摘要：兄弟連區塊鏈教程源代碼分析命令及子命令實現，年下半年，區塊鏈行業正逐漸褪去發展之初的浮躁回歸理性，表面上看相關人才需求與身價似乎正在回落。

　　兄弟連區塊鏈教程Fabric1.0源代碼分析Peer peer chaincode命令及子命令實現，2018年下半年，區塊鏈行業正逐漸褪去發展之初的浮躁、回歸理性，表面上看相關人才需求與身價似乎正在回落。但事實上，正是初期泡沫的漸退，讓人們更多的關注點放在了區塊鏈真正的技術之上。

peer chaincode install，將鏈碼的源碼和環境封裝為一個鏈碼安裝打包文件，并傳輸到背書節點。

peer chaincode install支持如下兩種方式：

指定代碼方式，peer chaincode install -n <鏈碼名稱> -v <鏈碼版本> -p <鏈碼路徑>

基于鏈碼打包文件方式，peer chaincode install <鏈碼打包文件>

有個圖3

cf, err = InitCmdFactory(true, false)
//代碼在peer/chaincode/install.go

cf, err = InitCmdFactory(true, false)代碼如下：

func InitCmdFactory(isEndorserRequired, isOrdererRequired bool) (*ChaincodeCmdFactory, error) {
????var err error
????var endorserClient pb.EndorserClient
????if isEndorserRequired {
????????//獲取Endorser客戶端
????????endorserClient, err = common.GetEndorserClientFnc() //func GetEndorserClient() (pb.EndorserClient, error)
????}
????//獲取簽名
????signer, err := common.GetDefaultSignerFnc()
????var broadcastClient common.BroadcastClient
????if isOrdererRequired {
????????//此處未用到，暫略
????}
????//構造ChaincodeCmdFactory
????return &ChaincodeCmdFactory{
????????EndorserClient:  endorserClient,
????????Signer:          signer,
????????BroadcastClient: broadcastClient,
????}, nil
}
//代碼在peer/chaincode/common.go

if ccpackfile == "" { //指定代碼方式，重新構造構造ChaincodeDeploymentSpec消息
????ccpackmsg, err = genChaincodeDeploymentSpec(cmd, chaincodeName, chaincodeVersion)
} else { //基于鏈碼打包文件方式，直接讀取ChaincodeDeploymentSpec消息
????var cds *pb.ChaincodeDeploymentSpec
????ccpackmsg, cds, err = getPackageFromFile(ccpackfile)
}
//代碼在peer/chaincode/install.go

ccpackmsg, err = genChaincodeDeploymentSpec(cmd, chaincodeName, chaincodeVersion)代碼如下：

func genChaincodeDeploymentSpec(cmd *cobra.Command, chaincodeName, chaincodeVersion string) (*pb.ChaincodeDeploymentSpec, error) {
????//已經存在，直接報錯
????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
}
//代碼在peer/chaincode/install.go

spec, err := getChaincodeSpec(cmd)代碼如下：

func getChaincodeSpec(cmd *cobra.Command) (*pb.ChaincodeSpec, error) {
????spec := &pb.ChaincodeSpec{}
????err := checkChaincodeCmdParams(cmd) //檢查參數合法性
????input := &pb.ChaincodeInput{}
????//flags.StringVarP(&chaincodeCtorJSON, "ctor", "c", "{}"，ctor為鏈碼具體執行參數信息，默認為{}
????err := json.Unmarshal([]byte(chaincodeCtorJSON), &input)
????//flags.StringVarP(&chaincodeLang, "lang", "l", "golang"，lang為鏈碼的編寫語言，默認為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
}
//代碼在peer/chaincode/common.go

cds, err := getChaincodeDeploymentSpec(spec, true)代碼如下：

func getChaincodeDeploymentSpec(spec *pb.ChaincodeSpec, crtPkg bool) (*pb.ChaincodeDeploymentSpec, error) {
????var codePackageBytes []byte
????if chaincode.IsDevMode() == false && crtPkg {
????????var err error
????????err = checkSpec(spec) //檢查spec合法性
????????codePackageBytes, err = container.GetChaincodePackageBytes(spec) //打包鏈碼文件及依賴文件
????}
????//構造ChaincodeDeploymentSpec
????chaincodeDeploymentSpec := &pb.ChaincodeDeploymentSpec{ChaincodeSpec: spec, CodePackage: codePackageBytes}
????return chaincodeDeploymentSpec, nil
//代碼在peer/chaincode/common.go

creator, err := cf.Signer.Serialize() //獲取簽名者
//按ChaincodeDeploymentSpec構造Proposal，即鏈碼ChaincodeDeploymentSpec消息作為參數傳遞給lscc系統鏈碼并調用
//調用createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")
prop, _, err := utils.CreateInstallProposalFromCDS(msg, creator) 
var signedProp *pb.SignedProposal
signedProp, err = utils.GetSignedProposal(prop, cf.Signer) //簽名提案
//代碼在peer/chaincode/install.go

createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")代碼如下：

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{ //構造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)
}
//代碼在protos/utils/proputils.go

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

peer chaincode instantiate命令通過構造生命周期管理系統鏈碼（LSCC）的交易，將安裝過的鏈碼在指定通道上進行實例化調用。
在peer上創建容器啟動，并執行初始化操作。

與2.1接近，附BroadcastClient初始化代碼如下：

cf, err = InitCmdFactory(true, true)
//代碼在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為orderer服務地址
????????broadcastClient, err = common.GetBroadcastClientFnc(orderingEndpoint, tls, caFile)
????}
}
//代碼在peer/chaincode/common.go

BroadcastClient更詳細內容，參考Fabric 1.0源代碼筆記 之 Peer #BroadcastClient（Broadcast客戶端）

spec, err := getChaincodeSpec(cmd) //構造ChaincodeSpec，參考本文1.2
//構造ChaincodeDeploymentSpec，參考本文1.2，但無法打包鏈碼文件
cds, err := getChaincodeDeploymentSpec(spec, false)
//代碼在peer/chaincode/instantiate.go

creator, err := cf.Signer.Serialize() //獲取簽名者
//policyMarhsalled為flags.StringVarP(&policy, "policy", "P", common.UndefinedParamValue,即鏈碼關聯的背書策略
//即調用 createProposalFromCDS(chainID, cds, creator, policy, escc, vscc, "deploy")，參考本文1.3
prop, _, err := utils.CreateDeployProposalFromCDS(chainID, cds, creator, policyMarhsalled, []byte(escc), []byte(vscc))
var signedProp *pb.SignedProposal
signedProp, err = utils.GetSignedProposal(prop, cf.Signer) //簽名提案
//代碼在peer/chaincode/instantiate.go

proposalResponse, err := cf.EndorserClient.ProcessProposal(context.Background(), signedProp)
if proposalResponse != nil {
????env, err := utils.CreateSignedTx(prop, cf.Signer, proposalResponse) //由Proposal創建簽名交易Envelope
????return env, nil
}
//代碼在peer/chaincode/instantiate.go

env, err := utils.CreateSignedTx(prop, cf.Signer, proposalResponse)代碼如下：

func CreateSignedTx(proposal *peer.Proposal, signer msp.SigningIdentity, resps ...*peer.ProposalResponse) (*common.Envelope, error) {
????hdr, err := GetHeader(proposal.Header) //反序列化為common.Header
????pPayl, err := GetChaincodeProposalPayload(proposal.Payload) //反序列化為peer.ChaincodeProposalPayload
????signerBytes, err := signer.Serialize() //signer序列化
????shdr, err := GetSignatureHeader(hdr.SignatureHeader) //反序列化為common.SignatureHeader
????if bytes.Compare(signerBytes, shdr.Creator) != 0 { //Proposal創建者需與當前簽名者相同
????????return nil, fmt.Errorf("The signer needs to be the same as the one referenced in the header")
????}
????hdrExt, err := GetChaincodeHeaderExtension(hdr) //Header.ChannelHeader反序列化為peer.ChaincodeHeaderExtension

????var a1 []byte
????for n, r := range resps {
????????if n == 0 {
????????????a1 = r.Payload
????????????if r.Response.Status != 200 { //檢查Response.Status是否為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 { //檢查所有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
????}

????//如下為逐層構建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
}

//代碼在protos/utils/txutils.go

common.Envelope更詳細內容，參考：Fabric 1.0源代碼筆記 之 附錄-關鍵數據結構

err = cf.BroadcastClient.Send(env)
//代碼在peer/chaincode/instantiate.go

通過invoke命令可以調用運行中的鏈碼的方法。
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參考本文1.1和2.1。

cf, err = InitCmdFactory(true, true)
//代碼在peer/chaincode/invoke.go

spec, err := getChaincodeSpec(cmd) //構造ChaincodeSpec
invocation := &pb.ChaincodeInvocationSpec{ChaincodeSpec: spec} //構造ChaincodeInvocationSpec
//代碼在peer/chaincode/common.go

creator, err := signer.Serialize()
var prop *pb.Proposal
prop, _, err = putils.CreateProposalFromCIS(pcommon.HeaderType_ENDORSER_TRANSACTION, cID, invocation, creator)
var signedProp *pb.SignedProposal
signedProp, err = putils.GetSignedProposal(prop, signer) //Proposal簽名
//代碼在peer/chaincode/common.go

var proposalResp *pb.ProposalResponse
proposalResp, err = endorserClient.ProcessProposal(context.Background(), signedProp)
//代碼在peer/chaincode/common.go

if invoke {
????env, err := putils.CreateSignedTx(prop, signer, proposalResp) //創建簽名交易
????err = bc.Send(env) //廣播交易
}
//代碼在peer/chaincode/common.go

與3、peer chaincode invoke子命令實現（調用鏈碼）基本相同，區別在于提交并處理Proposal后，不再創建交易以及廣播交易。