Method PopulateAndValidateSnapshot

src/validation.cpp:5773–5973

}

util::Result<void> ChainstateManager::PopulateAndValidateSnapshot(
    Chainstate& snapshot_chainstate,
    AutoFile& coins_file,
    const SnapshotMetadata& metadata)
{
    // It's okay to release cs_main before we're done using `coins_cache` because we know
    // that nothing else will be referencing the newly created snapshot_chainstate yet.
    CCoinsViewCache& coins_cache = *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());

    uint256 base_blockhash = metadata.m_base_blockhash;

    CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));

    if (!snapshot_start_block) {
        // Needed for ComputeUTXOStats to determine the
        // height and to avoid a crash when base_blockhash.IsNull()
        return util::Error{Untranslated(strprintf("Did not find snapshot start blockheader %s",
                  base_blockhash.ToString()))};
    }

    int base_height = snapshot_start_block->nHeight;
    const auto& maybe_au_data = GetParams().AssumeutxoForHeight(base_height);

    if (!maybe_au_data) {
        return util::Error{Untranslated(strprintf("Assumeutxo height in snapshot metadata not recognized "
                  "(%d) - refusing to load snapshot", base_height))};
    }

    const AssumeutxoData& au_data = *maybe_au_data;

    // This work comparison is a duplicate check with the one performed later in
    // ActivateSnapshot(), but is done so that we avoid doing the long work of staging
    // a snapshot that isn't actually usable.
    if (WITH_LOCK(::cs_main, return !CBlockIndexWorkComparator()(ActiveTip(), snapshot_start_block))) {
        return util::Error{Untranslated("Work does not exceed active chainstate")};
    }

    const uint64_t coins_count = metadata.m_coins_count;
    uint64_t coins_left = metadata.m_coins_count;

    LogInfo("[snapshot] loading %d coins from snapshot %s", coins_left, base_blockhash.ToString());
    int64_t coins_processed{0};

    while (coins_left > 0) {
        try {
            Txid txid;
            coins_file >> txid;
            size_t coins_per_txid{0};
            coins_per_txid = ReadCompactSize(coins_file);

            if (coins_per_txid > coins_left) {
                return util::Error{Untranslated("Mismatch in coins count in snapshot metadata and actual snapshot data")};
            }

            for (size_t i = 0; i < coins_per_txid; i++) {
                COutPoint outpoint;
                Coin coin;
                outpoint.n = static_cast<uint32_t>(ReadCompactSize(coins_file));