上一篇介绍了已有的scc,但如果需要构建一个自己的scc则必须了解它是如何生效的。
首先在scc目录下找到统一的入口register.go
// CreateSysCCs creates all of the system chaincodes which are compiled into fabric
func CreateSysCCs(ccp ccprovider.ChaincodeProvider, p *Provider, aclProvider aclmgmt.ACLProvider) []*SystemChaincode {
return builtInSystemChaincodes(ccp, p, aclProvider)
}
在peer/node/start.go内调用该方法
//Now that chaincode is initialized, register all system chaincodes.
sccs := scc.CreateSysCCs(ccp, sccp, aclProvider)
for _, cc := range sccs {
sccp.RegisterSysCC(cc)
}
pb.RegisterChaincodeSupportServer(grpcServer.Server(), ccSrv)
第一段代码返回的时scc的配置,为代码内写死的一段配置
func builtInSystemChaincodes(ccp ccprovider.ChaincodeProvider, p *Provider, aclProvider aclmgmt.ACLProvider) []*SystemChaincode {
return []*SystemChaincode{
{
Enabled: true,
Name: "cscc",
Path: "github.com/hyperledger/fabric/core/scc/cscc",
InitArgs: nil,
Chaincode: cscc.New(ccp, p, aclProvider),
InvokableExternal: true, // cscc is invoked to join a channel
},
{
Enabled: true,
Name: "lscc",
Path: "github.com/hyperledger/fabric/core/scc/lscc",
InitArgs: nil,
Chaincode: lscc.New(p, aclProvider),
InvokableExternal: true, // lscc is invoked to deploy new chaincodes
InvokableCC2CC: true, // lscc can be invoked by other chaincodes
},
{
Enabled: true,
Name: "qscc",
Path: "github.com/hyperledger/fabric/core/scc/qscc",
InitArgs: nil,
Chaincode: qscc.New(aclProvider),
InvokableExternal: true, // qscc can be invoked to retrieve blocks
InvokableCC2CC: true, // qscc can be invoked to retrieve blocks also by a cc
},
}
}
综上,它是通过获取定好的scc配置进行实例化,所以只需在此处添加类似路径即可完成自定义系统chain code的实例化。