Add a persistent screen showing basic node metrics

The screen is implemented using ANSI Escape sequences.

Closes #1331

src/miner.cpp

@@ -12,6 +12,7 @@
 #include "consensus/validation.h"
 #include "hash.h"
 #include "main.h"
+#include "metrics.h"
 #include "net.h"
 #include "pow.h"
 #include "primitives/transaction.h"
@@ -437,6 +438,8 @@ static bool ProcessBlockFound(CBlock* pblock, CWallet& wallet, CReserveKey& rese
     if (!ProcessNewBlock(state, NULL, pblock, true, NULL))
         return error("ZcashMiner: ProcessNewBlock, block not accepted");
 
+    minedBlocks.increment();
+
     return true;
 }
 
@@ -555,8 +558,11 @@ void static BitcoinMiner(CWallet *pwallet)
                     SetThreadPriority(THREAD_PRIORITY_LOWEST);
 
                     // In regression test mode, stop mining after a block is found.
-                    if (chainparams.MineBlocksOnDemand())
+                    if (chainparams.MineBlocksOnDemand()) {
+                        // Increment here because throwing skips the call below
+                        ehSolverRuns.increment();
                         throw boost::thread_interrupted();
+                    }
 
                     return true;
                 };
@@ -581,6 +587,7 @@ void static BitcoinMiner(CWallet *pwallet)
                         eq.showbsizes(r);
                     }
                     eq.digitK(0);
+                    ehSolverRuns.increment();
 
                     // Convert solution indices to byte array (decompress) and pass it to validBlock method.
                     for (size_t s = 0; s < eq.nsols; s++) {
@@ -600,8 +607,11 @@ void static BitcoinMiner(CWallet *pwallet)
                 } else {
                     try {
                         // If we find a valid block, we rebuild
-                        if (EhOptimisedSolve(n, k, curr_state, validBlock, cancelled))
+                        bool found = EhOptimisedSolve(n, k, curr_state, validBlock, cancelled);
+                        ehSolverRuns.increment();
+                        if (found) {
                             break;
+                        }
                     } catch (EhSolverCancelledException&) {
                         LogPrint("pow", "Equihash solver cancelled\n");
                         std::lock_guard<std::mutex> lock{m_cs};