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Fabric 1.0源代码分析(33) Peer ＃peer channel命令及子命令实现

2022-04-23 11:45:00 【yinchengmvp】

# Fabric 1.0源代码笔记之 Peer #peer channel命令及子命令实现

## 1、peer channel create子命令实现（创建通道）

### 1.1、初始化Orderer客户端

```go

const (

EndorserRequired EndorserRequirement = true

EndorserNotRequired EndorserRequirement = false

OrdererRequired OrdererRequirement = true

OrdererNotRequired OrdererRequirement = false

)

cf, err = InitCmdFactory(EndorserNotRequired, OrdererRequired)

//代码在peer/channel/create.go

```

cf, err = InitCmdFactory(EndorserNotRequired, OrdererRequired)代码如下：

```go

type ChannelCmdFactory struct {

EndorserClient pb.EndorserClient //EndorserClient

Signer msp.SigningIdentity //Signer

BroadcastClient common.BroadcastClient //BroadcastClient

DeliverClient deliverClientIntf //DeliverClient

BroadcastFactory BroadcastClientFactory //BroadcastClientFactory，type BroadcastClientFactory func() (common.BroadcastClient, error)

}

func InitCmdFactory(isEndorserRequired EndorserRequirement, isOrdererRequired OrdererRequirement) (*ChannelCmdFactory, error) {

var err error

cmdFact := &ChannelCmdFactory{}

cmdFact.Signer, err = common.GetDefaultSignerFnc() //GetDefaultSignerFnc = GetDefaultSigner

cmdFact.BroadcastFactory = func() (common.BroadcastClient, error) {

return common.GetBroadcastClientFnc(orderingEndpoint, tls, caFile) //GetBroadcastClientFnc = GetBroadcastClient

}

//peer channel join或list需要endorser，本处暂未使用

if isEndorserRequired {

cmdFact.EndorserClient, err = common.GetEndorserClientFnc()

}

//peer channel create或fetch需要orderer

if isOrdererRequired {

var opts []grpc.DialOption

if tls {

if caFile != "" {

creds, err := credentials.NewClientTLSFromFile(caFile, "")

opts = append(opts, grpc.WithTransportCredentials(creds))

}

} else {

opts = append(opts, grpc.WithInsecure())

}

conn, err := grpc.Dial(orderingEndpoint, opts...)

client, err := ab.NewAtomicBroadcastClient(conn).Deliver(context.TODO())

cmdFact.DeliverClient = newDeliverClient(conn, client, chainID) //构造deliverClient

}

return cmdFact, nil

}

//代码在peer/channel/channel.go

```

### 1.2、发送创建区块链的交易

```go

err = sendCreateChainTransaction(cf)

//代码在peer/channel/create.go

```

sendCreateChainTransaction(cf)代码如下：

```go

func sendCreateChainTransaction(cf *ChannelCmdFactory) error {

var err error

var chCrtEnv *cb.Envelope

if channelTxFile != "" { //peer channel create -f指定通道交易配置文件

chCrtEnv, err = createChannelFromConfigTx(channelTxFile) //获取创世区块

} else {

chCrtEnv, err = createChannelFromDefaults(cf) //没有指定通道交易配置文件

}

chCrtEnv, err = sanityCheckAndSignConfigTx(chCrtEnv) //检查和签名交易配置

var broadcastClient common.BroadcastClient

broadcastClient, err = cf.BroadcastFactory()

defer broadcastClient.Close()

err = broadcastClient.Send(chCrtEnv)

return err

}

//代码在peer/channel/create.go

```

### 1.3、获取创世区块并写入文件

```go

var block *cb.Block

block, err = getGenesisBlock(cf) //获取创世区块

b, err := proto.Marshal(block) //块序列化

err = ioutil.WriteFile(file, b, 0644) //写入文件

//代码在peer/channel/create.go

```

## 2、peer channel join子命令实现（加入通道）

### 2.1、初始化Endorser客户端

```go

cf, err = InitCmdFactory(EndorserRequired, OrdererNotRequired)

//代码在peer/channel/join.go

```

### 2.2、构造ChaincodeInvocationSpec消息（cscc.JoinChain）

```go

spec, err := getJoinCCSpec()

invocation := &pb.ChaincodeInvocationSpec{ChaincodeSpec: spec}

//代码在peer/channel/join.go

```

spec, err := getJoinCCSpec()代码如下：

```go

func getJoinCCSpec() (*pb.ChaincodeSpec, error) {

gb, err := ioutil.ReadFile(genesisBlockPath)

input := &pb.ChaincodeInput{Args: [][] byte{[]byte(cscc.JoinChain), gb}}

spec := &pb.ChaincodeSpec{

Type: pb.ChaincodeSpec_Type(pb.ChaincodeSpec_Type_value[ "GOLANG"]),

ChaincodeId: &pb.ChaincodeID{Name: "cscc"},

Input: input,

}

return spec, nil

}

//代码在peer/channel/join.go

```

### 2.3、创建cscc Proposal并签名

```go

creator, err := cf.Signer.Serialize()

//从CIS创建Proposal，CIS即ChaincodeInvocationSpec

//调用CreateChaincodeProposal(typ, chainID, cis, creator)

//而后调用CreateChaincodeProposalWithTransient(typ, chainID, cis, creator, nil)

prop, _, err = putils.CreateProposalFromCIS(pcommon.HeaderType_CONFIG, "", invocation, creator)

var signedProp *pb.SignedProposal

signedProp, err = putils.GetSignedProposal(prop, cf.Signer)

//代码在peer/channel/join.go

```

CreateChaincodeProposalWithTransient(typ, chainID, cis, creator, nil)代码如下：

```go

func CreateChaincodeProposalWithTransient(typ common.HeaderType, chainID string, cis *peer.ChaincodeInvocationSpec, creator [] byte, transientMap map[ string][] byte) (*peer.Proposal, str ing, error) {

//创建随机Nonce

nonce, err := crypto.GetRandomNonce()

//计算交易ID

//digest, err := factory.GetDefault().Hash(append(nonce, creator...),&bccsp.SHA256Opts{})

txid, err := ComputeProposalTxID(nonce, creator)

return CreateChaincodeProposalWithTxIDNonceAndTransient(txid, typ, chainID, cis, nonce, creator, transientMap)

}

//代码在protos/utils/proputils.go

```

CreateChaincodeProposalWithTxIDNonceAndTransient(txid, typ, chainID, cis, nonce, creator, transientMap)代码如下：

```go

func CreateChaincodeProposalWithTxIDNonceAndTransient(txid string, typ common.HeaderType, chainID string, cis *peer.ChaincodeInvocationSpec, nonce, creator [] byte, transientMap map[ string][] byte) (*peer.Proposal, string, error) {

ccHdrExt := &peer.ChaincodeHeaderExtension{ChaincodeId: cis.ChaincodeSpec.ChaincodeId}

ccHdrExtBytes, err := proto.Marshal(ccHdrExt)

cisBytes, err := proto.Marshal(cis)

ccPropPayload := &peer.ChaincodeProposalPayload{Input: cisBytes, TransientMap: transientMap}

ccPropPayloadBytes, err := proto.Marshal(ccPropPayload)

var epoch uint64 = 0

timestamp := util.CreateUtcTimestamp()

hdr := &common.Header{ChannelHeader: MarshalOrPanic(&common.ChannelHeader{

Type: int32(typ),

TxId: txid,

Timestamp: timestamp,

ChannelId: chainID,