Merge #17164: p2p: Avoid allocating memory for addrKnown where we don't need it

b6d2183858975abc961207c125c15791e531edcc Minor refactoring to remove implied m_addr_relay_peer. (User)
a552e8477c5bcd22a5457f4f73a2fd6db8acd2c2 added asserts to check m_addr_known when it's used (User)
090b75c14be6b9ba2efe38a17d141c6e6af575cb p2p: Avoid allocating memory for addrKnown where we don't need it (User)

Pull request description:

  We should allocate memory for addrKnown filter only for those peers which are expected to participate in address relay.

  Currently, we do it for all peers (including SPV and block-relay-only),  which results in extra RAM where it's not needed.

  Upd:
  In future, we would still allow SPVs to ask for addrs, so allocation still will be done by default.
  However, they will be able to opt-out via [this proposal](https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-October/017428.html) and then we could save some more memory.
  This PR still saves memory for block-relay-only peers immediately after merging.

Top commit has no ACKs.

Tree-SHA512: e84d93b2615556d466f5ca0e543580fde763911a3bfea3127c493ddfaba8f05c8605cb94ff795d165af542b594400995a2c51338185c298581408687e7812463

1 files changed, 4 insertions, 3 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index d03817834d..d25a2d36e8 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1340,7 +1340,7 @@ static void RelayAddress(const CAddress& addr, bool fReachable, CConnman* connma
 
     // Relay to a limited number of other nodes
     // Use deterministic randomness to send to the same nodes for 24 hours
-    // at a time so the addrKnowns of the chosen nodes prevent repeats
+    // at a time so the m_addr_knowns of the chosen nodes prevent repeats
     uint64_t hashAddr = addr.GetHash();
     const CSipHasher hasher = connman->GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY).Write(hashAddr << 32).Write((GetTime() + hashAddr) / (24*60*60));
     FastRandomContext insecure_rand;
@@ -3587,11 +3587,12 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
             pto->nNextAddrSend = PoissonNextSend(nNow, AVG_ADDRESS_BROADCAST_INTERVAL);
             std::vector<CAddress> vAddr;
             vAddr.reserve(pto->vAddrToSend.size());
+            assert(pto->m_addr_known);
             for (const CAddress& addr : pto->vAddrToSend)
             {
-                if (!pto->addrKnown.contains(addr.GetKey()))
+                if (!pto->m_addr_known->contains(addr.GetKey()))
                 {
-                    pto->addrKnown.insert(addr.GetKey());
+                    pto->m_addr_known->insert(addr.GetKey());
                     vAddr.push_back(addr);
                     // receiver rejects addr messages larger than 1000
                     if (vAddr.size() >= 1000)