xmpp.chapril.org-conversejs/src/headless/converse-smacks.js
2020-05-18 10:54:37 +02:00

255 lines
10 KiB
JavaScript

/**
* @module converse-smacks
* @copyright The Converse.js contributors
* @license Mozilla Public License (MPLv2)
* @description Converse.js plugin which adds support for XEP-0198: Stream Management
*/
import { _converse, api, converse } from "./converse-core";
import log from "./log";
const { Strophe } = converse.env;
const u = converse.env.utils;
Strophe.addNamespace('SM', 'urn:xmpp:sm:3');
converse.plugins.add('converse-smacks', {
initialize () {
// Configuration values for this plugin
// ====================================
// Refer to docs/source/configuration.rst for explanations of these
// configuration settings.
api.settings.update({
'enable_smacks': true,
'smacks_max_unacked_stanzas': 5,
});
function isStreamManagementSupported () {
if (api.connection.isType('bosh') && !_converse.isTestEnv()) {
return false;
}
return api.disco.stream.getFeature('sm', Strophe.NS.SM);
}
function handleAck (el) {
if (!_converse.session.get('smacks_enabled')) {
return true;
}
const handled = parseInt(el.getAttribute('h'), 10);
const last_known_handled = _converse.session.get('num_stanzas_handled_by_server');
const delta = handled - last_known_handled;
if (delta < 0) {
const err_msg = `New reported stanza count lower than previous. `+
`New: ${handled} - Previous: ${last_known_handled}`
log.error(err_msg);
}
const unacked_stanzas = _converse.session.get('unacked_stanzas');
if (delta > unacked_stanzas.length) {
const err_msg =
`Higher reported acknowledge count than unacknowledged stanzas. `+
`Reported Acknowledged Count: ${delta} -`+
`Unacknowledged Stanza Count: ${unacked_stanzas.length} -`+
`New: ${handled} - Previous: ${last_known_handled}`
log.error(err_msg);
}
_converse.session.save({
'num_stanzas_handled_by_server': handled,
'num_stanzas_since_last_ack': 0,
'unacked_stanzas': unacked_stanzas.slice(delta)
});
return true;
}
function sendAck() {
if (_converse.session.get('smacks_enabled')) {
const h = _converse.session.get('num_stanzas_handled');
const stanza = u.toStanza(`<a xmlns="${Strophe.NS.SM}" h="${h}"/>`);
api.send(stanza);
}
return true;
}
function stanzaHandler (el) {
if (_converse.session.get('smacks_enabled')) {
if (u.isTagEqual(el, 'iq') || u.isTagEqual(el, 'presence') || u.isTagEqual(el, 'message')) {
const h = _converse.session.get('num_stanzas_handled');
_converse.session.save('num_stanzas_handled', h+1);
}
}
return true;
}
function initSessionData () {
_converse.session.save({
'smacks_enabled': _converse.session.get('smacks_enabled') || false,
'num_stanzas_handled': _converse.session.get('num_stanzas_handled') || 0,
'num_stanzas_handled_by_server': _converse.session.get('num_stanzas_handled_by_server') || 0,
'num_stanzas_since_last_ack': _converse.session.get('num_stanzas_since_last_ack') || 0,
'unacked_stanzas': _converse.session.get('unacked_stanzas') || []
});
}
function resetSessionData () {
_converse.session && _converse.session.save({
'smacks_enabled': false,
'num_stanzas_handled': 0,
'num_stanzas_handled_by_server': 0,
'num_stanzas_since_last_ack': 0,
'unacked_stanzas': []
});
}
function saveSessionData (el) {
const data = {'smacks_enabled': true};
if (['1', 'true'].includes(el.getAttribute('resume'))) {
data['smacks_stream_id'] = el.getAttribute('id');
}
_converse.session.save(data);
return true;
}
function onFailedStanza (el) {
if (el.querySelector('item-not-found')) {
// Stream resumption must happen before resource binding but
// enabling a new stream must happen after resource binding.
// Since resumption failed, we simply continue.
//
// After resource binding, sendEnableStanza will be called
// based on the afterResourceBinding event.
log.warn('Could not resume previous SMACKS session, session id not found. '+
'A new session will be established.');
} else {
log.error('Failed to enable stream management');
log.error(el.outerHTML);
}
resetSessionData();
/**
* Triggered when the XEP-0198 stream could not be resumed.
* @event _converse#streamResumptionFailed
*/
api.trigger('streamResumptionFailed');
return true;
}
function resendUnackedStanzas () {
const stanzas = _converse.session.get('unacked_stanzas');
// We clear the unacked_stanzas array because it'll get populated
// again in `onStanzaSent`
_converse.session.save('unacked_stanzas', []);
// XXX: Currently we're resending *all* unacked stanzas, including
// IQ[type="get"] stanzas that longer have handlers (because the
// page reloaded or we reconnected, causing removal of handlers).
//
// *Side-note:* Is it necessary to clear handlers upon reconnection?
//
// I've considered not resending those stanzas, but then keeping
// track of what's been sent and ack'd and their order gets
// prohibitively complex.
//
// It's unclear how much of a problem this poses.
//
// Two possible solutions are running @converse/headless as a
// service worker or handling IQ[type="result"] stanzas
// differently, more like push stanzas, so that they don't need
// explicit handlers.
stanzas.forEach(s => api.send(s));
}
function onResumedStanza (el) {
saveSessionData(el);
handleAck(el);
resendUnackedStanzas();
_converse.connection.do_bind = false; // No need to bind our resource anymore
_converse.connection.authenticated = true;
_converse.connection.restored = true;
_converse.connection._changeConnectStatus(Strophe.Status.CONNECTED, null);
}
async function sendResumeStanza () {
const promise = u.getResolveablePromise();
_converse.connection._addSysHandler(el => promise.resolve(onResumedStanza(el)), Strophe.NS.SM, 'resumed');
_converse.connection._addSysHandler(el => promise.resolve(onFailedStanza(el)), Strophe.NS.SM, 'failed');
const previous_id = _converse.session.get('smacks_stream_id');
const h = _converse.session.get('num_stanzas_handled');
const stanza = u.toStanza(`<resume xmlns="${Strophe.NS.SM}" h="${h}" previd="${previous_id}"/>`);
api.send(stanza);
_converse.connection.flush();
await promise;
}
async function sendEnableStanza () {
if (!api.settings.get('enable_smacks') || _converse.session.get('smacks_enabled')) {
return;
}
if (await isStreamManagementSupported()) {
const promise = u.getResolveablePromise();
_converse.connection._addSysHandler(el => promise.resolve(saveSessionData(el)), Strophe.NS.SM, 'enabled');
_converse.connection._addSysHandler(el => promise.resolve(onFailedStanza(el)), Strophe.NS.SM, 'failed');
const resume = (api.connection.isType('websocket') || _converse.isTestEnv());
const stanza = u.toStanza(`<enable xmlns="${Strophe.NS.SM}" resume="${resume}"/>`);
api.send(stanza);
_converse.connection.flush();
await promise;
}
}
async function enableStreamManagement () {
if (!api.settings.get('enable_smacks')) {
return;
}
if (!(await isStreamManagementSupported())) {
return;
}
_converse.connection.addHandler(stanzaHandler);
_converse.connection.addHandler(sendAck, Strophe.NS.SM, 'r');
_converse.connection.addHandler(handleAck, Strophe.NS.SM, 'a');
if (_converse.session.get('smacks_stream_id')) {
await sendResumeStanza();
} else {
resetSessionData();
}
}
function onStanzaSent (stanza) {
if (!_converse.session) {
log.warn('No _converse.session!');
return;
}
if (!_converse.session.get('smacks_enabled')) {
return;
}
if (u.isTagEqual(stanza, 'iq') ||
u.isTagEqual(stanza, 'presence') ||
u.isTagEqual(stanza, 'message')) {
const stanza_string = Strophe.serialize(stanza);
_converse.session.save(
'unacked_stanzas',
(_converse.session.get('unacked_stanzas') || []).concat([stanza_string])
);
const max_unacked = api.settings.get('smacks_max_unacked_stanzas');
if (max_unacked > 0) {
const num = _converse.session.get('num_stanzas_since_last_ack') + 1;
if (num % max_unacked === 0) {
// Request confirmation of sent stanzas
api.send(u.toStanza(`<r xmlns="${Strophe.NS.SM}"/>`));
}
_converse.session.save({'num_stanzas_since_last_ack': num});
}
}
}
api.listen.on('userSessionInitialized', initSessionData);
api.listen.on('beforeResourceBinding', enableStreamManagement);
api.listen.on('afterResourceBinding', sendEnableStanza);
api.listen.on('send', onStanzaSent);
}
});