Fabric 1.0源代码笔记之 Orderer #multichain（多链支持包）

兄弟连区块链教程Fabric1.0源代码分析Orderer multichain多链支持包

1、multichain概述

multichain代码集中在orderer/multichain目录下，目录结构如下：

manager.go，Manager接口定义及实现。

chainsupport.go，ChainSupport接口定义及实现。

systemchain.go，system chain。

2、Manager接口定义及实现

2.1、Manager接口定义

用于链的创建和访问。

type Manager interface {    //获取ChainSupport，以及判断链是否存在    GetChain(chainID string) (ChainSupport, bool)    //获取系统通道的通道ID    SystemChannelID() string    //支持通道创建请求    NewChannelConfig(envConfigUpdate *cb.Envelope) (configtxapi.Manager, error)}//代码在orderer/multichain/manager.go

2.2、Manager接口实现

Manager接口实现，即multiLedger结构体及方法。

type multiLedger struct {    chains          map[string]*chainSupport    consenters      map[string]Consenter    ledgerFactory   ledger.Factory    signer          crypto.LocalSigner    systemChannelID string    systemChannel   *chainSupport}type configResources struct {    configtxapi.Manager}type ledgerResources struct {    *configResources    ledger ledger.ReadWriter}//代码在orderer/multichain/manager.go

涉及方法如下：

func (cr *configResources) SharedConfig() config.Orderer//获取配置交易Envelopefunc getConfigTx(reader ledger.Reader) *cb.Envelope//构造multiLedgerfunc NewManagerImpl(ledgerFactory ledger.Factory, consenters map[string]Consenter, signer crypto.LocalSigner) Manager//获取系统链IDfunc (ml *multiLedger) SystemChannelID() string//按chainID获取ChainSupportfunc (ml *multiLedger) GetChain(chainID string) (ChainSupport, bool)//构造ledgerResourcesfunc (ml *multiLedger) newLedgerResources(configTx *cb.Envelope) *ledgerResources//创建新链func (ml *multiLedger) newChain(configtx *cb.Envelope)//通道或链的个数func (ml *multiLedger) channelsCount() int//支持创建新的通道func (ml *multiLedger) NewChannelConfig(envConfigUpdate *cb.Envelope) (configtxapi.Manager, error)//代码在orderer/multichain/manager.go

func NewManagerImpl(ledgerFactory ledger.Factory, consenters map[string]Consenter, signer crypto.LocalSigner) Manager代码如下：

func NewManagerImpl(ledgerFactory ledger.Factory, consenters map[string]Consenter, signer crypto.LocalSigner) Manager {    ml := &multiLedger{        chains:        make(map[string]*chainSupport),        ledgerFactory: ledgerFactory,        consenters:    consenters,        signer:        signer,    }    existingChains := ledgerFactory.ChainIDs()    for _, chainID := range existingChains {        rl, err := ledgerFactory.GetOrCreate(chainID)        configTx := getConfigTx(rl)        ledgerResources := ml.newLedgerResources(configTx)        chainID := ledgerResources.ChainID()        if _, ok := ledgerResources.ConsortiumsConfig(); ok { //系统链            chain := newChainSupport(createSystemChainFilters(ml, ledgerResources), ledgerResources, consenters, signer)            ml.chains[chainID] = chain            ml.systemChannelID = chainID            ml.systemChannel = chain            defer chain.start()        } else { //普通链            chain := newChainSupport(createStandardFilters(ledgerResources), ledgerResources, consenters, signer)            ml.chains[chainID] = chain            chain.start()        }    }    return ml}//代码在orderer/multichain/manager.go

3、ChainSupport接口定义及实现

3.1、ChainSupport接口定义

type ChainSupport interface {    PolicyManager() policies.Manager //策略管理    Reader() ledger.Reader    Errored() <-chan struct{}    broadcast.Support    ConsenterSupport //嵌入ConsenterSupport接口    Sequence() uint64    //支持通道更新    ProposeConfigUpdate(env *cb.Envelope) (*cb.ConfigEnvelope, error)}type ConsenterSupport interface {    crypto.LocalSigner    BlockCutter() blockcutter.Receiver    SharedConfig() config.Orderer    CreateNextBlock(messages []*cb.Envelope) *cb.Block    WriteBlock(block *cb.Block, committers []filter.Committer, encodedMetadataValue []byte) *cb.Block    ChainID() string    Height() uint64}type Consenter interface { //定义支持排序机制    HandleChain(support ConsenterSupport, metadata *cb.Metadata) (Chain, error)}type Chain interface {    //接受消息    Enqueue(env *cb.Envelope) bool    Errored() <-chan struct{}    Start() //开始    Halt() //挂起}//代码在orderer/multichain/chainsupport.go

3.2、ChainSupport和ConsenterSupport接口实现

ChainSupport接口实现，即chainSupport结构体及方法。

type chainSupport struct {    *ledgerResources    chain         Chain    cutter        blockcutter.Receiver    filters       *filter.RuleSet    signer        crypto.LocalSigner    lastConfig    uint64    lastConfigSeq uint64}//代码在orderer/multichain/chainsupport.go