Fabric 1.0源代码分析(43) Tx（Transaction 交易）
# Fabric 1.0源代码笔记 之 Tx（Transaction 交易）
## 1、Tx概述
Tx，即Transaction，交易或事务。
Tx代码分布目录结构如下：
* protos/common/common.pb.go，交易的封装即Envelope结构体。也包括Payload、Header、ChannelHeader和SignatureHeader。
* protos/utils目录，交易相关部分工具函数，包括txutils.go、proputils.go和commonutils.go。
* core/ledger/kvledger/txmgmt目录
* rwsetutil目录，读写集相关结构体及方法。
* version目录，version.Height结构体及方法。
* validator目录，Validator接口及实现。
* txmgr目录，TxMgr接口及实现。
## 2、交易的封装Envelope结构体
### 2.1、Envelope结构体
Envelope直译为信封，封装Payload和Signature。
```go
type
Envelope
struct {
//用签名包装Payload，以便对信息做身份验证
Payload []
byte
//Payload序列化
Signature []
byte
//Payload header中指定的创建者签名
}
//代码在protos/common/common.pb.go
```
### 2.2、Payload相关结构体
Payload直译为有效载荷。Payload结构体：
```go
type
Payload
struct {
Header *Header
//Header
Data []
byte
//Transaction序列化
}
//代码在protos/common/common.pb.go
```
Header结构体：
```go
type
Header
struct {
ChannelHeader []
byte
SignatureHeader []
byte
}
//代码在protos/common/common.pb.go
```
ChannelHeader结构体：
```go
type
ChannelHeader
struct {
Type
int32
Version
int32
//消息协议版本
Timestamp *google_protobuf.Timestamp
//创建消息时的本地时间
ChannelId
string
//消息绑定的ChannelId
TxId
string
//TxId
Epoch
uint64
//纪元
Extension []
byte
//可附加的扩展
}
//代码在protos/common/common.pb.go
```
补充HeaderType:
```go
type
HeaderType
int32
const (
HeaderType_MESSAGE HeaderType =
0
HeaderType_CONFIG HeaderType =
1
HeaderType_CONFIG_UPDATE HeaderType =
2
HeaderType_ENDORSER_TRANSACTION HeaderType =
3
HeaderType_ORDERER_TRANSACTION HeaderType =
4
HeaderType_DELIVER_SEEK_INFO HeaderType =
5
HeaderType_CHAINCODE_PACKAGE HeaderType =
6
)
//代码在protos/common/common.pb.go
```
SignatureHeader结构体：
```go
type
SignatureHeader
struct {
Creator []
byte
//消息的创建者, 指定为证书链
Nonce []
byte
//可能只使用一次的任意数字，可用于检测重播攻击
}
//代码在protos/common/common.pb.go
```
### 2.3、Transaction相关结构体
Transaction结构体：
```go
type
Transaction
struct {
Actions []*TransactionAction
//Payload.Data是个TransactionAction数组，容纳每个交易
}
//代码在protos/peer/transaction.pb.go
```
TransactionAction结构体：
```go
type
TransactionAction
struct {
Header []
byte
Payload []
byte
}
//代码在protos/peer/transaction.pb.go
```
### 2.4、ChaincodeActionPayload相关结构体
ChaincodeActionPayload结构体：
```go
type
ChaincodeActionPayload
struct {
ChaincodeProposalPayload []
byte
Action *ChaincodeEndorsedAction
}
//代码在protos/peer/transaction.pb.go
```
ChaincodeEndorsedAction结构体：
```go
type
ChaincodeEndorsedAction
struct {
ProposalResponsePayload []
byte
//ProposalResponsePayload序列化
Endorsements []*Endorsement
}
//代码在protos/peer/transaction.pb.go
```
ProposalResponsePayload结构体：
```go
type
ProposalResponsePayload
struct {
ProposalHash []
byte
Extension []
byte
//ChaincodeAction序列化
}
//代码在protos/peer/proposal_response.pb.go
```
ChaincodeAction结构体：
```go
type
ChaincodeAction
struct {
Results []
byte
//TxRwSet序列化
Events []
byte
Response *Response
ChaincodeId *ChaincodeID
}
//代码在protos/peer/proposal.pb.go
```
## 3、交易验证代码TxValidationFlags
TxValidationFlags是交易验证代码的数组，在commiter验证块时使用。
```go
type
TxValidationFlags []
uint8
//创建TxValidationFlags数组
func NewTxValidationFlags(size
int) TxValidationFlags
//为指定的交易设置交易验证代码
func (obj TxValidationFlags) SetFlag(txIndex
int, flag peer.TxValidationCode)
//获取指定交易的交易验证代码
func (obj TxValidationFlags) Flag(txIndex
int) peer.TxValidationCode
//检查指定的交易是否有效
func (obj TxValidationFlags) IsValid(txIndex
int)
bool
//检查指定的交易是否无效
func (obj TxValidationFlags) IsInvalid(txIndex
int)
bool
//指定交易的交易验证代码与flag比较，相同为true
func (obj TxValidationFlags) IsSetTo(txIndex
int, flag peer.TxValidationCode)
bool
//代码在core/ledger/util/txvalidationflags.go
```
补充peer.TxValidationCode：
```go
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_OTHER_REASON TxValidationCode =
255
)
//代码在protos/peer/transaction.pb.go
```
## 4、交易相关部分工具函数（protos/utils包）
putils更详细内容，参考：[
Fabric 1.0源代码笔记 之 putils（protos/utils工具包）]
## 5、RWSet（读写集）
RWSet更详细内容，参考：[
Fabric 1.0源代码笔记 之 Tx #RWSet（读写集）]
## 6、version.Height结构体及方法
```go
type
Height
struct {
BlockNum
uint64
//区块编号
TxNum
uint64
//交易编号
}
func NewHeight(blockNum, txNum
uint64) *Height
//构造Height
func NewHeightFromBytes(b []
byte) (*Height,
int)
//[]byte反序列化构造Height
func (h *Height) ToBytes() []
byte
//Height序列化
func (h *Height) Compare(h1 *Height)
int
//比较两个Height
func AreSame(h1 *Height, h2 *Height)
bool
//比较两个Height是否相等
//代码在core/ledger/kvledger/txmgmt/version/version.go
```
## 7、Validator接口及实现（验证读写集）
### 7.1、Validator接口定义
```go
type
Validator
interface {
//验证和准备批处理
ValidateAndPrepareBatch(block *common.Block, doMVCCValidation
bool) (*statedb.UpdateBatch,
error)
}
//代码在core/ledger/kvledger/txmgmt/validator/validator.go
```
### 7.2、Validator接口实现
Validator接口实现，即statebasedval.Validator结构体及方法。Validator结构体定义如下：
```go
type
Validator
struct {
db statedb.VersionedDB
//statedb
}
//代码在core/ledger/kvledger/txmgmt/validator/statebasedval/state_based_validator.go
```
涉及方法如下：
```go
//构造Validator
func NewValidator(db statedb.VersionedDB) *Validator
//验证背书交易
func (v *Validator) validateEndorserTX(envBytes []
byte, doMVCCValidation
bool, updates *statedb.UpdateBatch) (*rwsetutil.TxRwSet, peer.TxValidationCode,
error)
//验证和准备批处理，Block中写集加入批处理
func (v *Validator) ValidateAndPrepareBatch(block *common.Block, doMVCCValidation
bool) (*statedb.UpdateBatch,
error)
func addWriteSetToBatch(txRWSet *rwsetutil.TxRwSet, txHeight *version.Height, batch *statedb.UpdateBatch)
func (v *Validator) validateTx(txRWSet *rwsetutil.TxRwSet, updates *statedb.UpdateBatch) (peer.TxValidationCode,
error)
func (v *Validator) validateReadSet(ns
string, kvReads []*kvrwset.KVRead, updates *statedb.UpdateBatch) (
bool,
error)
func (v *Validator) validateKVRead(ns
string, kvRead *kvrwset.KVRead, updates *statedb.UpdateBatch) (
bool,
error)
func (v *Validator) validateRangeQueries(ns
string, rangeQueriesInfo []*kvrwset.RangeQueryInfo, updates *statedb.UpdateBatch) (
bool,
error)
func (v *Validator) validateRangeQuery(ns
string, rangeQueryInfo *kvrwset.RangeQueryInfo, updates *statedb.UpdateBatch) (
bool,
error)
//代码在core/ledger/kvledger/txmgmt/validator/statebasedval/state_based_validator.go
```
func (v
*Validator) ValidateAndPrepareBatch(block *common.Block, doMVCCValidation bool) (*statedb.UpdateBatch, error)代码如下：
```go
updates := statedb.NewUpdateBatch()
//构造批处理
//type TxValidationFlags []uint8
txsFilter := util.TxValidationFlags(block.Metadata.Metadata[common.BlockMetadataIndex_TRANSACTIONS_FILTER])
if
len(txsFilter) ==
0 {
txsFilter = util.NewTxValidationFlags(
len(block.Data.Data))
block.Metadata.Metadata[common.BlockMetadataIndex_TRANSACTIONS_FILTER] = txsFilter
}
for txIndex, envBytes :=
range block.Data.Data {
if txsFilter.IsInvalid(txIndex) {
//验证交易是否有效
continue
}
env, err := putils.GetEnvelopeFromBlock(envBytes)
//Envelope
payload, err := putils.GetPayload(env)
//Payload
chdr, err := putils.UnmarshalChannelHeader(payload.Header.ChannelHeader)
//ChannelHeader
txType := common.HeaderType(chdr.Type)
//HeaderType
if txType != common.HeaderType_ENDORSER_TRANSACTION {
continue
}
//验证背书交易，获取读写集
txRWSet, txResult, err := v.validateEndorserTX(envBytes, doMVCCValidation, updates)
txsFilter.SetFlag(txIndex, txResult)
if txRWSet !=
nil {
committingTxHeight := version.NewHeight(block.Header.Number, uint64(txIndex))
//读写集中写集加入批处理
addWriteSetToBatch(txRWSet, committingTxHeight, updates)
txsFilter.SetFlag(txIndex, peer.TxValidationCode_VALID)
}
}
block.Metadata.Metadata[common.BlockMetadataIndex_TRANSACTIONS_FILTER] = txsFilter
return updates,
nil
//代码在core/ledger/kvledger/txmgmt/validator/statebasedval/state_based_validator.go
```
## 8、TxMgr接口及实现（交易管理）
### 8.1、TxMgr接口定义
```go
type
TxMgr
interface {
NewQueryExecutor() (ledger.QueryExecutor,
error)
NewTxSimulator() (ledger.TxSimulator,
error)
ValidateAndPrepare(block *common.Block, doMVCCValidation
bool)
error
//返回statedb一致的最高事务的高度
GetLastSavepoint() (*version.Height,
error)
ShouldRecover(lastAvailableBlock
uint64) (
bool,
uint64,
error)
CommitLostBlock(block *common.Block)
error
Commit()
error
Rollback()
Shutdown()
}
//代码在core/ledger/kvledger/txmgmt/txmgr/txmgr.go
```
### 8.2、TxMgr接口实现
TxMgr接口实现，即LockBasedTxMgr结构体及方法。LockBasedTxMgr结构体如下：
```go
type
LockBasedTxMgr
struct {
db statedb.VersionedDB
//statedb
validator validator.Validator
//Validator
batch *statedb.UpdateBatch
//批处理
currentBlock *common.Block
//Block
commitRWLock sync.RWMutex
//锁
}
//代码在core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/lockbased_txmgr.go
```
涉及方法如下：
```go
//构造LockBasedTxMgr
func NewLockBasedTxMgr(db statedb.VersionedDB) *LockBasedTxMgr
//调取txmgr.db.GetLatestSavePoint()，返回statedb一致的最高事务的高度
func (txmgr *LockBasedTxMgr) GetLastSavepoint() (*version.Height,
error)
//调取newQueryExecutor(txmgr)
func (txmgr *LockBasedTxMgr) NewQueryExecutor() (ledger.QueryExecutor,
error)
func (txmgr *LockBasedTxMgr) NewTxSimulator() (ledger.TxSimulator,
error)
//验证Block，并从Block中获取写集加入批处理txmgr.batch
func (txmgr *LockBasedTxMgr) ValidateAndPrepare(block *common.Block, doMVCCValidation
bool)
error
func (txmgr *LockBasedTxMgr) Shutdown()
//执行txmgr.batch，
func (txmgr *LockBasedTxMgr) Commit()
error
func (txmgr *LockBasedTxMgr) Rollback()
func (txmgr *LockBasedTxMgr) ShouldRecover(lastAvailableBlock
uint64) (
bool,
uint64,
error)
func (txmgr *LockBasedTxMgr) CommitLostBlock(block *common.Block)
error
//代码在core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/lockbased_txmgr.go
```
### 8.3、lockBasedQueryExecutor结构体及方法（实现ledger.QueryExecutor接口）
```go
type
lockBasedQueryExecutor
struct {
helper *queryHelper
id
string
}
func newQueryExecutor(txmgr *LockBasedTxMgr) *lockBasedQueryExecutor
func (q *lockBasedQueryExecutor) GetState(ns
string, key
string) ([]
byte,
error)
func (q *lockBasedQueryExecutor) GetStateMultipleKeys(namespace
string, keys []
string) ([][]
byte,
error)
func (q *lockBasedQueryExecutor) GetStateRangeScanIterator(namespace
string, startKey
string, endKey
string) (ledger.ResultsIterator,
error)
func (q *lockBasedQueryExecutor) ExecuteQuery(namespace, query
string) (ledger.ResultsIterator,
error)
func (q *lockBasedQueryExecutor) Done()
//代码在core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/lockbased_query_executer.go
```
### 8.4、queryHelper结构体及方法
queryHelper结构体及方法：
```go
type
queryHelper
struct {
txmgr *LockBasedTxMgr
//LockBasedTxMgr
rwsetBuilder *rwsetutil.RWSetBuilder
//读写集工具
itrs []*resultsItr
err
error
doneInvoked
bool
//是否调用完成
}
//statedb中获取versionedValue，并加入rwsetBuilder的nsRWs.readMap中
func (h *queryHelper) getState(ns
string, key
string) ([]
byte,
error)
//statedb中获取多个versionedValue，并加入rwsetBuilder的nsRWs.readMap中
func (h *queryHelper) getStateMultipleKeys(namespace
string, keys []
string) ([][]
byte,
error)
//构造resultsItr，并加入queryHelper.itrs
func (h *queryHelper) getStateRangeScanIterator(namespace
string, startKey
string, endKey
string) (commonledger.ResultsIterator,
error)
执行查询并构造queryResultsItr
func (h *queryHelper) executeQuery(namespace, query
string) (commonledger.ResultsIterator,
error)
//done
func (h *queryHelper) done()
func (h *queryHelper) checkDone()
//代码在core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/helper.go
```
resultsItr结构体及方法：
```go
type
resultsItr
struct {
ns
string
endKey
string
dbItr statedb.ResultsIterator
rwSetBuilder *rwsetutil.RWSetBuilder
rangeQueryInfo *kvrwset.RangeQueryInfo
rangeQueryResultsHelper *rwsetutil.RangeQueryResultsHelper
}
func newResultsItr(ns
string, startKey
string, endKey
string, db statedb.VersionedDB, rwsetBuilder *rwsetutil.RWSetBuilder, enableHashing
bool, maxDegree
uint32) (*resultsItr,
error)
func (itr *resultsItr) Next() (commonledger.QueryResult,
error)
func (itr *resultsItr) updateRangeQueryInfo(queryResult statedb.QueryResult)
func (itr *resultsItr) Close()
//代码在core/ledger/kvledger/txmgmt/txmgr/lockbasedtxmgr/helper.go
```
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