refactor: Use util::Result class in LoadChainstate and VerifyLoadedCh…

…ainstate

src/bitcoin-chainstate.cpp

@@ -133,13 +133,13 @@ int main(int argc, char* argv[])
     cache_sizes.coins = (450 << 20) - (2 << 20) - (2 << 22);
     node::ChainstateLoadOptions options;
     options.check_interrupt = [] { return false; };
-    auto [status, error] = node::LoadChainstate(chainman, cache_sizes, options);
-    if (status != node::ChainstateLoadStatus::SUCCESS) {
+    auto result = node::LoadChainstate(chainman, cache_sizes, options);
+    if (!result) {
         std::cerr << "Failed to load Chain state from your datadir." << std::endl;
         goto epilogue;
     } else {
-        std::tie(status, error) = node::VerifyLoadedChainstate(chainman, options);
-        if (status != node::ChainstateLoadStatus::SUCCESS) {
+        result = node::VerifyLoadedChainstate(chainman, options);
+        if (!result) {
             std::cerr << "Failed to verify loaded Chain state from your datadir." << std::endl;
             goto epilogue;
         }

src/init.cpp

@@ -1529,33 +1529,36 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
         uiInterface.InitMessage(_("Loading block index…").translated);
         const auto load_block_index_start_time{SteadyClock::now()};
-        auto catch_exceptions = [](auto&& f) {
+        auto catch_exceptions = [](auto&& f) -> util::Result<void, node::ChainstateLoadError> {
             try {
                 return f();
             } catch (const std::exception& e) {
                 LogPrintf("%s\n", e.what());
-                return std::make_tuple(node::ChainstateLoadStatus::FAILURE, _("Error opening block database"));
+                return {util::Error{_("Error opening block database")}, node::ChainstateLoadError::FAILURE};
             }
         };
-        auto [status, error] = catch_exceptions([&]{ return LoadChainstate(chainman, cache_sizes, options); });
-        if (status == node::ChainstateLoadStatus::SUCCESS) {
+        auto result = catch_exceptions([&]{ return LoadChainstate(chainman, cache_sizes, options); });
+        if (result) {
             uiInterface.InitMessage(_("Verifying blocks…").translated);
             if (chainman.m_blockman.m_have_pruned && options.check_blocks > MIN_BLOCKS_TO_KEEP) {
                 LogPrintfCategory(BCLog::PRUNE, "pruned datadir may not have more than %d blocks; only checking available blocks\n",
                                   MIN_BLOCKS_TO_KEEP);
             }
-            std::tie(status, error) = catch_exceptions([&]{ return VerifyLoadedChainstate(chainman, options);});
-            if (status == node::ChainstateLoadStatus::SUCCESS) {
+            result = catch_exceptions([&]{ return VerifyLoadedChainstate(chainman, options);});
+            if (result) {
                 fLoaded = true;
                 LogPrintf(" block index %15dms\n", Ticks<std::chrono::milliseconds>(SteadyClock::now() - load_block_index_start_time));
             }
         }
 
-        if (status == node::ChainstateLoadStatus::FAILURE_FATAL || status == node::ChainstateLoadStatus::FAILURE_INCOMPATIBLE_DB || status == node::ChainstateLoadStatus::FAILURE_INSUFFICIENT_DBCACHE) {
-            return InitError(error);
+        if (!result && (result.GetFailure() == node::ChainstateLoadError::FAILURE_FATAL ||
+                        result.GetFailure() == node::ChainstateLoadError::FAILURE_INCOMPATIBLE_DB ||
+                        result.GetFailure() == node::ChainstateLoadError::FAILURE_INSUFFICIENT_DBCACHE)) {
+            return InitError(util::ErrorString(result));
         }
 
         if (!fLoaded && !ShutdownRequested()) {
+            bilingual_str error = util::ErrorString(result);
             // first suggest a reindex
             if (!options.reindex) {
                 bool fRet = uiInterface.ThreadSafeQuestion(

src/node/chainstate.cpp

@@ -31,7 +31,7 @@
 namespace node {
 // Complete initialization of chainstates after the initial call has been made
 // to ChainstateManager::InitializeChainstate().
-static ChainstateLoadResult CompleteChainstateInitialization(
+static util::Result<void, ChainstateLoadError> CompleteChainstateInitialization(
     ChainstateManager& chainman,
     const CacheSizes& cache_sizes,
     const ChainstateLoadOptions& options) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
@@ -55,36 +55,36 @@ static ChainstateLoadResult CompleteChainstateInitialization(
         }
     }
 
-    if (options.check_interrupt && options.check_interrupt()) return {ChainstateLoadStatus::INTERRUPTED, {}};
+    if (options.check_interrupt && options.check_interrupt()) return {util::Error{}, ChainstateLoadError::INTERRUPTED};
 
     // LoadBlockIndex will load m_have_pruned if we've ever removed a
     // block file from disk.
     // Note that it also sets fReindex global based on the disk flag!
     // From here on, fReindex and options.reindex values may be different!
     if (!chainman.LoadBlockIndex()) {
-        if (options.check_interrupt && options.check_interrupt()) return {ChainstateLoadStatus::INTERRUPTED, {}};
-        return {ChainstateLoadStatus::FAILURE, _("Error loading block database")};
+        if (options.check_interrupt && options.check_interrupt()) return {util::Error{}, ChainstateLoadError::INTERRUPTED};
+        return {util::Error{_("Error loading block database")}, ChainstateLoadError::FAILURE};
     }
 
     if (!chainman.BlockIndex().empty() &&
             !chainman.m_blockman.LookupBlockIndex(chainman.GetConsensus().hashGenesisBlock)) {
         // If the loaded chain has a wrong genesis, bail out immediately
         // (we're likely using a testnet datadir, or the other way around).
-        return {ChainstateLoadStatus::FAILURE_INCOMPATIBLE_DB, _("Incorrect or no genesis block found. Wrong datadir for network?")};
+        return {util::Error{_("Incorrect or no genesis block found. Wrong datadir for network?")}, ChainstateLoadError::FAILURE_INCOMPATIBLE_DB};
     }
 
     // Check for changed -prune state.  What we are concerned about is a user who has pruned blocks
     // in the past, but is now trying to run unpruned.
     if (chainman.m_blockman.m_have_pruned && !options.prune) {
-        return {ChainstateLoadStatus::FAILURE, _("You need to rebuild the database using -reindex to go back to unpruned mode.  This will redownload the entire blockchain")};
+        return {util::Error{_("You need to rebuild the database using -reindex to go back to unpruned mode.  This will redownload the entire blockchain")}, ChainstateLoadError::FAILURE};
     }
 
     // At this point blocktree args are consistent with what's on disk.
     // If we're not mid-reindex (based on disk + args), add a genesis block on disk
     // (otherwise we use the one already on disk).
     // This is called again in ImportBlocks after the reindex completes.
     if (!fReindex && !chainman.ActiveChainstate().LoadGenesisBlock()) {
-        return {ChainstateLoadStatus::FAILURE, _("Error initializing block database")};
+        return {util::Error{_("Error initializing block database")}, ChainstateLoadError::FAILURE};
     }
 
     auto is_coinsview_empty = [&](Chainstate* chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
@@ -118,14 +118,15 @@ static ChainstateLoadResult CompleteChainstateInitialization(
         // Refuse to load unsupported database format.
         // This is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
         if (chainstate->CoinsDB().NeedsUpgrade()) {
-            return {ChainstateLoadStatus::FAILURE_INCOMPATIBLE_DB, _("Unsupported chainstate database format found. "
-                                                                     "Please restart with -reindex-chainstate. This will "
-                                                                     "rebuild the chainstate database.")};
+            return {util::Error{ _("Unsupported chainstate database format found. "
+                                   "Please restart with -reindex-chainstate. This will "
+                                   "rebuild the chainstate database.")},
+                    ChainstateLoadError::FAILURE_INCOMPATIBLE_DB};
         }
 
         // ReplayBlocks is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
         if (!chainstate->ReplayBlocks()) {
-            return {ChainstateLoadStatus::FAILURE, _("Unable to replay blocks. You will need to rebuild the database using -reindex-chainstate.")};
+            return {util::Error{_("Unable to replay blocks. You will need to rebuild the database using -reindex-chainstate.")}, ChainstateLoadError::FAILURE};
         }
 
         // The on-disk coinsdb is now in a good state, create the cache
@@ -135,7 +136,7 @@ static ChainstateLoadResult CompleteChainstateInitialization(
         if (!is_coinsview_empty(chainstate)) {
             // LoadChainTip initializes the chain based on CoinsTip()'s best block
             if (!chainstate->LoadChainTip()) {
-                return {ChainstateLoadStatus::FAILURE, _("Error initializing block database")};
+                return {util::Error{_("Error initializing block database")}, ChainstateLoadError::FAILURE};
             }
             assert(chainstate->m_chain.Tip() != nullptr);
         }
@@ -145,8 +146,8 @@ static ChainstateLoadResult CompleteChainstateInitialization(
         auto chainstates{chainman.GetAll()};
         if (std::any_of(chainstates.begin(), chainstates.end(),
                         [](const Chainstate* cs) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return cs->NeedsRedownload(); })) {
-            return {ChainstateLoadStatus::FAILURE, strprintf(_("Witness data for blocks after height %d requires validation. Please restart with -reindex."),
-                                                             chainman.GetConsensus().SegwitHeight)};
+            return {util::Error{strprintf(_("Witness data for blocks after height %d requires validation. Please restart with -reindex."),
+                                          chainman.GetConsensus().SegwitHeight)}, ChainstateLoadError::FAILURE};
         };
     }
 
@@ -155,11 +156,11 @@ static ChainstateLoadResult CompleteChainstateInitialization(
     // on the condition of each chainstate.
     chainman.MaybeRebalanceCaches();
 
-    return {ChainstateLoadStatus::SUCCESS, {}};
+    return {};
 }
 
-ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSizes& cache_sizes,
-                                    const ChainstateLoadOptions& options)
+util::Result<void, ChainstateLoadError> LoadChainstate(ChainstateManager& chainman, const CacheSizes& cache_sizes,
+                                                       const ChainstateLoadOptions& options)
 {
     if (!chainman.AssumedValidBlock().IsNull()) {
         LogPrintf("Assuming ancestors of block %s have valid signatures.\n", chainman.AssumedValidBlock().GetHex());
@@ -190,13 +191,13 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
     if (has_snapshot && (options.reindex || options.reindex_chainstate)) {
         LogPrintf("[snapshot] deleting snapshot chainstate due to reindexing\n");
         if (!chainman.DeleteSnapshotChainstate()) {
-            return {ChainstateLoadStatus::FAILURE_FATAL, Untranslated("Couldn't remove snapshot chainstate.")};
+            return {util::Error{Untranslated("Couldn't remove snapshot chainstate.")}, ChainstateLoadError::FAILURE_FATAL};
         }
     }
 
-    auto [init_status, init_error] = CompleteChainstateInitialization(chainman, cache_sizes, options);
-    if (init_status != ChainstateLoadStatus::SUCCESS) {
-        return {init_status, init_error};
+    auto result{CompleteChainstateInitialization(chainman, cache_sizes, options)};
+    if (!result) {
+        return result;
     }
 
     // If a snapshot chainstate was fully validated by a background chainstate during
@@ -214,7 +215,7 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
     } else if (snapshot_completion == SnapshotCompletionResult::SUCCESS) {
         LogPrintf("[snapshot] cleaning up unneeded background chainstate, then reinitializing\n");
         if (!chainman.ValidatedSnapshotCleanup()) {
-            return {ChainstateLoadStatus::FAILURE_FATAL, Untranslated("Background chainstate cleanup failed unexpectedly.")};
+            return {util::Error{Untranslated("Background chainstate cleanup failed unexpectedly.")}, ChainstateLoadError::FAILURE_FATAL};
         }
 
         // Because ValidatedSnapshotCleanup() has torn down chainstates with
@@ -230,20 +231,20 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
         // for the fully validated chainstate.
         chainman.ActiveChainstate().ClearBlockIndexCandidates();
 
-        auto [init_status, init_error] = CompleteChainstateInitialization(chainman, cache_sizes, options);
-        if (init_status != ChainstateLoadStatus::SUCCESS) {
-            return {init_status, init_error};
+        auto result{CompleteChainstateInitialization(chainman, cache_sizes, options)};
+        if (!result) {
+            return result;
         }
     } else {
-        return {ChainstateLoadStatus::FAILURE, _(
-           "UTXO snapshot failed to validate. "
+        return util::Error{
+           _("UTXO snapshot failed to validate. "
            "Restart to resume normal initial block download, or try loading a different snapshot.")};
     }
 
-    return {ChainstateLoadStatus::SUCCESS, {}};
+    return {};
 }
 
-ChainstateLoadResult VerifyLoadedChainstate(ChainstateManager& chainman, const ChainstateLoadOptions& options)
+util::Result<void, ChainstateLoadError> VerifyLoadedChainstate(ChainstateManager& chainman, const ChainstateLoadOptions& options)
 {
     auto is_coinsview_empty = [&](Chainstate* chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         return options.reindex || options.reindex_chainstate || chainstate->CoinsTip().GetBestBlock().IsNull();
@@ -255,9 +256,10 @@ ChainstateLoadResult VerifyLoadedChainstate(ChainstateManager& chainman, const C
         if (!is_coinsview_empty(chainstate)) {
             const CBlockIndex* tip = chainstate->m_chain.Tip();
             if (tip && tip->nTime > GetTime() + MAX_FUTURE_BLOCK_TIME) {
-                return {ChainstateLoadStatus::FAILURE, _("The block database contains a block which appears to be from the future. "
-                                                         "This may be due to your computer's date and time being set incorrectly. "
-                                                         "Only rebuild the block database if you are sure that your computer's date and time are correct")};
+                return {util::Error{_("The block database contains a block which appears to be from the future. "
+                                      "This may be due to your computer's date and time being set incorrectly. "
+                                      "Only rebuild the block database if you are sure that your computer's date and time are correct")},
+                        ChainstateLoadError::FAILURE};
             }
 
             VerifyDBResult result = CVerifyDB(chainman.GetNotifications()).VerifyDB(
@@ -269,18 +271,18 @@ ChainstateLoadResult VerifyLoadedChainstate(ChainstateManager& chainman, const C
             case VerifyDBResult::SKIPPED_MISSING_BLOCKS:
                 break;
             case VerifyDBResult::INTERRUPTED:
-                return {ChainstateLoadStatus::INTERRUPTED, _("Block verification was interrupted")};
+                return {util::Error{_("Block verification was interrupted")}, ChainstateLoadError::INTERRUPTED};
             case VerifyDBResult::CORRUPTED_BLOCK_DB:
-                return {ChainstateLoadStatus::FAILURE, _("Corrupted block database detected")};
+                return {util::Error{_("Corrupted block database detected")}, ChainstateLoadError::FAILURE};
             case VerifyDBResult::SKIPPED_L3_CHECKS:
                 if (options.require_full_verification) {
-                    return {ChainstateLoadStatus::FAILURE_INSUFFICIENT_DBCACHE, _("Insufficient dbcache for block verification")};
+                    return {util::Error{_("Insufficient dbcache for block verification")}, ChainstateLoadError::FAILURE_INSUFFICIENT_DBCACHE};
                 }
                 break;
             } // no default case, so the compiler can warn about missing cases
         }
     }
 
-    return {ChainstateLoadStatus::SUCCESS, {}};
+    return {};
 }
 } // namespace node

src/node/chainstate.h

@@ -5,6 +5,7 @@
 #ifndef BITCOIN_NODE_CHAINSTATE_H
 #define BITCOIN_NODE_CHAINSTATE_H
 
+#include <util/result.h>
 #include <util/translation.h>
 #include <validation.h>
 
@@ -36,38 +37,21 @@ struct ChainstateLoadOptions {
     std::function<void()> coins_error_cb;
 };
 
-//! Chainstate load status. Simple applications can just check for the success
-//! case, and treat other cases as errors. More complex applications may want to
-//! try reindexing in the generic failure case, and pass an interrupt callback
-//! and exit cleanly in the interrupted case.
-enum class ChainstateLoadStatus {
-    SUCCESS,
+//! Chainstate load errors. Simple applications can just treat all errors as
+//! failures. More complex applications may want to try reindexing in the
+//! generic error case, and pass an interrupt callback and exit cleanly in the
+//! interrupted case.
+enum class ChainstateLoadError {
     FAILURE, //!< Generic failure which reindexing may fix
     FAILURE_FATAL, //!< Fatal error which should not prompt to reindex
     FAILURE_INCOMPATIBLE_DB,
     FAILURE_INSUFFICIENT_DBCACHE,
     INTERRUPTED,
 };
 
-//! Chainstate load status code and optional error string.
-using ChainstateLoadResult = std::tuple<ChainstateLoadStatus, bilingual_str>;
-
-/** This sequence can have 4 types of outcomes:
- *
- *  1. Success
- *  2. Shutdown requested
- *    - nothing failed but a shutdown was triggered in the middle of the
- *      sequence
- *  3. Soft failure
- *    - a failure that might be recovered from with a reindex
- *  4. Hard failure
- *    - a failure that definitively cannot be recovered from with a reindex
- *
- *  LoadChainstate returns a (status code, error string) tuple.
- */
-ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSizes& cache_sizes,
-                                    const ChainstateLoadOptions& options);
-ChainstateLoadResult VerifyLoadedChainstate(ChainstateManager& chainman, const ChainstateLoadOptions& options);
+util::Result<void, ChainstateLoadError> LoadChainstate(ChainstateManager& chainman, const CacheSizes& cache_sizes,
+                                                       const ChainstateLoadOptions& options);
+util::Result<void, ChainstateLoadError> VerifyLoadedChainstate(ChainstateManager& chainman, const ChainstateLoadOptions& options);
 } // namespace node
 
 #endif // BITCOIN_NODE_CHAINSTATE_H

src/test/util/setup_common.cpp

@@ -221,11 +221,11 @@ void ChainTestingSetup::LoadVerifyActivateChainstate()
     options.check_blocks = m_args.GetIntArg("-checkblocks", DEFAULT_CHECKBLOCKS);
     options.check_level = m_args.GetIntArg("-checklevel", DEFAULT_CHECKLEVEL);
     options.require_full_verification = m_args.IsArgSet("-checkblocks") || m_args.IsArgSet("-checklevel");
-    auto [status, error] = LoadChainstate(chainman, m_cache_sizes, options);
-    assert(status == node::ChainstateLoadStatus::SUCCESS);
+    auto result = LoadChainstate(chainman, m_cache_sizes, options);
+    assert(result);
 
-    std::tie(status, error) = VerifyLoadedChainstate(chainman, options);
-    assert(status == node::ChainstateLoadStatus::SUCCESS);
+    result = VerifyLoadedChainstate(chainman, options);
+    assert(result);
 
     BlockValidationState state;
     if (!chainman.ActiveChainstate().ActivateBestChain(state)) {