package ethchain
import (
"bytes"
"container/list"
"errors"
"fmt"
"github.com/ethereum/eth-go/ethutil"
"github.com/ethereum/eth-go/ethwire"
"log"
"math/big"
"sync"
)
const (
txPoolQueueSize = 50
)
type TxPoolHook chan *Transaction
type TxMsgTy byte
const (
TxPre = iota
TxPost
minGasPrice = 1000000
)
type TxMsg struct {
Tx *Transaction
Type TxMsgTy
}
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{
//server: s,
mutex: sync.Mutex{},
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()})
}
/*
// Process transaction validates the Tx and processes funds from the
// sender to the recipient.
func (pool *TxPool) ProcessTransaction(tx *Transaction, state *State, toContract bool) (gas *big.Int, err error) {
fmt.Printf("state root before update %x\n", state.Root())
defer func() {
if r := recover(); r != nil {
ethutil.Config.Log.Infoln(r)
err = fmt.Errorf("%v", r)
}
}()
gas = new(big.Int)
addGas := func(g *big.Int) { gas.Add(gas, g) }
addGas(GasTx)
// Get the sender
sender := state.GetAccount(tx.Sender())
if sender.Nonce != tx.Nonce {
err = NonceError(tx.Nonce, sender.Nonce)
return
}
sender.Nonce += 1
defer func() {
//state.UpdateStateObject(sender)
// Notify all subscribers
pool.Ethereum.Reactor().Post("newTx:post", tx)
}()
txTotalBytes := big.NewInt(int64(len(tx.Data)))
txTotalBytes.Div(txTotalBytes, ethutil.Big32)
addGas(new(big.Int).Mul(txTotalBytes, GasSStore))
rGas := new(big.Int).Set(gas)
rGas.Mul(gas, tx.GasPrice)
// Make sure there's enough in the sender's account. Having insufficient
// funds won't invalidate this transaction but simple ignores it.
totAmount := new(big.Int).Add(tx.Value, rGas)
if sender.Amount.Cmp(totAmount) < 0 {
err = fmt.Errorf("[TXPL] Insufficient amount in sender's (%x) account", tx.Sender())
return
}
state.UpdateStateObject(sender)
fmt.Printf("state root after sender update %x\n", state.Root())
// Get the receiver
receiver := state.GetAccount(tx.Recipient)
// Send Tx to self
if bytes.Compare(tx.Recipient, tx.Sender()) == 0 {
// Subtract the fee
sender.SubAmount(rGas)
} else {
// Subtract the amount from the senders account
sender.SubAmount(totAmount)
// Add the amount to receivers account which should conclude this transaction
receiver.AddAmount(tx.Value)
state.UpdateStateObject(receiver)
fmt.Printf("state root after receiver update %x\n", state.Root())
}
ethutil.Config.Log.Infof("[TXPL] Processed Tx %x\n", tx.Hash())
return
}
*/
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.BlockChain().CurrentBlock
// Something has gone horribly wrong if this happens
if block == nil {
return errors.New("[TXPL] No last block on the block chain")
}
if len(tx.Recipient) != 20 {
return fmt.Errorf("[TXPL] Invalid recipient. len = %d", len(tx.Recipient))
}
// 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.Amount.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 to 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 {
ethutil.Config.Log.Debugln("Validating Tx failed", err)
} else {
// Call blocking version.
pool.addTransaction(tx)
ethutil.Config.Log.Debugf("(t) %x => %x (%v) %x\n", tx.Sender()[:4], tx.Recipient[:4], tx.Value, tx.Hash())
// Notify the subscribers
pool.Ethereum.Reactor().Post("newTx:pre", 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 *State) {
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 (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()
log.Println("[TXP] Stopped")
}
