The Great Rewrite (fixes #36, #61, #94, #101)

Rewrite of the file model and pulling mechanism. Needs lots of cleanup
and bugfixes, now...

protocol/protocol.go

@@ -46,16 +46,24 @@ type Model interface {
 	Close(nodeID string, err error)
 }
 
-type Connection struct {
+type Connection interface {
+	ID() string
+	Index(string, []FileInfo)
+	Request(repo, name string, offset int64, size int) ([]byte, error)
+	Statistics() Statistics
+	Option(key string) string
+}
+
+type rawConnection struct {
 	sync.RWMutex
 
 	id          string
 	receiver    Model
-	reader      io.Reader
+	reader      io.ReadCloser
 	xr          *xdr.Reader
-	writer      io.Writer
+	writer      io.WriteCloser
 	xw          *xdr.Writer
-	closed      bool
+	closed      chan struct{}
 	awaiting    map[int]chan asyncResult
 	nextID      int
 	indexSent   map[string]map[string][2]int64
@@ -79,20 +87,21 @@ const (
 	pingIdleTime = 5 * time.Minute
 )
 
-func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver Model, options map[string]string) *Connection {
+func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver Model, options map[string]string) Connection {
 	flrd := flate.NewReader(reader)
 	flwr, err := flate.NewWriter(writer, flate.BestSpeed)
 	if err != nil {
 		panic(err)
 	}
 
-	c := Connection{
+	c := rawConnection{
 		id:        nodeID,
-		receiver:  receiver,
+		receiver:  nativeModel{receiver},
 		reader:    flrd,
 		xr:        xdr.NewReader(flrd),
 		writer:    flwr,
 		xw:        xdr.NewWriter(flwr),
+		closed:    make(chan struct{}),
 		awaiting:  make(map[int]chan asyncResult),
 		indexSent: make(map[string]map[string][2]int64),
 	}
@@ -122,16 +131,20 @@ func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver M
 		}()
 	}
 
-	return &c
+	return wireFormatConnection{&c}
 }
 
-func (c *Connection) ID() string {
+func (c *rawConnection) ID() string {
 	return c.id
 }
 
 // Index writes the list of file information to the connected peer node
-func (c *Connection) Index(repo string, idx []FileInfo) {
+func (c *rawConnection) Index(repo string, idx []FileInfo) {
 	c.Lock()
+	if c.isClosed() {
+		c.Unlock()
+		return
+	}
 	var msgType int
 	if c.indexSent[repo] == nil {
 		// This is the first time we send an index.
@@ -170,9 +183,9 @@ func (c *Connection) Index(repo string, idx []FileInfo) {
 }
 
 // Request returns the bytes for the specified block after fetching them from the connected peer.
-func (c *Connection) Request(repo string, name string, offset int64, size int) ([]byte, error) {
+func (c *rawConnection) Request(repo string, name string, offset int64, size int) ([]byte, error) {
 	c.Lock()
-	if c.closed {
+	if c.isClosed() {
 		c.Unlock()
 		return nil, ErrClosed
 	}
@@ -201,9 +214,9 @@ func (c *Connection) Request(repo string, name string, offset int64, size int) (
 	return res.val, res.err
 }
 
-func (c *Connection) ping() bool {
+func (c *rawConnection) ping() bool {
 	c.Lock()
-	if c.closed {
+	if c.isClosed() {
 		c.Unlock()
 		return false
 	}
@@ -231,38 +244,45 @@ type flusher interface {
 	Flush() error
 }
 
-func (c *Connection) flush() error {
+func (c *rawConnection) flush() error {
 	if f, ok := c.writer.(flusher); ok {
 		return f.Flush()
 	}
 	return nil
 }
 
-func (c *Connection) close(err error) {
+func (c *rawConnection) close(err error) {
 	c.Lock()
-	if c.closed {
+	select {
+	case <-c.closed:
 		c.Unlock()
 		return
+	default:
 	}
-	c.closed = true
+	close(c.closed)
 	for _, ch := range c.awaiting {
 		close(ch)
 	}
 	c.awaiting = nil
+	c.writer.Close()
+	c.reader.Close()
 	c.Unlock()
 
 	c.receiver.Close(c.id, err)
 }
 
-func (c *Connection) isClosed() bool {
-	c.RLock()
-	defer c.RUnlock()
-	return c.closed
+func (c *rawConnection) isClosed() bool {
+	select {
+	case <-c.closed:
+		return true
+	default:
+		return false
+	}
 }
 
-func (c *Connection) readerLoop() {
+func (c *rawConnection) readerLoop() {
 loop:
-	for {
+	for !c.isClosed() {
 		var hdr header
 		hdr.decodeXDR(c.xr)
 		if c.xr.Error() != nil {
@@ -381,7 +401,7 @@ loop:
 	}
 }
 
-func (c *Connection) processRequest(msgID int, req RequestMessage) {
+func (c *rawConnection) processRequest(msgID int, req RequestMessage) {
 	data, _ := c.receiver.Request(c.id, req.Repository, req.Name, int64(req.Offset), int(req.Size))
 
 	c.Lock()
@@ -398,27 +418,31 @@ func (c *Connection) processRequest(msgID int, req RequestMessage) {
 	}
 }
 
-func (c *Connection) pingerLoop() {
+func (c *rawConnection) pingerLoop() {
 	var rc = make(chan bool, 1)
+	ticker := time.Tick(pingIdleTime / 2)
 	for {
-		time.Sleep(pingIdleTime / 2)
+		select {
+		case <-ticker:
+			c.RLock()
+			ready := c.hasRecvdIndex && c.hasSentIndex
+			c.RUnlock()
 
-		c.RLock()
-		ready := c.hasRecvdIndex && c.hasSentIndex
-		c.RUnlock()
-
-		if ready {
-			go func() {
-				rc <- c.ping()
-			}()
-			select {
-			case ok := <-rc:
-				if !ok {
-					c.close(fmt.Errorf("ping failure"))
+			if ready {
+				go func() {
+					rc <- c.ping()
+				}()
+				select {
+				case ok := <-rc:
+					if !ok {
+						c.close(fmt.Errorf("ping failure"))
+					}
+				case <-time.After(pingTimeout):
+					c.close(fmt.Errorf("ping timeout"))
 				}
-			case <-time.After(pingTimeout):
-				c.close(fmt.Errorf("ping timeout"))
 			}
+		case <-c.closed:
+			return
 		}
 	}
 }
@@ -429,7 +453,7 @@ type Statistics struct {
 	OutBytesTotal int
 }
 
-func (c *Connection) Statistics() Statistics {
+func (c *rawConnection) Statistics() Statistics {
 	c.statisticsLock.Lock()
 	defer c.statisticsLock.Unlock()
 
@@ -442,7 +466,7 @@ func (c *Connection) Statistics() Statistics {
 	return stats
 }
 
-func (c *Connection) Option(key string) string {
+func (c *rawConnection) Option(key string) string {
 	c.optionsLock.Lock()
 	defer c.optionsLock.Unlock()
 	return c.peerOptions[key]