Fabric 对区块内交易的校验

func (v *TxValidator) Validate(block *common.Block) error {
	txsfltr := txflags.New(len(block.Data.Data)) // []uint8，校验结果状态码最大为 255，校验结果初始化成 TxValidationCode_NOT_VALIDATED
    txidArray := make([]string, len(block.Data.Data))
    results := make(chan *blockValidationResult)
    go func() {
		for tIdx, d := range block.Data.Data { // tIdx 是交易在区块中的索引
			v.Semaphore.Acquire(context.Background()) // 控制并发数
			go func(index int, data []byte) {
				defer v.Semaphore.Release()
				v.validateTx(&blockValidationRequest{ // 具体校验逻辑
					d:     data,
					block: block,
					tIdx:  index,
				}, results)
			}(tIdx, d)
		}
	}()
	for i := 0; i < len(block.Data.Data); i++ {
		res := <-results
		if res.err != nil {
			// if there is an error, we buffer its value, wait for all workers to complete validation
			if err == nil || res.tIdx < errPos { // 标记第一个出现 err 的 tx 的位置，记录它的 err
				err = res.err
				errPos = res.tIdx
			}
		} else {
			txsfltr.SetFlag(res.tIdx, res.validationCode) // 设置校验结果
			if res.validationCode == peer.TxValidationCode_VALID {
				txidArray[res.tIdx] = res.txid // txidArray 记录合法交易的 tx id
			}
		}
	}
    // 返回第一个出现的 err 
	if err != nil {
		return err
	}
    // 将 txidArray 中重复实现的 txid 在 txsfltr 中打上 TxValidationCode_DUPLICATE_TXID 标记
    markTXIdDuplicates(txidArray, txsfltr)
    // 确保所有交易都得到了校验
    err = v.allValidated(txsfltr, block)
	if err != nil {
		return err
	}
    // Initialize metadata structure
	protoutil.InitBlockMetadata(block)
	block.Metadata.Metadata[common.BlockMetadataIndex_TRANSACTIONS_FILTER] = txsfltr
}

type TxValidationCode int32
const (
	TxValidationCode_VALID                        TxValidationCode = 0
	TxValidationCode_NIL_ENVELOPE                 TxValidationCode = 1
	TxValidationCode_BAD_PAYLOAD                  TxValidationCode = 2
	TxValidationCode_BAD_COMMON_HEADER            TxValidationCode = 3
	TxValidationCode_BAD_CREATOR_SIGNATURE        TxValidationCode = 4
	TxValidationCode_INVALID_ENDORSER_TRANSACTION TxValidationCode = 5
	TxValidationCode_INVALID_CONFIG_TRANSACTION   TxValidationCode = 6
	TxValidationCode_UNSUPPORTED_TX_PAYLOAD       TxValidationCode = 7
	TxValidationCode_BAD_PROPOSAL_TXID            TxValidationCode = 8
	TxValidationCode_DUPLICATE_TXID               TxValidationCode = 9
	TxValidationCode_ENDORSEMENT_POLICY_FAILURE   TxValidationCode = 10
	TxValidationCode_MVCC_READ_CONFLICT           TxValidationCode = 11
	TxValidationCode_PHANTOM_READ_CONFLICT        TxValidationCode = 12
	TxValidationCode_UNKNOWN_TX_TYPE              TxValidationCode = 13
	TxValidationCode_TARGET_CHAIN_NOT_FOUND       TxValidationCode = 14
	TxValidationCode_MARSHAL_TX_ERROR             TxValidationCode = 15
	TxValidationCode_NIL_TXACTION                 TxValidationCode = 16
	TxValidationCode_EXPIRED_CHAINCODE            TxValidationCode = 17
	TxValidationCode_CHAINCODE_VERSION_CONFLICT   TxValidationCode = 18
	TxValidationCode_BAD_HEADER_EXTENSION         TxValidationCode = 19
	TxValidationCode_BAD_CHANNEL_HEADER           TxValidationCode = 20
	TxValidationCode_BAD_RESPONSE_PAYLOAD         TxValidationCode = 21
	TxValidationCode_BAD_RWSET                    TxValidationCode = 22
	TxValidationCode_ILLEGAL_WRITESET             TxValidationCode = 23
	TxValidationCode_INVALID_WRITESET             TxValidationCode = 24
	TxValidationCode_INVALID_CHAINCODE            TxValidationCode = 25
	TxValidationCode_NOT_VALIDATED                TxValidationCode = 254
	TxValidationCode_INVALID_OTHER_REASON         TxValidationCode = 255
)

func (l *kvLedger) CommitLegacy(pvtdataAndBlock *ledger.BlockAndPvtData, commitOpts *ledger.CommitOptions) error {
    txstatsInfo, updateBatchBytes, err := l.txmgr.ValidateAndPrepare(pvtdataAndBlock, true)

    // 提交区块
    if err = l.commitToPvtAndBlockStore(pvtdataAndBlock); err != nil {
		return err
	}
    // 提交到状态库（l.txmgr.current）
    if err = l.txmgr.Commit(); err != nil {
		panic(errors.WithMessage(err, "error during commit to txmgr"))
	}

    if l.historyDB != nil {
		logger.Debugf("[%s] Committing block [%d] transactions to history database", l.ledgerID, blockNo)
		if err := l.historyDB.Commit(block); err != nil {
			panic(errors.WithMessage(err, "Error during commit to history db"))
		}
	}
    l.updateBlockStats(
		elapsedBlockProcessing,
		elapsedBlockstorageAndPvtdataCommit,
		elapsedCommitState,
		txstatsInfo,
	)
}

func (txmgr *LockBasedTxMgr) ValidateAndPrepare(blockAndPvtdata *ledger.BlockAndPvtData, doMVCCValidation bool) ([]*validation.TxStatInfo, []byte, error) {
    batch, txstatsInfo, err := txmgr.commitBatchPreparer.ValidateAndPrepareBatch(blockAndPvtdata, doMVCCValidation)
	if err != nil {
		txmgr.reset()
		return nil, nil, err
	}
    txmgr.current = &current{block: block, batch: batch}
    if err := txmgr.invokeNamespaceListeners(); err != nil {
		txmgr.reset()
		return nil, nil, err
	}
    updateBytes, err := deterministicBytesForPubAndHashUpdates(batch)
	return txstatsInfo, updateBytes, err
}

// * ValidateAndPrepareBatch performs validation of transactions in the block and prepares the batch of final writes
func (p *CommitBatchPreparer) ValidateAndPrepareBatch(blockAndPvtdata *ledger.BlockAndPvtData,
	doMVCCValidation bool) (*privacyenabledstate.UpdateBatch, []*TxStatInfo, error) {
    // 包含 MVCC 校验，校验通过的 tx 才会被加入 batch，最终被应用到状态数据库
    if pubAndHashUpdates, err = p.validator.validateAndPrepareBatch(internalBlock, doMVCCValidation); err != nil {
		return nil, nil, err
	}
	if pvtUpdates, err = validateAndPreparePvtBatch(
		internalBlock,
		p.db,
		pubAndHashUpdates,
		blockAndPvtdata.PvtData,
		p.customTxProcessors,
	); err != nil {
		return nil, nil, err
	}
    txsFilter := txflags.ValidationFlags(blk.Metadata.Metadata[common.BlockMetadataIndex_TRANSACTIONS_FILTER]) // 类型转换
	for i := range txsFilter {
		txsStatInfo[i].ValidationCode = txsFilter.Flag(i)
	}
	return &privacyenabledstate.UpdateBatch{
		PubUpdates:  pubAndHashUpdates.publicUpdates,
		HashUpdates: pubAndHashUpdates.hashUpdates,
		PvtUpdates:  pvtUpdates,
	}, txsStatInfo, nil
}