blockchain_blackball.cpp File Reference

#include <boost/range/adaptor/transformed.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/archive/portable_binary_iarchive.hpp>
#include <boost/archive/portable_binary_oarchive.hpp>
#include "common/unordered_containers_boost_serialization.h"
#include "common/command_line.h"
#include "common/varint.h"
#include "serialization/crypto.h"
#include "cryptonote_basic/cryptonote_boost_serialization.h"
#include "cryptonote_core/tx_pool.h"
#include "cryptonote_core/cryptonote_core.h"
#include "cryptonote_core/blockchain.h"
#include "blockchain_db/blockchain_db.h"
#include "blockchain_db/db_types.h"
#include "wallet/ringdb.h"
#include "version.h"

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Classes
struct	output_data

Macros
#define	ELECTRONEUM_DEFAULT_LOG_CATEGORY   "bcutil"

Functions
int	compare_uint64 (const MDB_val *a, const MDB_val *b)
int	main (int argc, char *argv[])

Macro Definition Documentation

ELECTRONEUM_DEFAULT_LOG_CATEGORY

#define ELECTRONEUM_DEFAULT_LOG_CATEGORY   "bcutil"

Definition at line 47 of file blockchain_blackball.cpp.

Function Documentation

compare_uint64()

int compare_uint64	(	const MDB_val *	a,
		const MDB_val *	b )

Definition at line 165 of file blockchain_blackball.cpp.

{
  const uint64_t va = *(const uint64_t *)a->mv_data;
  const uint64_t vb = *(const uint64_t *)b->mv_data;
  return (va < vb) ? -1 : va > vb;
}

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main()

int main	(	int	argc,
		char *	argv[] )

Definition at line 1057 of file blockchain_blackball.cpp.

{
  TRY_ENTRY();
 
  epee::string_tools::set_module_name_and_folder(argv[0]);
 
  std::string default_db_type = "lmdb";
 
  std::string available_dbs = cryptonote::blockchain_db_types(", ");
  available_dbs = "available: " + available_dbs;
 
  uint32_t log_level = 0;
 
  tools::on_startup();
 
  boost::filesystem::path output_file_path;
 
  po::options_description desc_cmd_only("Command line options");
  po::options_description desc_cmd_sett("Command line options and settings options");
  const command_line::arg_descriptor<std::string> arg_blackball_db_dir = {
      "spent-output-db-dir", "Specify spent output database directory",
      get_default_db_path(),
  };
  const command_line::arg_descriptor<std::string> arg_log_level  = {"log-level",  "0-4 or categories", ""};
  const command_line::arg_descriptor<std::string> arg_database = {
    "database", available_dbs.c_str(), default_db_type
  };
  const command_line::arg_descriptor<bool> arg_rct_only  = {"rct-only", "Only work on ringCT outputs", false};
  const command_line::arg_descriptor<bool> arg_check_subsets  = {"check-subsets", "Check ring subsets (very expensive)", false};
  const command_line::arg_descriptor<bool> arg_verbose  = {"verbose", "Verbose output)", false};
  const command_line::arg_descriptor<std::vector<std::string> > arg_inputs = {"inputs", "Path to Electroneum DB, and path to any fork DBs"};
  const command_line::arg_descriptor<std::string> arg_db_sync_mode = {
    "db-sync-mode"
  , "Specify sync option, using format [safe|fast|fastest]:[nrecords_per_sync]." 
  , "fast:1000"
  };
  const command_line::arg_descriptor<std::string> arg_extra_spent_list = {"extra-spent-list", "Optional list of known spent outputs",""};
  const command_line::arg_descriptor<std::string> arg_export = {"export", "Filename to export the backball list to"};
  const command_line::arg_descriptor<bool> arg_force_chain_reaction_pass = {"force-chain-reaction-pass", "Run the chain reaction pass even if no new blockchain data was processed"};
 
  command_line::add_arg(desc_cmd_sett, arg_blackball_db_dir);
  command_line::add_arg(desc_cmd_sett, arg_log_level);
  command_line::add_arg(desc_cmd_sett, arg_database);
  command_line::add_arg(desc_cmd_sett, arg_rct_only);
  command_line::add_arg(desc_cmd_sett, arg_check_subsets);
  command_line::add_arg(desc_cmd_sett, arg_verbose);
  command_line::add_arg(desc_cmd_sett, arg_db_sync_mode);
  command_line::add_arg(desc_cmd_sett, arg_extra_spent_list);
  command_line::add_arg(desc_cmd_sett, arg_export);
  command_line::add_arg(desc_cmd_sett, arg_force_chain_reaction_pass);
  command_line::add_arg(desc_cmd_sett, arg_inputs);
  command_line::add_arg(desc_cmd_only, command_line::arg_help);
 
  po::options_description desc_options("Allowed options");
  desc_options.add(desc_cmd_only).add(desc_cmd_sett);
 
  po::positional_options_description positional_options;
  positional_options.add(arg_inputs.name, -1);
 
  po::variables_map vm;
  bool r = command_line::handle_error_helper(desc_options, [&]()
  {
    auto parser = po::command_line_parser(argc, argv).options(desc_options).positional(positional_options);
    po::store(parser.run(), vm);
    po::notify(vm);
    return true;
  });
  if (! r)
    return 1;
 
  if (command_line::get_arg(vm, command_line::arg_help))
  {
    std::cout << "Electroneum '" << ELECTRONEUM_RELEASE_NAME << "' (v" << ELECTRONEUM_VERSION_FULL << ")" << ENDL << ENDL;
    std::cout << desc_options << std::endl;
    return 1;
  }
 
  mlog_configure(mlog_get_default_log_path("electroneum-blockchain-mark-spent-outputs.log"), true);
  if (!command_line::is_arg_defaulted(vm, arg_log_level))
    mlog_set_log(command_line::get_arg(vm, arg_log_level).c_str());
  else
    mlog_set_log(std::string(std::to_string(log_level) + ",bcutil:INFO").c_str());
 
  LOG_PRINT_L0("Starting...");
 
  output_file_path = command_line::get_arg(vm, arg_blackball_db_dir);
  bool opt_rct_only = command_line::get_arg(vm, arg_rct_only);
  bool opt_check_subsets = command_line::get_arg(vm, arg_check_subsets);
  bool opt_verbose = command_line::get_arg(vm, arg_verbose);
  bool opt_force_chain_reaction_pass = command_line::get_arg(vm, arg_force_chain_reaction_pass);
  std::string opt_export = command_line::get_arg(vm, arg_export);
  std::string extra_spent_list = command_line::get_arg(vm, arg_extra_spent_list);
  std::vector<std::pair<uint64_t, uint64_t>> extra_spent_outputs = extra_spent_list.empty() ? std::vector<std::pair<uint64_t, uint64_t>>() : load_outputs(extra_spent_list);
 
  std::string db_type = command_line::get_arg(vm, arg_database);
  if (!cryptonote::blockchain_valid_db_type(db_type))
  {
    std::cerr << "Invalid database type: " << db_type << std::endl;
    return 1;
  }
 
  std::string db_sync_mode = command_line::get_arg(vm, arg_db_sync_mode);
  if (!parse_db_sync_mode(db_sync_mode))
  {
    MERROR("Invalid db sync mode: " << db_sync_mode);
    return 1;
  }
 
  const std::vector<std::string> inputs = command_line::get_arg(vm, arg_inputs);
  if (inputs.empty())
  {
    LOG_PRINT_L0("No inputs given");
    return 1;
  }
 
  const std::string cache_dir = (output_file_path / "spent-outputs-cache").string();
  init(cache_dir);
 
  LOG_PRINT_L0("Scanning for spent outputs...");
 
  size_t done = 0;
 
  const uint64_t start_blackballed_outputs = get_num_spent_outputs();
 
  tools::ringdb ringdb(output_file_path.string(), epee::string_tools::pod_to_hex(get_genesis_block_hash(inputs[0])));
 
  bool stop_requested = false;
  tools::signal_handler::install([&stop_requested](int type) {
    stop_requested = true;
  });
 
  int dbr = resize_env(cache_dir.c_str());
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));
 
  // open first db
  MDB_env *env0;
  MDB_txn *txn0;
  MDB_dbi dbi0;
  MDB_cursor *cur0;
  open_db(inputs[0], &env0, &txn0, &cur0, &dbi0);
 
  if (!extra_spent_outputs.empty())
  {
    MINFO("Adding " << extra_spent_outputs.size() << " extra spent outputs");
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
 
    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    for (const std::pair<uint64_t, uint64_t> &output: extra_spent_outputs)
    {
      if (!is_output_spent(cur, output_data(output.first, output.second)))
      {
        blackballs.push_back(output);
        if (add_spent_output(cur, output_data(output.first, output.second)))
          inc_stat(txn, output.first ? "pre-rct-extra" : "rct-ring-extra");
      }
    }
    if (!blackballs.empty())
    {
      ringdb.blackball(blackballs);
      blackballs.clear();
    }
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
  }
 
  for (size_t n = 0; n < inputs.size(); ++n)
  {
    const std::string canonical = boost::filesystem::canonical(inputs[n]).string();
    uint64_t start_idx = get_processed_txidx(canonical);
    if (n > 0 && start_idx == 0)
    {
      start_idx = find_first_diverging_transaction(inputs[0], inputs[n]);
      LOG_PRINT_L0("First diverging transaction at " << start_idx);
    }
    LOG_PRINT_L0("Reading blockchain from " << inputs[n] << " from " << start_idx);
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
    size_t records = 0;
    const std::string filename = inputs[n];
    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    uint64_t n_txes;
    for_all_transactions(filename, start_idx, n_txes, [&](const cryptonote::transaction_prefix &tx)->bool
    {
      std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
      const bool miner_tx = tx.vin.size() == 1 && tx.vin[0].type() == typeid(txin_gen);
      for (const auto &in: tx.vin)
      {
        if (in.type() != typeid(txin_to_key))
          continue;
        const auto &txin = boost::get<txin_to_key>(in);
        if (opt_rct_only && txin.amount != 0)
          continue;
 
        const std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(txin.key_offsets);
        if (n == 0)
          for (uint64_t out: absolute)
            add_key_image(txn, output_data(txin.amount, out), txin.k_image);
 
        std::vector<uint64_t> relative_ring;
        std::vector<uint64_t> new_ring = canonicalize(txin.key_offsets);
        const uint32_t ring_size = txin.key_offsets.size();
        const uint64_t instances = inc_ring_instances(txn, txin.amount, new_ring);
        uint64_t pa_total = 0, pa_spent = 0;
        if (!opt_rct_only)
          get_per_amount_outputs(txn, txin.amount, pa_total, pa_spent);
        if (n == 0 && ring_size == 1)
        {
          const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[0]);
          if (opt_verbose)
          {
            MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in a 1-ring");
            std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
          }
          blackballs.push_back(output);
          if (add_spent_output(cur, output_data(txin.amount, absolute[0])))
            inc_stat(txn, txin.amount ? "pre-rct-ring-size-1" : "rct-ring-size-1");
        }
        else if (n == 0 && instances == new_ring.size())
        {
          for (size_t o = 0; o < new_ring.size(); ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in " << new_ring.size() << " identical " << new_ring.size() << "-rings");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, absolute[o])))
              inc_stat(txn, txin.amount ? "pre-rct-duplicate-rings" : "rct-duplicate-rings");
          }
        }
        else if (n == 0 && !opt_rct_only && pa_spent + 1 == pa_total)
        {
          for (size_t o = 0; o < pa_total; ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, o);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to as many outputs of that amount being spent as exist so far");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, o)))
              inc_stat(txn, txin.amount ? "pre-rct-full-count" : "rct-full-count");
          }
        }
        else if (n == 0 && opt_check_subsets && get_ring_subset_instances(txn, txin.amount, new_ring) >= new_ring.size())
        {
          for (size_t o = 0; o < new_ring.size(); ++o)
          {
            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
            if (opt_verbose)
            {
              MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in " << new_ring.size() << " subsets of " << new_ring.size() << "-rings");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            blackballs.push_back(output);
            if (add_spent_output(cur, output_data(txin.amount, absolute[o])))
              inc_stat(txn, txin.amount ? "pre-rct-subset-rings" : "rct-subset-rings");
          }
        }
        else if (n > 0 && get_relative_ring(txn, txin.k_image, relative_ring))
        {
          MDEBUG("Key image " << txin.k_image << " already seen: rings " <<
              boost::join(relative_ring | boost::adaptors::transformed([](uint64_t out){return std::to_string(out);}), " ") <<
              ", " << boost::join(txin.key_offsets | boost::adaptors::transformed([](uint64_t out){return std::to_string(out);}), " "));
          std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
          if (relative_ring != txin.key_offsets)
          {
            MDEBUG("Rings are different");
            std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            const std::vector<uint64_t> r0 = cryptonote::relative_output_offsets_to_absolute(relative_ring);
            const std::vector<uint64_t> r1 = cryptonote::relative_output_offsets_to_absolute(txin.key_offsets);
            std::vector<uint64_t> common;
            for (uint64_t out: r0)
            {
              if (std::find(r1.begin(), r1.end(), out) != r1.end())
                common.push_back(out);
            }
            if (common.empty())
            {
              MERROR("Rings for the same key image are disjoint");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
            }
            else if (common.size() == 1)
            {
              const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, common[0]);
              if (opt_verbose)
              {
                MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in rings with a single common element");
                std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
              }
              blackballs.push_back(output);
              if (add_spent_output(cur, output_data(txin.amount, common[0])))
                inc_stat(txn, txin.amount ? "pre-rct-key-image-attack" : "rct-key-image-attack");
            }
            else
            {
              MDEBUG("The intersection has more than one element, it's still ok");
              std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
              for (const auto &out: r0)
                if (std::find(common.begin(), common.end(), out) != common.end())
                  new_ring.push_back(out);
              new_ring = cryptonote::absolute_output_offsets_to_relative(new_ring);
            }
          }
        }
        if (n == 0)
        {
          set_relative_ring(txn, txin.k_image, new_ring);
          if (!opt_rct_only)
            inc_per_amount_outputs(txn, txin.amount, 0, 1);
        }
      }
      set_processed_txidx(txn, canonical, start_idx+1);
      if (!opt_rct_only)
      {
        for (const auto &out: tx.vout)
        {
          uint64_t amount = out.amount;
 
          if (opt_rct_only && amount != 0)
            continue;
          if (out.target.type() != typeid(txout_to_key))
            continue;
          inc_per_amount_outputs(txn, amount, 1, 0);
        }
      }
 
      ++records;
      if (records >= records_per_sync)
      {
        if (!blackballs.empty())
        {
          ringdb.blackball(blackballs);
          blackballs.clear();
        }
        mdb_cursor_close(cur);
        dbr = mdb_txn_commit(txn);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
        int dbr = resize_env(cache_dir.c_str());
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));
        dbr = mdb_txn_begin(env, NULL, 0, &txn);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
        dbr = mdb_cursor_open(txn, dbi_spent, &cur);
        CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
        records = 0;
      }
 
      if (stop_requested)
      {
        MINFO("Stopping scan...");
        return false;
      }
      return true;
    });
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
    LOG_PRINT_L0("blockchain from " << inputs[n] << " processed till tx idx " << start_idx);
    if (stop_requested)
      break;
  }
 
  std::vector<output_data> work_spent;
 
  if (stop_requested)
    goto skip_secondary_passes;
 
  if (opt_force_chain_reaction_pass || get_num_spent_outputs() > start_blackballed_outputs)
  {
    MDB_txn *txn;
    dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    work_spent = get_spent_outputs(txn);
    mdb_txn_abort(txn);
  }
 
  while (!work_spent.empty())
  {
    LOG_PRINT_L0("Secondary pass on " << work_spent.size() << " spent outputs");
 
    int dbr = resize_env(cache_dir.c_str());
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to resize LMDB database: " + std::string(mdb_strerror(dbr)));
 
    MDB_txn *txn;
    dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
 
    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
    std::vector<output_data> scan_spent = std::move(work_spent);
    work_spent.clear();
    for (const output_data &od: scan_spent)
    {
      std::vector<crypto::key_image> key_images = get_key_images(txn, od);
      for (const crypto::key_image &ki: key_images)
      {
        std::vector<uint64_t> relative_ring;
        CHECK_AND_ASSERT_THROW_MES(get_relative_ring(txn, ki, relative_ring), "Relative ring not found");
        std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(relative_ring);
        size_t known = 0;
        uint64_t last_unknown = 0;
        for (uint64_t out: absolute)
        {
          output_data new_od(od.amount, out);
          if (is_output_spent(cur, new_od))
            ++known;
          else
            last_unknown = out;
        }
        if (known == absolute.size() - 1)
        {
          const std::pair<uint64_t, uint64_t> output = std::make_pair(od.amount, last_unknown);
          if (opt_verbose)
          {
            MINFO("Marking output " << output.first << "/" << output.second << " as spent, due to being used in a " <<
                absolute.size() << "-ring where all other outputs are known to be spent");
          }
          blackballs.push_back(output);
          if (add_spent_output(cur, output_data(od.amount, last_unknown)))
            inc_stat(txn, od.amount ? "pre-rct-chain-reaction" : "rct-chain-reaction");
          work_spent.push_back(output_data(od.amount, last_unknown));
        }
      }
 
      if (stop_requested)
      {
        MINFO("Stopping secondary passes. Secondary passes are not incremental, they will re-run fully.");
        return 0;
      }
    }
    if (!blackballs.empty())
    {
      ringdb.blackball(blackballs);
      blackballs.clear();
    }
    mdb_cursor_close(cur);
    dbr = mdb_txn_commit(txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
  }
 
skip_secondary_passes:
  uint64_t diff = get_num_spent_outputs() - start_blackballed_outputs;
  LOG_PRINT_L0(std::to_string(diff) << " new outputs marked as spent, " << get_num_spent_outputs() << " total outputs marked as spent");
 
  MDB_txn *txn;
  dbr = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
  CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
  uint64_t pre_rct = 0, rct = 0;
  get_num_outputs(txn0, cur0, dbi0, pre_rct, rct);
  MINFO("Total pre-rct outputs: " << pre_rct);
  MINFO("Total rct outputs: " << rct);
  static const struct { const char *key; uint64_t base; } stat_keys[] = {
    { "pre-rct-ring-size-1", pre_rct }, { "rct-ring-size-1", rct },
    { "pre-rct-duplicate-rings", pre_rct }, { "rct-duplicate-rings", rct },
    { "pre-rct-subset-rings", pre_rct }, { "rct-subset-rings", rct },
    { "pre-rct-full-count", pre_rct }, { "rct-full-count", rct },
    { "pre-rct-key-image-attack", pre_rct }, { "rct-key-image-attack", rct },
    { "pre-rct-extra", pre_rct }, { "rct-ring-extra", rct },
    { "pre-rct-chain-reaction", pre_rct }, { "rct-chain-reaction", rct },
  };
  for (const auto &key: stat_keys)
  {
    uint64_t data;
    if (!get_stat(txn, key.key, data))
      data = 0;
    float percent = key.base ? 100.0f * data / key.base : 0.0f;
    MINFO(key.key << ": " << data << " (" << percent << "%)");
  }
  mdb_txn_abort(txn);
 
  if (!opt_export.empty())
  {
    MDB_txn *txn;
    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
    MDB_cursor *cur;
    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
    export_spent_outputs(cur, opt_export);
    mdb_cursor_close(cur);
    mdb_txn_abort(txn);
  }
 
  LOG_PRINT_L0("Blockchain spent output data exported OK");
  close_db(env0, txn0, cur0, dbi0);
  close();
  return 0;
 
  CATCH_ENTRY("Error", 1);
}

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