From 7e38de27108f231639a80cfa069c3d99e992f023 Mon Sep 17 00:00:00 2001
From: Gav Wood <i@gavwood.com>
Date: Mon, 3 Mar 2014 12:21:23 +0000
Subject: [PATCH] Avoid reprocessing future transactions until it's possible
 they're valid.

---
 libethereum/PeerNetwork.cpp      |  5 ++--
 libethereum/State.cpp            | 44 ++++++++++++++++++++------------
 libethereum/TransactionQueue.cpp | 17 ++++++++++++
 libethereum/TransactionQueue.h   |  6 ++++-
 4 files changed, 51 insertions(+), 21 deletions(-)

diff --git a/libethereum/PeerNetwork.cpp b/libethereum/PeerNetwork.cpp
index c77af38eb..c7d699461 100644
--- a/libethereum/PeerNetwork.cpp
+++ b/libethereum/PeerNetwork.cpp
@@ -830,9 +830,8 @@ void PeerServer::ensureAccepting()
 				{
 					clog(NetWarn) << "ERROR: " << _e.what();
 				}
-
 			m_accepting = false;
-			if (m_mode == NodeMode::PeerServer || m_peers.size() < m_idealPeerCount * 2)
+			if (ec.value() != 1 && m_mode == NodeMode::PeerServer || m_peers.size() < m_idealPeerCount * 2)
 				ensureAccepting();
 		});
 	}
@@ -926,7 +925,7 @@ bool PeerServer::sync(BlockChain& _bc, TransactionQueue& _tq, Overlay& _o)
 	{
 		for (auto it = m_incomingTransactions.begin(); it != m_incomingTransactions.end(); ++it)
 			if (_tq.import(*it))
-				ret = true;
+			{}//ret = true;		// just putting a transaction in the queue isn't enough to change the state - it might have an invalid nonce...
 			else
 				m_transactionsSent.insert(sha3(*it));	// if we already had the transaction, then don't bother sending it on.
 		m_incomingTransactions.clear();
diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index 74db7aeb4..f14c8c18c 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -288,31 +288,41 @@ bool State::sync(TransactionQueue& _tq)
 	// TRANSACTIONS
 	bool ret = false;
 	auto ts = _tq.transactions();
-	for (auto const& i: ts)
+	vector<pair<h256, bytes>> futures;
+
+	for (int goodTxs = 1; goodTxs;)
 	{
-		if (!m_transactionSet.count(i.first))
+		goodTxs = 0;
+		for (auto const& i: ts)
 		{
-			// don't have it yet! Execute it now.
-			try
+			if (!m_transactionSet.count(i.first))
 			{
-				execute(i.second);
-				ret = true;
-			}
-			catch (InvalidNonce const& in)
-			{
-				if (in.required > in.candidate)
+				// don't have it yet! Execute it now.
+				try
+				{
+					execute(i.second);
+					ret = true;
+					_tq.noteGood(i);
+					++goodTxs;
+				}
+				catch (InvalidNonce const& in)
+				{
+					if (in.required > in.candidate)
+					{
+						// too old
+						_tq.drop(i.first);
+						ret = true;
+					}
+					else
+						_tq.setFuture(i);
+				}
+				catch (std::exception const&)
 				{
-					// too old
+					// Something else went wrong - drop it.
 					_tq.drop(i.first);
 					ret = true;
 				}
 			}
-			catch (std::exception const&)
-			{
-				// Something else went wrong - drop it.
-				_tq.drop(i.first);
-				ret = true;
-			}
 		}
 	}
 	return ret;
diff --git a/libethereum/TransactionQueue.cpp b/libethereum/TransactionQueue.cpp
index 2b908d8b2..1c6144eab 100644
--- a/libethereum/TransactionQueue.cpp
+++ b/libethereum/TransactionQueue.cpp
@@ -51,3 +51,20 @@ bool TransactionQueue::import(bytes const& _block)
 
 	return true;
 }
+
+void TransactionQueue::setFuture(std::pair<h256, bytes> const& _t)
+{
+	if (m_data.count(_t.first))
+	{
+		m_data.erase(_t.first);
+		m_future.insert(make_pair(Transaction(_t.second).sender(), _t));
+	}
+}
+
+void TransactionQueue::noteGood(std::pair<h256, bytes> const& _t)
+{
+	auto r = m_future.equal_range(Transaction(_t.second).sender());
+	for (auto it = r.first; it != r.second; ++it)
+		m_data.insert(_t);
+	m_future.erase(r.first);
+}
diff --git a/libethereum/TransactionQueue.h b/libethereum/TransactionQueue.h
index 8f2ccaef1..89e889cc1 100644
--- a/libethereum/TransactionQueue.h
+++ b/libethereum/TransactionQueue.h
@@ -40,14 +40,18 @@ public:
 	void drop(h256 _txHash) { m_data.erase(_txHash); }
 	std::map<h256, bytes> const& transactions() const { return m_data; }
 
+	void setFuture(std::pair<h256, bytes> const& _t);
+	void noteGood(std::pair<h256, bytes> const& _t);
+
 	Transactions interestQueue() { Transactions ret; swap(ret, m_interestQueue); return ret; }
 	void pushInterest(Address _a) { m_interest[_a]++; }
 	void popInterest(Address _a) { if (m_interest[_a] > 1) m_interest[_a]--; else if (m_interest[_a]) m_interest.erase(_a); }
 
 private:
-	std::map<h256, bytes> m_data;	///< the queue.
+	std::map<h256, bytes> m_data;		///< Map of SHA3(tx) to tx.
 	Transactions m_interestQueue;
 	std::map<Address, int> m_interest;
+	std::multimap<Address, std::pair<h256, bytes>> m_future;		///< For transactions that have a future nonce; we map their sender address to the tx stuff, and insert once the sender has a valid TX.
 };
 
 }