peer需要改变的

[yfhk]

1. Gossip（）往别人发的时候只往同一个channel的peer发；
2. fetch的时候，只从同一个channel的peer取；
3. broadcast的时候给同一个channel的order发送；
   4 .deliver的时候给同一个channel的peer发送；
4. 跨链调用的逻辑；
5. 查询某侧链币余额的逻辑（放到手机端来做）；

[yfhk]

// IsChannelRestricted returns whether this GossipMessage should be routed
// only in its channel
func (m *GossipMessage) IsChannelRestricted() bool {
return m.Tag == GossipMessage_CHAN_AND_ORG || m.Tag == GossipMessage_CHAN_ONLY || m.Tag == GossipMessage_CHAN_OR_ORG
}

[yfhk]

fabric/gossip/gossip/gossip_impl.go

[yfhk]

func (g *gossipServiceImpl) handleMessage(m proto.ReceivedMessage) {
if g.toDie() {
return
}

if m == nil || m.GetGossipMessage() == nil {
	return
}

msg := m.GetGossipMessage()

g.logger.Debug("Entering,", m.GetConnectionInfo(), "sent us", msg)
defer g.logger.Debug("Exiting")

if !g.validateMsg(m) {
	g.logger.Warning("Message", msg, "isn't valid")
	return
}

if msg.IsChannelRestricted() {
	if gc := g.chanState.lookupChannelForMsg(m); gc == nil {
		// If we're not in the channel, we should still forward to peers of our org
		// in case it's a StateInfo message
		if g.isInMyorg(discovery.NetworkMember{ERC20ADDR: m.GetConnectionInfo().ID}) && msg.IsStateInfoMsg() {
			if g.stateInfoMsgStore.Add(msg) {
				g.emitter.Add(&emittedGossipMessage{
					SignedGossipMessage: msg,
					filter:              m.GetConnectionInfo().ID.IsNotSameFilter,
				})
			}
		}
		if !g.toDie() {
			g.logger.Debug("No such channel", msg.Channel, "discarding message", msg)
		}

[yfhk]

// Gossip sends a message to other peers to the network
func (g *gossipServiceImpl) Gossip(msg *proto.GossipMessage) {
// Educate developers to Gossip messages with the right tags.
// See IsTagLegal() for wanted behavior.
if err := msg.IsTagLegal(); err != nil {
panic(errors.WithStack(err))
}

sMsg := &proto.SignedGossipMessage{
	GossipMessage: msg,
}

var err error
if sMsg.IsDataMsg() {
	sMsg, err = sMsg.NoopSign()
} else {
	_, err = sMsg.Sign(func(msg []byte) ([]byte, error) {
		return g.mcs.Sign(msg)
	})
}

if err != nil {
	g.logger.Warningf("Failed signing message: %+v", errors.WithStack(err))
	return
}

if msg.IsChannelRestricted() {
	gc := g.chanState.getGossipChannelByChainID(msg.Channel)
	if gc == nil {
		g.logger.Warning("Failed obtaining gossipChannel of", msg.Channel, "aborting")
		return
	}
	if msg.IsDataMsg() {
		gc.AddToMsgStore(sMsg)
	}
}

[yfhk]

http://wutongtree.github.io/translations/Kafka-based-Ordering-Service_zh
从这个里面的图可以看出，OSN不用relay给其他的order节点

[yfhk]

// Fetcher interface which defines API to fetch missing
// private data elements
type Fetcher interface {
fetch(dig2src dig2sources) ([]*gossip2.PvtDataElement, error)
}