-- Copyright (C) 2016 Kim Alvefur
-- Copyright (C) 2017 Thilo Molitor
--
local filter_muc = module:get_option_boolean("csi_battery_saver_filter_muc", false);
local queue_size = module:get_option_number("csi_battery_saver_queue_size", 256);
module:depends"csi"
if filter_muc then module:depends"track_muc_joins"; end -- only depend on this module if we actually use it
local s_match = string.match;
local s_sub = string.sub;
local jid = require "util.jid";
local new_queue = require "util.queue".new;
local datetime = require "util.datetime";
local st = require "util.stanza";
local xmlns_delay = "urn:xmpp:delay";
-- a log id for this module instance
local id = s_sub(require "util.hashes".sha256(datetime.datetime(), true), 1, 4);
-- Returns a forwarded message, and either "in" or "out" depending on the direction
-- Returns nil if the message is not a carbon
local function extract_carbon(stanza)
local carbon = stanza:child_with_ns("urn:xmpp:carbons:2") or stanza:child_with_ns("urn:xmpp:carbons:1");
if not carbon then return; end
local direction = carbon.name == "sent" and "out" or "in";
local forward = carbon:get_child("forwarded", "urn:xmpp:forward:0");
local message = forward and forward:child_with_name("message") or nil;
if not message then return; end
return message, direction;
end
local function new_pump(session, output, ...)
-- luacheck: ignore 212/self
local q = new_queue(...);
local flush = true;
function q:pause()
flush = false;
end
function q:resume()
flush = true;
return q:flush();
end
local push = q.push;
function q:push(item)
local ok = push(self, item);
if not ok then
session.log("debug", "mod_csi_battery_saver(%s): Queue full (%d items), forcing flush...", id, q:count());
q:flush();
output(item, self);
elseif flush then
return q:flush();
end
return true;
end
function q:flush(alternative_output)
local out = alternative_output or output;
local item = self:pop();
while item do
out(item, self);
item = self:pop();
end
return true;
end
return q;
end
local function is_stamp_needed(stanza, session)
local st_name = stanza and stanza.name or nil;
if st_name == "presence" then
return true;
elseif st_name == "message" then
if stanza:get_child("delay", xmlns_delay) then return false; end
if stanza.attr.type == "chat" or stanza.attr.type == "groupchat" then return true; end
end
return false;
end
local function add_stamp(stanza, session)
local bare_jid = jid.bare(session.full_jid or session.host);
stanza = stanza:tag("delay", { xmlns = xmlns_delay, from = bare_jid, stamp = datetime.datetime()});
return stanza;
end
local function is_important(stanza, session)
local st_name = stanza and stanza.name or nil;
if not st_name then return true; end -- nonzas are always important
if st_name == "presence" then
-- TODO check for MUC status codes?
return false;
elseif st_name == "message" then
-- unpack carbon copies
local carbon, stanza_direction = extract_carbon(stanza);
--session.log("debug", "mod_csi_battery_saver(%s): stanza_direction = %s, carbon = %s, stanza = %s", id, stanza_direction, carbon and "true" or "false", tostring(stanza));
if carbon then stanza = carbon; end
local st_type = stanza.attr.type;
-- headline message are always not important
if st_type == "headline" then return false; end
-- chat markers (XEP-0333) are important, too, because some clients use them to update their notifications
if stanza:child_with_ns("urn:xmpp:chat-markers:0") then return true; end;
-- carbon copied outgoing messages are important (some clients update their notifications upon receiving those) --> don't return false here
--if carbon and stanza_direction == "out" then return false; end
-- We can't check for body contents in encrypted messages, so let's treat them as important
-- Some clients don't even set a body or an empty body for encrypted messages
-- check omemo https://xmpp.org/extensions/inbox/omemo.html
if stanza:get_child("encrypted", "eu.siacs.conversations.axolotl") or stanza:get_child("encrypted", "urn:xmpp:omemo:0") then return true; end
-- check xep27 pgp https://xmpp.org/extensions/xep-0027.html
if stanza:get_child("x", "jabber:x:encrypted") then return true; end
-- check xep373 pgp (OX) https://xmpp.org/extensions/xep-0373.html
if stanza:get_child("openpgp", "urn:xmpp:openpgp:0") then return true; end
-- check eme
if stanza:get_child("encryption", "urn:xmpp:eme:0") then return true; end
local body = stanza:get_child_text("body");
if st_type == "groupchat" then
if stanza:get_child_text("subject") then return true; end
if body == nil or body == "" then return false; end
-- body contains text, let's see if we want to process it further
if not filter_muc then -- default case
local stanza_important = module:fire_event("csi-is-stanza-important", { stanza = stanza, session = session });
if stanza_important ~= nil then return stanza_important; end
return true; -- deemed unknown/high priority by mod_csi_muc_priorities or some other module
else
if body:find(session.username, 1, true) then return true; end
local rooms = session.rooms_joined;
if not rooms then return false; end
local room_nick = rooms[jid.bare(stanza_direction == "in" and stanza.attr.from or stanza.attr.to)];
if room_nick and body:find(room_nick, 1, true) then return true; end
return false;
end
end
return body ~= nil and body ~= "";
end
return true;
end
module:hook("csi-client-inactive", function (event)
local session = event.origin;
if session.pump then
session.log("debug", "mod_csi_battery_saver(%s): Client is inactive, buffering unimportant outgoing stanzas", id);
session.pump:pause();
else
session.log("debug", "mod_csi_battery_saver(%s): Client is inactive the first time, initializing module for this session", id);
local pump = new_pump(session, session.send, queue_size);
pump:pause();
session.pump = pump;
session._pump_orig_send = session.send;
function session.send(stanza)
session.log("debug", "mod_csi_battery_saver(%s): Got outgoing stanza: <%s>", id, tostring(stanza.name or stanza));
local important = is_important(stanza, session);
-- clone stanzas before adding delay stamp and putting them into the queue
if st.is_stanza(stanza) then stanza = st.clone(stanza); end
-- add delay stamp to unimportant (buffered) stanzas that can/need be stamped
if not important and is_stamp_needed(stanza, session) then stanza = add_stamp(stanza, session); end
-- add stanza to outgoing queue and flush the buffer if needed
pump:push(stanza);
if important then
session.log("debug", "mod_csi_battery_saver(%s): Encountered important stanza, flushing buffer: <%s>", id, tostring(stanza.name or stanza));
pump:flush();
end
return true;
end
end
end);
module:hook("csi-client-active", function (event)
local session = event.origin;
if session.pump then
session.log("debug", "mod_csi_battery_saver(%s): Client is active, resuming direct delivery", id);
session.pump:resume();
end
end);
-- clean up this session on hibernation end
-- but don't change resumed.send(), it is already overwritten with session.send() by the smacks module
module:hook("smacks-hibernation-end", function (event)
local session = event.resumed;
if session.pump then
session.log("debug", "mod_csi_battery_saver(%s): Hibernation ended, flushing buffer and afterwards disabling for this session", id);
session.pump:flush(session.send); -- use the fresh session.send() introduced by the smacks resume
-- don't reset session.send() because this is not the send previously overwritten by this module, but a fresh one
-- session.send = session._pump_orig_send;
session.pump = nil;
session._pump_orig_send = nil;
end
end, 1000); -- high priority to prevent message reordering on resumption (we want to flush our buffers *first*)
function module.unload()
module:log("info", "%s: Unloading module, flushing all buffers", id);
local host_sessions = prosody.hosts[module.host].sessions;
for _, user in pairs(host_sessions) do
for _, session in pairs(user.sessions) do
if session.pump then
session.log("debug", "mod_csi_battery_saver(%s): Flushing buffer and restoring to original session.send()", id);
session.pump:flush();
session.send = session._pump_orig_send;
session.pump = nil;
session._pump_orig_send = nil;
end
end
end
end
module:log("info", "%s: Successfully loaded module", id);