net: Rework CNode spans

- Extract a reload function for recreating them.
- Record the peer id.
- Remove the peer id and address from the CNode constructor log
  (it will always be shown by the span at that log level).

src/net.cpp

@@ -2109,22 +2109,16 @@ CNode::CNode(SOCKET hSocketIn, const CAddress& addrIn, const std::string& addrNa
     fPingQueued = false;
     nMinPingUsecTime = std::numeric_limits<int64_t>::max();
 
-    if (fLogIPs) {
-        span = TracingSpanFields("info", "net", "CNode", "addr", addrName.c_str());
-    } else {
-        span = TracingSpan("info", "net", "CNode");
-    }
-    auto spanGuard = span.Enter();
-
     {
         LOCK(cs_nLastNodeId);
         id = nLastNodeId++;
     }
+    idStr = tfm::format("%d", id);
 
-    if (fLogIPs)
-        LogPrint("net", "Added connection to %s peer=%d\n", addrName, id);
-    else
-        LogPrint("net", "Added connection peer=%d\n", id);
+    ReloadTracingSpan();
+
+    auto spanGuard = span.Enter();
+    LogPrint("net", "Added connection");
 
     // Be shy and don't send version until we hear
     if (hSocket != INVALID_SOCKET && !fInbound)
@@ -2143,6 +2137,18 @@ CNode::~CNode()
     GetNodeSignals().FinalizeNode(GetId());
 }
 
+void CNode::ReloadTracingSpan()
+{
+    if (fLogIPs) {
+        span = TracingSpanFields("info", "net", "Peer",
+            "id", idStr.c_str(),
+            "addr", addrName.c_str());
+    } else {
+        span = TracingSpanFields("info", "net", "Peer",
+            "id", idStr.c_str());
+    }
+}
+
 void CNode::AskFor(const CInv& inv)
 {
     if (mapAskFor.size() > MAPASKFOR_MAX_SZ || setAskFor.size() > SETASKFOR_MAX_SZ)

src/net.h

@@ -298,6 +298,8 @@ public:
     CBloomFilter* pfilter;
     int nRefCount;
     NodeId id;
+    // Stored so we can pass a pointer to it across the Rust FFI for span.
+    std::string idStr;
 
     tracing::Span span;
 protected:
@@ -359,6 +361,10 @@ private:
 
 public:
 
+    // Regenerate the span for this CNode. This re-queries the log filter to see
+    // if the span should be enabled, and re-collects the logged variables.
+    void ReloadTracingSpan();
+
     NodeId GetId() const {
       return id;
     }