// Gossip receives gossiped information from a peer node.
// The received delta is combined with the infostore, and this
// node's own gossip is returned to requesting client.
func (s *server) Gossip(args *proto.GossipRequest, reply *proto.GossipResponse) error {
s.mu.Lock()
defer s.mu.Unlock()
addr, err := args.Addr.NetAddr()
if err != nil {
return util.Errorf("addr %s could not be converted to net.Addr: %s", args.Addr, err)
}
lAddr, err := args.LAddr.NetAddr()
if err != nil {
return util.Errorf("local addr %s could not be converted to net.Addr: %s", args.LAddr, err)
}
// If there is no more capacity to accept incoming clients, return
// a random already-being-serviced incoming client as an alternate.
if !s.incoming.hasAddr(addr) {
if !s.incoming.hasSpace() {
reply.Alternate = proto.FromNetAddr(s.incoming.selectRandom())
return nil
}
s.incoming.addAddr(addr)
// This lookup map allows the incoming client to be removed from
// the incoming addr set when its connection is closed. See
// server.serveConn() below.
s.clientAddrMap[lAddr.String()] = addr
}
// Update infostore with gossiped infos.
if args.Delta != nil {
delta := &infoStore{}
if err := gob.NewDecoder(bytes.NewBuffer(args.Delta)).Decode(delta); err != nil {
return util.Errorf("infostore could not be decoded: %s", err)
}
log.V(1).Infof("received delta infostore from client %s: %s", addr, delta)
s.is.combine(delta)
}
// If requested max sequence is not -1, wait for gossip interval to expire.
if args.MaxSeq != -1 {
s.ready.Wait()
}
// The exit condition for waiting clients.
if s.closed {
return util.Errorf("gossip server shutdown")
}
// Return reciprocal delta.
delta := s.is.delta(addr, args.MaxSeq)
if delta != nil {
var buf bytes.Buffer
if err := gob.NewEncoder(&buf).Encode(delta); err != nil {
log.Fatalf("infostore could not be encoded: %s", err)
}
reply.Delta = buf.Bytes()
log.Infof("gossip: client %s sent %d info(s)", addr, delta.infoCount())
}
return nil
}
// Gossip receives gossiped information from a peer node.
// The received delta is combined with the infostore, and this
// node's own gossip is returned to requesting client.
func (s *server) Gossip(args *proto.GossipRequest, reply *proto.GossipResponse) error {
s.mu.Lock()
defer s.mu.Unlock()
addr, err := args.Addr.NetAddr()
if err != nil {
return util.Errorf("addr %s could not be converted to net.Addr: %s", args.Addr, err)
}
lAddr, err := args.LAddr.NetAddr()
if err != nil {
return util.Errorf("local addr %s could not be converted to net.Addr: %s", args.LAddr, err)
}
// If there is no more capacity to accept incoming clients, return
// a random already-being-serviced incoming client as an alternate.
if !s.incoming.hasNode(args.NodeID) {
if !s.incoming.hasSpace() {
idx := rand.Intn(len(s.lAddrMap))
count := 0
for _, cInfo := range s.lAddrMap {
if count == idx {
reply.Alternate = cInfo.addr
return nil
}
count++
}
}
s.incoming.addNode(args.NodeID)
// This lookup map allows the incoming client to be removed from
// the incoming addr set when its connection is closed. See
// server.serveConn() below.
s.lAddrMap[lAddr.String()] = clientInfo{args.NodeID, &args.Addr}
}
// Update infostore with gossiped infos.
if args.Delta != nil {
delta := &infoStore{}
if err := gob.NewDecoder(bytes.NewBuffer(args.Delta)).Decode(delta); err != nil {
return util.Errorf("infostore could not be decoded: %s", err)
}
if delta.infoCount() > 0 {
if log.V(1) {
log.Infof("gossip: received %s", delta)
} else {
log.Infof("gossip: received %d info(s) from %s", delta.infoCount(), addr)
}
}
s.is.combine(delta)
}
// The exit condition for waiting clients.
if s.closed {
return util.Errorf("gossip server shutdown")
}
// If requested max sequence is not -1, wait for gossip interval to expire.
if args.MaxSeq != -1 {
s.ready.Wait()
}
// Return reciprocal delta.
delta := s.is.delta(args.NodeID, args.MaxSeq)
if delta != nil {
var buf bytes.Buffer
if err := gob.NewEncoder(&buf).Encode(delta); err != nil {
log.Fatalf("infostore could not be encoded: %s", err)
}
reply.Delta = buf.Bytes()
}
return nil
}
