兄弟連區塊鏈技術培訓Fabric 1.0原始碼分析(33) Peer #peer channel命令及子命令實現

兄弟連區塊鏈技術培訓Fabric 1.0原始碼分析(33) Peer #peer channel命令及子命令實現

# Fabric 1.0原始碼筆記 之 Peer #peer channel命令及子命令實現

## 1、peer channel create子命令實現（建立通道）

### 1.1、初始化Orderer用戶端

```go

const (

    EndorserRequired EndorserRequirement = true

    EndorserNotRequired EndorserRequirement = false

    OrdererRequired OrdererRequirement = true

    OrdererNotRequired OrdererRequirement = false

)

cf, err = InitCmdFactory(EndorserNotRequired, OrdererRequired)

//代碼在peer/channel/create.go

```

cf, err = InitCmdFactory(EndorserNotRequired, OrdererRequired)代碼如下：

```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，本處暫未使用

    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) //構造deliverClient

    }

    return cmdFact, nil

}

//代碼在peer/channel/channel.go

```

### 1.2、發送建立區塊鏈的交易

```go

err = sendCreateChainTransaction(cf)

//代碼在peer/channel/create.go

```

sendCreateChainTransaction(cf)代碼如下：

```go

func sendCreateChainTransaction(cf *ChannelCmdFactory) error {

    var err error

    var chCrtEnv *cb.Envelope

    if channelTxFile != "" { //peer channel create -f指定通道交易設定檔

        chCrtEnv, err = createChannelFromConfigTx(channelTxFile) //擷取創世區塊

    } else {

        chCrtEnv, err = createChannelFromDefaults(cf) //沒有指定通道交易設定檔

    }

    chCrtEnv, err = sanityCheckAndSignConfigTx(chCrtEnv) //檢查和簽名交易配置

    var broadcastClient common.BroadcastClient

    broadcastClient, err = cf.BroadcastFactory()

    defer broadcastClient.Close()

    err = broadcastClient.Send(chCrtEnv)

    return err

}

//代碼在peer/channel/create.go

```

### 1.3、擷取創世區塊並寫入檔案

```go

var block *cb.Block

block, err = getGenesisBlock(cf) //擷取創世區塊

b, err := proto.Marshal(block) //塊序列化

err = ioutil.WriteFile(file, b, 0644) //寫入檔案

//代碼在peer/channel/create.go

```

## 2、peer channel join子命令實現（加入通道）

### 2.1、初始化Endorser用戶端

```go

cf, err = InitCmdFactory(EndorserRequired, OrdererNotRequired)

//代碼在peer/channel/join.go

```

### 2.2、構造ChaincodeInvocationSpec訊息（cscc.JoinChain）

```go

spec, err := getJoinCCSpec()

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

//代碼在peer/channel/join.go

```

spec, err := getJoinCCSpec()代碼如下：

```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

}

//代碼在peer/channel/join.go

```

### 2.3、建立cscc Proposal並簽名

```go

creator, err := cf.Signer.Serialize()

//從CIS建立Proposal，CIS即ChaincodeInvocationSpec

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

//而後調用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)

//代碼在peer/channel/join.go

```

CreateChaincodeProposalWithTransient(typ, chainID, cis, creator, nil)代碼如下：

```go

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

    //建立隨機Nonce

    nonce, err := crypto.GetRandomNonce()

    //計算交易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)

}

//代碼在protos/utils/proputils.go

```

CreateChaincodeProposalWithTxIDNonceAndTransient(txid, typ, chainID, cis, nonce, creator, transientMap)代碼如下：

```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,

        Extension: ccHdrExtBytes,

        Epoch: epoch}),

        SignatureHeader: MarshalOrPanic(&common.SignatureHeader{Nonce: nonce, Creator: creator})}

    hdrBytes, err := proto.Marshal(hdr)

    return &peer.Proposal{Header: hdrBytes, Payload: ccPropPayloadBytes}, txid, nil

}

//代碼在protos/utils/proputils.go

```

### 2.4、提交並處理Proposal

```go

var proposalResp *pb.ProposalResponse

proposalResp, err = cf.EndorserClient.ProcessProposal(context.Background(), signedProp)

//代碼在peer/channel/join.go

```

## 3、peer channel update（更新錨節點配置）

```go

cf, err = InitCmdFactory(EndorserNotRequired, OrdererRequired)

fileData, err := ioutil.ReadFile(channelTxFile)

ctxEnv, err := utils.UnmarshalEnvelope(fileData)

sCtxEnv, err := sanityCheckAndSignConfigTx(ctxEnv)

var broadcastClient common.BroadcastClient

broadcastClient, err = cf.BroadcastFactory()

defer broadcastClient.Close()

return broadcastClient.Send(sCtxEnv)

//代碼在peer/channel

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