Misc tidying

TODO

@@ -2,4 +2,4 @@
  * Emulate a UDP server in the UDP tracker tests.
  * Make use of sparse file regions in download data for faster hashing.
  * If we're choked and interested, we never send not-interested if there's nothing we want?
- * Perform announce as part of GetPeers, to reduce closest node calculation overhead, and wasting discarded nodes during the search.
+ * Don't announce torrents that don't need active peers. It spams UDP, fills memory, and publicizes what we have loaded.

client.go

@@ -759,6 +759,10 @@ type handshakeResult struct {
 	InfoHash
 }
 
+// ih is nil if we expect the peer to declare the InfoHash, such as when the
+// peer initiated the connection. Returns ok if the handshake was successful,
+// and err if there was an unexpected condition other than the peer simply
+// abandoning the handshake.
 func handshake(sock io.ReadWriteCloser, ih *InfoHash, peerID [20]byte) (res handshakeResult, ok bool, err error) {
 	// Bytes to be sent to the peer. Should never block the sender.
 	postCh := make(chan []byte, 4)
@@ -1839,7 +1843,7 @@ func (me *Client) addOrMergeTorrent(ih InfoHash, announceList [][]string) (T Tor
 	return
 }
 
-// Adds the torrent to the client.
+// Adds a torrent to the client.
 func (me *Client) AddTorrent(metaInfo *metainfo.MetaInfo) (t Torrent, err error) {
 	var ih InfoHash
 	CopyExact(&ih, metaInfo.Info.Hash)

testutil/testutil.go

@@ -20,10 +20,11 @@ const GreetingFileContents = "hello, world\n"
 func CreateDummyTorrentData(dirName string) string {
 	f, _ := os.Create(filepath.Join(dirName, "greeting"))
 	defer f.Close()
-	f.WriteString("hello, world\n")
+	f.WriteString(GreetingFileContents)
 	return f.Name()
 }
 
+// Writes to w, a metainfo containing the file at name.
 func CreateMetaInfo(name string, w io.Writer) {
 	builder := metainfo.Builder{}
 	builder.AddFile(name)