Method ReadBlockUndo

src/node/blockstorage.cpp:715–748

}

bool BlockManager::ReadBlockUndo(CBlockUndo& blockundo, const CBlockIndex& index) const
{
    const FlatFilePos pos{WITH_LOCK(::cs_main, return index.GetUndoPos())};

    // Open history file to read
    AutoFile file{OpenUndoFile(pos, true)};
    if (file.IsNull()) {
        LogError("OpenUndoFile failed for %s while reading block undo", pos.ToString());
        return false;
    }
    BufferedReader filein{std::move(file)};

    try {
        // Read block
        HashVerifier verifier{filein}; // Use HashVerifier, as reserializing may lose data, c.f. commit d3424243

        verifier << index.pprev->GetBlockHash();
        verifier >> blockundo;

        uint256 hashChecksum;
        filein >> hashChecksum;

        // Verify checksum
        if (hashChecksum != verifier.GetHash()) {
            LogError("Checksum mismatch at %s while reading block undo", pos.ToString());
            return false;
        }
    } catch (const std::exception& e) {
        LogError("Deserialize or I/O error - %s at %s while reading block undo", e.what(), pos.ToString());
        return false;
    }

    return true;
}

bool BlockManager::FlushUndoFile(int block_file, bool finalize)
{