refactor: assumeutxo M3 review follow-ups

src/node/chainstate.cpp

@@ -11,6 +11,7 @@
 #include <deploymentstatus.h>
 #include <node/blockstorage.h>
 #include <node/caches.h>
+#include <node/utxo_snapshot.h>
 #include <sync.h>
 #include <threadsafety.h>
 #include <tinyformat.h>
@@ -39,9 +40,12 @@ namespace node {
 static bool RecoverSnapshotCleanup(CEvoDB& evodb, const fs::path& data_dir, bilingual_str& error)
 {
     const fs::path normal{data_dir / "chainstate"};
-    const fs::path snapshot{data_dir / "chainstate_snapshot"};
-    const fs::path to_delete{data_dir / "chainstate_todelete"};
-    const fs::path invalid{data_dir / "chainstate_snapshot_INVALID"};
+    fs::path snapshot{normal};
+    snapshot += SNAPSHOT_CHAINSTATE_SUFFIX;
+    fs::path to_delete{normal};
+    to_delete += SNAPSHOT_TODELETE_SUFFIX;
+    fs::path invalid{snapshot};
+    invalid += SNAPSHOT_INVALID_SUFFIX;
 
     uint256 snapshot_tip;
     const bool has_snapshot_tip{evodb.ReadBestBlock(EvoDbIdentity::SNAPSHOT, snapshot_tip)};

src/node/utxo_snapshot.h

@@ -60,6 +60,14 @@ std::optional<uint256> ReadSnapshotBaseBlockhash(fs::path chaindir)
 //! a snapshot.
 constexpr std::string_view SNAPSHOT_CHAINSTATE_SUFFIX = "_snapshot";
 
+//! Suffix appended to the snapshot chainstate dir when the snapshot fails
+//! validation and the directory is set aside for later inspection.
+constexpr std::string_view SNAPSHOT_INVALID_SUFFIX = "_INVALID";
+
+//! Suffix appended to the background chainstate dir while a fully validated
+//! snapshot chainstate is moved into its place.
+constexpr std::string_view SNAPSHOT_TODELETE_SUFFIX = "_todelete";
+
 
 //! Return a path to the snapshot-based chainstate dir, if one exists.
 std::optional<fs::path> FindSnapshotChainstateDir();

src/validation.cpp

@@ -3848,9 +3848,10 @@ void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex, bool ignore_chainlo
 
     // Failure flags and m_best_invalid are shared by all chainstates, so
     // candidate admission must be recomputed for all of them as well.
+    const auto chainstates{m_chainman.GetAll()};
     for (CBlockIndex* reconsidered : reconsidered_blocks) {
         if (!reconsidered->IsValid(BLOCK_VALID_TRANSACTIONS) || !reconsidered->HaveTxsDownloaded()) continue;
-        for (Chainstate* chainstate : m_chainman.GetAll()) {
+        for (Chainstate* chainstate : chainstates) {
             chainstate->TryAddBlockIndexCandidate(reconsidered);
         }
     }
@@ -6096,7 +6097,6 @@ SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation(
     int curr_height = m_ibd_chainstate->m_chain.Height();
 
     assert(snapshot_base_height == curr_height);
-    assert(snapshot_base_height == index_new.nHeight);
     assert(this->IsUsable(m_snapshot_chainstate.get()));
     assert(this->GetAll().size() == 2);
 
@@ -6404,7 +6404,8 @@ util::Result<void> Chainstate::InvalidateCoinsDBOnDisk()
     // Coins views no longer usable.
     m_coins_views.reset();
 
-    auto invalid_path = snapshot_datadir + "_INVALID";
+    fs::path invalid_path{snapshot_datadir};
+    invalid_path += node::SNAPSHOT_INVALID_SUFFIX;
     std::string dbpath = fs::PathToString(snapshot_datadir);
     std::string target = fs::PathToString(invalid_path);
     LogPrintf("[snapshot] renaming snapshot datadir %s to %s\n", dbpath, target);
@@ -6486,7 +6487,8 @@ bool ChainstateManager::ValidatedSnapshotCleanup()
     LogPrintf("[snapshot] deleting background chainstate directory (now unnecessary) (%s)\n",
               fs::PathToString(ibd_chainstate_path));
 
-    fs::path tmp_old{ibd_chainstate_path + "_todelete"};
+    fs::path tmp_old{ibd_chainstate_path};
+    tmp_old += node::SNAPSHOT_TODELETE_SUFFIX;
 
     auto rename_failed_abort = [](
                                    fs::path p_old,