support opaque user data (hypercore-protocol#13)

Author: scriptjs

README.md

@@ -37,6 +37,7 @@ Options include:
 {
   id: optionalPeerId, // you can use this to detect if you connect to yourself
   live: keepStreamOpen, // signal to the other peer that you want to keep this stream open forever
+  userData: opaqueUserData // include user data that you can retrieve on handshake
   encrypt: true, // set to false to disable encryption if you are already piping through a encrypted stream
   timeout: 5000 // stream timeout. set to 0 or false to disable.
 }
@@ -54,7 +55,7 @@ should be the same one. The key of the first feed is also used to encrypt the st
 
 #### `stream.on('handshake')`
 
-Emitted when a protocol handshake has been received. Afterwards you can check `.remoteId` to get the remote peer id and `.remoteLive` to get their live status.
+Emitted when a protocol handshake has been received. Afterwards you can check `.remoteId` to get the remote peer id, `.remoteLive` to get its live status, or `.remoteUserData` to get its user data.
 
 #### `stream.on('feed', discoveryKey)`
 

index.js

@@ -15,8 +15,10 @@ function Protocol (opts) {
 
   this.id = opts.id || randomBytes(32)
   this.live = !!opts.live
+  this.userData = opts.userData || null
   this.remoteId = null
   this.remoteLive = false
+  this.remoteUserData = null
 
   this.destroyed = false
   this.encrypted = opts.encrypt !== false
@@ -129,7 +131,7 @@ Protocol.prototype.feed = function (key, opts) {
   if (this.destroyed) return null
 
   if (first) {
-    ch.handshake({id: this.id, live: this.live})
+    ch.handshake({id: this.id, live: this.live, userData: this.userData})
   }
 
   if (ch._buffer.length) ch._resume()
@@ -235,6 +237,7 @@ Protocol.prototype._onhandshake = function (handshake) {
   if (this.remoteId) return
   this.remoteId = handshake.id || randomBytes(32)
   this.remoteLive = handshake.live
+  this.remoteUserData = handshake.userData
   this.emit('handshake')
 }
 

schema.proto

@@ -11,6 +11,7 @@ message Feed {
 message Handshake {
   optional bytes id = 1;
   optional bool live = 2; // keep the connection open forever? both ends have to agree
+  optional bytes userData = 3;
 }
 
 // type=2, message indicating state changes etc.

test.js

@@ -26,9 +26,14 @@ tape('basic', function (t) {
 })
 
 tape('basic with handshake options', function (t) {
-  t.plan(8)
+  t.plan(12)
 
-  var a = protocol({id: new Buffer('a'), live: true})
+  var data = [
+    'eeaa62fbb11ba521cce58cf3fae42deb15d94a0436fc7fa0cbba8f130e7c0499',
+    '8c797667bf307d82c51a8308fe477b781a13708e0ec1f2cc7f497392574e2464'
+  ]
+
+  var a = protocol({id: new Buffer('a'), live: true, userData: new Buffer(data)})
   var b = protocol({id: new Buffer('b'), live: false})
 
   a.feed(KEY)
@@ -37,15 +42,19 @@ tape('basic with handshake options', function (t) {
   a.once('handshake', function () {
     t.same(a.id, new Buffer('a'))
     t.same(a.live, true)
+    t.same(a.userData, new Buffer(data))
     t.same(a.remoteId, new Buffer('b'))
     t.same(a.remoteLive, false)
+    t.same(a.remoteUserData, null)
   })
 
   b.once('handshake', function () {
     t.same(b.id, new Buffer('b'))
     t.same(b.live, false)
+    t.same(b.userData, null)
     t.same(b.remoteId, new Buffer('a'))
     t.same(b.remoteLive, true)
+    t.same(b.remoteUserData, new Buffer(data))
   })
 
   a.pipe(b).pipe(a)