core: implemented a queued approach processing transactions

Implemented a new transaction queue. Transactions with a holes in their
nonce sequence are also not propagated over the network.

N: 0,1,2,5,6,7 = propagate 0..2 -- 5..N is kept in the tx pool

core/transaction_pool.go

@@ -4,7 +4,9 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
+	"sort"
 	"sync"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
@@ -17,7 +19,7 @@ import (
 
 var (
 	ErrInvalidSender      = errors.New("Invalid sender")
-	ErrImpossibleNonce    = errors.New("Impossible nonce")
+	ErrNonce              = errors.New("Nonce too low")
 	ErrNonExistentAccount = errors.New("Account does not exist")
 	ErrInsufficientFunds  = errors.New("Insufficient funds")
 	ErrIntrinsicGas       = errors.New("Intrinsic gas too low")
@@ -54,20 +56,37 @@ type TxPool struct {
 	txs           map[common.Hash]*types.Transaction
 	invalidHashes *set.Set
 
+	queue map[common.Address]types.Transactions
+
 	subscribers []chan TxMsg
 
 	eventMux *event.TypeMux
 }
 
 func NewTxPool(eventMux *event.TypeMux, currentStateFn stateFn) *TxPool {
-	return &TxPool{
+	txPool := &TxPool{
 		txs:           make(map[common.Hash]*types.Transaction),
+		queue:         make(map[common.Address]types.Transactions),
 		queueChan:     make(chan *types.Transaction, txPoolQueueSize),
 		quit:          make(chan bool),
 		eventMux:      eventMux,
 		invalidHashes: set.New(),
 		currentState:  currentStateFn,
 	}
+	return txPool
+}
+
+func (pool *TxPool) Start() {
+	ticker := time.NewTicker(300 * time.Millisecond)
+done:
+	for {
+		select {
+		case <-ticker.C:
+			pool.checkQueue()
+		case <-pool.quit:
+			break done
+		}
+	}
 }
 
 func (pool *TxPool) ValidateTransaction(tx *types.Transaction) error {
@@ -100,14 +119,15 @@ func (pool *TxPool) ValidateTransaction(tx *types.Transaction) error {
 	}
 
 	if pool.currentState().GetNonce(from) > tx.Nonce() {
-		return ErrImpossibleNonce
+		return ErrNonce
 	}
 
 	return nil
 }
 
 func (self *TxPool) addTx(tx *types.Transaction) {
-	self.txs[tx.Hash()] = tx
+	from, _ := tx.From()
+	self.queue[from] = append(self.queue[from], tx)
 }
 
 func (self *TxPool) add(tx *types.Transaction) error {
@@ -144,9 +164,6 @@ func (self *TxPool) add(tx *types.Transaction) error {
 		glog.Infof("(t) %x => %s (%v) %x\n", from, toname, tx.Value, tx.Hash())
 	}
 
-	// Notify the subscribers
-	go self.eventMux.Post(TxPreEvent{tx})
-
 	return nil
 }
 
@@ -189,34 +206,65 @@ func (self *TxPool) GetTransactions() (txs types.Transactions) {
 	return
 }
 
-func (self *TxPool) RemoveSet(txs types.Transactions) {
+func (self *TxPool) RemoveTransactions(txs types.Transactions) {
 	self.mu.Lock()
 	defer self.mu.Unlock()
+
 	for _, tx := range txs {
 		delete(self.txs, tx.Hash())
 	}
 }
 
-func (self *TxPool) InvalidateSet(hashes *set.Set) {
-	self.mu.Lock()
-	defer self.mu.Unlock()
-
-	hashes.Each(func(v interface{}) bool {
-		delete(self.txs, v.(common.Hash))
-		return true
-	})
-	self.invalidHashes.Merge(hashes)
-}
-
 func (pool *TxPool) Flush() {
 	pool.txs = make(map[common.Hash]*types.Transaction)
 }
 
-func (pool *TxPool) Start() {
-}
-
 func (pool *TxPool) Stop() {
 	pool.Flush()
+	close(pool.quit)
 
 	glog.V(logger.Info).Infoln("TX Pool stopped")
 }
+
+// check queue will attempt to insert
+func (pool *TxPool) checkQueue() {
+	pool.mu.Lock()
+	defer pool.mu.Unlock()
+
+	for address, txs := range pool.queue {
+		sort.Sort(types.TxByNonce{txs})
+
+		var (
+			nonce = pool.currentState().GetNonce(address)
+			start int
+		)
+		// Clean up the transactions first and determine the start of the nonces
+		for _, tx := range txs {
+			if tx.Nonce() >= nonce {
+				break
+			}
+			start++
+		}
+		pool.queue[address] = txs[start:]
+
+		// expected nonce
+		enonce := nonce
+		for _, tx := range pool.queue[address] {
+			// If the expected nonce does not match up with the next one
+			// (i.e. a nonce gap), we stop the loop
+			if enonce != tx.Nonce() {
+				break
+			}
+			enonce++
+
+			pool.txs[tx.Hash()] = tx
+			// Notify the subscribers
+			go pool.eventMux.Post(TxPreEvent{tx})
+		}
+		//pool.queue[address] = txs[i:]
+		// delete the entire queue entry if it's empty. There's no need to keep it
+		if len(pool.queue[address]) == 0 {
+			delete(pool.queue, address)
+		}
+	}
+}