aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_csi_simple.lua
blob: fb3d80c553d93739323a6baa954197734f03670a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
-- Copyright (C) 2016-2020 Kim Alvefur
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

module:depends"csi"

local jid = require "util.jid";
local st = require "util.stanza";
local dt = require "util.datetime";
local filters = require "util.filters";

local queue_size = module:get_option_number("csi_queue_size", 256);

local important_payloads = module:get_option_set("csi_important_payloads", { });

function is_important(stanza) --> boolean, reason: string
	if not st.is_stanza(stanza) then
		-- whitespace pings etc
		return true;
	end
	if stanza.attr.xmlns ~= nil then
		-- stream errors, stream management etc
		return true, "nonza";
	end
	local st_name = stanza.name;
	if not st_name then return false; end
	local st_type = stanza.attr.type;
	if st_name == "presence" then
		if st_type == nil or st_type == "unavailable" or st_type == "error" then
			return false, "presence update";
		end
		-- TODO Some MUC awareness, e.g. check for the 'this relates to you' status code
		return true, "subscription request";
	elseif st_name == "message" then
		if st_type == "headline" then
			-- Headline messages are ephemeral by definition
			return false, "headline";
		end
		if st_type == "error" then
			return true, "delivery failure";
		end
		if stanza:get_child("sent", "urn:xmpp:carbons:2") then
			return true, "carbon";
		end
		local forwarded = stanza:find("{urn:xmpp:carbons:2}received/{urn:xmpp:forward:0}/{jabber:client}message");
		if forwarded then
			stanza = forwarded;
		end
		if stanza:get_child("body") then
			return true, "body";
		end
		if stanza:get_child("subject") then
			-- Last step of a MUC join
			return true, "subject";
		end
		if stanza:get_child("encryption", "urn:xmpp:eme:0") then
			-- Since we can't know what an encrypted message contains, we assume it's important
			-- XXX Experimental XEP
			return true, "encrypted";
		end
		if stanza:get_child("x", "jabber:x:conference") or stanza:find("{http://jabber.org/protocol/muc#user}x/invite") then
			return true, "invite";
		end
		if stanza:get_child(nil, "urn:xmpp:jingle-message:0") then
			-- XXX Experimental XEP stuck in Proposed for almost a year at the time of this comment
			return true, "jingle call";
		end
		for important in important_payloads do
			if stanza:find(important) then
				return true;
			end
		end
		return false;
	elseif st_name == "iq" then
		return true;
	end
end

module:hook("csi-is-stanza-important", function (event)
	local important, why = is_important(event.stanza);
	event.reason = why;
	return important;
end, -1);

local function should_flush(stanza, session, ctr) --> boolean, reason: string
	if ctr >= queue_size then
		return true, "queue size limit reached";
	end
	local event = { stanza = stanza, session = session };
	local ret = module:fire_event("csi-is-stanza-important", event)
	return ret, event.reason;
end

local function with_timestamp(stanza, from)
	if st.is_stanza(stanza) and stanza.attr.xmlns == nil and stanza.name ~= "iq" then
		stanza = st.clone(stanza);
		stanza:add_direct_child(st.stanza("delay", {xmlns = "urn:xmpp:delay", from = from, stamp = dt.datetime()}));
	end
	return stanza;
end

local function manage_buffer(stanza, session)
	local ctr = session.csi_counter or 0;
	local flush, why = should_flush(stanza, session, ctr);
	if flush then
		session.log("debug", "Flushing buffer (%s; queue size is %d)", why or "important", session.csi_counter);
		session.conn:resume_writes();
	else
		session.log("debug", "Holding buffer (%s; queue size is %d)", why or "unimportant", session.csi_counter);
		stanza = with_timestamp(stanza, jid.join(session.username, session.host))
	end
	session.csi_counter = ctr + 1;
	return stanza;
end

local function flush_buffer(data, session)
	session.log("debug", "Client sent something, flushing buffer once (queue size is %d)", session.csi_counter);
	session.conn:resume_writes();
	return data;
end

function enable_optimizations(session)
	if session.conn and session.conn.pause_writes then
		session.conn:pause_writes();
		filters.add_filter(session, "stanzas/out", manage_buffer);
		filters.add_filter(session, "bytes/in", flush_buffer);
	else
		session.log("warn", "Session connection does not support write pausing");
	end
end

function disable_optimizations(session)
	filters.remove_filter(session, "stanzas/out", manage_buffer);
	filters.remove_filter(session, "bytes/in", flush_buffer);
	session.csi_counter = nil;
	if session.conn and session.conn.resume_writes then
		session.conn:resume_writes();
	end
end

module:hook("csi-client-inactive", function (event)
	local session = event.origin;
	enable_optimizations(session);
end);

module:hook("csi-client-active", function (event)
	local session = event.origin;
	disable_optimizations(session);
end);

module:hook("pre-resource-unbind", function (event)
	local session = event.session;
	disable_optimizations(session);
end, 1);

module:hook("c2s-ondrain", function (event)
	local session = event.session;
	if session.state == "inactive" and session.conn and session.conn.pause_writes then
		session.conn:pause_writes();
		session.log("debug", "Buffer flushed, resuming inactive mode (queue size was %d)", session.csi_counter);
		session.csi_counter = 0;
	end
end);

function module.load()
	for _, user_session in pairs(prosody.hosts[module.host].sessions) do
		for _, session in pairs(user_session.sessions) do
			if session.state == "inactive" then
				enable_optimizations(session);
			end
		end
	end
end

function module.unload()
	for _, user_session in pairs(prosody.hosts[module.host].sessions) do
		for _, session in pairs(user_session.sessions) do
			if session.state == "inactive" then
				disable_optimizations(session);
			end
		end
	end
end