contact_bare) then
			module:log("debug", "Presence from jid not in roster");
			return;
		end

		local cache_key = username .. "\0" .. contact_full;
		local bare_cache_key = username .. "\0" .. contact_bare;

		local jids = bare_cache[bare_cache_key];

		if typ == "unavailable" then -- remove from cache
			presence_cache:set(cache_key, nil);
			on_evict(cache_key);
			return;
		end

		local presence_bits = {
			stamp = datetime.datetime();
			show = stanza:get_child_text("show");
		};
		if jids then
			jids[contact_full] = presence_bits;
		else
			jids = { [contact_full] = presence_bits };
			bare_cache[bare_cache_key] = jids;
		end
		presence_cache:set(cache_key, true);
	end
end

module:hook("presence/bare", cache_hook, 10);
-- module:hook("presence/full", cache_hook, 10);

local function answer_probe_from_cache(event)
	local origin, stanza = event.origin, event.stanza;
	if stanza.attr.type ~= "probe" then return; end

	local username = origin.username;
	local contact_bare = stanza.attr.to;
	if not contact_bare then return; end -- probe to self

	local bare_cache_key = username .. "\0" .. contact_bare;

	local cached = bare_cache[bare_cache_key];
	if not cached then return end
	local user_bare = jid_bare(origin.full_jid);
	for jid, presence_bits in pairs(cached) do
		local presence = st.presence({ to = origin.full_jid, from = jid })
		if presence_bits.show then
			presence:tag("show"):text(presence_bits.show):up();
		end
		if presence_bits.stamp then
			presence:tag("delay", { xmlns = "urn:xmpp:delay", from = user_bare, stamp = presence_bits.stamp }):up();
		end
		origin.send(presence);
	end
end

module:hook("pre-presence/bare", answer_probe_from_cache, 10);

local function clear_cache_from_s2s(remote, reason)
	if not remote then return end
	-- FIXME Ignore if connection closed for being idle

	module:log("debug", "Dropping cached presence from host %s", remote);

	for bare, cached in pairs(bare_cache) do
		if jid_host(bare) == remote then
			for jid in pairs(cached) do
				presence_cache:set(jid, nil);
			end
			bare_cache[bare] = nil;
		end
	end
end

module:hook("s2sin-destroyed", function (event)
	return clear_cache_from_s2s(event.session.from_host, event.reason);
end);

module:hook("s2sout-destroyed", function (event)
	return clear_cache_from_s2s(event.session.to_host, event.reason);
end);