1 files changed, 47 insertions, 78 deletions

diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 7392830261..763fd29744 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -28,10 +28,45 @@ bool fHavePruned = false;
 bool fPruneMode = false;
 uint64_t nPruneTarget = 0;
 
+bool CBlockIndexWorkComparator::operator()(const CBlockIndex* pa, const CBlockIndex* pb) const
+{
+    // First sort by most total work, ...
+    if (pa->nChainWork > pb->nChainWork) return false;
+    if (pa->nChainWork < pb->nChainWork) return true;
+
+    // ... then by earliest time received, ...
+    if (pa->nSequenceId < pb->nSequenceId) return false;
+    if (pa->nSequenceId > pb->nSequenceId) return true;
+
+    // Use pointer address as tie breaker (should only happen with blocks
+    // loaded from disk, as those all have id 0).
+    if (pa < pb) return false;
+    if (pa > pb) return true;
+
+    // Identical blocks.
+    return false;
+}
+
+bool CBlockIndexHeightOnlyComparator::operator()(const CBlockIndex* pa, const CBlockIndex* pb) const
+{
+    return pa->nHeight < pb->nHeight;
+}
+
 static FILE* OpenUndoFile(const FlatFilePos& pos, bool fReadOnly = false);
 static FlatFileSeq BlockFileSeq();
 static FlatFileSeq UndoFileSeq();
 
+std::vector<CBlockIndex*> BlockManager::GetAllBlockIndices()
+{
+    AssertLockHeld(cs_main);
+    std::vector<CBlockIndex*> rv;
+    rv.reserve(m_block_index.size());
+    for (auto& [_, block_index] : m_block_index) {
+        rv.push_back(&block_index);
+    }
+    return rv;
+}
+
 CBlockIndex* BlockManager::LookupBlockIndex(const uint256& hash)
 {
     AssertLockHeld(cs_main);
@@ -203,8 +238,7 @@ CBlockIndex* BlockManager::InsertBlockIndex(const uint256& hash)
         return nullptr;
     }
 
-    // Return existing or create new
-    auto [mi, inserted] = m_block_index.try_emplace(hash);
+    const auto [mi, inserted]{m_block_index.try_emplace(hash)};
     CBlockIndex* pindex = &(*mi).second;
     if (inserted) {
         pindex->phashBlock = &((*mi).first);
@@ -212,46 +246,19 @@ CBlockIndex* BlockManager::InsertBlockIndex(const uint256& hash)
     return pindex;
 }
 
-bool BlockManager::LoadBlockIndex(
-    const Consensus::Params& consensus_params,
-    ChainstateManager& chainman)
+bool BlockManager::LoadBlockIndex(const Consensus::Params& consensus_params)
 {
     if (!m_block_tree_db->LoadBlockIndexGuts(consensus_params, [this](const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return this->InsertBlockIndex(hash); })) {
         return false;
     }
 
     // Calculate nChainWork
-    std::vector<std::pair<int, CBlockIndex*>> vSortedByHeight;
-    vSortedByHeight.reserve(m_block_index.size());
-    for (auto& [_, block_index] : m_block_index) {
-        CBlockIndex* pindex = &block_index;
-        vSortedByHeight.push_back(std::make_pair(pindex->nHeight, pindex));
-    }
-    sort(vSortedByHeight.begin(), vSortedByHeight.end());
-
-    // Find start of assumed-valid region.
-    int first_assumed_valid_height = std::numeric_limits<int>::max();
-
-    for (const auto& [height, block] : vSortedByHeight) {
-        if (block->IsAssumedValid()) {
-            auto chainstates = chainman.GetAll();
-
-            // If we encounter an assumed-valid block index entry, ensure that we have
-            // one chainstate that tolerates assumed-valid entries and another that does
-            // not (i.e. the background validation chainstate), since assumed-valid
-            // entries should always be pending validation by a fully-validated chainstate.
-            auto any_chain = [&](auto fnc) { return std::any_of(chainstates.cbegin(), chainstates.cend(), fnc); };
-            assert(any_chain([](auto chainstate) { return chainstate->reliesOnAssumedValid(); }));
-            assert(any_chain([](auto chainstate) { return !chainstate->reliesOnAssumedValid(); }));
-
-            first_assumed_valid_height = height;
-            break;
-        }
-    }
+    std::vector<CBlockIndex*> vSortedByHeight{GetAllBlockIndices()};
+    std::sort(vSortedByHeight.begin(), vSortedByHeight.end(),
+              CBlockIndexHeightOnlyComparator());
 
-    for (const std::pair<int, CBlockIndex*>& item : vSortedByHeight) {
+    for (CBlockIndex* pindex : vSortedByHeight) {
         if (ShutdownRequested()) return false;
-        CBlockIndex* pindex = item.second;
         pindex->nChainWork = (pindex->pprev ? pindex->pprev->nChainWork : 0) + GetBlockProof(*pindex);
         pindex->nTimeMax = (pindex->pprev ? std::max(pindex->pprev->nTimeMax, pindex->nTime) : pindex->nTime);
 
@@ -275,43 +282,6 @@ bool BlockManager::LoadBlockIndex(
             pindex->nStatus |= BLOCK_FAILED_CHILD;
             m_dirty_blockindex.insert(pindex);
         }
-        if (pindex->IsAssumedValid() ||
-                (pindex->IsValid(BLOCK_VALID_TRANSACTIONS) &&
-                 (pindex->HaveTxsDownloaded() || pindex->pprev == nullptr))) {
-
-            // Fill each chainstate's block candidate set. Only add assumed-valid
-            // blocks to the tip candidate set if the chainstate is allowed to rely on
-            // assumed-valid blocks.
-            //
-            // If all setBlockIndexCandidates contained the assumed-valid blocks, the
-            // background chainstate's ActivateBestChain() call would add assumed-valid
-            // blocks to the chain (based on how FindMostWorkChain() works). Obviously
-            // we don't want this since the purpose of the background validation chain
-            // is to validate assued-valid blocks.
-            //
-            // Note: This is considering all blocks whose height is greater or equal to
-            // the first assumed-valid block to be assumed-valid blocks, and excluding
-            // them from the background chainstate's setBlockIndexCandidates set. This
-            // does mean that some blocks which are not technically assumed-valid
-            // (later blocks on a fork beginning before the first assumed-valid block)
-            // might not get added to the background chainstate, but this is ok,
-            // because they will still be attached to the active chainstate if they
-            // actually contain more work.
-            //
-            // Instead of this height-based approach, an earlier attempt was made at
-            // detecting "holistically" whether the block index under consideration
-            // relied on an assumed-valid ancestor, but this proved to be too slow to
-            // be practical.
-            for (CChainState* chainstate : chainman.GetAll()) {
-                if (chainstate->reliesOnAssumedValid() ||
-                        pindex->nHeight < first_assumed_valid_height) {
-                    chainstate->setBlockIndexCandidates.insert(pindex);
-                }
-            }
-        }
-        if (pindex->nStatus & BLOCK_FAILED_MASK && (!chainman.m_best_invalid || pindex->nChainWork > chainman.m_best_invalid->nChainWork)) {
-            chainman.m_best_invalid = pindex;
-        }
         if (pindex->pprev) {
             pindex->BuildSkip();
         }
@@ -355,9 +325,9 @@ bool BlockManager::WriteBlockIndexDB()
     return true;
 }
 
-bool BlockManager::LoadBlockIndexDB(ChainstateManager& chainman)
+bool BlockManager::LoadBlockIndexDB()
 {
-    if (!LoadBlockIndex(::Params().GetConsensus(), chainman)) {
+    if (!LoadBlockIndex(::Params().GetConsensus())) {
         return false;
     }
 
@@ -382,9 +352,8 @@ bool BlockManager::LoadBlockIndexDB(ChainstateManager& chainman)
     LogPrintf("Checking all blk files are present...\n");
     std::set<int> setBlkDataFiles;
     for (const auto& [_, block_index] : m_block_index) {
-        const CBlockIndex* pindex = &block_index;
-        if (pindex->nStatus & BLOCK_HAVE_DATA) {
-            setBlkDataFiles.insert(pindex->nFile);
+        if (block_index.nStatus & BLOCK_HAVE_DATA) {
+            setBlkDataFiles.insert(block_index.nFile);
         }
     }
     for (std::set<int>::iterator it = setBlkDataFiles.begin(); it != setBlkDataFiles.end(); it++) {
@@ -408,13 +377,13 @@ bool BlockManager::LoadBlockIndexDB(ChainstateManager& chainman)
     return true;
 }
 
-CBlockIndex* BlockManager::GetLastCheckpoint(const CCheckpointData& data)
+const CBlockIndex* BlockManager::GetLastCheckpoint(const CCheckpointData& data)
 {
     const MapCheckpoints& checkpoints = data.mapCheckpoints;
 
     for (const MapCheckpoints::value_type& i : reverse_iterate(checkpoints)) {
         const uint256& hash = i.second;
-        CBlockIndex* pindex = LookupBlockIndex(hash);
+        const CBlockIndex* pindex = LookupBlockIndex(hash);
         if (pindex) {
             return pindex;
         }