Add some metrics that match existing zebrad metrics

The metric names match those used in zebrad, so the same visualisers can
be used for both nodes.

See https://github.com/ZcashFoundation/zebra/issues/1381 for discussion
about potential naming changes.

src/main.cpp

@@ -46,6 +46,7 @@
 #include <boost/thread.hpp>
 
 #include <rust/ed25519.h>
+#include <rust/metrics.h>
 
 using namespace std;
 
@@ -3237,6 +3238,7 @@ void static UpdateTip(CBlockIndex *pindexNew, const CChainParams& chainParams) {
         "date", date.c_str(),
         "progress", progress.c_str(),
         "cache", cache.c_str());
+    MetricsGauge("block.verified.block.height", pindexNew->nHeight);
 
     cvBlockChange.notify_all();
 }
@@ -3369,6 +3371,7 @@ bool static ConnectTip(CValidationState& state, const CChainParams& chainparams,
     int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
     LogPrint("bench", "  - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
     LogPrint("bench", "- Connect block: %.2fms [%.2fs]\n", (nTime6 - nTime1) * 0.001, nTimeTotal * 0.000001);
+    MetricsIncrementCounter("block.verified.block.count");
     return true;
 }
 
@@ -6226,6 +6229,7 @@ bool static ProcessMessage(const CChainParams& chainparams, CNode* pfrom, string
 
         CInv inv(MSG_BLOCK, block.GetHash());
         LogPrint("net", "received block %s peer=%d\n", inv.hash.ToString(), pfrom->id);
+        MetricsIncrementCounter("sync.downloaded.block.count");
 
         pfrom->AddInventoryKnown(inv);
 
@@ -6244,6 +6248,8 @@ bool static ProcessMessage(const CChainParams& chainparams, CNode* pfrom, string
                 LOCK(cs_main);
                 Misbehaving(pfrom->GetId(), nDoS);
             }
+        } else if (state.IsValid()) {
+            MetricsIncrementCounter("sync.verified.block.count");
         }
 
     }

src/net.cpp

@@ -31,6 +31,8 @@
 
 #include <boost/thread.hpp>
 
+#include <rust/metrics.h>
+
 // Dump addresses to peers.dat and banlist.dat every 15 minutes (900s)
 #define DUMP_ADDRESSES_INTERVAL 900
 
@@ -702,6 +704,7 @@ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes)
 
         if (msg.complete()) {
             msg.nTime = GetTimeMicros();
+            MetricsIncrementCounter("peer.inbound.messages");
             messageHandlerCondition.notify_one();
         }
     }
@@ -1104,6 +1107,7 @@ void ThreadSocketHandler()
         }
         if (vNodesSize != nPrevNodeCount) {
             nPrevNodeCount = vNodesSize;
+            MetricsGauge("pool.num_peers", nPrevNodeCount);
             uiInterface.NotifyNumConnectionsChanged(nPrevNodeCount);
         }
 
@@ -2001,12 +2005,14 @@ void CNode::RecordBytesRecv(uint64_t bytes)
 {
     LOCK(cs_totalBytesRecv);
     nTotalBytesRecv += bytes;
+    MetricsCounter("bytes.read", bytes);
 }
 
 void CNode::RecordBytesSent(uint64_t bytes)
 {
     LOCK(cs_totalBytesSent);
     nTotalBytesSent += bytes;
+    MetricsCounter("bytes.written", bytes);
 
     uint64_t now = GetTime();
     if (nMaxOutboundCycleStartTime + nMaxOutboundTimeframe < now)
@@ -2280,6 +2286,7 @@ void CNode::AbortMessage() UNLOCK_FUNCTION(cs_vSend)
 
 void CNode::EndMessage() UNLOCK_FUNCTION(cs_vSend)
 {
+    MetricsIncrementCounter("peer.outbound.messages");
     // The -*messagestest options are intentionally not documented in the help message,
     // since they are only used during development to debug the networking code and are
     // not intended for end-users.