API fixes

lib/messages.js

@@ -23,9 +23,9 @@ exports.version = {
   NONCE: new Buffer("20bde0a3355dad78", "hex"),
 
   /**
-   * Decode `version` payload.
+   * Decode `version` message payload.
    * NOTE: `nonce` is copied.
-   * @param {Buffer} buf - `version` payload
+   * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `version` structure.
    */
   decode: function(buf) {
@@ -60,9 +60,9 @@ exports.version = {
   },
 
   /**
-   * Encode `version` payload.
+   * Encode `version` message payload.
    * @param {Object} opts - Version options
-   * @return {Buffer} Encoded `version` payload.
+   * @return {Buffer} Encoded payload.
    */
   encode: function(opts) {
     // Deal with default options.
@@ -107,8 +107,8 @@ exports.version = {
  */
 exports.addr = {
   /**
-   * Decode `addr` payload.
-   * @param {Buffer} buf - `addr` payload
+   * Decode `addr` message payload.
+   * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `addr` structure.
    */
   decode: function(buf) {
@@ -130,9 +130,9 @@ exports.addr = {
   },
 
   /**
-   * Encode `addr` payload.
+   * Encode `addr` message payload.
    * @param {Object[]} addrs - Network addresses
-   * @return {Buffer} Encoded `addr` payload.
+   * @return {Buffer} Encoded payload.
    */
   encode: function(addrs) {
     assert(addrs.length <= 1000, "Too many address entires");
@@ -150,8 +150,8 @@ exports.addr = {
  */
 var inv = exports.inv = {
   /**
-   * Decode `inv` payload.
-   * @param {Buffer} buf - `inv` payload
+   * Decode `inv` message payload.
+   * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `inv` structure.
    */
   decode: function(buf) {
@@ -173,9 +173,9 @@ var inv = exports.inv = {
   },
 
   /**
-   * Encode `inv` payload.
+   * Encode `inv` message payload.
    * @param {Buffer[]} inventory - Inventory vector list (encoded)
-   * @return {Buffer} Encoded `inv` payload.
+   * @return {Buffer} Encoded payload.
    */
   encode: function(inventory) {
     assert(inventory.length <= 50000, "Too many inventory entires");
@@ -216,8 +216,8 @@ var error = exports.error = {
   FATAL: 2,
 
   /**
-   * Decode `error` payload.
-   * @param {Buffer} buf - `error` payload
+   * Decode `error` message payload.
+   * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `error` structure.
    */
   decode: function(buf) {
@@ -243,9 +243,9 @@ var error = exports.error = {
   },
 
   /**
-   * Encode `error` payload.
+   * Encode `error` message payload.
    * @param {Object} opts - Error options
-   * @return {Buffer} Encoded `error` payload.
+   * @return {Buffer} Encoded payload.
    */
   encode: function(opts) {
     var fatal = opts.fatal || error.WARNING;
@@ -265,44 +265,66 @@ var error = exports.error = {
  * `object` message. An `object` is a message which is shared throughout
  * a stream. It is the only message which propagates; all others are
  * only between two nodes.  
+ * NOTE: You shouldn't use `encode` and `decode` methods directly.
+ * Instead, get type of the object and encode/decode it with appropriate
+ * function from `objects` module.
  * @see {@link https://bitmessage.org/wiki/Protocol_specification#object}
  * @namespace
  */
 exports.object = {
+  // Known types.
+  GETPUBKEY: 0,
+  PUBKEY: 1,
+  MSG: 2,
+  BROADCAST: 3,
+
   /**
-   * Decode `object` payload.
-   * NOTE: `nonce` and `payload` are copied.
-   * @param {Buffer} buf - `object` payload
+   * Returns type of the `object` message if we can parse it. Per spec
+   * we should still relay unknown objects.
+   * @param {Buffer} buf - Message payload
+   * @return {?number} Object type.
+   */
+  getType: function(buf) {
+    // Per v3 spec object starts with nonce (8 bytes), expiresTime (8
+    // bytes) and objectType (4 bytes). So we need only first 20 bytes
+    // to read the type.
+    if (buf.length >= 20) {
+      return buf.readUInt32BE(16, true);
+    }
+  },
+
+  /**
+   * Decode `object` message payload.
+   * NOTE: `nonce` is copied, `payload` references input buffer.
+   * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `object` structure.
    */
   decode: function(buf) {
     // 8 + 8 + 4 + (1+) + (1+)
-    assert(buf.length >= 22, "Buffer is too small");
+    assert(buf.length >= 22, "object message payload is too small");
     var nonce = new Buffer(8);
     buf.copy(nonce, 0, 0, 8);
     var expiresTime = util.readTimestamp64BE(buf.slice(8, 16));
     var ttl = expiresTime - util.tnow();
     assert(ttl >= -3600, "Object expired more than a hour ago");
     assert(ttl <= 2430000, "expiresTime is too far in the future");
-    var type = buf.readUInt32BE(16);
+    var type = buf.readUInt32BE(16, true);
     var decodedVersion = structs.var_int.decode(buf.slice(20));
     var decodedStream = structs.var_int.decode(decodedVersion.rest);
-    var payload = new Buffer(decodedStream.rest.length);
-    decodedStream.rest.copy(payload);
     return {
       nonce: nonce,
       ttl: ttl,
       type: type,
       version: decodedVersion.value,
       stream: decodedStream.value,
-      payload: payload,
+      payload: decodedStream.rest,
     };
   },
 
   /**
-   * Encode `object` payload.
+   * Encode `object` message payload.
    * @param {Object} opts - Object options
-   * @return {Buffer} Encoded `object` payload.
+   * @return {Buffer} Encoded payload.
    */
   encode: function(opts) {
     assert(opts.nonce.length === 8, "Bad nonce");

test.js

@@ -410,6 +410,18 @@ describe("Message types", function() {
         payload: Buffer("test"),
       })).to.throw(Error);
     });
+
+    it("should return type of the object", function() {
+      var encoded = object.encode({
+        nonce: Buffer(8),
+        ttl: 100,
+        type: object.BROADCAST,
+        version: 1,
+        payload: Buffer("test"),
+      });
+      expect(object.getType(encoded)).to.equal(3);
+      expect(object.decode(encoded).type).to.equal(3);
+    });
   });
 });