Fabric 1.0源代码笔记之 Chaincode（链码）

1、Chaincode概述

Chaincode，即链码或智能合约，代码分布在protos/peer目录、core/chaincode和core/common/ccprovider目录，目录结构如下：

protos/peer目录：
* chaincode.pb.go，ChaincodeDeploymentSpec、ChaincodeInvocationSpec结构体定义。
core/chaincode目录：
* platforms目录，链码的编写语言平台实现，如golang或java。

        * platforms.go，Platform接口定义，及部分工具函数。
        * java目录，java语言平台实现。
        * golang目录，golang语言平台实现。

core/common/ccprovider目录：ccprovider相关实现。

2、protos相关结构体定义

2.1、ChaincodeDeploymentSpec结构体定义（用于Chaincode部署）

2.1.1 ChaincodeDeploymentSpec结构体定义

type ChaincodeDeploymentSpec struct {
    ChaincodeSpec *ChaincodeSpec //ChaincodeSpec消息
    EffectiveDate *google_protobuf1.Timestamp
    CodePackage   []byte //链码文件打包
    ExecEnv       ChaincodeDeploymentSpec_ExecutionEnvironment //链码执行环境，DOCKER或SYSTEM
}

type ChaincodeDeploymentSpec_ExecutionEnvironment int32

const (
    ChaincodeDeploymentSpec_DOCKER ChaincodeDeploymentSpec_ExecutionEnvironment = 0
    ChaincodeDeploymentSpec_SYSTEM ChaincodeDeploymentSpec_ExecutionEnvironment = 1
)
//代码在protos/peer/chaincode.pb.go

2.1.2、ChaincodeSpec结构体定义

type ChaincodeSpec struct {
    Type        ChaincodeSpec_Type //链码的编写语言，GOLANG、JAVA
    ChaincodeId *ChaincodeID //ChaincodeId，链码路径、链码名称、链码版本
    Input       *ChaincodeInput //链码的具体执行参数信息
    Timeout     int32
}

type ChaincodeSpec_Type int32

const (
    ChaincodeSpec_UNDEFINED ChaincodeSpec_Type = 0
    ChaincodeSpec_GOLANG    ChaincodeSpec_Type = 1
    ChaincodeSpec_NODE      ChaincodeSpec_Type = 2
    ChaincodeSpec_CAR       ChaincodeSpec_Type = 3
    ChaincodeSpec_JAVA      ChaincodeSpec_Type = 4
)

type ChaincodeID struct {
    Path string
    Name string
    Version string
}

type ChaincodeInput struct { //链码的具体执行参数信息
    Args [][]byte
}
//代码在protos/peer/chaincode.pb.go

2.2、ChaincodeInvocationSpec结构体定义

type ChaincodeInvocationSpec struct {
    ChaincodeSpec *ChaincodeSpec //参考本文2.2
    IdGenerationAlg string
}
//代码在protos/peer/chaincode.pb.go

3、ccprovider目录相关实现

3.1、ChaincodeData结构体

type ChaincodeData struct {
    Name string
    Version string
    Escc string
    Vscc string
    Policy []byte //chaincode 实例的背书策略
    Data []byte
    Id []byte
    InstantiationPolicy []byte //实例化策略
}

//获取ChaincodeData，优先从缓存中读取
func GetChaincodeData(ccname string, ccversion string) (*ChaincodeData, error)
//代码在core/common/ccprovider/ccprovider.go

func GetChaincodeData(ccname string, ccversion string) (*ChaincodeData, error)代码如下：

var ccInfoFSProvider = &CCInfoFSImpl{}
var ccInfoCache = NewCCInfoCache(ccInfoFSProvider)

func GetChaincodeData(ccname string, ccversion string) (*ChaincodeData, error) {
    //./peer/node/start.go: ccprovider.EnableCCInfoCache()
    //如果启用ccInfoCache，优先从缓存中读取ChaincodeData
    if ccInfoCacheEnabled { 
        return ccInfoCache.GetChaincodeData(ccname, ccversion)
    }
    ccpack, err := ccInfoFSProvider.GetChaincode(ccname, ccversion)
    return ccpack.GetChaincodeData(), nil
}
//代码在core/common/ccprovider/ccprovider.go

3.2、ccInfoCacheImpl结构体

type ccInfoCacheImpl struct {
    sync.RWMutex
    cache        map[string]*ChaincodeData //ChaincodeData
    cacheSupport CCCacheSupport
}

//构造ccInfoCacheImpl
func NewCCInfoCache(cs CCCacheSupport) *ccInfoCacheImpl
//获取ChaincodeData，优先从c.cache中获取，如果c.cache中没有，则从c.cacheSupport（即CCInfoFSImpl）中获取并写入c.cache
func (c *ccInfoCacheImpl) GetChaincodeData(ccname string, ccversion string) (*ChaincodeData, error) 
//代码在core/common/ccprovider/ccinfocache.go

func (c ccInfoCacheImpl) GetChaincodeData(ccname string, ccversion string) (ChaincodeData, error) 代码如下：

func (c *ccInfoCacheImpl) GetChaincodeData(ccname string, ccversion string) (*ChaincodeData, error) {
    key := ccname + "/" + ccversion
    c.RLock()
    ccdata, in := c.cache[key] //优先从c.cache中获取
    c.RUnlock()

    if !in { //如果c.cache中没有
        var err error
        //从c.cacheSupport中获取
        ccpack, err := c.cacheSupport.GetChaincode(ccname, ccversion)
        c.Lock()
        //并写入c.cache
        ccdata = ccpack.GetChaincodeData()
        c.cache[key] = ccdata
        c.Unlock()
    }
    return ccdata, nil
}
//代码在core/common/ccprovider/ccinfocache.go

3.3、CCCacheSupport接口定义及实现

3.3.1、CCCacheSupport接口定义

type CCCacheSupport interface {
    //获取Chaincode包
    GetChaincode(ccname string, ccversion string) (CCPackage, error)
}
//代码在core/common/ccprovider/ccprovider.go

3.3.2、CCCacheSupport接口实现（即CCInfoFSImpl结构体）

type CCInfoFSImpl struct{}

//从文件系统中读取并构造CDSPackage或SignedCDSPackage
func (*CCInfoFSImpl) GetChaincode(ccname string, ccversion string) (CCPackage, error) {
    cccdspack := &CDSPackage{}
    _, _, err := cccdspack.InitFromFS(ccname, ccversion)
    if err != nil {
        //try signed CDS
        ccscdspack := &SignedCDSPackage{}
        _, _, err = ccscdspack.InitFromFS(ccname, ccversion)
        if err != nil {
            return nil, err
        }
        return ccscdspack, nil
    }
    return cccdspack, nil
}

//将ChaincodeDeploymentSpec序列化后写入文件系统
func (*CCInfoFSImpl) PutChaincode(depSpec *pb.ChaincodeDeploymentSpec) (CCPackage, error) {
    buf, err := proto.Marshal(depSpec)
    cccdspack := &CDSPackage{}
    _, err := cccdspack.InitFromBuffer(buf)
    err = cccdspack.PutChaincodeToFS()
}
//代码在core/common/ccprovider/ccprovider.go

3.4、CCPackage接口定义及实现

3.4.1、CCPackage接口定义

type CCPackage interface {
    //从字节初始化包
    InitFromBuffer(buf []byte) (*ChaincodeData, error)
    //从文件系统初始化包
    InitFromFS(ccname string, ccversion string) ([]byte, *pb.ChaincodeDeploymentSpec, error)
    //将chaincode包写入文件系统
    PutChaincodeToFS() error
    //从包中获取ChaincodeDeploymentSpec
    GetDepSpec() *pb.ChaincodeDeploymentSpec
    //从包中获取序列化的ChaincodeDeploymentSpec
    GetDepSpecBytes() []byte
    //校验ChaincodeData
    ValidateCC(ccdata *ChaincodeData) error
    //包转换为proto.Message
    GetPackageObject() proto.Message
    //获取ChaincodeData
    GetChaincodeData() *ChaincodeData
    //基于包计算获取chaincode Id
    GetId() []byte
}
//代码在core/common/ccprovider/ccprovider.go

3.4.2、CCPackage接口实现（CDSPackage）

type CDSData struct {
    CodeHash []byte //ChaincodeDeploymentSpec.CodePackage哈希
    MetaDataHash []byte //ChaincodeSpec.ChaincodeId.Name和ChaincodeSpec.ChaincodeId.Version哈希
}

type CDSPackage struct {
    buf     []byte //ChaincodeDeploymentSpec哈希
    depSpec *pb.ChaincodeDeploymentSpec //ChaincodeDeploymentSpec
    data    *CDSData
    datab   []byte
    id      []byte //id为CDSData.CodeHash和CDSData.MetaDataHash求哈希
}

//获取ccpack.id
func (ccpack *CDSPackage) GetId() []byte
//获取ccpack.depSpec
func (ccpack *CDSPackage) GetDepSpec() *pb.ChaincodeDeploymentSpec
//获取ccpack.buf，即ChaincodeDeploymentSpec哈希
func (ccpack *CDSPackage) GetDepSpecBytes() []byte
//获取ccpack.depSpec
func (ccpack *CDSPackage) GetPackageObject() proto.Message
//构造ChaincodeData
func (ccpack *CDSPackage) GetChaincodeData() *ChaincodeData
//获取ChaincodeDeploymentSpec哈希、CDSData、id
func (ccpack *CDSPackage) getCDSData(cds *pb.ChaincodeDeploymentSpec) ([]byte, []byte, *CDSData, error)
//校验CDSPackage和ChaincodeData
func (ccpack *CDSPackage) ValidateCC(ccdata *ChaincodeData) error
//[]byte反序列化为ChaincodeDeploymentSpec，构造CDSPackage，进而构造ChaincodeData
func (ccpack *CDSPackage) InitFromBuffer(buf []byte) (*ChaincodeData, error)
//从文件系统中获取ChaincodeData，即buf, err := GetChaincodePackage(ccname, ccversion)和_, err = ccpack.InitFromBuffer(buf)
func (ccpack *CDSPackage) InitFromFS(ccname string, ccversion string) ([]byte, *pb.ChaincodeDeploymentSpec, error)
//ccpack.buf写入文件，文件名为/var/hyperledger/production/chaincodes/Name.Version
func (ccpack *CDSPackage) PutChaincodeToFS() error
//代码在core/common/ccprovider/cdspackage.go

3.5、CCContext结构体

type CCContext struct { //ChaincodeD上下文
    ChainID string
    Name string
    Version string
    TxID string
    Syscc bool
    SignedProposal *pb.SignedProposal
    Proposal *pb.Proposal
    canonicalName string
}

//构造CCContext
func NewCCContext(cid, name, version, txid string, syscc bool, signedProp *pb.SignedProposal, prop *pb.Proposal) *CCContext
//name + ":" + version
func (cccid *CCContext) GetCanonicalName() string
//代码在core/common/ccprovider/ccprovider.go

4、chaincode目录相关实现

4.1、ChaincodeProviderFactory接口定义及实现

4.1.1、ChaincodeProviderFactory接口定义

type ChaincodeProviderFactory interface {
    //构造ChaincodeProvider实例
    NewChaincodeProvider() ChaincodeProvider
}

func RegisterChaincodeProviderFactory(ccfact ChaincodeProviderFactory) {
    ccFactory = ccfact
}
func GetChaincodeProvider() ChaincodeProvider {
    return ccFactory.NewChaincodeProvider()
}
//代码在core/common/ccprovider/ccprovider.go

4.1.2、ChaincodeProviderFactory接口实现

type ccProviderFactory struct {
}

func (c *ccProviderFactory) NewChaincodeProvider() ccprovider.ChaincodeProvider {
    return &ccProviderImpl{}
}

func init() {
    ccprovider.RegisterChaincodeProviderFactory(&ccProviderFactory{})
}
//代码在core/chaincode/ccproviderimpl.go

4.2、ChaincodeProvider接口定义及实现

4.2.1、ChaincodeProvider接口定义

type ChaincodeProvider interface {
    GetContext(ledger ledger.PeerLedger) (context.Context, error)
    GetCCContext(cid, name, version, txid string, syscc bool, signedProp *pb.SignedProposal, prop *pb.Proposal) interface{}
    GetCCValidationInfoFromLSCC(ctxt context.Context, txid string, signedProp *pb.SignedProposal, prop *pb.Proposal, chainID string, chaincodeID string) (string, []byte, error)
    ExecuteChaincode(ctxt context.Context, cccid interface{}, args [][]byte) (*pb.Response, *pb.ChaincodeEvent, error)
    Execute(ctxt context.Context, cccid interface{}, spec interface{}) (*pb.Response, *pb.ChaincodeEvent, error)
    ExecuteWithErrorFilter(ctxt context.Context, cccid interface{}, spec interface{}) ([]byte, *pb.ChaincodeEvent, error)
    Stop(ctxt context.Context, cccid interface{}, spec *pb.ChaincodeDeploymentSpec) error
    ReleaseContext()
}
//代码在core/common/ccprovider/ccprovider.go

4.2.2、ChaincodeProvider接口实现

type ccProviderImpl struct {
    txsim ledger.TxSimulator //交易模拟器
}

type ccProviderContextImpl struct {
    ctx *ccprovider.CCContext
}

//获取context.Context，添加TXSimulatorKey绑定c.txsim
func (c *ccProviderImpl) GetContext(ledger ledger.PeerLedger) (context.Context, error)
//构造CCContext，并构造ccProviderContextImpl
func (c *ccProviderImpl) GetCCContext(cid, name, version, txid string, syscc bool, signedProp *pb.SignedProposal, prop *pb.Proposal) interface{}
//调用GetChaincodeDataFromLSCC(ctxt, txid, signedProp, prop, chainID, chaincodeID)获取ChaincodeData中Vscc和Policy
func (c *ccProviderImpl) GetCCValidationInfoFromLSCC(ctxt context.Context, txid string, signedProp *pb.SignedProposal, prop *pb.Proposal, chainID string, chaincodeID string) (string, []byte, error)
//调用ExecuteChaincode(ctxt, cccid.(*ccProviderContextImpl).ctx, args)执行上下文中指定的链码
func (c *ccProviderImpl) ExecuteChaincode(ctxt context.Context, cccid interface{}, args [][]byte) (*pb.Response, *pb.ChaincodeEvent, error)
//调用Execute(ctxt, cccid.(*ccProviderContextImpl).ctx, spec)
func (c *ccProviderImpl) Execute(ctxt context.Context, cccid interface{}, spec interface{}) (*pb.Response, *pb.ChaincodeEvent, error)
//调用ExecuteWithErrorFilter(ctxt, cccid.(*ccProviderContextImpl).ctx, spec)
func (c *ccProviderImpl) ExecuteWithErrorFilter(ctxt context.Context, cccid interface{}, spec interface{}) ([]byte, *pb.ChaincodeEvent, error)
//调用theChaincodeSupport.Stop(ctxt, cccid.(*ccProviderContextImpl).ctx, spec)
func (c *ccProviderImpl) Stop(ctxt context.Context, cccid interface{}, spec *pb.ChaincodeDeploymentSpec) error
//调用c.txsim.Done()
func (c *ccProviderImpl) ReleaseContext() {
//代码在core/chaincode/ccproviderimpl.go

4.3、ChaincodeSupport结构体

ChaincodeSupport更详细内容，参考：Fabric 1.0源代码笔记之 Chaincode（链码） #ChaincodeSupport（链码支持服务端）

4.4、ExecuteChaincode函数（执行链码）

执行链码上下文中指定的链码。

func ExecuteChaincode(ctxt context.Context, cccid *ccprovider.CCContext, args [][]byte) (*pb.Response, *pb.ChaincodeEvent, error) {
    var spec *pb.ChaincodeInvocationSpec
    var err error
    var res *pb.Response
    var ccevent *pb.ChaincodeEvent

    spec, err = createCIS(cccid.Name, args) //构造ChaincodeInvocationSpec
    res, ccevent, err = Execute(ctxt, cccid, spec)
    return res, ccevent, err
}
//代码在core/chaincode/chaincodeexec.go

res, ccevent, err = Execute(ctxt, cccid, spec)代码如下：

func Execute(ctxt context.Context, cccid *ccprovider.CCContext, spec interface{}) (*pb.Response, *pb.ChaincodeEvent, error) {
    var err error
    var cds *pb.ChaincodeDeploymentSpec
    var ci *pb.ChaincodeInvocationSpec

    cctyp := pb.ChaincodeMessage_INIT //初始化
    if cds, _ = spec.(*pb.ChaincodeDeploymentSpec); cds == nil { //优先判断ChaincodeDeploymentSpec
        if ci, _ = spec.(*pb.ChaincodeInvocationSpec); ci == nil { //其次判断ChaincodeInvocationSpec
            panic("Execute should be called with deployment or invocation spec")
        }
        cctyp = pb.ChaincodeMessage_TRANSACTION //交易
    }

    _, cMsg, err := theChaincodeSupport.Launch(ctxt, cccid, spec)
    var ccMsg *pb.ChaincodeMessage
    ccMsg, err = createCCMessage(cctyp, cccid.TxID, cMsg)
    resp, err := theChaincodeSupport.Execute(ctxt, cccid, ccMsg, theChaincodeSupport.executetimeout)
    if resp.ChaincodeEvent != nil {
        resp.ChaincodeEvent.ChaincodeId = cccid.Name
        resp.ChaincodeEvent.TxId = cccid.TxID
    }
    if resp.Type == pb.ChaincodeMessage_COMPLETED {
        res := &pb.Response{}
        unmarshalErr := proto.Unmarshal(resp.Payload, res)
        return res, resp.ChaincodeEvent, nil
    }
}
//代码在core/chaincode

5、platforms（链码的编写语言平台）

参考上一篇文章

区块链教程Fabric1.0源代码分析Chaincode（链码）体系总结-兄弟连

Fabric 1.0源代码笔记之 Chaincode（链码）

1、Chaincode概述

2、protos相关结构体定义

2.1、ChaincodeDeploymentSpec结构体定义（用于Chaincode部署）

2.1.1 ChaincodeDeploymentSpec结构体定义

2.1.2、ChaincodeSpec结构体定义

2.2、ChaincodeInvocationSpec结构体定义

3、ccprovider目录相关实现

3.1、ChaincodeData结构体

3.2、ccInfoCacheImpl结构体

3.3、CCCacheSupport接口定义及实现

3.3.1、CCCacheSupport接口定义

3.3.2、CCCacheSupport接口实现（即CCInfoFSImpl结构体）

3.4、CCPackage接口定义及实现

3.4.1、CCPackage接口定义

3.4.2、CCPackage接口实现（CDSPackage）

3.5、CCContext结构体

4、chaincode目录相关实现

4.1、ChaincodeProviderFactory接口定义及实现

4.1.1、ChaincodeProviderFactory接口定义

4.1.2、ChaincodeProviderFactory接口实现

4.2、ChaincodeProvider接口定义及实现

4.2.1、ChaincodeProvider接口定义

4.2.2、ChaincodeProvider接口实现

4.3、ChaincodeSupport结构体

4.4、ExecuteChaincode函数（执行链码）

5、platforms（链码的编写语言平台）

热门文章

最新文章

相关电子书

相关实验场景

区块链教程Fabric1.0源代码分析Chaincode（链码）体系总结-兄弟连

Fabric 1.0源代码笔记 之 Chaincode（链码）

1、Chaincode概述

2、protos相关结构体定义

2.1、ChaincodeDeploymentSpec结构体定义（用于Chaincode部署）

2.1.1 ChaincodeDeploymentSpec结构体定义

2.1.2、ChaincodeSpec结构体定义

2.2、ChaincodeInvocationSpec结构体定义

3、ccprovider目录相关实现

3.1、ChaincodeData结构体

3.2、ccInfoCacheImpl结构体

3.3、CCCacheSupport接口定义及实现

3.3.1、CCCacheSupport接口定义

3.3.2、CCCacheSupport接口实现（即CCInfoFSImpl结构体）

3.4、CCPackage接口定义及实现

3.4.1、CCPackage接口定义

3.4.2、CCPackage接口实现（CDSPackage）

3.5、CCContext结构体

4、chaincode目录相关实现

4.1、ChaincodeProviderFactory接口定义及实现

4.1.1、ChaincodeProviderFactory接口定义

4.1.2、ChaincodeProviderFactory接口实现

4.2、ChaincodeProvider接口定义及实现

4.2.1、ChaincodeProvider接口定义

4.2.2、ChaincodeProvider接口实现

4.3、ChaincodeSupport结构体

4.4、ExecuteChaincode函数（执行链码）

5、platforms（链码的编写语言平台）

热门文章

最新文章

相关电子书

相关实验场景

Fabric 1.0源代码笔记之 Chaincode（链码）