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.gocf, 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.go1.2、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.goccpackmsg, 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.gospec, 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.gocds, 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.go1.3、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.SignedProposal
signedProp, err = utils.GetSignedProposal(prop, cf.Signer) //签名提案
//代码在peer/chaincode/install.gocreateProposalFromCDS(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.go1.4、提交并处理Proposal
proposalResponse, err := cf.EndorserClient.ProcessProposal(context.Background(), signedProp)
//代码在peer/chaincode/install.go2、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.gofunc 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.go2.2、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.go2.3、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1.3
prop, _, err := utils.CreateDeployProposalFromCDS(chainID, cds, creator, policyMarhsalled, []byte(escc), []byte(vscc))
var signedProp *pb.SignedProposal
signedProp, err = utils.GetSignedProposal(prop, cf.Signer) //签名提案
//代码在peer/chaincode/instantiate.go2.4、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.goenv, 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.gocommon.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.go3、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.go3.2、构造ChaincodeInvocationSpec
spec, err := getChaincodeSpec(cmd) //构造ChaincodeSpec
invocation := &pb.ChaincodeInvocationSpec{ChaincodeSpec: spec} //构造ChaincodeInvocationSpec
//代码在peer/chaincode/common.go3.3、创建Chaincode Proposal并签名
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签名
//代码在peer/chaincode/common.go3.4、提交并处理Proposal、获取Proposal响应
var proposalResp *pb.ProposalResponse
proposalResp, err = endorserClient.ProcessProposal(context.Background(), signedProp)
//代码在peer/chaincode/common.go3.5、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.go4、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。