Add support for peer-to-peer DBus

Author: oleavr

index.js

@@ -41,6 +41,16 @@ module.exports.sessionBus = function(opts) {
   return createClient(opts);
 };
 
+/**
+ * Create a new {@link MessageBus} client to communicate peer-to-peer.
+ *
+ * @param {object} [stream] - Duplex stream for communication.
+ * @param {object} [options] - Options for `MessageBus` creation.
+ */
+module.exports.peerBus = function(stream, opts) {
+  return createClient(Object.assign({}, opts, { stream }));
+};
+
 /**
  * Use JSBI as a polyfill for long integer types ('x' and 't') in the client
  * and the service. This is required for Node verisons that do not support the

lib/bus.js

@@ -74,7 +74,7 @@ class MessageBus extends EventEmitter {
 
     /**
      * The unique name of the bus connection. This will be `null` until the
-     * `MessageBus` is connected.
+     * `MessageBus` is connected, unless we're operating in peer-to-peer mode.
      * @memberof MessageBus#
      * @member {string} name
      */
@@ -159,22 +159,28 @@ class MessageBus extends EventEmitter {
       this.emit('error', err);
     });
 
-    const helloMessage = new Message({
-      path: '/org/freedesktop/DBus',
-      destination: 'org.freedesktop.DBus',
-      interface: 'org.freedesktop.DBus',
-      member: 'Hello'
-    });
-
-    this.call(helloMessage)
-      .then((msg) => {
-        this.name = msg.body[0];
+    if (conn.mode === 'p2p') {
+      process.nextTick(() => {
         this.emit('connect');
-      })
-      .catch((err) => {
-        this.emit('error', err);
-        throw new Error(err);
       });
+    } else {
+      const helloMessage = new Message({
+        path: '/org/freedesktop/DBus',
+        destination: 'org.freedesktop.DBus',
+        interface: 'org.freedesktop.DBus',
+        member: 'Hello'
+      });
+
+      this.call(helloMessage)
+        .then((msg) => {
+          this.name = msg.body[0];
+          this.emit('connect');
+        })
+        .catch((err) => {
+          this.emit('error', err);
+          throw new Error(err);
+        });
+    }
   }
 
   /**
@@ -468,6 +474,10 @@ class MessageBus extends EventEmitter {
 
     this._matchRules[match] = 1;
 
+    if (this._connection.mode === 'p2p') {
+      return Promise.resolve();
+    }
+
     // TODO catch error and update refcount
     const msg = new Message({
       path: '/org/freedesktop/DBus',
@@ -496,6 +506,10 @@ class MessageBus extends EventEmitter {
 
     delete this._matchRules[match];
 
+    if (this._connection.mode === 'p2p') {
+      return Promise.resolve();
+    }
+
     // TODO catch error and update refcount
     const msg = new Message({
       path: '/org/freedesktop/DBus',

lib/connection.js

@@ -90,8 +90,15 @@ function createStream (opts) {
 function createConnection (opts) {
   const self = new EventEmitter();
   opts = opts || {};
-  const stream = (self.stream = createStream(opts));
-  stream.setNoDelay && stream.setNoDelay();
+  let { stream } = opts;
+  if (stream) {
+    self.mode = 'p2p';
+  } else {
+    self.mode = 'bus';
+    stream = createStream(opts);
+    stream.setNoDelay && stream.setNoDelay();
+  }
+  self.stream = stream;
 
   stream.on('error', function (err) {
     // forward network and stream errors

types.d.ts

@@ -1,6 +1,7 @@
 
 declare module 'dbus-next' {
     import { EventEmitter } from "events";
+    import { Duplex } from "stream";
 
     export type ObjectPath = string;
     export type PropertyAccess = "read" | "write" | "readwrite";
@@ -142,4 +143,5 @@ declare module 'dbus-next' {
     export function setBigIntCompat(state: boolean): void;
     export function systemBus(): MessageBus;
     export function sessionBus(options?: BusOptions): MessageBus;
+    export function peerBus(stream: Duplex, options?: BusOptions): MessageBus;
 }