package ethchain import ( "bytes" "container/list" "fmt" "math/big" "sync" "github.com/ethereum/go-ethereum/ethlog" "github.com/ethereum/go-ethereum/ethstate" "github.com/ethereum/go-ethereum/ethwire" ) var txplogger = ethlog.NewLogger("TXP") const ( txPoolQueueSize = 50 ) type TxPoolHook chan *Transaction type TxMsgTy byte const ( TxPre = iota TxPost minGasPrice = 1000000 ) var MinGasPrice = big.NewInt(10000000000000) type TxMsg struct { Tx *Transaction Type TxMsgTy } func EachTx(pool *list.List, it func(*Transaction, *list.Element) bool) { for e := pool.Front(); e != nil; e = e.Next() { if it(e.Value.(*Transaction), e) { break } } } func FindTx(pool *list.List, finder func(*Transaction, *list.Element) bool) *Transaction { for e := pool.Front(); e != nil; e = e.Next() { if tx, ok := e.Value.(*Transaction); ok { if finder(tx, e) { return tx } } } return nil } type TxProcessor interface { ProcessTransaction(tx *Transaction) } // The tx pool a thread safe transaction pool handler. In order to // guarantee a non blocking pool we use a queue channel which can be // independently read without needing access to the actual pool. If the // pool is being drained or synced for whatever reason the transactions // will simple queue up and handled when the mutex is freed. type TxPool struct { Ethereum EthManager // The mutex for accessing the Tx pool. mutex sync.Mutex // Queueing channel for reading and writing incoming // transactions to queueChan chan *Transaction // Quiting channel quit chan bool // The actual pool pool *list.List SecondaryProcessor TxProcessor subscribers []chan TxMsg } func NewTxPool(ethereum EthManager) *TxPool { return &TxPool{ pool: list.New(), queueChan: make(chan *Transaction, txPoolQueueSize), quit: make(chan bool), Ethereum: ethereum, } } // Blocking function. Don't use directly. Use QueueTransaction instead func (pool *TxPool) addTransaction(tx *Transaction) { pool.mutex.Lock() defer pool.mutex.Unlock() pool.pool.PushBack(tx) // Broadcast the transaction to the rest of the peers pool.Ethereum.Broadcast(ethwire.MsgTxTy, []interface{}{tx.RlpData()}) } func (pool *TxPool) ValidateTransaction(tx *Transaction) error { // Get the last block so we can retrieve the sender and receiver from // the merkle trie block := pool.Ethereum.ChainManager().CurrentBlock // Something has gone horribly wrong if this happens if block == nil { return fmt.Errorf("[TXPL] No last block on the block chain") } if len(tx.Recipient) != 0 && len(tx.Recipient) != 20 { return fmt.Errorf("[TXPL] Invalid recipient. len = %d", len(tx.Recipient)) } if tx.GasPrice.Cmp(MinGasPrice) < 0 { return fmt.Errorf("Gas price to low. Require %v > Got %v", MinGasPrice, tx.GasPrice) } // Get the sender //sender := pool.Ethereum.StateManager().procState.GetAccount(tx.Sender()) sender := pool.Ethereum.StateManager().CurrentState().GetAccount(tx.Sender()) totAmount := new(big.Int).Set(tx.Value) // Make sure there's enough in the sender's account. Having insufficient // funds won't invalidate this transaction but simple ignores it. if sender.Balance().Cmp(totAmount) < 0 { return fmt.Errorf("[TXPL] Insufficient amount in sender's (%x) account", tx.Sender()) } if tx.IsContract() { if tx.GasPrice.Cmp(big.NewInt(minGasPrice)) < 0 { return fmt.Errorf("[TXPL] Gasprice too low, %s given should be at least %d.", tx.GasPrice, minGasPrice) } } // Increment the nonce making each tx valid only once to prevent replay // attacks return nil } func (pool *TxPool) queueHandler() { out: for { select { case tx := <-pool.queueChan: hash := tx.Hash() foundTx := FindTx(pool.pool, func(tx *Transaction, e *list.Element) bool { return bytes.Compare(tx.Hash(), hash) == 0 }) if foundTx != nil { break } // Validate the transaction err := pool.ValidateTransaction(tx) if err != nil { txplogger.Debugln("Validating Tx failed", err) } else { // Call blocking version. pool.addTransaction(tx) tmp := make([]byte, 4) copy(tmp, tx.Recipient) txplogger.Debugf("(t) %x => %x (%v) %x\n", tx.Sender()[:4], tmp, tx.Value, tx.Hash()) // Notify the subscribers pool.Ethereum.EventMux().Post(TxEvent{TxPre, tx}) } case <-pool.quit: break out } } } func (pool *TxPool) QueueTransaction(tx *Transaction) { pool.queueChan <- tx } func (pool *TxPool) CurrentTransactions() []*Transaction { pool.mutex.Lock() defer pool.mutex.Unlock() txList := make([]*Transaction, pool.pool.Len()) i := 0 for e := pool.pool.Front(); e != nil; e = e.Next() { tx := e.Value.(*Transaction) txList[i] = tx i++ } return txList } func (pool *TxPool) RemoveInvalid(state *ethstate.State) { pool.mutex.Lock() defer pool.mutex.Unlock() for e := pool.pool.Front(); e != nil; e = e.Next() { tx := e.Value.(*Transaction) sender := state.GetAccount(tx.Sender()) err := pool.ValidateTransaction(tx) if err != nil || sender.Nonce >= tx.Nonce { pool.pool.Remove(e) } } } func (self *TxPool) RemoveSet(txs Transactions) { self.mutex.Lock() defer self.mutex.Unlock() for _, tx := range txs { EachTx(self.pool, func(t *Transaction, element *list.Element) bool { if t == tx { self.pool.Remove(element) return true // To stop the loop } return false }) } } func (pool *TxPool) Flush() []*Transaction { txList := pool.CurrentTransactions() // Recreate a new list all together // XXX Is this the fastest way? pool.pool = list.New() return txList } func (pool *TxPool) Start() { go pool.queueHandler() } func (pool *TxPool) Stop() { close(pool.quit) pool.Flush() txplogger.Infoln("Stopped") }