miner, core: sort txs by price, nonce

core/types/transaction.go

@@ -289,3 +289,22 @@ type TxByNonce struct{ Transactions }
 func (s TxByNonce) Less(i, j int) bool {
 	return s.Transactions[i].data.AccountNonce < s.Transactions[j].data.AccountNonce
 }
+
+type TxByPrice struct{ Transactions }
+
+func (s TxByPrice) Less(i, j int) bool {
+	return s.Transactions[i].data.Price.Cmp(s.Transactions[j].data.Price) > 0
+}
+
+type TxByPriceAndNonce struct{ Transactions }
+
+func (s TxByPriceAndNonce) Less(i, j int) bool {
+	// we can ignore the error here. Sorting shouldn't care about validness
+	ifrom, _ := s.Transactions[i].From()
+	jfrom, _ := s.Transactions[j].From()
+	// favour nonce if they are from the same recipient
+	if ifrom == jfrom {
+		return s.Transactions[i].data.AccountNonce < s.Transactions[j].data.AccountNonce
+	}
+	return s.Transactions[i].data.Price.Cmp(s.Transactions[j].data.Price) > 0
+}