1 files changed, 85 insertions, 0 deletions
diff --git a/src/node/chainstate.h b/src/node/chainstate.h
new file mode 100644
index 0000000000..11278a0991
--- /dev/null
+++ b/src/node/chainstate.h
@@ -0,0 +1,85 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_NODE_CHAINSTATE_H
+#define BITCOIN_NODE_CHAINSTATE_H
+
+#include <cstdint>
+#include <functional>
+#include <optional>
+
+class ChainstateManager;
+namespace Consensus {
+    struct Params;
+}
+class CTxMemPool;
+
+enum class ChainstateLoadingError {
+    ERROR_LOADING_BLOCK_DB,
+    ERROR_BAD_GENESIS_BLOCK,
+    ERROR_PRUNED_NEEDS_REINDEX,
+    ERROR_LOAD_GENESIS_BLOCK_FAILED,
+    ERROR_CHAINSTATE_UPGRADE_FAILED,
+    ERROR_REPLAYBLOCKS_FAILED,
+    ERROR_LOADCHAINTIP_FAILED,
+    ERROR_GENERIC_BLOCKDB_OPEN_FAILED,
+    ERROR_BLOCKS_WITNESS_INSUFFICIENTLY_VALIDATED,
+    SHUTDOWN_PROBED,
+};
+
+/** 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
+ *
+ *  Currently, LoadChainstate returns a std::optional<ChainstateLoadingError>
+ *  which:
+ *
+ *  - if has_value()
+ *      - Either "Soft failure", "Hard failure", or "Shutdown requested",
+ *        differentiable by the specific enumerator.
+ *
+ *        Note that a return value of SHUTDOWN_PROBED means ONLY that "during
+ *        this sequence, when we explicitly checked shutdown_requested() at
+ *        arbitrary points, one of those calls returned true". Therefore, a
+ *        return value other than SHUTDOWN_PROBED does not guarantee that
+ *        shutdown_requested() hasn't been called indirectly.
+ *  - else
+ *      - Success!
+ */
+std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
+                                                     ChainstateManager& chainman,
+                                                     CTxMemPool* mempool,
+                                                     bool fPruneMode,
+                                                     const Consensus::Params& consensus_params,
+                                                     bool fReindexChainState,
+                                                     int64_t nBlockTreeDBCache,
+                                                     int64_t nCoinDBCache,
+                                                     int64_t nCoinCacheUsage,
+                                                     bool block_tree_db_in_memory,
+                                                     bool coins_db_in_memory,
+                                                     std::function<bool()> shutdown_requested = nullptr,
+                                                     std::function<void()> coins_error_cb = nullptr);
+
+enum class ChainstateLoadVerifyError {
+    ERROR_BLOCK_FROM_FUTURE,
+    ERROR_CORRUPTED_BLOCK_DB,
+    ERROR_GENERIC_FAILURE,
+};
+
+std::optional<ChainstateLoadVerifyError> VerifyLoadedChainstate(ChainstateManager& chainman,
+                                                                bool fReset,
+                                                                bool fReindexChainState,
+                                                                const Consensus::Params& consensus_params,
+                                                                unsigned int check_blocks,
+                                                                unsigned int check_level,
+                                                                std::function<int64_t()> get_unix_time_seconds);
+
+#endif // BITCOIN_NODE_CHAINSTATE_H