int main()
{
// Our address.
h256 privkey = sha3("123");
Address us = toPublic(privkey); // TODO: should be loaded from config file/set at command-line.
BlockChain bc; // Maintains block database.
TransactionQueue tq; // Maintains list of incoming transactions not yet on the block chain.
State s(us);
// Synchronise the state according to the block chain - i.e. replay all transactions in block chain, in order.
// In practise this won't need to be done since the State DB will contain the keys for the tries for most recent (and many old) blocks.
// TODO: currently it contains keys for *all* blocks. Make it remove old ones.
s.sync(bc);
s.sync(tq);
PeerNetwork net; // TODO: Implement - should run in background and send us events when blocks found and allow us to send blocks as required.
while (true)
{
// Process network events.
net.process();
// Synchronise block chain with network.
// Will broadcast any of our (new) transactions and blocks, and collect & add any of their (new) transactions and blocks.
net.sync(bc, tq);
// Synchronise state to block chain.
// This should remove any transactions on our queue that are included within our state.
// It also guarantees that the state reflects the longest (valid!) chain on the block chain.
// This might mean reverting to an earlier state and replaying some blocks, or, (worst-case:
// if there are no checkpoints before our fork) reverting to the genesis block and replaying
// all blocks.
s.sync(bc); // Resynchronise state with block chain & trans
s.sync(tq);
// Mine for a while.
if (s.mine(100))
{
// Mined block
bytes b = s.blockData();
// Import block.
bc.import(b);
}
}
return 0;
}
bool PeerServer::sync(BlockChain& _bc, TransactionQueue& _tq, Overlay& _o)
{
bool ret = ensureInitialised(_bc, _tq);
if (sync())
ret = true;
if (m_mode == NodeMode::Full)
{
for (auto it = m_incomingTransactions.begin(); it != m_incomingTransactions.end(); ++it)
if (_tq.import(*it))
{}//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();
auto h = _bc.currentHash();
bool resendAll = (h != m_latestBlockSent);
// Send any new transactions.
for (auto j: m_peers)
if (auto p = j.second.lock())
{
bytes b;
uint n = 0;
for (auto const& i: _tq.transactions())
if ((!m_transactionsSent.count(i.first) && !p->m_knownTransactions.count(i.first)) || p->m_requireTransactions || resendAll)
{
b += i.second;
++n;
m_transactionsSent.insert(i.first);
}
if (n)
{
RLPStream ts;
PeerSession::prep(ts);
ts.appendList(n + 1) << TransactionsPacket;
ts.appendRaw(b, n).swapOut(b);
seal(b);
p->send(&b);
}
p->m_knownTransactions.clear();
p->m_requireTransactions = false;
}
// Send any new blocks.
if (h != m_latestBlockSent)
{
// TODO: find where they diverge and send complete new branch.
RLPStream ts;
PeerSession::prep(ts);
ts.appendList(2) << BlocksPacket;
bytes b;
ts.appendRaw(_bc.block(_bc.currentHash())).swapOut(b);
seal(b);
for (auto j: m_peers)
if (auto p = j.second.lock())
{
if (!p->m_knownBlocks.count(_bc.currentHash()))
p->send(&b);
p->m_knownBlocks.clear();
}
}
m_latestBlockSent = h;
for (int accepted = 1, n = 0; accepted; ++n)
{
accepted = 0;
if (m_incomingBlocks.size())
for (auto it = prev(m_incomingBlocks.end());; --it)
{
try
{
_bc.import(*it, _o);
it = m_incomingBlocks.erase(it);
++accepted;
ret = true;
}
catch (UnknownParent)
{
// Don't (yet) know its parent. Leave it for later.
m_unknownParentBlocks.push_back(*it);
it = m_incomingBlocks.erase(it);
}
catch (...)
{
// Some other error - erase it.
it = m_incomingBlocks.erase(it);
}
if (it == m_incomingBlocks.begin())
break;
}
if (!n && accepted)
{
for (auto i: m_unknownParentBlocks)
m_incomingBlocks.push_back(i);
m_unknownParentBlocks.clear();
}
}
// Connect to additional peers
while (m_peers.size() < m_idealPeerCount)
{
if (m_freePeers.empty())
{
if (chrono::steady_clock::now() > m_lastPeersRequest + chrono::seconds(10))
{
RLPStream s;
bytes b;
(PeerSession::prep(s).appendList(1) << GetPeersPacket).swapOut(b);
seal(b);
for (auto const& i: m_peers)
if (auto p = i.second.lock())
if (p->isOpen())
p->send(&b);
m_lastPeersRequest = chrono::steady_clock::now();
}
if (!m_accepting)
ensureAccepting();
break;
}
auto x = time(0) % m_freePeers.size();
m_incomingPeers[m_freePeers[x]].second++;
connect(m_incomingPeers[m_freePeers[x]].first);
m_freePeers.erase(m_freePeers.begin() + x);
}
}
// platform for consensus of social contract.
// restricts your freedom but does so fairly. and that's the value proposition.
// guarantees that everyone else respect the rules of the system. (i.e. obeys laws).
// We'll keep at most twice as many as is ideal, halfing what counts as "too young to kill" until we get there.
for (uint old = 15000; m_peers.size() > m_idealPeerCount * 2 && old > 100; old /= 2)
while (m_peers.size() > m_idealPeerCount)
{
// look for worst peer to kick off
// first work out how many are old enough to kick off.
shared_ptr<PeerSession> worst;
unsigned agedPeers = 0;
for (auto i: m_peers)
if (auto p = i.second.lock())
if ((m_mode != NodeMode::PeerServer || p->m_caps != 0x01) && chrono::steady_clock::now() > p->m_connect + chrono::milliseconds(old)) // don't throw off new peers; peer-servers should never kick off other peer-servers.
{
++agedPeers;
if ((!worst || p->m_rating < worst->m_rating || (p->m_rating == worst->m_rating && p->m_connect > worst->m_connect))) // kill older ones
worst = p;
}
if (!worst || agedPeers <= m_idealPeerCount)
break;
worst->disconnect(TooManyPeers);
}
return ret;
}