From 9b604c0207b526c008617cdca210f35db5e344db Mon Sep 17 00:00:00 2001
From: James O'Beirne <james.obeirne@pm.me>
Date: Tue, 13 Apr 2021 10:05:28 -0400
Subject: [PATCH] validation: prepare VerifyDB for assumeutxo

Removes assumptions of use only on the active chainstate.
---
 src/init.cpp           |  7 ++-----
 src/rpc/blockchain.cpp |  3 ++-
 src/validation.cpp     | 16 ++++++++++------
 src/validation.h       |  2 +-
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index ccf36808173..2b1cd3e2aa9 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1550,11 +1550,8 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
                             break;
                         }
 
-                        // Only verify the DB of the active chainstate. This is fixed in later
-                        // work when we allow VerifyDB to be parameterized by chainstate.
-                        if (&::ChainstateActive() == chainstate &&
-                            !CVerifyDB().VerifyDB(
-                                *chainstate, chainparams, &chainstate->CoinsDB(),
+                        if (!CVerifyDB().VerifyDB(
+                                *chainstate, chainparams, chainstate->CoinsDB(),
                                 args.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
                                 args.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS))) {
                             strLoadError = _("Corrupted block database detected");
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 8e029b134bf..d36814716bb 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1239,7 +1239,8 @@ static RPCHelpMan verifychain()
     LOCK(cs_main);
 
     CChainState& active_chainstate = chainman.ActiveChainstate();
-    return CVerifyDB().VerifyDB(active_chainstate, Params(), &active_chainstate.CoinsTip(), check_level, check_depth);
+    return CVerifyDB().VerifyDB(
+        active_chainstate, Params(), active_chainstate.CoinsTip(), check_level, check_depth);
 },
     };
 }
diff --git a/src/validation.cpp b/src/validation.cpp
index 6fe096465af..332a38119aa 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -4104,7 +4104,7 @@ CVerifyDB::~CVerifyDB()
 bool CVerifyDB::VerifyDB(
     CChainState& chainstate,
     const CChainParams& chainparams,
-    CCoinsView* coinsview,
+    CCoinsView& coinsview,
     int nCheckLevel, int nCheckDepth)
 {
     AssertLockHeld(cs_main);
@@ -4118,13 +4118,16 @@ bool CVerifyDB::VerifyDB(
         nCheckDepth = chainstate.m_chain.Height();
     nCheckLevel = std::max(0, std::min(4, nCheckLevel));
     LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
-    CCoinsViewCache coins(coinsview);
+    CCoinsViewCache coins(&coinsview);
     CBlockIndex* pindex;
     CBlockIndex* pindexFailure = nullptr;
     int nGoodTransactions = 0;
     BlockValidationState state;
     int reportDone = 0;
     LogPrintf("[0%%]..."); /* Continued */
+
+    bool is_snapshot_cs = !chainstate.m_from_snapshot_blockhash.IsNull();
+
     for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev; pindex = pindex->pprev) {
         const int percentageDone = std::max(1, std::min(99, (int)(((double)(chainstate.m_chain.Height() - pindex->nHeight)) / (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100))));
         if (reportDone < percentageDone/10) {
@@ -4135,8 +4138,9 @@ bool CVerifyDB::VerifyDB(
         uiInterface.ShowProgress(_("Verifying blocks...").translated, percentageDone, false);
         if (pindex->nHeight <= chainstate.m_chain.Height()-nCheckDepth)
             break;
-        if (fPruneMode && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
-            // If pruning, only go back as far as we have data.
+        if ((fPruneMode || is_snapshot_cs) && !(pindex->nStatus & BLOCK_HAVE_DATA)) {
+            // If pruning or running under an assumeutxo snapshot, only go
+            // back as far as we have data.
             LogPrintf("VerifyDB(): block verification stopping at height %d (pruning, no data)\n", pindex->nHeight);
             break;
         }
@@ -4158,9 +4162,9 @@ bool CVerifyDB::VerifyDB(
             }
         }
         // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
-        int64_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage();
+        size_t curr_coins_usage = coins.DynamicMemoryUsage() + chainstate.CoinsTip().DynamicMemoryUsage();
 
-        if (nCheckLevel >= 3 && static_cast<unsigned long>(curr_coins_usage) <= chainstate.m_coinstip_cache_size_bytes) {
+        if (nCheckLevel >= 3 && curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
             assert(coins.GetBestBlock() == pindex->GetBlockHash());
             DisconnectResult res = chainstate.DisconnectBlock(block, pindex, coins);
             if (res == DISCONNECT_FAILED) {
diff --git a/src/validation.h b/src/validation.h
index b4e1c080fe1..d3341f491ec 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -332,7 +332,7 @@ public:
     bool VerifyDB(
         CChainState& chainstate,
         const CChainParams& chainparams,
-        CCoinsView* coinsview,
+        CCoinsView& coinsview,
         int nCheckLevel,
         int nCheckDepth) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 };