区块链教程Fabric1.0源代码分析Peer peer chaincode命令及子命令实现，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 Peer #peer chaincode命令及子命令实现

1、peer chaincode install子命令实现（安装链码）

1.0、peer chaincode install子命令概述

peer chaincode install，将链码的源码和环境封装为一个链码安装打包文件，并传输到背书节点。

peer chaincode install支持如下两种方式：

• 指定代码方式，peer chaincode install -n <链码名称> -v <链码版本> -p <链码路径>
• 基于链码打包文件方式，peer chaincode install <链码打包文件>
  

  1.1、初始化Endorser客户端

cf, err = InitCmdFactory(true, false)//代码在peer/chaincode/install.go

cf, err = InitCmdFactory(true, false)代码如下：

func InitCmdFactory(isEndorserRequired, isOrdererRequired bool) (*ChaincodeCmdFactory, error) {    var err error    var endorserClient pb.EndorserClient    if isEndorserRequired {        //获取Endorser客户端        endorserClient, err = common.GetEndorserClientFnc() //func GetEndorserClient() (pb.EndorserClient, error)    }    //获取签名    signer, err := common.GetDefaultSignerFnc()    var broadcastClient common.BroadcastClient    if isOrdererRequired {        //此处未用到，暂略    }    //构造ChaincodeCmdFactory    return &ChaincodeCmdFactory{        EndorserClient:  endorserClient,        Signer:          signer,        BroadcastClient: broadcastClient,    }, nil}//代码在peer/chaincode/common.go

1.2、构造ChaincodeDeploymentSpec消息（链码信息及链码文件打包）

if ccpackfile == "" { //指定代码方式，重新构造构造ChaincodeDeploymentSpec消息    ccpackmsg, err = genChaincodeDeploymentSpec(cmd, chaincodeName, chaincodeVersion)} else { //基于链码打包文件方式，直接读取ChaincodeDeploymentSpec消息    var cds *pb.ChaincodeDeploymentSpec    ccpackmsg, cds, err = getPackageFromFile(ccpackfile)}//代码在peer/chaincode/install.go

ccpackmsg, err = genChaincodeDeploymentSpec(cmd, chaincodeName, chaincodeVersion)代码如下：

func genChaincodeDeploymentSpec(cmd *cobra.Command, chaincodeName, chaincodeVersion string) (*pb.ChaincodeDeploymentSpec, error) {    //已经存在，直接报错    if existed, _ := ccprovider.ChaincodePackageExists(chaincodeName, chaincodeVersion); existed {        return nil, fmt.Errorf("chaincode %s:%s already exists", chaincodeName, chaincodeVersion)    }    spec, err := getChaincodeSpec(cmd)    cds, err := getChaincodeDeploymentSpec(spec, true)    return cds, nil}//代码在peer/chaincode/install.go

spec, err := getChaincodeSpec(cmd)代码如下：

func getChaincodeSpec(cmd *cobra.Command) (*pb.ChaincodeSpec, error) {    spec := &pb.ChaincodeSpec{}    err := checkChaincodeCmdParams(cmd) //检查参数合法性    input := &pb.ChaincodeInput{}    //flags.StringVarP(&chaincodeCtorJSON, "ctor", "c", "{}"，ctor为链码具体执行参数信息，默认为{}    err := json.Unmarshal([]byte(chaincodeCtorJSON), &input)    //flags.StringVarP(&chaincodeLang, "lang", "l", "golang"，lang为链码的编写语言，默认为golang    chaincodeLang = strings.ToUpper(chaincodeLang)    spec = &pb.ChaincodeSpec{        Type:        pb.ChaincodeSpec_Type(pb.ChaincodeSpec_Type_value[chaincodeLang]),        ChaincodeId: &pb.ChaincodeID{Path: chaincodePath, Name: chaincodeName, Version: chaincodeVersion},        Input:       input,    }    return spec, nil}//代码在peer/chaincode/common.go

cds, err := getChaincodeDeploymentSpec(spec, true)代码如下：

func getChaincodeDeploymentSpec(spec *pb.ChaincodeSpec, crtPkg bool) (*pb.ChaincodeDeploymentSpec, error) {    var codePackageBytes []byte    if chaincode.IsDevMode() == false && crtPkg {        var err error        err = checkSpec(spec) //检查spec合法性        codePackageBytes, err = container.GetChaincodePackageBytes(spec) //打包链码文件及依赖文件    }    //构造ChaincodeDeploymentSpec    chaincodeDeploymentSpec := &pb.ChaincodeDeploymentSpec{ChaincodeSpec: spec, CodePackage: codePackageBytes}    return chaincodeDeploymentSpec, nil//代码在peer/chaincode/common.go

1.3、创建lscc Proposal并签名

creator, err := cf.Signer.Serialize() //获取签名者//按ChaincodeDeploymentSpec构造Proposal，即链码ChaincodeDeploymentSpec消息作为参数传递给lscc系统链码并调用//调用createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")prop, _, err := utils.CreateInstallProposalFromCDS(msg, creator) var signedProp *pb.SignedProposalsignedProp, err = utils.GetSignedProposal(prop, cf.Signer) //签名提案//代码在peer/chaincode/install.go

createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")代码如下：

func createProposalFromCDS(chainID string, msg proto.Message, creator []byte, policy []byte, escc []byte, vscc []byte, propType string) (*peer.Proposal, string, error) {    var ccinp *peer.ChaincodeInput    var b []byte    var err error    b, err = proto.Marshal(msg)    switch propType {    case "deploy":        fallthrough    case "upgrade":         cds, ok := msg.(*peer.ChaincodeDeploymentSpec)        ccinp = &peer.ChaincodeInput{Args: [][]byte{[]byte(propType), []byte(chainID), b, policy, escc, vscc}}    case "install":         ccinp = &peer.ChaincodeInput{Args: [][]byte{[]byte(propType), b}}    }    lsccSpec := &peer.ChaincodeInvocationSpec{ //构造lscc ChaincodeInvocationSpec        ChaincodeSpec: &peer.ChaincodeSpec{            Type:        peer.ChaincodeSpec_GOLANG,            ChaincodeId: &peer.ChaincodeID{Name: "lscc"},            Input:       ccinp}}    return CreateProposalFromCIS(common.HeaderType_ENDORSER_TRANSACTION, chainID, lsccSpec, creator)}//代码在protos/utils/proputils.go

1.4、提交并处理Proposal

proposalResponse, err := cf.EndorserClient.ProcessProposal(context.Background(), signedProp)//代码在peer/chaincode/install.go

2、peer chaincode instantiate子命令实现（实例化链码）

2.0、peer chaincode instantiate概述

peer chaincode instantiate命令通过构造生命周期管理系统链码（LSCC）的交易，将安装过的链码在指定通道上进行实例化调用。

在peer上创建容器启动，并执行初始化操作。

2.1、初始化EndorserClient、Signer、及BroadcastClient

与2.1接近，附BroadcastClient初始化代码如下：

cf, err = InitCmdFactory(true, true)//代码在peer/chaincode/instantiate.go

func InitCmdFactory(isEndorserRequired, isOrdererRequired bool) (*ChaincodeCmdFactory, error) {    //初始化EndorserClient、Signer    var broadcastClient common.BroadcastClient    if isOrdererRequired {        //flags.StringVarP(&orderingEndpoint, "orderer", "o", "", "Ordering service endpoint")        //orderingEndpoint为orderer服务地址        broadcastClient, err = common.GetBroadcastClientFnc(orderingEndpoint, tls, caFile)    }}//代码在peer/chaincode/common.go

2.2、构造ChaincodeDeploymentSpec消息

spec, err := getChaincodeSpec(cmd) //构造ChaincodeSpec，参考本文1.2//构造ChaincodeDeploymentSpec，参考本文1.2，但无法打包链码文件cds, err := getChaincodeDeploymentSpec(spec, false)//代码在peer/chaincode/instantiate.go

2.3、创建lscc Proposal并签名

creator, err := cf.Signer.Serialize() //获取签名者//policyMarhsalled为flags.StringVarP(&policy, "policy", "P", common.UndefinedParamValue,即链码关联的背书策略//即调用 createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")，参考本文1.3prop, _, err := utils.CreateDeployProposalFromCDS(chainID, cds, creator, policyMarhsalled, []byte(escc), []byte(vscc))var signedProp *pb.SignedProposalsignedProp, err = utils.GetSignedProposal(prop, cf.Signer) //签名提案//代码在peer/chaincode/instantiate.go

2.4、提交并处理Proposal、获取Proposal响应并创建签名交易Envelope

proposalResponse, err := cf.EndorserClient.ProcessProposal(context.Background(), signedProp)if proposalResponse != nil {    env, err := utils.CreateSignedTx(prop, cf.Signer, proposalResponse) //由Proposal创建签名交易Envelope    return env, nil}//代码在peer/chaincode/instantiate.go

env, err := utils.CreateSignedTx(prop, cf.Signer, proposalResponse)代码如下：

func CreateSignedTx(proposal *peer.Proposal, signer msp.SigningIdentity, resps ...*peer.ProposalResponse) (*common.Envelope, error) {    hdr, err := GetHeader(proposal.Header) //反序列化为common.Header    pPayl, err := GetChaincodeProposalPayload(proposal.Payload) //反序列化为peer.ChaincodeProposalPayload    signerBytes, err := signer.Serialize() //signer序列化    shdr, err := GetSignatureHeader(hdr.SignatureHeader) //反序列化为common.SignatureHeader    if bytes.Compare(signerBytes, shdr.Creator) != 0 { //Proposal创建者需与当前签名者相同        return nil, fmt.Errorf("The signer needs to be the same as the one referenced in the header")    }    hdrExt, err := GetChaincodeHeaderExtension(hdr) //Header.ChannelHeader反序列化为peer.ChaincodeHeaderExtension    var a1 []byte    for n, r := range resps {        if n == 0 {            a1 = r.Payload            if r.Response.Status != 200 { //检查Response.Status是否为200                return nil, fmt.Errorf("Proposal response was not successful, error code %d, msg %s", r.Response.Status, r.Response.Message)            }            continue        }        if bytes.Compare(a1, r.Payload) != 0 { //检查所有ProposalResponse.Payload是否相同            return nil, fmt.Errorf("ProposalResponsePayloads do not match")        }    }    endorsements := make([]*peer.Endorsement, len(resps))    for n, r := range resps {        endorsements[n] = r.Endorsement    }    //如下为逐层构建common.Envelope    cea := &peer.ChaincodeEndorsedAction{ProposalResponsePayload: resps[0].Payload, Endorsements: endorsements}    propPayloadBytes, err := GetBytesProposalPayloadForTx(pPayl, hdrExt.PayloadVisibility)    cap := &peer.ChaincodeActionPayload{ChaincodeProposalPayload: propPayloadBytes, Action: cea}    capBytes, err := GetBytesChaincodeActionPayload(cap)    taa := &peer.TransactionAction{Header: hdr.SignatureHeader, Payload: capBytes}    taas := make([]*peer.TransactionAction, 1)    taas[0] = taa    tx := &peer.Transaction{Actions: taas}    txBytes, err := GetBytesTransaction(tx)    payl := &common.Payload{Header: hdr, Data: txBytes}    paylBytes, err := GetBytesPayload(payl)    sig, err := signer.Sign(paylBytes)    return &common.Envelope{Payload: paylBytes, Signature: sig}, nil}//代码在protos/utils/txutils.go

common.Envelope更详细内容，参考：Fabric 1.0源代码笔记 之 附录-关键数据结构

2.5、向orderer广播交易Envelope

err = cf.BroadcastClient.Send(env)//代码在peer/chaincode/instantiate.go

3、peer chaincode invoke子命令实现（调用链码）

3.0、peer chaincode invoke概述

通过invoke命令可以调用运行中的链码的方法。

3.1、初始化EndorserClient、Signer、及BroadcastClient

参考本文1.1和2.1。

cf, err = InitCmdFactory(true, true)//代码在peer/chaincode/invoke.go

3.2、构造ChaincodeInvocationSpec

spec, err := getChaincodeSpec(cmd) //构造ChaincodeSpecinvocation := &pb.ChaincodeInvocationSpec{ChaincodeSpec: spec} //构造ChaincodeInvocationSpec//代码在peer/chaincode/common.go

3.3、创建Chaincode Proposal并签名

creator, err := signer.Serialize()var prop *pb.Proposalprop, _, err = putils.CreateProposalFromCIS(pcommon.HeaderType_ENDORSER_TRANSACTION, cID, invocation, creator)var signedProp *pb.SignedProposalsignedProp, err = putils.GetSignedProposal(prop, signer) //Proposal签名//代码在peer/chaincode/common.go

3.4、提交并处理Proposal、获取Proposal响应

var proposalResp *pb.ProposalResponseproposalResp, err = endorserClient.ProcessProposal(context.Background(), signedProp)//代码在peer/chaincode/common.go

3.5、创建签名交易Envelope并向orderer广播交易Envelope

if invoke {    env, err := putils.CreateSignedTx(prop, signer, proposalResp) //创建签名交易    err = bc.Send(env) //广播交易}//代码在peer/chaincode/common.go

4、peer chaincode query子命令实现（查询链码）

与3、peer chaincode invoke子命令实现（调用链码）基本相同，区别在于提交并处理Proposal后，不再创建交易以及广播交易。