validation.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-present 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_VALIDATION_H
#define BITCOIN_VALIDATION_H
 
#include <arith_uint256.h>
#include <attributes.h>
#include <chain.h>
#include <checkqueue.h>
#include <coins.h>
#include <consensus/amount.h>
#include <cuckoocache.h>
#include <deploymentstatus.h>
#include <kernel/chain.h>
#include <kernel/chainparams.h>
#include <kernel/chainstatemanager_opts.h>
#include <kernel/cs_main.h> // IWYU pragma: export
#include <node/blockstorage.h>
#include <policy/feerate.h>
#include <policy/packages.h>
#include <policy/policy.h>
#include <script/script_error.h>
#include <script/sigcache.h>
#include <script/verify_flags.h>
#include <sync.h>
#include <txdb.h>
#include <txmempool.h>
#include <uint256.h>
#include <util/byte_units.h>
#include <util/check.h>
#include <util/fs.h>
#include <util/hasher.h>
#include <util/result.h>
#include <util/time.h>
#include <util/translation.h>
#include <versionbits.h>
 
#include <algorithm>
#include <atomic>
#include <cstdint>
#include <map>
#include <memory>
#include <optional>
#include <set>
#include <span>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
 
class Chainstate;
class CTxMemPool;
class ChainstateManager;
struct ChainTxData;
class DisconnectedBlockTransactions;
struct PrecomputedTransactionData;
struct LockPoints;
struct AssumeutxoData;
namespace kernel {
struct ChainstateRole;
} // namespace kernel
namespace node {
class SnapshotMetadata;
} // namespace node
namespace Consensus {
struct Params;
} // namespace Consensus
namespace util {
class SignalInterrupt;
} // namespace util

static const unsigned int MIN_BLOCKS_TO_KEEP = 288;
static const signed int DEFAULT_CHECKBLOCKS = 6;
static constexpr int DEFAULT_CHECKLEVEL{3};
// Require that user allocate at least 550 MiB for block & undo files (blk???.dat and rev???.dat)
// At 1MB per block, 288 blocks = 288MB.
// Add 15% for Undo data = 331MB
// Add 20% for Orphan block rate = 397MB
// We want the low water mark after pruning to be at least 397 MB and since we prune in
// full block file chunks, we need the high water mark which triggers the prune to be
// one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB
// Setting the target to >= 550 MiB will make it likely we can respect the target.
static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;

static constexpr int MAX_SCRIPTCHECK_THREADS{15};

enum class SynchronizationState {
    INIT_REINDEX,
    INIT_DOWNLOAD,
    POST_INIT
};

extern const std::vector<std::string> CHECKLEVEL_DOC;
 
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams);
 
bool FatalError(kernel::Notifications& notifications, BlockValidationState& state, const bilingual_str& message);

void PruneBlockFilesManual(Chainstate& active_chainstate, int nManualPruneHeight);

struct MempoolAcceptResult {
    enum class ResultType {
        VALID, 
        INVALID, 
        MEMPOOL_ENTRY, 
        DIFFERENT_WITNESS, 
    };

    const ResultType m_result_type;

    const TxValidationState m_state;

    const std::list<CTransactionRef> m_replaced_transactions;
    const std::optional<int64_t> m_vsize;
    const std::optional<CAmount> m_base_fees;
    const std::optional<CFeeRate> m_effective_feerate;
    const std::optional<std::vector<Wtxid>> m_wtxids_fee_calculations;

    const std::optional<Wtxid> m_other_wtxid;
 
    static MempoolAcceptResult Failure(TxValidationState state) {
        return MempoolAcceptResult(state);
    }
 
    static MempoolAcceptResult FeeFailure(TxValidationState state,
                                          CFeeRate effective_feerate,
                                          const std::vector<Wtxid>& wtxids_fee_calculations) {
        return MempoolAcceptResult(state, effective_feerate, wtxids_fee_calculations);
    }
 
    static MempoolAcceptResult Success(std::list<CTransactionRef>&& replaced_txns,
                                       int64_t vsize,
                                       CAmount fees,
                                       CFeeRate effective_feerate,
                                       const std::vector<Wtxid>& wtxids_fee_calculations) {
        return MempoolAcceptResult(std::move(replaced_txns), vsize, fees,
                                   effective_feerate, wtxids_fee_calculations);
    }
 
    static MempoolAcceptResult MempoolTx(int64_t vsize, CAmount fees) {
        return MempoolAcceptResult(vsize, fees);
    }
 
    static MempoolAcceptResult MempoolTxDifferentWitness(const Wtxid& other_wtxid) {
        return MempoolAcceptResult(other_wtxid);
    }
 
// Private constructors. Use static methods MempoolAcceptResult::Success, etc. to construct.
private:
    explicit MempoolAcceptResult(TxValidationState state)
        : m_result_type(ResultType::INVALID), m_state(state) {
            Assume(!state.IsValid()); // Can be invalid or error
        }

    explicit MempoolAcceptResult(std::list<CTransactionRef>&& replaced_txns,
                                 int64_t vsize,
                                 CAmount fees,
                                 CFeeRate effective_feerate,
                                 const std::vector<Wtxid>& wtxids_fee_calculations)
        : m_result_type(ResultType::VALID),
        m_replaced_transactions(std::move(replaced_txns)),
        m_vsize{vsize},
        m_base_fees(fees),
        m_effective_feerate(effective_feerate),
        m_wtxids_fee_calculations(wtxids_fee_calculations) {}

    explicit MempoolAcceptResult(TxValidationState state,
                                 CFeeRate effective_feerate,
                                 const std::vector<Wtxid>& wtxids_fee_calculations)
        : m_result_type(ResultType::INVALID),
        m_state(state),
        m_effective_feerate(effective_feerate),
        m_wtxids_fee_calculations(wtxids_fee_calculations) {}

    explicit MempoolAcceptResult(int64_t vsize, CAmount fees)
        : m_result_type(ResultType::MEMPOOL_ENTRY), m_vsize{vsize}, m_base_fees(fees) {}

    explicit MempoolAcceptResult(const Wtxid& other_wtxid)
        : m_result_type(ResultType::DIFFERENT_WITNESS), m_other_wtxid(other_wtxid) {}
};

struct PackageMempoolAcceptResult
{
    PackageValidationState m_state;
    std::map<Wtxid, MempoolAcceptResult> m_tx_results;
 
    explicit PackageMempoolAcceptResult(PackageValidationState state,
                                        std::map<Wtxid, MempoolAcceptResult>&& results)
        : m_state{state}, m_tx_results(std::move(results)) {}
 
    explicit PackageMempoolAcceptResult(PackageValidationState state, CFeeRate feerate,
                                        std::map<Wtxid, MempoolAcceptResult>&& results)
        : m_state{state}, m_tx_results(std::move(results)) {}

    explicit PackageMempoolAcceptResult(const Wtxid& wtxid, const MempoolAcceptResult& result)
        : m_tx_results{ {wtxid, result} } {}
};

MempoolAcceptResult AcceptToMemoryPool(Chainstate& active_chainstate, const CTransactionRef& tx,
                                       int64_t accept_time, bool bypass_limits, bool test_accept)
    EXCLUSIVE_LOCKS_REQUIRED(cs_main);

PackageMempoolAcceptResult ProcessNewPackage(Chainstate& active_chainstate, CTxMemPool& pool,
                                                   const Package& txns, bool test_accept, const std::optional<CFeeRate>& client_maxfeerate)
                                                   EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
/* Mempool validation helper functions */

bool CheckFinalTxAtTip(const CBlockIndex& active_chain_tip, const CTransaction& tx) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

std::optional<LockPoints> CalculateLockPointsAtTip(
    CBlockIndex* tip,
    const CCoinsView& coins_view,
    const CTransaction& tx);

bool CheckSequenceLocksAtTip(CBlockIndex* tip,
                             const LockPoints& lock_points);

class CScriptCheck
{
private:
    CTxOut m_tx_out;
    const CTransaction *ptxTo;
    unsigned int nIn;
    script_verify_flags m_flags;
    bool cacheStore;
    PrecomputedTransactionData *txdata;
    SignatureCache* m_signature_cache;
 
public:
    CScriptCheck(const CTxOut& outIn, const CTransaction& txToIn, SignatureCache& signature_cache, unsigned int nInIn, script_verify_flags flags, bool cacheIn, PrecomputedTransactionData* txdataIn) :
        m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), m_flags(flags), cacheStore(cacheIn), txdata(txdataIn), m_signature_cache(&signature_cache) { }
 
    CScriptCheck(const CScriptCheck&) = delete;
    CScriptCheck& operator=(const CScriptCheck&) = delete;
    CScriptCheck(CScriptCheck&&) = default;
    CScriptCheck& operator=(CScriptCheck&&) = default;
 
    std::optional<std::pair<ScriptError, std::string>> operator()();
};
 
// CScriptCheck is used a lot in std::vector, make sure that's efficient
static_assert(std::is_nothrow_move_assignable_v<CScriptCheck>);
static_assert(std::is_nothrow_move_constructible_v<CScriptCheck>);
static_assert(std::is_nothrow_destructible_v<CScriptCheck>);

class ValidationCache
{
private:
    CSHA256 m_script_execution_cache_hasher;
 
public:
    CuckooCache::cache<uint256, SignatureCacheHasher> m_script_execution_cache;
    SignatureCache m_signature_cache;
 
    ValidationCache(size_t script_execution_cache_bytes, size_t signature_cache_bytes);
 
    ValidationCache(const ValidationCache&) = delete;
    ValidationCache& operator=(const ValidationCache&) = delete;

    CSHA256 ScriptExecutionCacheHasher() const { return m_script_execution_cache_hasher; }
};


bool CheckBlock(const CBlock& block, BlockValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true, bool fCheckMerkleRoot = true);

BlockValidationState TestBlockValidity(
    Chainstate& chainstate,
    const CBlock& block,
    bool check_pow,
    bool check_merkle_root) EXCLUSIVE_LOCKS_REQUIRED(cs_main);

bool HasValidProofOfWork(std::span<const CBlockHeader> headers, const Consensus::Params& consensusParams);

bool IsBlockMutated(const CBlock& block, bool check_witness_root);

arith_uint256 CalculateClaimedHeadersWork(std::span<const CBlockHeader> headers);
 
enum class VerifyDBResult {
    SUCCESS,
    CORRUPTED_BLOCK_DB,
    INTERRUPTED,
    SKIPPED_L3_CHECKS,
    SKIPPED_MISSING_BLOCKS,
};

class CVerifyDB
{
private:
    kernel::Notifications& m_notifications;
 
public:
    explicit CVerifyDB(kernel::Notifications& notifications);
    ~CVerifyDB();
    [[nodiscard]] VerifyDBResult VerifyDB(
        Chainstate& chainstate,
        const Consensus::Params& consensus_params,
        CCoinsView& coinsview,
        int nCheckLevel,
        int nCheckDepth) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
};
 
enum DisconnectResult
{
    DISCONNECT_OK,      // All good.
    DISCONNECT_UNCLEAN, // Rolled back, but UTXO set was inconsistent with block.
    DISCONNECT_FAILED   // Something else went wrong.
};
 
class ConnectTrace;

inline constexpr std::array FlushStateModeNames{"NONE", "IF_NEEDED", "PERIODIC", "FORCE_FLUSH", "FORCE_SYNC"};
enum class FlushStateMode: uint8_t {
    NONE,
    IF_NEEDED,
    PERIODIC,
    FORCE_FLUSH,
    FORCE_SYNC,
};

class CoinsViews {
 
public:
    CCoinsViewDB m_dbview GUARDED_BY(cs_main);

    CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main);

    std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main);

    std::unique_ptr<CoinsViewOverlay> m_connect_block_view GUARDED_BY(cs_main);

    CoinsViews(DBParams db_params, CoinsViewOptions options);

    void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
};
 
enum class CoinsCacheSizeState
{
    CRITICAL = 2,
    LARGE = 1,
    OK = 0
};
 
constexpr int64_t LargeCoinsCacheThreshold(int64_t total_space) noexcept
{
    // No periodic flush needed if at least this much space is free
    constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES{int64_t(10_MiB)};
    return std::max((total_space * 9) / 10,
                    total_space - MAX_BLOCK_COINSDB_USAGE_BYTES);
}

enum class Assumeutxo {
    VALIDATED,
    UNVALIDATED,
    INVALID,
};

class Chainstate
{
protected:
    Mutex m_chainstate_mutex;

    CTxMemPool* m_mempool;

    std::unique_ptr<CoinsViews> m_coins_views;

    mutable const CBlockIndex* m_cached_snapshot_base GUARDED_BY(::cs_main){nullptr};

    mutable const CBlockIndex* m_cached_target_block GUARDED_BY(::cs_main){nullptr};
 
    std::optional<const char*> m_last_script_check_reason_logged GUARDED_BY(::cs_main){};
 
public:
    node::BlockManager& m_blockman;

    ChainstateManager& m_chainman;
 
    explicit Chainstate(
        CTxMemPool* mempool,
        node::BlockManager& blockman,
        ChainstateManager& chainman,
        std::optional<uint256> from_snapshot_blockhash = std::nullopt);

    fs::path StoragePath() const;

    kernel::ChainstateRole GetRole() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    void InitCoinsDB(
        size_t cache_size_bytes,
        bool in_memory,
        bool should_wipe);

    void InitCoinsCache(size_t cache_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    bool CanFlushToDisk() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        return m_coins_views && m_coins_views->m_cacheview;
    }

    CChain m_chain;

    Assumeutxo m_assumeutxo GUARDED_BY(::cs_main);

    const std::optional<uint256> m_from_snapshot_blockhash;

    std::optional<uint256> m_target_blockhash GUARDED_BY(::cs_main);

    std::optional<AssumeutxoHash> m_target_utxohash GUARDED_BY(::cs_main);

    const CBlockIndex* SnapshotBase() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    const CBlockIndex* TargetBlock() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
    void SetTargetBlock(CBlockIndex* block) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
    void SetTargetBlockHash(uint256 block_hash) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    bool ReachedTarget() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        const CBlockIndex* target_block{TargetBlock()};
        assert(!target_block || target_block->GetAncestor(m_chain.Height()) == m_chain.Tip());
        return target_block && target_block == m_chain.Tip();
    }

    std::set<CBlockIndex*, node::CBlockIndexWorkComparator> setBlockIndexCandidates;

    CCoinsViewCache& CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        Assert(m_coins_views);
        return *Assert(m_coins_views->m_cacheview);
    }

    CCoinsViewDB& CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        return Assert(m_coins_views)->m_dbview;
    }

    CTxMemPool* GetMempool()
    {
        return m_mempool;
    }

    CCoinsViewErrorCatcher& CoinsErrorCatcher() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        return Assert(m_coins_views)->m_catcherview;
    }

    void ResetCoinsViews() { m_coins_views.reset(); }

    size_t m_coinsdb_cache_size_bytes{0};

    size_t m_coinstip_cache_size_bytes{0};

    bool ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
        EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    bool FlushStateToDisk(
        BlockValidationState& state,
        FlushStateMode mode,
        int nManualPruneHeight = 0);

    void ForceFlushStateToDisk(bool wipe_cache = true);

    void PruneAndFlush();

    bool ActivateBestChain(
        BlockValidationState& state,
        std::shared_ptr<const CBlock> pblock = nullptr)
        EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex)
        LOCKS_EXCLUDED(::cs_main);
 
    // Block (dis)connection on a given view:
    DisconnectResult DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
        EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
    bool ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex,
                      CCoinsViewCache& view, bool fJustCheck = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    // Apply the effects of a block disconnection on the UTXO set.
    bool DisconnectTip(BlockValidationState& state, DisconnectedBlockTransactions* disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs);
 
    // Manual block validity manipulation:
    bool PreciousBlock(BlockValidationState& state, CBlockIndex* pindex)
        EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex)
        LOCKS_EXCLUDED(::cs_main);

    bool InvalidateBlock(BlockValidationState& state, CBlockIndex* pindex)
        EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex)
        LOCKS_EXCLUDED(::cs_main);

    void SetBlockFailureFlags(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    void ResetBlockFailureFlags(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    bool ReplayBlocks();

    [[nodiscard]] bool NeedsRedownload() const EXCLUSIVE_LOCKS_REQUIRED(cs_main);
    bool LoadGenesisBlock();

    void TryAddBlockIndexCandidate(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    void PruneBlockIndexCandidates();
 
    void ClearBlockIndexCandidates() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    void PopulateBlockIndexCandidates() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    const CBlockIndex* FindForkInGlobalIndex(const CBlockLocator& locator) const EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    bool LoadChainTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    CoinsCacheSizeState GetCoinsCacheSizeState() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
    CoinsCacheSizeState GetCoinsCacheSizeState(
        size_t max_coins_cache_size_bytes,
        size_t max_mempool_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
    std::string ToString() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    RecursiveMutex* MempoolMutex() const LOCK_RETURNED(m_mempool->cs)
    {
        return m_mempool ? &m_mempool->cs : nullptr;
    }

    std::pair<int, int> GetPruneRange(int last_height_can_prune) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
protected:
    bool ActivateBestChainStep(BlockValidationState& state, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs);
    bool ConnectTip(
        BlockValidationState& state,
        CBlockIndex* pindexNew,
        std::shared_ptr<const CBlock> block_to_connect,
        ConnectTrace& connectTrace,
        DisconnectedBlockTransactions& disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs);
 
    void InvalidBlockFound(CBlockIndex* pindex, const BlockValidationState& state) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
    CBlockIndex* FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    bool RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
    void InvalidChainFound(CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    void MaybeUpdateMempoolForReorg(
        DisconnectedBlockTransactions& disconnectpool,
        bool fAddToMempool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs);

    void UpdateTip(const CBlockIndex* pindexNew)
        EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
    NodeClock::time_point m_next_write{NodeClock::time_point::max()};

    [[nodiscard]] util::Result<void> InvalidateCoinsDBOnDisk() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
    friend ChainstateManager;
};
 
enum class SnapshotCompletionResult {
    SUCCESS,
    SKIPPED,
 
    // Expected assumeutxo configuration data is not found for the height of the
    // base block.
    MISSING_CHAINPARAMS,
 
    // Failed to generate UTXO statistics (to check UTXO set hash) for the
    // validated chainstate.
    STATS_FAILED,
 
    // The UTXO set hash of the validated chainstate does not match the one
    // expected by assumeutxo chainparams.
    HASH_MISMATCH,
};

class ChainstateManager
{
private:

    CBlockIndex* m_last_notified_header GUARDED_BY(GetMutex()){nullptr};
 
    bool NotifyHeaderTip() LOCKS_EXCLUDED(GetMutex());

    [[nodiscard]] util::Result<void> PopulateAndValidateSnapshot(
        Chainstate& snapshot_chainstate,
        AutoFile& coins_file,
        const node::SnapshotMetadata& metadata);

    bool AcceptBlockHeader(
        const CBlockHeader& block,
        BlockValidationState& state,
        CBlockIndex** ppindex,
        bool min_pow_checked) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
    friend Chainstate;

    MockableSteadyClock::time_point m_last_presync_update GUARDED_BY(GetMutex()){};

    CCheckQueue<CScriptCheck> m_script_check_queue;

    SteadyClock::duration GUARDED_BY(::cs_main) time_check{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_forks{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_connect{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_verify{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_undo{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_index{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_total{};
    int64_t GUARDED_BY(::cs_main) num_blocks_total{0};
    SteadyClock::duration GUARDED_BY(::cs_main) time_connect_total{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_flush{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_chainstate{};
    SteadyClock::duration GUARDED_BY(::cs_main) time_post_connect{};
 
protected:
    CBlockIndex* m_best_invalid GUARDED_BY(::cs_main){nullptr};
 
public:
    using Options = kernel::ChainstateManagerOpts;
 
    explicit ChainstateManager(const util::SignalInterrupt& interrupt, Options options, node::BlockManager::Options blockman_options);

    std::function<void()> snapshot_download_completed = std::function<void()>();
 
    const CChainParams& GetParams() const { return m_options.chainparams; }
    const Consensus::Params& GetConsensus() const { return m_options.chainparams.GetConsensus(); }
    bool ShouldCheckBlockIndex() const;
    const arith_uint256& MinimumChainWork() const { return *Assert(m_options.minimum_chain_work); }
    const uint256& AssumedValidBlock() const { return *Assert(m_options.assumed_valid_block); }
    kernel::Notifications& GetNotifications() const { return m_options.notifications; };

    void CheckBlockIndex() const;

    RecursiveMutex& GetMutex() const LOCK_RETURNED(::cs_main) { return ::cs_main; }
 
    const util::SignalInterrupt& m_interrupt;
    const Options m_options;
    node::BlockManager m_blockman;
 
    ValidationCache m_validation_cache;

    std::atomic_bool m_cached_is_ibd{true};

    int32_t nBlockSequenceId GUARDED_BY(::cs_main) = SEQ_ID_INIT_FROM_DISK + 1;
    int32_t nBlockReverseSequenceId = -1;
    arith_uint256 nLastPreciousChainwork = 0;
 
    // Reset the memory-only sequence counters we use to track block arrival
    // (used by tests to reset state)
    void ResetBlockSequenceCounters() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        nBlockSequenceId = SEQ_ID_INIT_FROM_DISK + 1;
        nBlockReverseSequenceId = -1;
    }
 

    CBlockIndex* m_best_header GUARDED_BY(::cs_main){nullptr};

    size_t m_total_coinstip_cache{0};
    //
    size_t m_total_coinsdb_cache{0};

    //                                  constructor
    Chainstate& InitializeChainstate(CTxMemPool* mempool) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    [[nodiscard]] util::Result<CBlockIndex*> ActivateSnapshot(
        AutoFile& coins_file, const node::SnapshotMetadata& metadata, bool in_memory);

    SnapshotCompletionResult MaybeValidateSnapshot(Chainstate& validated_cs, Chainstate& unvalidated_cs) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    Chainstate& CurrentChainstate() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex())
    {
        for (auto& cs : m_chainstates) {
            if (cs && cs->m_assumeutxo != Assumeutxo::INVALID && !cs->m_target_blockhash) return *cs;
        }
        abort();
    }

    Chainstate* HistoricalChainstate() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex())
    {
        for (auto& cs : m_chainstates) {
            if (cs && cs->m_assumeutxo != Assumeutxo::INVALID && cs->m_target_blockhash && !cs->m_target_utxohash) return cs.get();
        }
        return nullptr;
    }

    Chainstate& ValidatedChainstate() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex())
    {
        for (auto* cs : {&CurrentChainstate(), HistoricalChainstate()}) {
            if (cs && cs->m_assumeutxo == Assumeutxo::VALIDATED) return *cs;
        }
        abort();
    }

    std::unique_ptr<Chainstate> RemoveChainstate(Chainstate& chainstate) EXCLUSIVE_LOCKS_REQUIRED(GetMutex())
    {
        auto it{std::find_if(m_chainstates.begin(), m_chainstates.end(), [&](auto& cs) { return cs.get() == &chainstate; })};
        if (it != m_chainstates.end()) {
            auto ret{std::move(*it)};
            m_chainstates.erase(it);
            return ret;
        }
        return nullptr;
    }

    Chainstate& ActiveChainstate() const;
    CChain& ActiveChain() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChainstate().m_chain; }
    int ActiveHeight() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChain().Height(); }
    CBlockIndex* ActiveTip() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) { return ActiveChain().Tip(); }

    void UpdateIBDStatus() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    node::BlockMap& BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
    {
        AssertLockHeld(::cs_main);
        return m_blockman.m_block_index;
    }

    mutable VersionBitsCache m_versionbitscache;

    bool IsInitialBlockDownload() const noexcept;

    double GuessVerificationProgress(const CBlockIndex* pindex) const EXCLUSIVE_LOCKS_REQUIRED(GetMutex());

    void LoadExternalBlockFile(
        AutoFile& file_in,
        FlatFilePos* dbp = nullptr,
        std::multimap<uint256, FlatFilePos>* blocks_with_unknown_parent = nullptr);

    bool ProcessNewBlock(const std::shared_ptr<const CBlock>& block, bool force_processing, bool min_pow_checked, bool* new_block) LOCKS_EXCLUDED(cs_main);

    bool ProcessNewBlockHeaders(std::span<const CBlockHeader> headers, bool min_pow_checked, BlockValidationState& state, const CBlockIndex** ppindex = nullptr) LOCKS_EXCLUDED(cs_main);

    bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock, bool min_pow_checked) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
    void ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos) EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    [[nodiscard]] MempoolAcceptResult ProcessTransaction(const CTransactionRef& tx, bool test_accept=false)
        EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    bool LoadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(cs_main);

    void MaybeRebalanceCaches() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev) const;

    void GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev) const;

    void ReportHeadersPresync(int64_t height, int64_t timestamp);

    Chainstate* LoadAssumeutxoChainstate() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    Chainstate& AddChainstate(std::unique_ptr<Chainstate> chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
    void ResetChainstates() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    [[nodiscard]] bool DeleteChainstate(Chainstate& chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    bool ValidatedSnapshotCleanup(Chainstate& validated_cs, Chainstate& unvalidated_cs) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    std::optional<std::pair<const CBlockIndex*, const CBlockIndex*>> GetHistoricalBlockRange() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    util::Result<void> ActivateBestChains() LOCKS_EXCLUDED(::cs_main);

    void RecalculateBestHeader() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);

    std::optional<int> BlocksAheadOfTip() const LOCKS_EXCLUDED(::cs_main);
 
    CCheckQueue<CScriptCheck>& GetCheckQueue() { return m_script_check_queue; }
 
    ~ChainstateManager();

    std::vector<std::unique_ptr<Chainstate>> m_chainstates GUARDED_BY(::cs_main);
};

template<typename DEP>
bool DeploymentActiveAfter(const CBlockIndex* pindexPrev, const ChainstateManager& chainman, DEP dep)
{
    return DeploymentActiveAfter(pindexPrev, chainman.GetConsensus(), dep, chainman.m_versionbitscache);
}
 
template<typename DEP>
bool DeploymentActiveAt(const CBlockIndex& index, const ChainstateManager& chainman, DEP dep)
{
    return DeploymentActiveAt(index, chainman.GetConsensus(), dep, chainman.m_versionbitscache);
}
 
template<typename DEP>
bool DeploymentEnabled(const ChainstateManager& chainman, DEP dep)
{
    return DeploymentEnabled(chainman.GetConsensus(), dep);
}

bool IsBIP30Repeat(const CBlockIndex& block_index);

bool IsBIP30Unspendable(const uint256& block_hash, int block_height);
 
// Returns the script flags which should be checked for a given block
script_verify_flags GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman);
 
#endif // BITCOIN_VALIDATION_H