1. 每日区块链首页
  2. 独家专栏

兄弟连区块链教程Fabric1.0源代码分析Orderer BroadcastServer

兄弟连区块链教程Fabric1.0源代码分析Orderer BroadcastServer

区块链教程Fabric1.0源代码分析Orderer BroadcastServer,2018年下半年,区块链行业正逐渐褪去发展之初的浮躁、回归理性,表面上看相关人才需求与身价似乎正在回落。但事实上,正是初期泡沫的渐退,让人们更多的关注点放在了区块链真正的技术之上。

Fabric 1.0源代码笔记 之 Orderer #BroadcastServer(Broadcast服务端)

1、BroadcastServer概述

BroadcastServer相关代码在protos/orderer、orderer目录下。

protos/orderer/ab.pb.go,AtomicBroadcastServer接口定义。
orderer/server.go,go,AtomicBroadcastServer接口实现。
有个图

2、AtomicBroadcastServer接口定义

2.1、AtomicBroadcastServer接口定义

type AtomicBroadcastServer interface {
Broadcast(AtomicBroadcast_BroadcastServer) error
Deliver(AtomicBroadcast_DeliverServer) error
}
//代码在protos/orderer/ab.pb.go
···

### 2.2、gRPC相关实现

“`go
var _AtomicBroadcast_serviceDesc = grpc.ServiceDesc{
ServiceName: \”orderer.AtomicBroadcast\”,
HandlerType: (*AtomicBroadcastServer)(nil),
Methods: []grpc.MethodDesc{},
Streams: []grpc.StreamDesc{
{
StreamName: \”Broadcast\”,
Handler: _AtomicBroadcast_Broadcast_Handler,
ServerStreams: true,
ClientStreams: true,
},
{
StreamName: \”Deliver\”,
Handler: _AtomicBroadcast_Deliver_Handler,
ServerStreams: true,
ClientStreams: true,
},
},
Metadata: \”orderer/ab.proto\”,
}

func RegisterAtomicBroadcastServer(s *grpc.Server, srv AtomicBroadcastServer) {
s.RegisterService(&_AtomicBroadcast_serviceDesc, srv)
}

func _AtomicBroadcast_Broadcast_Handler(srv interface{}, stream grpc.ServerStream) error {
return srv.(AtomicBroadcastServer).Broadcast(&atomicBroadcastBroadcastServer{stream})
}

func _AtomicBroadcast_Deliver_Handler(srv interface{}, stream grpc.ServerStream) error {
return srv.(AtomicBroadcastServer).Deliver(&atomicBroadcastDeliverServer{stream})
}
//代码在protos/orderer/ab.pb.go

3、AtomicBroadcastServer接口实现

3.1、server结构体

server结构体:

type server struct {
bh broadcast.Handler
dh deliver.Handler
}

type broadcastSupport struct {
multichain.Manager
broadcast.ConfigUpdateProcessor
}
//代码在orderer/server.go

broadcast.Handler:

type Handler interface {
Handle(srv ab.AtomicBroadcast_BroadcastServer) error
}

type handlerImpl struct {
sm SupportManager
}

func NewHandlerImpl(sm SupportManager) Handler {
return &handlerImpl{
sm: sm,
}
}

type SupportManager interface {
ConfigUpdateProcessor
GetChain(chainID string) (Support, bool)
}

type ConfigUpdateProcessor interface { //处理通道配置更新
Process(envConfigUpdate *cb.Envelope) (*cb.Envelope, error)
}
//代码在orderer/common/broadcast/broadcast.go

deliver.Handler:

type Handler interface {
Handle(srv ab.AtomicBroadcast_DeliverServer) error
}

type deliverServer struct {
sm SupportManager
}

type SupportManager interface {
GetChain(chainID string) (Support, bool)
}
//代码在orderer/common/deliver/deliver.go

3.2、server结构体相关方法

//构建server结构体
func NewServer(ml multichain.Manager, signer crypto.LocalSigner) ab.AtomicBroadcastServer
//s.bh.Handle(srv)
func (s *server) Broadcast(srv ab.AtomicBroadcast_BroadcastServer) error
//s.dh.Handle(srv)
func (s *server) Deliver(srv ab.AtomicBroadcast_DeliverServer) error
//代码在orderer/server.go

func NewServer(ml multichain.Manager, signer crypto.LocalSigner) ab.AtomicBroadcastServer代码如下:

func NewServer(ml multichain.Manager, signer crypto.LocalSigner) ab.AtomicBroadcastServer {
s := &server{
dh: deliver.NewHandlerImpl(deliverSupport{Manager: ml}),
bh: broadcast.NewHandlerImpl(broadcastSupport{
Manager: ml,
ConfigUpdateProcessor: configupdate.New(ml.SystemChannelID(), configUpdateSupport{Manager: ml}, signer),
}),
}
return s
}
//代码在orderer/server.go

3.3、Broadcast服务端Broadcast处理流程

Broadcast服务端Broadcast处理流程,即broadcast.handlerImpl.Handle方法。

3.3.1、接收Envelope消息,并获取Payload和ChannelHeader

msg, err := srv.Recv() //接收Envelope消息
payload, err := utils.UnmarshalPayload(msg.Payload) //反序列化获取Payload
chdr, err := utils.UnmarshalChannelHeader(payload.Header.ChannelHeader) //反序列化获取ChannelHeader
//代码在orderer/common/broadcast/broadcast.go

3.3.2、如果消息类型为channel配置或更新,则使用multichain.Manager处理消息

if chdr.Type == int32(cb.HeaderType_CONFIG_UPDATE) { //如果是channel配置或更新
msg, err = bh.sm.Process(msg) //configupdate.Processor.Process方法
}
//代码在orderer/common/broadcast/broadcast.go

msg, err = bh.sm.Process(msg)代码如下:

func (p *Processor) Process(envConfigUpdate *cb.Envelope) (*cb.Envelope, error) {
channelID, err := channelID(envConfigUpdate) //获取ChannelHeader.ChannelId
//multichain.Manager.GetChain方法,获取chainSupport,以及chain是否存在
support, ok := p.manager.GetChain(channelID)
if ok {
//已存在的channel配置,调取multichain.Manager.ProposeConfigUpdate方法
return p.existingChannelConfig(envConfigUpdate, channelID, support)
}
//新channel配置,调取multichain.Manager.NewChannelConfig方法
return p.newChannelConfig(channelID, envConfigUpdate)
}
//代码在orderer/configupdate/configupdate.go

3.3.3、其他消息类型或channel消息处理后,接受消息并加入排序

support, ok := bh.sm.GetChain(chdr.ChannelId) //获取chainSupport
_, filterErr := support.Filters().Apply(msg) //filter.RuleSet.Apply方法
//调取Chain.Enqueue方法,接受消息,加入排序
support.Enqueue(msg)
//代码在orderer/common/broadcast/broadcast.go

3.3.4、向客户端发送响应信息

err = srv.Send(&ab.BroadcastResponse{Status: cb.Status_SUCCESS})
//代码在orderer/common/broadcast/broadcast.go

3.4、Broadcast服务端Deliver处理流程

Broadcast服务端Deliver处理流程,即deliver.deliverServer.Handle方法。

func (ds *deliverServer) Handle(srv ab.AtomicBroadcast_DeliverServer) error {
for {
//接收客户端查询请求
envelope, err := srv.Recv()
payload, err := utils.UnmarshalPayload(envelope.Payload)
chdr, err := utils.UnmarshalChannelHeader(payload.Header.ChannelHeader)
chain, ok := ds.sm.GetChain(chdr.ChannelId)

erroredChan := chain.Errored()
select {
case <-erroredChan:
return sendStatusReply(srv, cb.Status_SERVICE_UNAVAILABLE)
default:

}

lastConfigSequence := chain.Sequence()

sf := sigfilter.New(policies.ChannelReaders, chain.PolicyManager())
result, _ := sf.Apply(envelope)

seekInfo := &ab.SeekInfo{}
err = proto.Unmarshal(payload.Data, seekInfo)

cursor, number := chain.Reader().Iterator(seekInfo.Start)
var stopNum uint64
switch stop := seekInfo.Stop.Type.(type) {
case *ab.SeekPosition_Oldest:
stopNum = number
case *ab.SeekPosition_Newest:
stopNum = chain.Reader().Height() – 1
case *ab.SeekPosition_Specified:
stopNum = stop.Specified.Number
if stopNum < number {
return sendStatusReply(srv, cb.Status_BAD_REQUEST)
}
}

for {
if seekInfo.Behavior == ab.SeekInfo_BLOCK_UNTIL_READY {
select {
case <-erroredChan:
return sendStatusReply(srv, cb.Status_SERVICE_UNAVAILABLE)
case <-cursor.ReadyChan():
}
} else {
select {
case lastConfigSequence {
lastConfigSequence = currentConfigSequence
sf := sigfilter.New(policies.ChannelReaders, chain.PolicyManager())
result, _ := sf.Apply(envelope)

}

block, status := cursor.Next()
err := sendBlockReply(srv, block)
if stopNum == block.Header.Number {
break
}
}

err := sendStatusReply(srv, cb.Status_SUCCESS)
}
}

原创文章,作者:兄弟连区块链学院,如若转载,请注明出处:http://www.dayqkl.com/54234.html

发表评论

登录后才能评论
QR code