Fix progress reporting issue

Reimplementation of https://github.com/Blockstream/liquid/pull/6

src/interfaces/node.cpp

@@ -179,7 +179,7 @@ class NodeImpl : public Node
             LOCK(::cs_main);
             tip = ::chainActive.Tip();
         }
-        return GuessVerificationProgress(Params().TxData(), tip);
+        return GuessVerificationProgress(tip, Params().GetConsensus().nPowTargetSpacing);
     }
     bool isInitialBlockDownload() override { return IsInitialBlockDownload(); }
     bool getReindex() override { return ::fReindex; }
@@ -266,7 +266,7 @@ class NodeImpl : public Node
     {
         return MakeHandler(::uiInterface.NotifyBlockTip_connect([fn](bool initial_download, const CBlockIndex* block) {
             fn(initial_download, block->nHeight, block->GetBlockTime(),
-                GuessVerificationProgress(Params().TxData(), block));
+                GuessVerificationProgress(block, Params().GetConsensus().nPowTargetSpacing));
         }));
     }
     std::unique_ptr<Handler> handleNotifyHeaderTip(NotifyHeaderTipFn fn) override
@@ -274,7 +274,7 @@ class NodeImpl : public Node
         return MakeHandler(
             ::uiInterface.NotifyHeaderTip_connect([fn](bool initial_download, const CBlockIndex* block) {
                 fn(initial_download, block->nHeight, block->GetBlockTime(),
-                    GuessVerificationProgress(Params().TxData(), block));
+                    GuessVerificationProgress(block, Params().GetConsensus().nPowTargetSpacing));
             }));
     }
 };

src/rpc/blockchain.cpp

@@ -1292,7 +1292,7 @@ UniValue getblockchaininfo(const JSONRPCRequest& request)
         obj.pushKV("difficulty",            (double)GetDifficulty(chainActive.Tip()));
     }
     obj.pushKV("mediantime",            (int64_t)chainActive.Tip()->GetMedianTimePast());
-    obj.pushKV("verificationprogress",  GuessVerificationProgress(chainparams.TxData(), chainActive.Tip()));
+    obj.pushKV("verificationprogress",  GuessVerificationProgress(chainActive.Tip(), chainparams.GetConsensus().nPowTargetSpacing));
     obj.pushKV("initialblockdownload",  IsInitialBlockDownload());
     if (!g_signed_blocks) {
         obj.pushKV("chainwork",             chainActive.Tip()->nChainWork.GetHex());

src/validation.cpp

@@ -2394,7 +2394,8 @@ void static UpdateTip(const CBlockIndex *pindexNew, const CChainParams& chainPar
       pindexNew->GetBlockHash().ToString(), pindexNew->nHeight, pindexNew->nVersion,
       log(pindexNew->nChainWork.getdouble())/log(2.0), (unsigned long)pindexNew->nChainTx,
       FormatISO8601DateTime(pindexNew->GetBlockTime()),
-      GuessVerificationProgress(chainParams.TxData(), pindexNew), pcoinsTip->DynamicMemoryUsage() * (1.0 / (1<<20)), pcoinsTip->GetCacheSize());
+      GuessVerificationProgress(pindexNew, chainParams.GetConsensus().nPowTargetSpacing),
+      pcoinsTip->DynamicMemoryUsage() * (1.0 / (1<<20)), pcoinsTip->GetCacheSize());
     if (!warningMessages.empty())
         LogPrintf(" warning='%s'", warningMessages); /* Continued */
     LogPrintf("\n");
@@ -4203,10 +4204,10 @@ bool LoadChainTip(const CChainParams& chainparams)
 
     g_chainstate.PruneBlockIndexCandidates();
 
-    LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
+    LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%.3f\n",
         chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(),
         FormatISO8601DateTime(chainActive.Tip()->GetBlockTime()),
-        GuessVerificationProgress(chainparams.TxData(), chainActive.Tip()));
+        GuessVerificationProgress(chainActive.Tip(), chainparams.GetConsensus().nPowTargetSpacing));
     return true;
 }
 
@@ -5067,23 +5068,22 @@ bool DumpMempool(void)
     return true;
 }
 
-//! Guess how far we are in the verification process at the given block index
-//! require cs_main if pindex has not been validated yet (because nChainTx might be unset)
-double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex *pindex) {
-    if (pindex == nullptr)
+//! Guess how far we are in the verification process at the given block index.
+//! Since we have signed fixed-interval blocks, estimating progress is a very easy.
+//! We can extrapolate the last block time to the current time to estimate how many more blocks
+//! we expect.
+double GuessVerificationProgress(const CBlockIndex* pindex, int64_t blockInterval) {
+    if (pindex == NULL || pindex->nHeight < 1) {
         return 0.0;
-
-    int64_t nNow = time(nullptr);
-
-    double fTxTotal;
-
-    if (pindex->nChainTx <= data.nTxCount) {
-        fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
-    } else {
-        fTxTotal = pindex->nChainTx + (nNow - pindex->GetBlockTime()) * data.dTxRate;
     }
 
-    return pindex->nChainTx / fTxTotal;
+    int64_t nNow = GetTime();
+    int64_t moreBlocksExpected = (nNow - pindex->GetBlockTime()) / blockInterval;
+    double progress = (pindex->nHeight + 0.0) / (pindex->nHeight + moreBlocksExpected);
+    // Round to 3 digits to avoid 0.999999 when finished.
+    progress = ceil(progress * 1000.0) / 1000.0;
+    // Avoid higher than one if last block is newer than current time.
+    return std::min(1.0, progress);
 }
 
 class CMainCleanup

src/validation.h

@@ -289,7 +289,7 @@ bool ActivateBestChain(CValidationState& state, const CChainParams& chainparams,
 CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams);
 
 /** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */
-double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex* pindex);
+double GuessVerificationProgress(const CBlockIndex* pindex, int64_t blockInterval);
 
 /** Calculate the amount of disk space the block & undo files currently use */
 uint64_t CalculateCurrentUsage();

src/wallet/wallet.cpp

@@ -1708,12 +1708,12 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
         double progress_end;
         {
             LOCK(cs_main);
-            progress_begin = GuessVerificationProgress(chainParams.TxData(), pindex);
+            progress_begin = GuessVerificationProgress(pindex, chainParams.GetConsensus().nPowTargetSpacing);
             if (pindexStop == nullptr) {
                 tip = chainActive.Tip();
-                progress_end = GuessVerificationProgress(chainParams.TxData(), tip);
+                progress_end = GuessVerificationProgress(tip, chainParams.GetConsensus().nPowTargetSpacing);
             } else {
-                progress_end = GuessVerificationProgress(chainParams.TxData(), pindexStop);
+                progress_end = GuessVerificationProgress(pindexStop, chainParams.GetConsensus().nPowTargetSpacing);
             }
         }
         double progress_current = progress_begin;
@@ -1748,11 +1748,11 @@ CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, CBlock
             {
                 LOCK(cs_main);
                 pindex = chainActive.Next(pindex);
-                progress_current = GuessVerificationProgress(chainParams.TxData(), pindex);
+                progress_current = GuessVerificationProgress(pindex, chainParams.GetConsensus().nPowTargetSpacing);
                 if (pindexStop == nullptr && tip != chainActive.Tip()) {
                     tip = chainActive.Tip();
                     // in case the tip has changed, update progress max
-                    progress_end = GuessVerificationProgress(chainParams.TxData(), tip);
+                    progress_end = GuessVerificationProgress(tip, chainParams.GetConsensus().nPowTargetSpacing);
                 }
             }
         }

test/functional/feature_progress.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+# Copyright (c) 2015-2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#
+# Test progress code
+#
+
+import time
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    Decimal,
+)
+
+def assert_close(f1, f2):
+    assert(abs(Decimal(f1)-f2) < 0.1)
+
+class ProgressTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 2
+        self.extra_args = [["-debug", "-con_npowtargetspacing=1", "-maxtimeadjustment=0"]] * self.num_nodes
+
+    def setup_network(self):
+        self.setup_nodes()
+        self.is_network_split = True
+        self.starttime = int(time.time())
+
+    def setmocktime(self, ntime):
+        for node in self.nodes:
+            node.setmocktime(self.starttime + ntime)
+
+    def run_test(self):
+        node1 = self.nodes[0]
+        node2 = self.nodes[1]
+        self.setmocktime(0)
+
+        blocks = []
+        for i in range(10):
+            self.setmocktime(i)
+            blocks.extend(node1.generate(1))
+
+        self.setmocktime(19)
+        assert_close(0.5, node1.getblockchaininfo()["verificationprogress"])
+
+        assert(node2.getblockchaininfo()["initialblockdownload"])
+
+        self.setmocktime(10)
+        for i in range(10):
+            node2.submitblock(node1.getblock(blocks[i], False))
+            progress = node2.getblockchaininfo()["verificationprogress"]
+            assert_close(i/10.0, progress)
+
+        assert(not node2.getblockchaininfo()["initialblockdownload"])
+
+if __name__ == '__main__':
+    ProgressTest().main()

test/functional/test_runner.py

@@ -73,6 +73,7 @@ BASE_SCRIPTS = [
     'feature_default_asset_name.py',
     'feature_assetsdir.py',
     'feature_initial_reissuance_token.py',
+    'feature_progress.py',
     # Longest test should go first, to favor running tests in parallel
     'wallet_hd.py',
     'wallet_backup.py',