Initial work on adding support for XEP-0198

Updates #316

docs/source/configuration.rst

@@ -1288,6 +1288,15 @@ show_send_button
 
 If set to ``true``, a button will be visible which can be clicked to send a message.
 
+smacks_max_unacked_stanzas
+--------------------------
+
+* Default: ``5``
+
+This setting relates to `XEP-0198 <https://xmpp.org/extensions/xep-0198.html>`_
+and determines the number of stanzas to be sent before Converse will ask the
+server for acknowledgement of those stanzas.
+
 sounds_path
 -----------
 

src/headless/converse-disco.js

@@ -264,9 +264,9 @@ converse.plugins.add('converse-disco', {
                                 });
                             });
                     }
+                    _converse.emit('streamFeaturesAdded');
                 }
             });
-            _converse.emit('streamFeaturesAdded');
         }
 
         async function initializeDisco () {

src/headless/converse-smacks.js

@@ -0,0 +1,159 @@
+// Converse.js
+// http://conversejs.org
+//
+// Copyright (c) 2013-2018, the Converse.js developers
+// Licensed under the Mozilla Public License (MPLv2)
+
+/* This is a Converse.js plugin which add support for XEP-0198: Stream Management */
+
+import converse from "./converse-core";
+
+const { Strophe, $build, _ } = converse.env;
+Strophe.addNamespace('SM', 'urn:xmpp:sm:3');
+
+
+converse.plugins.add('converse-smacks', {
+
+    initialize () {
+        const { _converse } = this;
+
+        // Configuration values for this plugin
+        // ====================================
+        // Refer to docs/source/configuration.rst for explanations of these
+        // configuration settings.
+        _converse.api.settings.update({
+            'smacks_max_unacked_stanzas': 5,
+        });
+
+        function isStreamManagementSupported () {
+            return _converse.api.disco.stream.getFeature('sm', Strophe.NS.SM);
+        }
+
+        function handleAck (el) {
+            if (_converse.session.get('smacks_enabled')) {
+                const handled = parseInt(el.getAttribute('h'), 10),
+                      last_known_handled = _converse.session.get('num_stanzas_handled_by_server'),
+                      delta = handled - last_known_handled;
+
+                if (delta < 0) {
+                    return new Error(
+                        `New reported stanza count lower than previous. `+
+                        `New: ${handled} - Previous: ${last_known_handled}`
+                    );
+                }
+                const unacked_stanzas = _converse.session.get('unacked_stanzas');
+                if (delta > _converse.session.get('unacked_stanzas').length) {
+                    return new Error(
+                        `Higher reported acknowledge count than unacknowledged stanzas. `+
+                        `Reported Acknowledged Count: ${delta} -`+
+                        `Unacknowledged Stanza Count: ${unacked_stanzas.length} -`+
+                        `New: ${handled} - Previous: ${last_known_handled}`
+                    );
+                }
+                _converse.session.save({
+                    'num_stanzas_handled_by_server': handled,
+                    'num_stanzas_since_last_ack': 0,
+                    'unacked_stanzas': unacked_stanzas.slice(delta)
+                });
+            }
+            return true;
+        }
+
+        function sendAck() {
+            if (_converse.session.get('smacks_enabled')) {
+                converse.connection.send($build('a', {
+                    'xmlns': Strophe.NS.SM,
+                    'h': _converse.session.get('num_stanzas_handled')
+                }));
+            }
+            return true;
+        }
+
+        function requestAcknowledgement () {
+            _converse.session.set('num_stanzas_since_last_ack', 0);
+            _converse.connection.send($build('r', {'xmlns': Strophe.NS.SM}));
+        }
+
+        function stanzaHandler (el) {
+            if (_converse.session.get('smacks_enabled')) {
+                if (Strophe.isTagEqual(el, 'iq') || Strophe.isTagEqual(el, 'presence') || Strophe.isTagEqual(el, 'message'))  {
+                    const h = _converse.session.get('num_stanzas_handled');
+                    _converse.session.save('num_stanzas_handled', h+1);
+                }
+            }
+            return true;
+        }
+
+        function initSMACKS(el) {
+            let enabled;
+            if (Strophe.isTagEqual(el, 'failed')) {
+                enabled = false;
+                _converse.log('Failed to enable stream management', Strophe.LogLevel.ERROR);
+                _converse.log(el.outerHTML, Strophe.LogLevel.ERROR);
+            } else {
+                enabled = true;
+            }
+            _converse.session.save({
+                'smacks_enabled': enabled,
+                'num_stanzas_handled': 0,
+                'num_stanzas_handled_by_server': 0,
+                'num_stanzas_since_last_ack': 0,
+                'unacked_stanzas': []
+            });
+            _converse.connection.resume();
+            return true;
+        }
+
+        async function enable () {
+            if (!(await isStreamManagementSupported())) {
+                return;
+            }
+            _converse.connection.addHandler(stanzaHandler);
+            _converse.connection.addHandler(sendAck, Strophe.NS.SM, 'r');
+            _converse.connection.addHandler(handleAck, Strophe.NS.SM, 'a');
+            _converse.connection.addHandler(initSMACKS, Strophe.NS.SM, 'enabled');
+            _converse.connection.addHandler(initSMACKS, Strophe.NS.SM, 'failed');
+
+            _converse.session.save('stanzas_sent', 0);
+
+            const stanza = $build('enable', {
+                'xmlns': Strophe.NS.SM,
+                'resume': false
+            });
+            _converse.connection.send(stanza);
+            _converse.connection.flush();
+            _converse.connection.pause();
+        }
+
+
+        function onStanzaSent (el) {
+            if (_converse.session.get('smacks_enabled')) {
+                return;
+            }
+            for (let i = 0; i < el.children.length; i++) {
+                const child = el.children[i];
+                if (Strophe.isTagEqual(child, 'iq') ||
+                    Strophe.isTagEqual(child, 'presence') ||
+                    Strophe.isTagEqual(child, 'message')) {
+
+                    _converse.session.save(
+                        'unacked_stanzas',
+                        _converse.session.get('unacked_stanzas').concat([el])
+                    );
+                    if (_converse.smacks_max_unacked_stanzas > 0) {
+                        _converse.session.save(
+                            'num_stanzas_since_last_ack',
+                            _converse.session.get('num_stanzas_since_last_ack') + 1
+                        );
+                        if (_converse.session.get('num_stanzas_since_last_ack') === _converse.smacks_max_unacked_stanzas) {
+                            this.requestAcknowledgement();
+                        }
+                    }
+                }
+            }
+        }
+
+        _converse.api.listen.on('streamFeaturesAdded', enable);
+        _converse.api.listen.on('send', enable);
+    }
+});