package txselector // current: very simple version of TxSelector import ( "bytes" "fmt" "math/big" "sort" ethCommon "github.com/ethereum/go-ethereum/common" "github.com/hermeznetwork/hermez-node/common" "github.com/hermeznetwork/hermez-node/db/l2db" "github.com/hermeznetwork/hermez-node/db/statedb" "github.com/hermeznetwork/hermez-node/log" "github.com/hermeznetwork/hermez-node/txprocessor" "github.com/hermeznetwork/tracerr" "github.com/iden3/go-iden3-crypto/babyjub" ) // txs implements the interface Sort for an array of Tx type txs []common.PoolL2Tx func (t txs) Len() int { return len(t) } func (t txs) Swap(i, j int) { t[i], t[j] = t[j], t[i] } func (t txs) Less(i, j int) bool { return t[i].AbsoluteFee > t[j].AbsoluteFee } // CoordAccount contains the data of the Coordinator account, that will be used // to create new transactions of CreateAccountDeposit type to add new TokenID // accounts for the Coordinator to receive the fees. type CoordAccount struct { Addr ethCommon.Address BJJ babyjub.PublicKeyComp AccountCreationAuth []byte // signature in byte array format } // SelectionConfig contains the parameters of configuration of the selection of // transactions for the next batch type SelectionConfig struct { // MaxL1UserTxs is the maximum L1-user-tx for a batch MaxL1UserTxs uint64 // TxProcessorConfig contains the config for ProcessTxs TxProcessorConfig txprocessor.Config } // TxSelector implements all the functionalities to select the txs for the next // batch type TxSelector struct { l2db *l2db.L2DB localAccountsDB *statedb.LocalStateDB coordAccount *CoordAccount } // NewTxSelector returns a *TxSelector func NewTxSelector(coordAccount *CoordAccount, dbpath string, synchronizerStateDB *statedb.StateDB, l2 *l2db.L2DB) (*TxSelector, error) { localAccountsDB, err := statedb.NewLocalStateDB(dbpath, 128, synchronizerStateDB, statedb.TypeTxSelector, 0) // without merkletree if err != nil { return nil, tracerr.Wrap(err) } return &TxSelector{ l2db: l2, localAccountsDB: localAccountsDB, coordAccount: coordAccount, }, nil } // LocalAccountsDB returns the LocalStateDB of the TxSelector func (txsel *TxSelector) LocalAccountsDB() *statedb.LocalStateDB { return txsel.localAccountsDB } // Reset tells the TxSelector to get it's internal AccountsDB // from the required `batchNum` func (txsel *TxSelector) Reset(batchNum common.BatchNum) error { err := txsel.localAccountsDB.Reset(batchNum, true) if err != nil { return tracerr.Wrap(err) } return nil } func (txsel *TxSelector) getCoordIdx(tokenID common.TokenID) (common.Idx, error) { return txsel.localAccountsDB.GetIdxByEthAddrBJJ(txsel.coordAccount.Addr, txsel.coordAccount.BJJ, tokenID) } // coordAccountForTokenID creates a new L1CoordinatorTx to create a new // Coordinator account for the given TokenID in the case that the account does // not exist yet in the db, and does not exist a L1CoordinatorTx to creat that // account in the given array of L1CoordinatorTxs. If a new Coordinator account // needs to be created, a new L1CoordinatorTx will be returned from this // function. After calling this method, if the l1CoordinatorTx is added to the // selection, positionL1 must be increased 1. func (txsel *TxSelector) coordAccountForTokenID(l1CoordinatorTxs []common.L1Tx, tokenID common.TokenID, positionL1 int) (*common.L1Tx, int, error) { // check if CoordinatorAccount for TokenID is already pending to create if checkAlreadyPendingToCreate(l1CoordinatorTxs, tokenID, txsel.coordAccount.Addr, txsel.coordAccount.BJJ) { return nil, positionL1, nil } _, err := txsel.getCoordIdx(tokenID) if tracerr.Unwrap(err) == statedb.ErrIdxNotFound { // create L1CoordinatorTx to create new CoordAccount for // TokenID l1CoordinatorTx := common.L1Tx{ Position: positionL1, UserOrigin: false, FromEthAddr: txsel.coordAccount.Addr, FromBJJ: txsel.coordAccount.BJJ, TokenID: tokenID, Amount: big.NewInt(0), DepositAmount: big.NewInt(0), Type: common.TxTypeCreateAccountDeposit, } return &l1CoordinatorTx, positionL1, nil } if err != nil { return nil, positionL1, tracerr.Wrap(err) } // CoordAccount for TokenID already exists return nil, positionL1, nil } // GetL2TxSelection returns the L1CoordinatorTxs and a selection of the L2Txs // for the next batch, from the L2DB pool. // It returns: the CoordinatorIdxs used to receive the fees of the selected // L2Txs. An array of bytearrays with the signatures of the // AccountCreationAuthorization of the accounts of the users created by the // Coordinator with L1CoordinatorTxs of those accounts that does not exist yet // but there is a transactions to them and the authorization of account // creation exists. The L1UserTxs, L1CoordinatorTxs, PoolL2Txs that will be // included in the next batch. func (txsel *TxSelector) GetL2TxSelection(selectionConfig *SelectionConfig) ([]common.Idx, [][]byte, []common.L1Tx, []common.PoolL2Tx, error) { coordIdxs, accCreationAuths, _, l1CoordinatorTxs, l2Txs, err := txsel.GetL1L2TxSelection(selectionConfig, []common.L1Tx{}) return coordIdxs, accCreationAuths, l1CoordinatorTxs, l2Txs, tracerr.Wrap(err) } // GetL1L2TxSelection returns the selection of L1 + L2 txs. // It returns: the CoordinatorIdxs used to receive the fees of the selected // L2Txs. An array of bytearrays with the signatures of the // AccountCreationAuthorization of the accounts of the users created by the // Coordinator with L1CoordinatorTxs of those accounts that does not exist yet // but there is a transactions to them and the authorization of account // creation exists. The L1UserTxs, L1CoordinatorTxs, PoolL2Txs that will be // included in the next batch. func (txsel *TxSelector) GetL1L2TxSelection(selectionConfig *SelectionConfig, l1UserTxs []common.L1Tx) ([]common.Idx, [][]byte, []common.L1Tx, []common.L1Tx, []common.PoolL2Tx, error) { // WIP.0: the TxSelector is not optimized and will need a redesign. The // current version is implemented in order to have a functional // implementation that can be used asap. // // WIP.1: this method uses a 'cherry-pick' of internal calls of the // StateDB, a refactor of the StateDB to reorganize it internally is // planned once the main functionallities are covered, with that // refactor the TxSelector will be updated also. // get pending l2-tx from tx-pool l2TxsRaw, err := txsel.l2db.GetPendingTxs() if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } txselStateDB := txsel.localAccountsDB.StateDB tp := txprocessor.NewTxProcessor(txselStateDB, selectionConfig.TxProcessorConfig) // Process L1UserTxs for i := 0; i < len(l1UserTxs); i++ { // assumption: l1usertx are sorted by L1Tx.Position _, _, _, _, err := tp.ProcessL1Tx(nil, &l1UserTxs[i]) if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } } var l1CoordinatorTxs []common.L1Tx positionL1 := len(l1UserTxs) var accAuths [][]byte // sort l2TxsRaw (cropping at MaxTx at this point) l2Txs0 := txsel.getL2Profitable(l2TxsRaw, selectionConfig.TxProcessorConfig.MaxTx) noncesMap := make(map[common.Idx]common.Nonce) var l2Txs []common.PoolL2Tx // iterate over l2Txs // - if tx.TokenID does not exist at CoordsIdxDB // - create new L1CoordinatorTx creating a CoordAccount, for // Coordinator to receive the fee of the new TokenID for i := 0; i < len(l2Txs0); i++ { accSender, err := tp.StateDB().GetAccount(l2Txs0[i].FromIdx) if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } l2Txs0[i].TokenID = accSender.TokenID // populate the noncesMap used at the next iteration noncesMap[l2Txs0[i].FromIdx] = accSender.Nonce // if TokenID does not exist yet, create new L1CoordinatorTx to // create the CoordinatorAccount for that TokenID, to receive // the fees. Only in the case that there does not exist yet a // pending L1CoordinatorTx to create the account for the // Coordinator for that TokenID var newL1CoordTx *common.L1Tx newL1CoordTx, positionL1, err = txsel.coordAccountForTokenID(l1CoordinatorTxs, accSender.TokenID, positionL1) if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } if newL1CoordTx != nil { // if there is no space for the L1CoordinatorTx, discard the L2Tx if len(l1CoordinatorTxs) >= int(selectionConfig.MaxL1UserTxs)-len(l1UserTxs) { // discard L2Tx continue } // increase positionL1 positionL1++ l1CoordinatorTxs = append(l1CoordinatorTxs, *newL1CoordTx) accAuths = append(accAuths, txsel.coordAccount.AccountCreationAuth) } l2Txs = append(l2Txs, l2Txs0[i]) } var validTxs []common.PoolL2Tx // iterate over l2TxsRaw // - check Nonces // - check enough Balance for the Amount+Fee // - if needed, create new L1CoordinatorTxs for unexisting ToIdx // - keep used accAuths // - put the valid txs into validTxs array for i := 0; i < len(l2Txs); i++ { if !tp.CheckEnoughBalance(l2Txs[i]) { // not valid Amount with current Balance continue } // check if Nonce is correct nonce := noncesMap[l2Txs[i].FromIdx] if l2Txs[i].Nonce == nonce { noncesMap[l2Txs[i].FromIdx]++ } else { // not valid Nonce at tx continue } // If tx.ToIdx>=256, tx.ToIdx should exist to localAccountsDB, // if so, tx is used. If tx.ToIdx==0, for an L2Tx will be the // case of TxToEthAddr or TxToBJJ, check if // tx.ToEthAddr/tx.ToBJJ exist in localAccountsDB, if yes tx is // used; if not, check if tx.ToEthAddr is in // AccountCreationAuthDB, if so, tx is used and L1CoordinatorTx // of CreateAccountAndDeposit is created. If tx.ToIdx==1, is a // Exit type and is used. if l2Txs[i].ToIdx == 0 { // ToEthAddr/ToBJJ case validL2Tx, l1CoordinatorTx, accAuth, err := txsel.processTxToEthAddrBJJ(validTxs, selectionConfig, len(l1UserTxs), l1CoordinatorTxs, positionL1, l2Txs[i]) if err != nil { log.Debug(err) continue } if accAuth != nil && l1CoordinatorTx != nil { accAuths = append(accAuths, accAuth.Signature) l1CoordinatorTxs = append(l1CoordinatorTxs, *l1CoordinatorTx) positionL1++ } if validL2Tx != nil { validTxs = append(validTxs, *validL2Tx) } } else if l2Txs[i].ToIdx >= common.IdxUserThreshold { receiverAcc, err := txsel.localAccountsDB.GetAccount(l2Txs[i].ToIdx) if err != nil { // tx not valid log.Debugw("invalid L2Tx: ToIdx not found in StateDB", "ToIdx", l2Txs[i].ToIdx) continue } if l2Txs[i].ToEthAddr != common.EmptyAddr { if l2Txs[i].ToEthAddr != receiverAcc.EthAddr { log.Debugw("invalid L2Tx: ToEthAddr does not correspond to the Account.EthAddr", "ToIdx", l2Txs[i].ToIdx, "tx.ToEthAddr", l2Txs[i].ToEthAddr, "account.EthAddr", receiverAcc.EthAddr) continue } } if l2Txs[i].ToBJJ != common.EmptyBJJComp { if l2Txs[i].ToBJJ != receiverAcc.BJJ { log.Debugw("invalid L2Tx: ToBJJ does not correspond to the Account.BJJ", "ToIdx", l2Txs[i].ToIdx, "tx.ToEthAddr", l2Txs[i].ToBJJ, "account.BJJ", receiverAcc.BJJ) continue } } // Account found in the DB, include the l2Tx in the selection validTxs = append(validTxs, l2Txs[i]) } else if l2Txs[i].ToIdx == common.Idx(1) { // valid txs (of Exit type) validTxs = append(validTxs, l2Txs[i]) } } // Process L1CoordinatorTxs for i := 0; i < len(l1CoordinatorTxs); i++ { _, _, _, _, err := tp.ProcessL1Tx(nil, &l1CoordinatorTxs[i]) if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } } // get CoordIdxsMap for the TokenIDs coordIdxsMap := make(map[common.TokenID]common.Idx) for i := 0; i < len(validTxs); i++ { // get TokenID from tx.Sender accSender, err := tp.StateDB().GetAccount(validTxs[i].FromIdx) if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } tokenID := accSender.TokenID coordIdx, err := txsel.getCoordIdx(tokenID) if err != nil { // if err is db.ErrNotFound, should not happen, as all // the validTxs.TokenID should have a CoordinatorIdx // created in the DB at this point return nil, nil, nil, nil, nil, tracerr.Wrap(err) } coordIdxsMap[tokenID] = coordIdx } var coordIdxs []common.Idx tp.AccumulatedFees = make(map[common.Idx]*big.Int) for _, idx := range coordIdxsMap { tp.AccumulatedFees[idx] = big.NewInt(0) coordIdxs = append(coordIdxs, idx) } // sort CoordIdxs sort.SliceStable(coordIdxs, func(i, j int) bool { return coordIdxs[i] < coordIdxs[j] }) // get most profitable L2-tx maxL2Txs := int(selectionConfig.TxProcessorConfig.MaxTx) - len(l1UserTxs) - len(l1CoordinatorTxs) selectedL2Txs := validTxs if len(validTxs) > maxL2Txs { selectedL2Txs = selectedL2Txs[:maxL2Txs] } var finalL2Txs []common.PoolL2Tx for i := 0; i < len(selectedL2Txs); i++ { _, _, _, err = tp.ProcessL2Tx(coordIdxsMap, nil, nil, &selectedL2Txs[i]) if err != nil { // the error can be due not valid tx data, or due other // cases (such as StateDB error). At this initial // version of the TxSelector, we discard the L2Tx and // log the error, assuming that this will be iterated // in a near future. log.Error(err) continue } finalL2Txs = append(finalL2Txs, selectedL2Txs[i]) } // distribute the AccumulatedFees from the processed L2Txs into the // Coordinator Idxs for idx, accumulatedFee := range tp.AccumulatedFees { cmp := accumulatedFee.Cmp(big.NewInt(0)) if cmp == 1 { // accumulatedFee>0 // send the fee to the Idx of the Coordinator for the TokenID accCoord, err := txsel.localAccountsDB.GetAccount(idx) if err != nil { log.Errorw("Can not distribute accumulated fees to coordinator account: No coord Idx to receive fee", "idx", idx) return nil, nil, nil, nil, nil, tracerr.Wrap(err) } accCoord.Balance = new(big.Int).Add(accCoord.Balance, accumulatedFee) _, err = txsel.localAccountsDB.UpdateAccount(idx, accCoord) if err != nil { log.Error(err) return nil, nil, nil, nil, nil, tracerr.Wrap(err) } } } err = tp.StateDB().MakeCheckpoint() if err != nil { return nil, nil, nil, nil, nil, tracerr.Wrap(err) } return coordIdxs, accAuths, l1UserTxs, l1CoordinatorTxs, finalL2Txs, nil } // processTxsToEthAddrBJJ process the common.PoolL2Tx in the case where // ToIdx==0, which can be the tx type of ToEthAddr or ToBJJ. If the receiver // does not have an account yet, a new L1CoordinatorTx of type // CreateAccountDeposit (with 0 as DepositAmount) is created and added to the // l1CoordinatorTxs array, and then the PoolL2Tx is added into the validTxs // array. func (txsel *TxSelector) processTxToEthAddrBJJ(validTxs []common.PoolL2Tx, selectionConfig *SelectionConfig, nL1UserTxs int, l1CoordinatorTxs []common.L1Tx, positionL1 int, l2Tx common.PoolL2Tx) (*common.PoolL2Tx, *common.L1Tx, *common.AccountCreationAuth, error) { // if L2Tx needs a new L1CoordinatorTx of CreateAccount type, and a // previous L2Tx in the current process already created a // L1CoordinatorTx of this type, in the DB there still seem that needs // to create a new L1CoordinatorTx, but as is already created, the tx // is valid if checkAlreadyPendingToCreate(l1CoordinatorTxs, l2Tx.TokenID, l2Tx.ToEthAddr, l2Tx.ToBJJ) { return &l2Tx, nil, nil, nil } var l1CoordinatorTx *common.L1Tx var accAuth *common.AccountCreationAuth if !bytes.Equal(l2Tx.ToEthAddr.Bytes(), common.EmptyAddr.Bytes()) && !bytes.Equal(l2Tx.ToEthAddr.Bytes(), common.FFAddr.Bytes()) { // case: ToEthAddr != 0x00 neither 0xff if l2Tx.ToBJJ != common.EmptyBJJComp { // case: ToBJJ!=0: // if idx exist for EthAddr&BJJ use it _, err := txsel.localAccountsDB.GetIdxByEthAddrBJJ(l2Tx.ToEthAddr, l2Tx.ToBJJ, l2Tx.TokenID) if err == nil { // account for ToEthAddr&ToBJJ already exist, // there is no need to create a new one. // tx valid, StateDB will use the ToIdx==0 to define the AuxToIdx return &l2Tx, nil, nil, nil } // if not, check if AccountCreationAuth exist for that // ToEthAddr accAuth, err = txsel.l2db.GetAccountCreationAuth(l2Tx.ToEthAddr) if err != nil { // not found, l2Tx will not be added in the selection return nil, nil, nil, tracerr.Wrap(fmt.Errorf("invalid L2Tx: ToIdx not found in StateDB, neither ToEthAddr found in AccountCreationAuths L2DB. ToIdx: %d, ToEthAddr: %s", l2Tx.ToIdx, l2Tx.ToEthAddr.Hex())) } if accAuth.BJJ != l2Tx.ToBJJ { // if AccountCreationAuth.BJJ is not the same // than in the tx, tx is not accepted return nil, nil, nil, tracerr.Wrap(fmt.Errorf("invalid L2Tx: ToIdx not found in StateDB, neither ToEthAddr & ToBJJ found in AccountCreationAuths L2DB. ToIdx: %d, ToEthAddr: %s, ToBJJ: %s", l2Tx.ToIdx, l2Tx.ToEthAddr.Hex(), l2Tx.ToBJJ.String())) } } else { // case: ToBJJ==0: // if idx exist for EthAddr use it _, err := txsel.localAccountsDB.GetIdxByEthAddr(l2Tx.ToEthAddr, l2Tx.TokenID) if err == nil { // account for ToEthAddr already exist, // there is no need to create a new one. // tx valid, StateDB will use the ToIdx==0 to define the AuxToIdx return &l2Tx, nil, nil, nil } // if not, check if AccountCreationAuth exist for that ToEthAddr accAuth, err = txsel.l2db.GetAccountCreationAuth(l2Tx.ToEthAddr) if err != nil { // not found, l2Tx will not be added in the selection return nil, nil, nil, tracerr.Wrap(fmt.Errorf("invalid L2Tx: ToIdx not found in StateDB, neither ToEthAddr found in AccountCreationAuths L2DB. ToIdx: %d, ToEthAddr: %s", l2Tx.ToIdx, l2Tx.ToEthAddr)) } } // create L1CoordinatorTx for the accountCreation l1CoordinatorTx = &common.L1Tx{ Position: positionL1, UserOrigin: false, FromEthAddr: accAuth.EthAddr, FromBJJ: accAuth.BJJ, TokenID: l2Tx.TokenID, Amount: big.NewInt(0), DepositAmount: big.NewInt(0), Type: common.TxTypeCreateAccountDeposit, } } else if bytes.Equal(l2Tx.ToEthAddr.Bytes(), common.FFAddr.Bytes()) && l2Tx.ToBJJ != common.EmptyBJJComp { // if idx exist for EthAddr&BJJ use it _, err := txsel.localAccountsDB.GetIdxByEthAddrBJJ(l2Tx.ToEthAddr, l2Tx.ToBJJ, l2Tx.TokenID) if err == nil { // account for ToEthAddr&ToBJJ already exist, (where ToEthAddr==0xff) // there is no need to create a new one. // tx valid, StateDB will use the ToIdx==0 to define the AuxToIdx return &l2Tx, nil, nil, nil } // if idx don't exist for EthAddr&BJJ, coordinator can create a // new account without L1Authorization, as ToEthAddr==0xff // create L1CoordinatorTx for the accountCreation l1CoordinatorTx = &common.L1Tx{ Position: positionL1, UserOrigin: false, FromEthAddr: l2Tx.ToEthAddr, FromBJJ: l2Tx.ToBJJ, TokenID: l2Tx.TokenID, Amount: big.NewInt(0), DepositAmount: big.NewInt(0), Type: common.TxTypeCreateAccountDeposit, } } if len(l1CoordinatorTxs) >= int(selectionConfig.MaxL1UserTxs)-nL1UserTxs { // L2Tx discarded return nil, nil, nil, tracerr.Wrap(fmt.Errorf("L2Tx discarded due not slots for L1CoordinatorTx to create a new account for receiver of L2Tx")) } return &l2Tx, l1CoordinatorTx, accAuth, nil } func checkAlreadyPendingToCreate(l1CoordinatorTxs []common.L1Tx, tokenID common.TokenID, addr ethCommon.Address, bjj babyjub.PublicKeyComp) bool { for i := 0; i < len(l1CoordinatorTxs); i++ { if bytes.Equal(l1CoordinatorTxs[i].FromEthAddr.Bytes(), addr.Bytes()) && l1CoordinatorTxs[i].TokenID == tokenID && l1CoordinatorTxs[i].FromBJJ == bjj { return true } } return false } // getL2Profitable returns the profitable selection of L2Txssorted by Nonce func (txsel *TxSelector) getL2Profitable(l2Txs []common.PoolL2Tx, max uint32) []common.PoolL2Tx { sort.Sort(txs(l2Txs)) if len(l2Txs) < int(max) { return l2Txs } l2Txs = l2Txs[:max] // sort l2Txs by Nonce. This can be done in many different ways, what // is needed is to output the l2Txs where the Nonce of l2Txs for each // Account is sorted, but the l2Txs can not be grouped by sender Account // neither by Fee. This is because later on the Nonces will need to be // sequential for the zkproof generation. sort.SliceStable(l2Txs, func(i, j int) bool { return l2Txs[i].Nonce < l2Txs[j].Nonce }) return l2Txs }