Add PeerDb::handleGossipedRC

llarp/dht/messages/gotrouter.cpp

@@ -127,6 +127,10 @@ namespace llarp
           auto* router = dht.GetRouter();
           router->NotifyRouterEvent<tooling::RCGossipReceivedEvent>(router->pubkey(), rc);
           router->GossipRCIfNeeded(rc);
+
+          auto peerDb = router->peerDb();
+          if (peerDb)
+            peerDb->handleGossipedRC(rc);
         }
       }
       return true;

llarp/peerstats/peer_db.cpp

@@ -121,6 +121,31 @@ namespace llarp
       return itr->second;
   }
 
+  void
+  PeerDb::handleGossipedRC(const RouterContact& rc, llarp_time_t now)
+  {
+    std::lock_guard gaurd(m_statsLock);
+
+    RouterID id(rc.pubkey);
+    auto& stats = m_peerStats[id];
+
+    if (stats.lastRCUpdated < rc.last_updated.count())
+    {
+      // we track max expiry as the delta between (time received - last expiration time),
+      // and this value will often be negative for a healthy router
+      // TODO: handle case where new RC is also expired? just ignore?
+      int64_t expiry = (now.count() - (stats.lastRCUpdated + RouterContact::Lifetime.count()));
+
+      if (stats.numDistinctRCsReceived == 0)
+        stats.mostExpiredRCMs = expiry;
+      else
+        stats.mostExpiredRCMs = std::max(stats.mostExpiredRCMs, expiry);
+
+      stats.numDistinctRCsReceived++;
+      stats.lastRCUpdated = rc.last_updated.count();
+    }
+  }
+
   void
   PeerDb::configure(const RouterConfig& routerConfig)
   {

llarp/peerstats/peer_db.hpp

@@ -81,6 +81,16 @@ namespace llarp
     std::optional<PeerStats>
     getCurrentPeerStats(const RouterID& routerId) const;
 
+    /// Handles a new gossiped RC, updating stats as needed. The database tracks the last
+    /// advertised update time, so it knows whether this is a new RC or not.
+    ///
+    /// The given RC is assumed to be valid.
+    ///
+    /// @param rc is the RouterContact to handle
+    /// @param now is an optional time representing the current time
+    void
+    handleGossipedRC(const RouterContact& rc, llarp_time_t now = time_now_ms());
+
     /// Configures the PeerDb based on RouterConfig
     ///
     /// @param routerConfig

llarp/peerstats/types.hpp

@@ -32,6 +32,7 @@ namespace llarp
     double peakBandwidthBytesPerSec = 0;
     int64_t longestRCReceiveIntervalMs = 0;
     int64_t mostExpiredRCMs = 0;
+    int64_t lastRCUpdated = 0;
 
     PeerStats();
     PeerStats(const RouterID& routerId);

llarp/router/abstractrouter.hpp

@@ -11,6 +11,7 @@
 #include <functional>
 #include <router_contact.hpp>
 #include <tooling/router_event.hpp>
+#include <peerstats/peer_db.hpp>
 
 #ifdef LOKINET_HIVE
 #include "tooling/router_hive.hpp"
@@ -151,6 +152,9 @@ namespace llarp
     virtual I_RCLookupHandler&
     rcLookupHandler() = 0;
 
+    virtual std::shared_ptr<PeerDb>
+    peerDb() = 0;
+
     virtual bool
     Sign(Signature& sig, const llarp_buffer_t& buf) const = 0;
 

llarp/router/router.cpp

@@ -582,7 +582,7 @@ namespace llarp
     if (conf->router.m_enablePeerStats)
     {
       LogInfo("Initializing peerdb...");
-      m_peerDb = std::make_unique<PeerDb>();
+      m_peerDb = std::make_shared<PeerDb>();
       m_peerDb->configure(conf->router);
     }
 

llarp/router/router.hpp

@@ -307,6 +307,12 @@ namespace llarp
       return _rcLookupHandler;
     }
 
+    std::shared_ptr<PeerDb>
+    peerDb() override
+    {
+      return m_peerDb;
+    }
+
     void
     GossipRCIfNeeded(const RouterContact rc) override;
 
@@ -496,7 +502,7 @@ namespace llarp
     llarp_time_t m_LastStatsReport = 0s;
 
     std::shared_ptr<llarp::KeyManager> m_keyManager;
-    std::unique_ptr<PeerDb> m_peerDb;
+    std::shared_ptr<PeerDb> m_peerDb;
 
     uint32_t path_build_count = 0;
 

test/peerstats/test_peer_db.cpp

@@ -3,6 +3,8 @@
 
 #include <numeric>
 #include <catch2/catch.hpp>
+#include "router_contact.hpp"
+#include "util/time.hpp"
 
 TEST_CASE("Test PeerDb PeerStats memory storage", "[PeerDb]")
 {
@@ -111,3 +113,42 @@ TEST_CASE("Test PeerDb modifyPeerStats", "[PeerDb]")
   CHECK(stats.has_value());
   CHECK(stats.value().numPathBuilds == 42);
 }
+
+TEST_CASE("Test PeerDb handleGossipedRC", "[PeerDb]")
+{
+  const llarp::RouterID id = llarp::test::makeBuf<llarp::RouterID>(0xCA);
+
+  auto rcLifetime = llarp::RouterContact::Lifetime;
+  llarp_time_t now = 0s;
+
+  llarp::RouterContact rc;
+  rc.pubkey = llarp::PubKey(id);
+  rc.last_updated = 10s;
+
+  llarp::PeerDb db;
+  db.handleGossipedRC(rc, now);
+
+  auto stats = db.getCurrentPeerStats(id);
+  CHECK(stats.has_value());
+  CHECK(stats.value().mostExpiredRCMs == (0s - rcLifetime).count());
+  CHECK(stats.value().numDistinctRCsReceived == 1);
+  CHECK(stats.value().lastRCUpdated == 10000);
+
+  now = 9s;
+  db.handleGossipedRC(rc, now);
+  stats = db.getCurrentPeerStats(id);
+  CHECK(stats.has_value());
+  // these values should remain unchanged, this is not a new RC
+  CHECK(stats.value().mostExpiredRCMs == (0s - rcLifetime).count());
+  CHECK(stats.value().numDistinctRCsReceived == 1);
+  CHECK(stats.value().lastRCUpdated == 10000);
+
+  rc.last_updated = 11s;
+
+  db.handleGossipedRC(rc, now);
+  stats = db.getCurrentPeerStats(id);
+  // new RC received at 9sec, making it (expiration time - 9 sec) expired (a negative number)
+  CHECK(stats.value().mostExpiredRCMs == (9s - (now + rcLifetime)).count());
+  CHECK(stats.value().numDistinctRCsReceived == 2);
+  CHECK(stats.value().lastRCUpdated == 11000);
+}