monero/src/cryptonote_core/blockchain_storage.cpp

// Copyright (c) 2014-2015, The Monero Project
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
// 
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
// 
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers

#include <algorithm>
#include <cstdio>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>

#include "include_base_utils.h"
#include "cryptonote_basic_impl.h"
#include "blockchain_storage.h"
#include "cryptonote_format_utils.h"
#include "cryptonote_boost_serialization.h"
#include "blockchain_storage_boost_serialization.h"
#include "cryptonote_config.h"
#include "miner.h"
#include "misc_language.h"
#include "profile_tools.h"
#include "file_io_utils.h"
#include "common/boost_serialization_helper.h"
#include "warnings.h"
#include "crypto/hash.h"
#include "cryptonote_core/checkpoints_create.h"
//#include "serialization/json_archive.h"

using namespace cryptonote;

DISABLE_VS_WARNINGS(4267)

//------------------------------------------------------------------
bool blockchain_storage::have_tx(const crypto::hash &id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  return m_transactions.find(id) != m_transactions.end();
}
//------------------------------------------------------------------
bool blockchain_storage::have_tx_keyimg_as_spent(const crypto::key_image &key_im)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  return  m_spent_keys.find(key_im) != m_spent_keys.end();
}
//------------------------------------------------------------------
transaction *blockchain_storage::get_tx(const crypto::hash &id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  auto it = m_transactions.find(id);
  if (it == m_transactions.end())
    return NULL;

  return &it->second.tx;
}
//------------------------------------------------------------------
uint64_t blockchain_storage::get_current_blockchain_height()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  return m_blocks.size();
}
//------------------------------------------------------------------
bool blockchain_storage::init(const std::string& config_folder, bool testnet)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  m_config_folder = config_folder;
  m_testnet = testnet;
  LOG_PRINT_L0("Loading blockchain...");
  const std::string filename = m_config_folder + "/" CRYPTONOTE_BLOCKCHAINDATA_FILENAME;
  if(tools::unserialize_obj_from_file(*this, filename))
  {

      // checkpoints
      
      // mainchain
      for (size_t height=0; height < m_blocks.size(); ++height) 
      {
	CHECK_AND_ASSERT_MES((!m_checkpoints.is_in_checkpoint_zone(height)) || m_checkpoints.check_block(height,get_block_hash(m_blocks[height].bl)),false,"checkpoint fail, blockchain.bin invalid");
      }

      // check alt chains
      #if 0
      // doesn't work when a checkpoint is added and there are already alt chains. However, the rest of the blockchain code suffers from the same issue, so ignore for now
      // see issue #118
      BOOST_FOREACH(blocks_ext_by_hash::value_type& alt_block, m_alternative_chains)
      {
	CHECK_AND_ASSERT_MES(m_checkpoints.is_alternative_block_allowed(m_blocks.size()-1,alt_block.second.height),false,"stored alternative block not allowed, blockchain.bin invalid");
      }
      #endif
  }
  else
  {
      LOG_PRINT_L0("Can't load blockchain storage from file, generating genesis block.");
      block bl = boost::value_initialized<block>();
      block_verification_context bvc = boost::value_initialized<block_verification_context>();
      if (testnet)
      {
        generate_genesis_block(bl, config::testnet::GENESIS_TX, config::testnet::GENESIS_NONCE);
      }
      else
      {
        generate_genesis_block(bl, config::GENESIS_TX, config::GENESIS_NONCE);
      }
      add_new_block(bl, bvc);
      CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed && bvc.m_added_to_main_chain, false, "Failed to add genesis block to blockchain");
  }
  if(!m_blocks.size())
  {
    LOG_PRINT_L0("Blockchain not loaded, generating genesis block.");

    if (!store_genesis_block(testnet)) {
      return false;
    }
  } else {
    cryptonote::block b;

    if (testnet)
    {
      generate_genesis_block(b, config::testnet::GENESIS_TX, config::testnet::GENESIS_NONCE);
    }
    else
    {
      generate_genesis_block(b, config::GENESIS_TX, config::GENESIS_NONCE);
    }

    crypto::hash genesis_hash = get_block_hash(m_blocks[0].bl);
    crypto::hash testnet_genesis_hash = get_block_hash(b);
    if (genesis_hash != testnet_genesis_hash) {
      LOG_ERROR("Failed to init: genesis block mismatch. Probably you set --testnet flag with data dir with non-test blockchain or another network.");
      return false;
    }
  }
  uint64_t timestamp_diff = time(NULL) - m_blocks.back().bl.timestamp;
  if(!m_blocks.back().bl.timestamp)
    timestamp_diff = time(NULL) - 1341378000;
  LOG_PRINT_GREEN("Blockchain initialized. last block: " << m_blocks.size() - 1 << ", " << epee::misc_utils::get_time_interval_string(timestamp_diff) << " time ago, current difficulty: " << get_difficulty_for_next_block(), LOG_LEVEL_0);
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::store_genesis_block(bool testnet) {
  block bl = ::boost::value_initialized<block>();
  block_verification_context bvc = boost::value_initialized<block_verification_context>();

  if (testnet)
  {
    generate_genesis_block(bl, config::testnet::GENESIS_TX, config::testnet::GENESIS_NONCE);
  }
  else
  {
    generate_genesis_block(bl, config::GENESIS_TX, config::GENESIS_NONCE);
  }

  add_new_block(bl, bvc);
  CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed, false, "Failed to add genesis block to blockchain");
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::store_blockchain()
{
  m_is_blockchain_storing = true;
  epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){m_is_blockchain_storing=false;});

  LOG_PRINT_L0("Storing blockchain...");
  if (!tools::create_directories_if_necessary(m_config_folder))
  {
    LOG_PRINT_L0("Failed to create data directory: " << m_config_folder);
    return false;
  }

  const std::string temp_filename = m_config_folder + "/" CRYPTONOTE_BLOCKCHAINDATA_TEMP_FILENAME;
  // There is a chance that temp_filename and filename are hardlinks to the same file
  std::remove(temp_filename.c_str());
  if(!tools::serialize_obj_to_file(*this, temp_filename))
  {
    //achtung!
    LOG_ERROR("Failed to save blockchain data to file: " << temp_filename);
    return false;
  }
  const std::string filename = m_config_folder + "/" CRYPTONOTE_BLOCKCHAINDATA_FILENAME;
  std::error_code ec = tools::replace_file(temp_filename, filename);
  if (ec)
  {
    LOG_ERROR("Failed to rename blockchain data file " << temp_filename << " to " << filename << ": " << ec.message() << ':' << ec.value());
    return false;
  }
  LOG_PRINT_L0("Blockchain stored OK.");
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::deinit()
{
  return store_blockchain();
}
//------------------------------------------------------------------
bool blockchain_storage::pop_block_from_blockchain()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  CHECK_AND_ASSERT_MES(m_blocks.size() > 1, false, "pop_block_from_blockchain: can't pop from blockchain with size = " << m_blocks.size());
  size_t h = m_blocks.size()-1;
  block_extended_info& bei = m_blocks[h];
  //crypto::hash id = get_block_hash(bei.bl);
  bool r = purge_block_data_from_blockchain(bei.bl, bei.bl.tx_hashes.size());
  CHECK_AND_ASSERT_MES(r, false, "Failed to purge_block_data_from_blockchain for block " << get_block_hash(bei.bl) << " on height " << h);

  //remove from index
  auto bl_ind = m_blocks_index.find(get_block_hash(bei.bl));
  CHECK_AND_ASSERT_MES(bl_ind != m_blocks_index.end(), false, "pop_block_from_blockchain: blockchain id not found in index");
  m_blocks_index.erase(bl_ind);
  //pop block from core
  m_blocks.pop_back();
  m_tx_pool.on_blockchain_dec(m_blocks.size()-1, get_tail_id());
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::reset_and_set_genesis_block(const block& b)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  m_transactions.clear();
  m_spent_keys.clear();
  m_blocks.clear();
  m_blocks_index.clear();
  m_alternative_chains.clear();
  m_outputs.clear();

  block_verification_context bvc = boost::value_initialized<block_verification_context>();
  add_new_block(b, bvc);
  return bvc.m_added_to_main_chain && !bvc.m_verifivation_failed;
}
//------------------------------------------------------------------
bool blockchain_storage::purge_transaction_keyimages_from_blockchain(const transaction& tx, bool strict_check)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
    struct purge_transaction_visitor: public boost::static_visitor<bool>
  {
    key_images_container& m_spent_keys;
    bool m_strict_check;
    purge_transaction_visitor(key_images_container& spent_keys, bool strict_check):m_spent_keys(spent_keys), m_strict_check(strict_check){}

    bool operator()(const txin_to_key& inp) const
    {
      //const crypto::key_image& ki = inp.k_image;
      auto r = m_spent_keys.find(inp.k_image);
      if(r != m_spent_keys.end())
      {
        m_spent_keys.erase(r);
      }else
      {
        CHECK_AND_ASSERT_MES(!m_strict_check, false, "purge_block_data_from_blockchain: key image in transaction not found");
      }
      return true;
    }
    bool operator()(const txin_gen& inp) const
    {
      return true;
    }
    bool operator()(const txin_to_script& tx) const
    {
      return false;
    }

    bool operator()(const txin_to_scripthash& tx) const
    {
      return false;
    }
  };

  BOOST_FOREACH(const txin_v& in, tx.vin)
  {
    bool r = boost::apply_visitor(purge_transaction_visitor(m_spent_keys, strict_check), in);
    CHECK_AND_ASSERT_MES(!strict_check || r, false, "failed to process purge_transaction_visitor");
  }
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::purge_transaction_from_blockchain(const crypto::hash& tx_id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  auto tx_index_it = m_transactions.find(tx_id);
  CHECK_AND_ASSERT_MES(tx_index_it != m_transactions.end(), false, "purge_block_data_from_blockchain: transaction not found in blockchain index!!");
  transaction& tx = tx_index_it->second.tx;

  purge_transaction_keyimages_from_blockchain(tx, true);

  if(!is_coinbase(tx))
  {
    cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
    bool r = m_tx_pool.add_tx(tx, tvc, true);
    CHECK_AND_ASSERT_MES(r, false, "purge_block_data_from_blockchain: failed to add transaction to transaction pool");
  }

  bool res = pop_transaction_from_global_index(tx, tx_id);
  m_transactions.erase(tx_index_it);
  LOG_PRINT_L1("Removed transaction from blockchain history:" << tx_id << ENDL);
  return res;
}
//------------------------------------------------------------------
bool blockchain_storage::purge_block_data_from_blockchain(const block& bl, size_t processed_tx_count)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  bool res = true;
  CHECK_AND_ASSERT_MES(processed_tx_count <= bl.tx_hashes.size(), false, "wrong processed_tx_count in purge_block_data_from_blockchain");
  for(size_t count = 0; count != processed_tx_count; count++)
  {
    res = purge_transaction_from_blockchain(bl.tx_hashes[(processed_tx_count -1)- count]) && res;
  }

  res = purge_transaction_from_blockchain(get_transaction_hash(bl.miner_tx)) && res;

  return res;
}
//------------------------------------------------------------------
crypto::hash blockchain_storage::get_tail_id(uint64_t& height)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  height = get_current_blockchain_height()-1;
  return get_tail_id();
}
//------------------------------------------------------------------
crypto::hash blockchain_storage::get_tail_id()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  crypto::hash id = null_hash;
  if(m_blocks.size())
  {
    get_block_hash(m_blocks.back().bl, id);
  }
  return id;
}
//------------------------------------------------------------------
bool blockchain_storage::get_short_chain_history(std::list<crypto::hash>& ids)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  size_t i = 0;
  size_t current_multiplier = 1;
  size_t sz = m_blocks.size();
  if(!sz)
    return true;
  size_t current_back_offset = 1;
  bool genesis_included = false;
  while(current_back_offset < sz)
  {
    ids.push_back(get_block_hash(m_blocks[sz-current_back_offset].bl));
    if(sz-current_back_offset == 0)
      genesis_included = true;
    if(i < 10)
    {
      ++current_back_offset;
    }else
    {
      current_back_offset += current_multiplier *= 2;
    }
    ++i;
  }
  if(!genesis_included)
    ids.push_back(get_block_hash(m_blocks[0].bl));

  return true;
}
//------------------------------------------------------------------
crypto::hash blockchain_storage::get_block_id_by_height(uint64_t height)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(height >= m_blocks.size())
    return null_hash;

  return get_block_hash(m_blocks[height].bl);
}
//------------------------------------------------------------------
bool blockchain_storage::get_block_by_hash(const crypto::hash &h, block &blk) {
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  // try to find block in main chain
  blocks_by_id_index::const_iterator it = m_blocks_index.find(h);
  if (m_blocks_index.end() != it) {
    blk = m_blocks[it->second].bl;
    return true;
  }

  // try to find block in alternative chain
  blocks_ext_by_hash::const_iterator it_alt = m_alternative_chains.find(h);
  if (m_alternative_chains.end() != it_alt) {
    blk = it_alt->second.bl;
    return true;
  }

  return false;
}
//------------------------------------------------------------------
void blockchain_storage::get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) {
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  BOOST_FOREACH(blocks_by_id_index::value_type &v, m_blocks_index)
    main.push_back(v.first);

  BOOST_FOREACH(blocks_ext_by_hash::value_type &v, m_alternative_chains)
    alt.push_back(v.first);

  BOOST_FOREACH(blocks_ext_by_hash::value_type &v, m_invalid_blocks)
    invalid.push_back(v.first);
}
//------------------------------------------------------------------
difficulty_type blockchain_storage::get_difficulty_for_next_block()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  std::vector<uint64_t> timestamps;
  std::vector<difficulty_type> commulative_difficulties;
  size_t offset = m_blocks.size() - std::min(m_blocks.size(), static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT));
  if(!offset)
    ++offset;//skip genesis block
  for(; offset < m_blocks.size(); offset++)
  {
    timestamps.push_back(m_blocks[offset].bl.timestamp);
    commulative_difficulties.push_back(m_blocks[offset].cumulative_difficulty);
  }
  return next_difficulty(timestamps, commulative_difficulties);
}
//------------------------------------------------------------------
bool blockchain_storage::rollback_blockchain_switching(std::list<block>& original_chain, size_t rollback_height)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  // fail if rollback_height passed is too high
  if (rollback_height > m_blocks.size())
  {
    return true;
  }

  //remove failed subchain
  for(size_t i = m_blocks.size()-1; i >=rollback_height; i--)
  {
    bool r = pop_block_from_blockchain();
    CHECK_AND_ASSERT_MES(r, false, "PANIC! failed to remove block while chain switching during the rollback!");
  }
  //return back original chain
  BOOST_FOREACH(auto& bl, original_chain)
  {
    block_verification_context bvc = boost::value_initialized<block_verification_context>();
    bool r = handle_block_to_main_chain(bl, bvc);
    CHECK_AND_ASSERT_MES(r && bvc.m_added_to_main_chain, false, "PANIC! failed to add (again) block while chain switching during the rollback!");
  }

  LOG_PRINT_L1("Rollback success.");
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  CHECK_AND_ASSERT_MES(alt_chain.size(), false, "switch_to_alternative_blockchain: empty chain passed");

  size_t split_height = alt_chain.front()->second.height;
  CHECK_AND_ASSERT_MES(m_blocks.size() > split_height, false, "switch_to_alternative_blockchain: blockchain size is lower than split height");

  //disconnecting old chain
  std::list<block> disconnected_chain;
  for(size_t i = m_blocks.size()-1; i >=split_height; i--)
  {
    block b = m_blocks[i].bl;
    bool r = pop_block_from_blockchain();
    CHECK_AND_ASSERT_MES(r, false, "failed to remove block on chain switching");
    disconnected_chain.push_front(b);
  }

  //connecting new alternative chain
  for(auto alt_ch_iter = alt_chain.begin(); alt_ch_iter != alt_chain.end(); alt_ch_iter++)
  {
    auto ch_ent = *alt_ch_iter;
    block_verification_context bvc = boost::value_initialized<block_verification_context>();
    bool r = handle_block_to_main_chain(ch_ent->second.bl, bvc);
    if(!r || !bvc.m_added_to_main_chain)
    {
      LOG_PRINT_L1("Failed to switch to alternative blockchain");
      rollback_blockchain_switching(disconnected_chain, split_height);
      add_block_as_invalid(ch_ent->second, get_block_hash(ch_ent->second.bl));
      LOG_PRINT_L1("The block was inserted as invalid while connecting new alternative chain, block_id: " << get_block_hash(ch_ent->second.bl));
      m_alternative_chains.erase(ch_ent);

      for(auto alt_ch_to_orph_iter = ++alt_ch_iter; alt_ch_to_orph_iter != alt_chain.end(); alt_ch_to_orph_iter++)
      {
        //block_verification_context bvc = boost::value_initialized<block_verification_context>();
        add_block_as_invalid((*alt_ch_iter)->second, (*alt_ch_iter)->first);
        m_alternative_chains.erase(*alt_ch_to_orph_iter);
      }
      return false;
    }
  }

  if(!discard_disconnected_chain)
  {
    //pushing old chain as alternative chain
    BOOST_FOREACH(auto& old_ch_ent, disconnected_chain)
    {
      block_verification_context bvc = boost::value_initialized<block_verification_context>();
      bool r = handle_alternative_block(old_ch_ent, get_block_hash(old_ch_ent), bvc);
      if(!r)
      {
        LOG_PRINT_L1("Failed to push ex-main chain blocks to alternative chain ");
        rollback_blockchain_switching(disconnected_chain, split_height);
        return false;
      }
    }
  }

  //removing all_chain entries from alternative chain
  BOOST_FOREACH(auto ch_ent, alt_chain)
  {
    m_alternative_chains.erase(ch_ent);
  }

  LOG_PRINT_GREEN("REORGANIZE SUCCESS! on height: " << split_height << ", new blockchain size: " << m_blocks.size(), LOG_LEVEL_0);
  return true;
}
//------------------------------------------------------------------
difficulty_type blockchain_storage::get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei)
{
  std::vector<uint64_t> timestamps;
  std::vector<difficulty_type> commulative_difficulties;
  if(alt_chain.size()< DIFFICULTY_BLOCKS_COUNT)
  {
    CRITICAL_REGION_LOCAL(m_blockchain_lock);
    size_t main_chain_stop_offset = alt_chain.size() ? alt_chain.front()->second.height : bei.height;
    size_t main_chain_count = DIFFICULTY_BLOCKS_COUNT - std::min(static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT), alt_chain.size());
    main_chain_count = std::min(main_chain_count, main_chain_stop_offset);
    size_t main_chain_start_offset = main_chain_stop_offset - main_chain_count;

    if(!main_chain_start_offset)
      ++main_chain_start_offset; //skip genesis block
    for(; main_chain_start_offset < main_chain_stop_offset; ++main_chain_start_offset)
    {
      timestamps.push_back(m_blocks[main_chain_start_offset].bl.timestamp);
      commulative_difficulties.push_back(m_blocks[main_chain_start_offset].cumulative_difficulty);
    }

    CHECK_AND_ASSERT_MES((alt_chain.size() + timestamps.size()) <= DIFFICULTY_BLOCKS_COUNT, false, "Internal error, alt_chain.size()["<< alt_chain.size()
                                                                                    << "] + vtimestampsec.size()[" << timestamps.size() << "] NOT <= DIFFICULTY_WINDOW[]" << DIFFICULTY_BLOCKS_COUNT );
    BOOST_FOREACH(auto it, alt_chain)
    {
      timestamps.push_back(it->second.bl.timestamp);
      commulative_difficulties.push_back(it->second.cumulative_difficulty);
    }
  }else
  {
    timestamps.resize(std::min(alt_chain.size(), static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT)));
    commulative_difficulties.resize(std::min(alt_chain.size(), static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT)));
    size_t count = 0;
    size_t max_i = timestamps.size()-1;
    BOOST_REVERSE_FOREACH(auto it, alt_chain)
    {
      timestamps[max_i - count] = it->second.bl.timestamp;
      commulative_difficulties[max_i - count] = it->second.cumulative_difficulty;
      count++;
      if(count >= DIFFICULTY_BLOCKS_COUNT)
        break;
    }
  }
  return next_difficulty(timestamps, commulative_difficulties);
}
//------------------------------------------------------------------
bool blockchain_storage::prevalidate_miner_transaction(const block& b, uint64_t height)
{
  CHECK_AND_ASSERT_MES(b.miner_tx.vin.size() == 1, false, "coinbase transaction in the block has no inputs");
  CHECK_AND_ASSERT_MES(b.miner_tx.vin[0].type() == typeid(txin_gen), false, "coinbase transaction in the block has the wrong type");
  if(boost::get<txin_gen>(b.miner_tx.vin[0]).height != height)
  {
    LOG_PRINT_RED_L1("The miner transaction in block has invalid height: " << boost::get<txin_gen>(b.miner_tx.vin[0]).height << ", expected: " << height);
    return false;
  }
  CHECK_AND_ASSERT_MES(b.miner_tx.unlock_time == height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW,
                  false,
                  "coinbase transaction transaction has the wrong unlock time=" << b.miner_tx.unlock_time << ", expected " << height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW);

  //check outs overflow
  if(!check_outs_overflow(b.miner_tx))
  {
    LOG_PRINT_RED_L1("miner transaction has money overflow in block " << get_block_hash(b));
    return false;
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins)
{
  //validate reward
  uint64_t money_in_use = 0;
  BOOST_FOREACH(auto& o, b.miner_tx.vout)
    money_in_use += o.amount;

  std::vector<size_t> last_blocks_sizes;
  get_last_n_blocks_sizes(last_blocks_sizes, CRYPTONOTE_REWARD_BLOCKS_WINDOW);
  if (!get_block_reward(epee::misc_utils::median(last_blocks_sizes), cumulative_block_size, already_generated_coins, base_reward)) {
    LOG_PRINT_L1("block size " << cumulative_block_size << " is bigger than allowed for this blockchain");
    return false;
  }
  if(base_reward + fee < money_in_use)
  {
    LOG_PRINT_L1("coinbase transaction spend too much money (" << print_money(money_in_use) << "). Block reward is " << print_money(base_reward + fee) << "(" << print_money(base_reward) << "+" << print_money(fee) << ")");
    return false;
  }
  if(base_reward + fee != money_in_use)
  {
    LOG_PRINT_L1("coinbase transaction doesn't use full amount of block reward:  spent: "
                            << print_money(money_in_use) << ",  block reward " << print_money(base_reward + fee) << "(" << print_money(base_reward) << "+" << print_money(fee) << ")");
    return false;
  }
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_backward_blocks_sizes(size_t from_height, std::vector<size_t>& sz, size_t count)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  CHECK_AND_ASSERT_MES(from_height < m_blocks.size(), false, "Internal error: get_backward_blocks_sizes called with from_height=" << from_height << ", blockchain height = " << m_blocks.size());

  size_t start_offset = (from_height+1) - std::min((from_height+1), count);
  for(size_t i = start_offset; i != from_height+1; i++)
    sz.push_back(m_blocks[i].block_cumulative_size);

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(!m_blocks.size())
    return true;
  return get_backward_blocks_sizes(m_blocks.size() -1, sz, count);
}
//------------------------------------------------------------------
uint64_t blockchain_storage::get_current_comulative_blocksize_limit()
{
  return m_current_block_cumul_sz_limit;
}
//------------------------------------------------------------------
bool blockchain_storage::create_block_template(block& b, const account_public_address& miner_address, difficulty_type& diffic, uint64_t& height, const blobdata& ex_nonce)
{
  size_t median_size;
  uint64_t already_generated_coins;

  CRITICAL_REGION_BEGIN(m_blockchain_lock);
  b.major_version = CURRENT_BLOCK_MAJOR_VERSION;
  b.minor_version = CURRENT_BLOCK_MINOR_VERSION;
  b.prev_id = get_tail_id();
  b.timestamp = time(NULL);
  height = m_blocks.size();
  diffic = get_difficulty_for_next_block();
  CHECK_AND_ASSERT_MES(diffic, false, "difficulty owverhead.");

  median_size = m_current_block_cumul_sz_limit / 2;
  already_generated_coins = m_blocks.back().already_generated_coins;

  CRITICAL_REGION_END();

  size_t txs_size;
  uint64_t fee;
  if (!m_tx_pool.fill_block_template(b, median_size, already_generated_coins, txs_size, fee)) {
    return false;
  }
#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
  size_t real_txs_size = 0;
  uint64_t real_fee = 0;
  CRITICAL_REGION_BEGIN(m_tx_pool.m_transactions_lock);
  BOOST_FOREACH(crypto::hash &cur_hash, b.tx_hashes) {
    auto cur_res = m_tx_pool.m_transactions.find(cur_hash);
    if (cur_res == m_tx_pool.m_transactions.end()) {
      LOG_ERROR("Creating block template: error: transaction not found");
      continue;
    }
    tx_memory_pool::tx_details &cur_tx = cur_res->second;
    real_txs_size += cur_tx.blob_size;
    real_fee += cur_tx.fee;
    if (cur_tx.blob_size != get_object_blobsize(cur_tx.tx)) {
      LOG_ERROR("Creating block template: error: invalid transaction size");
    }
    uint64_t inputs_amount;
    if (!get_inputs_money_amount(cur_tx.tx, inputs_amount)) {
      LOG_ERROR("Creating block template: error: cannot get inputs amount");
    } else if (cur_tx.fee != inputs_amount - get_outs_money_amount(cur_tx.tx)) {
      LOG_ERROR("Creating block template: error: invalid fee");
    }
  }
  if (txs_size != real_txs_size) {
    LOG_ERROR("Creating block template: error: wrongly calculated transaction size");
  }
  if (fee != real_fee) {
    LOG_ERROR("Creating block template: error: wrongly calculated fee");
  }
  CRITICAL_REGION_END();
  LOG_PRINT_L1("Creating block template: height " << height <<
    ", median size " << median_size <<
    ", already generated coins " << already_generated_coins <<
    ", transaction size " << txs_size <<
    ", fee " << fee);
#endif

  /*
     two-phase miner transaction generation: we don't know exact block size until we prepare block, but we don't know reward until we know
     block size, so first miner transaction generated with fake amount of money, and with phase we know think we know expected block size
  */
  //make blocks coin-base tx looks close to real coinbase tx to get truthful blob size
  bool r = construct_miner_tx(height, median_size, already_generated_coins, txs_size, fee, miner_address, b.miner_tx, ex_nonce, 11);
  CHECK_AND_ASSERT_MES(r, false, "Failed to construc miner tx, first chance");
  size_t cumulative_size = txs_size + get_object_blobsize(b.miner_tx);
#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
  LOG_PRINT_L1("Creating block template: miner tx size " << get_object_blobsize(b.miner_tx) <<
    ", cumulative size " << cumulative_size);
#endif
  for (size_t try_count = 0; try_count != 10; ++try_count) {
    r = construct_miner_tx(height, median_size, already_generated_coins, cumulative_size, fee, miner_address, b.miner_tx, ex_nonce, 11);

    CHECK_AND_ASSERT_MES(r, false, "Failed to construc miner tx, second chance");
    size_t coinbase_blob_size = get_object_blobsize(b.miner_tx);
    if (coinbase_blob_size > cumulative_size - txs_size) {
      cumulative_size = txs_size + coinbase_blob_size;
#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
      LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
        ", cumulative size " << cumulative_size << " is greater then before");
#endif
      continue;
    }

    if (coinbase_blob_size < cumulative_size - txs_size) {
      size_t delta = cumulative_size - txs_size - coinbase_blob_size;
#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
      LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
        ", cumulative size " << txs_size + coinbase_blob_size <<
        " is less then before, adding " << delta << " zero bytes");
#endif
      b.miner_tx.extra.insert(b.miner_tx.extra.end(), delta, 0);
      //here  could be 1 byte difference, because of extra field counter is varint, and it can become from 1-byte len to 2-bytes len.
      if (cumulative_size != txs_size + get_object_blobsize(b.miner_tx)) {
        CHECK_AND_ASSERT_MES(cumulative_size + 1 == txs_size + get_object_blobsize(b.miner_tx), false, "unexpected case: cumulative_size=" << cumulative_size << " + 1 is not equal txs_cumulative_size=" << txs_size << " + get_object_blobsize(b.miner_tx)=" << get_object_blobsize(b.miner_tx));
        b.miner_tx.extra.resize(b.miner_tx.extra.size() - 1);
        if (cumulative_size != txs_size + get_object_blobsize(b.miner_tx)) {
          //fuck, not lucky, -1 makes varint-counter size smaller, in that case we continue to grow with cumulative_size
          LOG_PRINT_RED("Miner tx creation has no luck with delta_extra size = " << delta << " and " << delta - 1 , LOG_LEVEL_2);
          cumulative_size += delta - 1;
          continue;
        }
        LOG_PRINT_GREEN("Setting extra for block: " << b.miner_tx.extra.size() << ", try_count=" << try_count, LOG_LEVEL_1);
      }
    }
    CHECK_AND_ASSERT_MES(cumulative_size == txs_size + get_object_blobsize(b.miner_tx), false, "unexpected case: cumulative_size=" << cumulative_size << " is not equal txs_cumulative_size=" << txs_size << " + get_object_blobsize(b.miner_tx)=" << get_object_blobsize(b.miner_tx));
#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
    LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
      ", cumulative size " << cumulative_size << " is now good");
#endif
    return true;
  }
  LOG_ERROR("Failed to create_block_template with " << 10 << " tries");
  return false;
}
//------------------------------------------------------------------
bool blockchain_storage::complete_timestamps_vector(uint64_t start_top_height, std::vector<uint64_t>& timestamps)
{

  if(timestamps.size() >= BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW)
    return true;

  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  size_t need_elements = BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW - timestamps.size();
  CHECK_AND_ASSERT_MES(start_top_height < m_blocks.size(), false, "internal error: passed start_height = " << start_top_height << " not less then m_blocks.size()=" << m_blocks.size());
  size_t stop_offset = start_top_height > need_elements ? start_top_height - need_elements:0;
  do
  {
    timestamps.push_back(m_blocks[start_top_height].bl.timestamp);
    if(start_top_height == 0)
      break;
    --start_top_height;
  }while(start_top_height != stop_offset);
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::handle_alternative_block(const block& b, const crypto::hash& id, block_verification_context& bvc)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  uint64_t block_height = get_block_height(b);
  if(0 == block_height)
  {
    LOG_PRINT_L1("Block with id: " << epee::string_tools::pod_to_hex(id) << " (as alternative) has wrong miner transaction");
    bvc.m_verifivation_failed = true;
    return false;
  }
  if (!m_checkpoints.is_alternative_block_allowed(get_current_blockchain_height(), block_height))
  {
    LOG_PRINT_RED_L1("Block with id: " << id
      << ENDL << " can't be accepted for alternative chain, block height: " << block_height
      << ENDL << " blockchain height: " << get_current_blockchain_height());
    bvc.m_verifivation_failed = true;
    return false;
  }

  //Block is not related with head of main chain
  //first of all - look in alternative chains container
  auto it_main_prev = m_blocks_index.find(b.prev_id);
  auto it_prev = m_alternative_chains.find(b.prev_id);
  if(it_prev != m_alternative_chains.end() || it_main_prev != m_blocks_index.end())
  {
    //we have new block in alternative chain

    //build alternative subchain, front -> mainchain, back -> alternative head
    blocks_ext_by_hash::iterator alt_it = it_prev; //m_alternative_chains.find()
    std::list<blocks_ext_by_hash::iterator> alt_chain;
    std::vector<uint64_t> timestamps;
    while(alt_it != m_alternative_chains.end())
    {
      alt_chain.push_front(alt_it);
      timestamps.push_back(alt_it->second.bl.timestamp);
      alt_it = m_alternative_chains.find(alt_it->second.bl.prev_id);
    }

    if(alt_chain.size())
    {
      //make sure that it has right connection to main chain
      CHECK_AND_ASSERT_MES(m_blocks.size() > alt_chain.front()->second.height, false, "main blockchain wrong height");
      crypto::hash h = null_hash;
      get_block_hash(m_blocks[alt_chain.front()->second.height - 1].bl, h);
      CHECK_AND_ASSERT_MES(h == alt_chain.front()->second.bl.prev_id, false, "alternative chain has wrong connection to main chain");
      complete_timestamps_vector(alt_chain.front()->second.height - 1, timestamps);
    }else
    {
      CHECK_AND_ASSERT_MES(it_main_prev != m_blocks_index.end(), false, "internal error: broken imperative condition it_main_prev != m_blocks_index.end()");
      complete_timestamps_vector(it_main_prev->second, timestamps);
    }
    //check timestamp correct
    if(!check_block_timestamp(timestamps, b))
    {
      LOG_PRINT_RED_L1("Block with id: " << id
        << ENDL << " for alternative chain, has invalid timestamp: " << b.timestamp);
      //add_block_as_invalid(b, id);//do not add blocks to invalid storage before proof of work check was passed
      bvc.m_verifivation_failed = true;
      return false;
    }

    block_extended_info bei = boost::value_initialized<block_extended_info>();
    bei.bl = b;
    bei.height = alt_chain.size() ? it_prev->second.height + 1 : it_main_prev->second + 1;

    bool is_a_checkpoint;
    if(!m_checkpoints.check_block(bei.height, id, is_a_checkpoint))
    {
      LOG_ERROR("CHECKPOINT VALIDATION FAILED");
      bvc.m_verifivation_failed = true;
      return false;
    }

    // Always check PoW for alternative blocks
    m_is_in_checkpoint_zone = false;
    difficulty_type current_diff = get_next_difficulty_for_alternative_chain(alt_chain, bei);
    CHECK_AND_ASSERT_MES(current_diff, false, "!!!!!!! DIFFICULTY OVERHEAD !!!!!!!");
    crypto::hash proof_of_work = null_hash;
    get_block_longhash(bei.bl, proof_of_work, bei.height);
    if(!check_hash(proof_of_work, current_diff))
    {
      LOG_PRINT_RED_L1("Block with id: " << id
        << ENDL << " for alternative chain, does not have enough proof of work: " << proof_of_work
        << ENDL << " expected difficulty: " << current_diff);
      bvc.m_verifivation_failed = true;
      return false;
    }

    if(!prevalidate_miner_transaction(b, bei.height))
    {
      LOG_PRINT_RED_L1("Block with id: " << epee::string_tools::pod_to_hex(id)
        << " (as alternative) has incorrect miner transaction.");
      bvc.m_verifivation_failed = true;
      return false;

    }

    bei.cumulative_difficulty = alt_chain.size() ? it_prev->second.cumulative_difficulty: m_blocks[it_main_prev->second].cumulative_difficulty;
    bei.cumulative_difficulty += current_diff;

#ifdef _DEBUG
    auto i_dres = m_alternative_chains.find(id);
    CHECK_AND_ASSERT_MES(i_dres == m_alternative_chains.end(), false, "insertion of new alternative block returned as it already exist");
#endif
    auto i_res = m_alternative_chains.insert(blocks_ext_by_hash::value_type(id, bei));
    CHECK_AND_ASSERT_MES(i_res.second, false, "insertion of new alternative block returned as it already exist");
    alt_chain.push_back(i_res.first);

    if(is_a_checkpoint)
    {
      //do reorganize!
      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_blocks.size() - 1 <<
        ", checkpoint is found in alternative chain on height " << bei.height, LOG_LEVEL_0);
      bool r = switch_to_alternative_blockchain(alt_chain, true);
      if(r) bvc.m_added_to_main_chain = true;
      else bvc.m_verifivation_failed = true;
      return r;
    }else if(m_blocks.back().cumulative_difficulty < bei.cumulative_difficulty) //check if difficulty bigger then in main chain
    {
      //do reorganize!
      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_blocks.size() - 1 << " with cum_difficulty " << m_blocks.back().cumulative_difficulty
        << ENDL << " alternative blockchain size: " << alt_chain.size() << " with cum_difficulty " << bei.cumulative_difficulty, LOG_LEVEL_0);
      bool r = switch_to_alternative_blockchain(alt_chain, false);
      if(r) bvc.m_added_to_main_chain = true;
      else bvc.m_verifivation_failed = true;
      return r;
    }else
    {
      LOG_PRINT_BLUE("----- BLOCK ADDED AS ALTERNATIVE ON HEIGHT " << bei.height
        << ENDL << "id:\t" << id
        << ENDL << "PoW:\t" << proof_of_work
        << ENDL << "difficulty:\t" << current_diff, LOG_LEVEL_0);
      return true;
    }
  }else
  {
    //block orphaned
    bvc.m_marked_as_orphaned = true;
    LOG_PRINT_RED_L1("Block recognized as orphaned and rejected, id = " << id);
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(start_offset >= m_blocks.size())
    return false;
  for(size_t i = start_offset; i < start_offset + count && i < m_blocks.size();i++)
  {
    blocks.push_back(m_blocks[i].bl);
    std::list<crypto::hash> missed_ids;
    get_transactions(m_blocks[i].bl.tx_hashes, txs, missed_ids);
    CHECK_AND_ASSERT_MES(!missed_ids.size(), false, "has missed transactions in own block in main blockchain");
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(start_offset >= m_blocks.size())
    return false;

  for(size_t i = start_offset; i < start_offset + count && i < m_blocks.size();i++)
    blocks.push_back(m_blocks[i].bl);
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request& arg, NOTIFY_RESPONSE_GET_OBJECTS::request& rsp)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  rsp.current_blockchain_height = get_current_blockchain_height();
  std::list<block> blocks;
  get_blocks(arg.blocks, blocks, rsp.missed_ids);

  BOOST_FOREACH(const auto& bl, blocks)
  {
    std::list<crypto::hash> missed_tx_id;
    std::list<transaction> txs;
    get_transactions(bl.tx_hashes, txs, rsp.missed_ids);
    CHECK_AND_ASSERT_MES(!missed_tx_id.size(), false, "Internal error: has missed missed_tx_id.size()=" << missed_tx_id.size()
      << ENDL << "for block id = " << get_block_hash(bl));
   rsp.blocks.push_back(block_complete_entry());
   block_complete_entry& e = rsp.blocks.back();
   //pack block
   e.block = t_serializable_object_to_blob(bl);
   //pack transactions
   BOOST_FOREACH(transaction& tx, txs)
     e.txs.push_back(t_serializable_object_to_blob(tx));

  }
  //get another transactions, if need
  std::list<transaction> txs;
  get_transactions(arg.txs, txs, rsp.missed_ids);
  //pack aside transactions
  BOOST_FOREACH(const auto& tx, txs)
    rsp.txs.push_back(t_serializable_object_to_blob(tx));

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_alternative_blocks(std::list<block>& blocks)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  BOOST_FOREACH(const auto& alt_bl, m_alternative_chains)
  {
    blocks.push_back(alt_bl.second.bl);
  }
  return true;
}
//------------------------------------------------------------------
size_t blockchain_storage::get_alternative_blocks_count()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  return m_alternative_chains.size();
}
//------------------------------------------------------------------
bool blockchain_storage::add_out_to_get_random_outs(std::vector<std::pair<crypto::hash, size_t> >& amount_outs, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  transactions_container::iterator tx_it = m_transactions.find(amount_outs[i].first);
  CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "internal error: transaction with id " << amount_outs[i].first << ENDL <<
    ", used in mounts global index for amount=" << amount << ": i=" << i << "not found in transactions index");
  CHECK_AND_ASSERT_MES(tx_it->second.tx.vout.size() > amount_outs[i].second, false, "internal error: in global outs index, transaction out index="
    << amount_outs[i].second << " more than transaction outputs = " << tx_it->second.tx.vout.size() << ", for tx id = " << amount_outs[i].first);
  transaction& tx = tx_it->second.tx;
  CHECK_AND_ASSERT_MES(tx.vout[amount_outs[i].second].target.type() == typeid(txout_to_key), false, "unknown tx out type");

  //check if transaction is unlocked
  if(!is_tx_spendtime_unlocked(tx.unlock_time))
    return false;

  COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::out_entry& oen = *result_outs.outs.insert(result_outs.outs.end(), COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::out_entry());
  oen.global_amount_index = i;
  oen.out_key = boost::get<txout_to_key>(tx.vout[amount_outs[i].second].target).key;
  return true;
}
//------------------------------------------------------------------
size_t blockchain_storage::find_end_of_allowed_index(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(!amount_outs.size())
    return 0;
  size_t i = amount_outs.size();
  do
  {
    --i;
    transactions_container::iterator it = m_transactions.find(amount_outs[i].first);
    CHECK_AND_ASSERT_MES(it != m_transactions.end(), 0, "internal error: failed to find transaction from outputs index with tx_id=" << amount_outs[i].first);
    if(it->second.m_keeper_block_height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW <= get_current_blockchain_height() )
      return i+1;
  } while (i != 0);
  return 0;
}
//------------------------------------------------------------------
bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  BOOST_FOREACH(uint64_t amount, req.amounts)
  {
    COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs = *res.outs.insert(res.outs.end(), COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount());
    result_outs.amount = amount;
    auto it = m_outputs.find(amount);
    if(it == m_outputs.end())
    {
      LOG_PRINT_L1("COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS: not outs for amount " << amount << ", wallet should use some real outs when it lookup for some mix, so, at least one out for this amount should exist");
      continue;//actually this is strange situation, wallet should use some real outs when it lookup for some mix, so, at least one out for this amount should exist
    }
    std::vector<std::pair<crypto::hash, size_t> >& amount_outs  = it->second;
    //it is not good idea to use top fresh outs, because it increases possibility of transaction canceling on split
    //lets find upper bound of not fresh outs
    size_t up_index_limit = find_end_of_allowed_index(amount_outs);
    CHECK_AND_ASSERT_MES(up_index_limit <= amount_outs.size(), false, "internal error: find_end_of_allowed_index returned wrong index=" << up_index_limit << ", with amount_outs.size = " << amount_outs.size());
    if(amount_outs.size() > req.outs_count)
    {
      std::set<size_t> used;
      size_t try_count = 0;
      for(uint64_t j = 0; j != req.outs_count && try_count < up_index_limit;)
      {
        size_t i = crypto::rand<size_t>()%up_index_limit;
        if(used.count(i))
          continue;
        bool added = add_out_to_get_random_outs(amount_outs, result_outs, amount, i);
        used.insert(i);
        if(added)
          ++j;
        ++try_count;
      }
    }else
    {
      for(size_t i = 0; i != up_index_limit; i++)
        add_out_to_get_random_outs(amount_outs, result_outs, amount, i);
    }
  }
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  if(!qblock_ids.size() /*|| !req.m_total_height*/)
  {
    LOG_PRINT_L1("Client sent wrong NOTIFY_REQUEST_CHAIN: m_block_ids.size()=" << qblock_ids.size() << /*", m_height=" << req.m_total_height <<*/ ", dropping connection");
    return false;
  }
  //check genesis match
  if(qblock_ids.back() != get_block_hash(m_blocks[0].bl))
  {
    LOG_PRINT_L1("Client sent wrong NOTIFY_REQUEST_CHAIN: genesis block missmatch: " << ENDL << "id: "
      << qblock_ids.back() << ", " << ENDL << "expected: " << get_block_hash(m_blocks[0].bl)
      << "," << ENDL << " dropping connection");
    return false;
  }

  /* Figure out what blocks we should request to get state_normal */
  size_t i = 0;
  auto bl_it = qblock_ids.begin();
  auto block_index_it = m_blocks_index.find(*bl_it);
  for(; bl_it != qblock_ids.end(); bl_it++, i++)
  {
    block_index_it = m_blocks_index.find(*bl_it);
    if(block_index_it != m_blocks_index.end())
      break;
  }

  if(bl_it == qblock_ids.end())
  {
    LOG_PRINT_L1("Internal error handling connection, can't find split point");
    return false;
  }

  if(block_index_it == m_blocks_index.end())
  {
    //this should NEVER happen, but, dose of paranoia in such cases is not too bad
    LOG_PRINT_L1("Internal error handling connection, can't find split point");
    return false;
  }

  //we start to put block ids INCLUDING last known id, just to make other side be sure
  starter_offset = block_index_it->second;
  return true;
}
//------------------------------------------------------------------
uint64_t blockchain_storage::block_difficulty(size_t i)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  CHECK_AND_ASSERT_MES(i < m_blocks.size(), false, "wrong block index i = " << i << " at blockchain_storage::block_difficulty()");
  if(i == 0)
    return m_blocks[i].cumulative_difficulty;

  return m_blocks[i].cumulative_difficulty - m_blocks[i-1].cumulative_difficulty;
}
//------------------------------------------------------------------
void blockchain_storage::print_blockchain(uint64_t start_index, uint64_t end_index)
{
  std::stringstream ss;
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(start_index >=m_blocks.size())
  {
    LOG_PRINT_L1("Wrong starter index set: " << start_index << ", expected max index " << m_blocks.size()-1);
    return;
  }

  for(size_t i = start_index; i != m_blocks.size() && i != end_index; i++)
  {
    ss << "height " << i << ", timestamp " << m_blocks[i].bl.timestamp << ", cumul_dif " << m_blocks[i].cumulative_difficulty << ", cumul_size " << m_blocks[i].block_cumulative_size
      << "\nid\t\t" <<  get_block_hash(m_blocks[i].bl)
      << "\ndifficulty\t\t" << block_difficulty(i) << ", nonce " << m_blocks[i].bl.nonce << ", tx_count " << m_blocks[i].bl.tx_hashes.size() << ENDL;
  }
  LOG_PRINT_L1("Current blockchain:" << ENDL << ss.str());
  LOG_PRINT_L0("Blockchain printed with log level 1");
}
//------------------------------------------------------------------
void blockchain_storage::print_blockchain_index()
{
  std::stringstream ss;
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  BOOST_FOREACH(const blocks_by_id_index::value_type& v, m_blocks_index)
    ss << "id\t\t" <<  v.first << " height" <<  v.second << ENDL << "";

  LOG_PRINT_L0("Current blockchain index:" << ENDL << ss.str());
}
//------------------------------------------------------------------
void blockchain_storage::print_blockchain_outs(const std::string& file)
{
  std::stringstream ss;
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  BOOST_FOREACH(const outputs_container::value_type& v, m_outputs)
  {
    const std::vector<std::pair<crypto::hash, size_t> >& vals = v.second;
    if(vals.size())
    {
      ss << "amount: " <<  v.first << ENDL;
      for(size_t i = 0; i != vals.size(); i++)
        ss << "\t" << vals[i].first << ": " << vals[i].second << ENDL;
    }
  }
  if(epee::file_io_utils::save_string_to_file(file, ss.str()))
  {
    LOG_PRINT_L0("Current outputs index writen to file: " << file);
  }else
  {
    LOG_PRINT_L0("Failed to write current outputs index to file: " << file);
  }
}
//------------------------------------------------------------------
bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(!find_blockchain_supplement(qblock_ids, resp.start_height))
    return false;

  resp.total_height = get_current_blockchain_height();
  size_t count = 0;
  for(size_t i = resp.start_height; i != m_blocks.size() && count < BLOCKS_IDS_SYNCHRONIZING_DEFAULT_COUNT; i++, count++)
    resp.m_block_ids.push_back(get_block_hash(m_blocks[i].bl));
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(req_start_block > 0) {
     start_height = req_start_block; 
  } else {
    if(!find_blockchain_supplement(qblock_ids, start_height))
      return false;
  }

  total_height = get_current_blockchain_height();
  size_t count = 0;
  for(size_t i = start_height; i != m_blocks.size() && count < max_count; i++, count++)
  {
    blocks.resize(blocks.size()+1);
    blocks.back().first = m_blocks[i].bl;
    std::list<crypto::hash> mis;
    get_transactions(m_blocks[i].bl.tx_hashes, blocks.back().second, mis);
    CHECK_AND_ASSERT_MES(!mis.size(), false, "internal error, transaction from block not found");
  }
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::add_block_as_invalid(const block& bl, const crypto::hash& h)
{
  block_extended_info bei = AUTO_VAL_INIT(bei);
  bei.bl = bl;
  return add_block_as_invalid(bei, h);
}
//------------------------------------------------------------------
bool blockchain_storage::add_block_as_invalid(const block_extended_info& bei, const crypto::hash& h)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  auto i_res = m_invalid_blocks.insert(std::map<crypto::hash, block_extended_info>::value_type(h, bei));
  CHECK_AND_ASSERT_MES(i_res.second, false, "at insertion invalid by tx returned status existed");
  LOG_PRINT_L1("BLOCK ADDED AS INVALID: " << h << ENDL << ", prev_id=" << bei.bl.prev_id << ", m_invalid_blocks count=" << m_invalid_blocks.size());
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::have_block(const crypto::hash& id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(m_blocks_index.count(id))
    return true;
  if(m_alternative_chains.count(id))
    return true;
  /*if(m_orphaned_blocks.get<by_id>().count(id))
    return true;*/

  /*if(m_orphaned_by_tx.count(id))
    return true;*/
  if(m_invalid_blocks.count(id))
    return true;

  return false;
}
//------------------------------------------------------------------
bool blockchain_storage::handle_block_to_main_chain(const block& bl, block_verification_context& bvc)
{
  crypto::hash id = get_block_hash(bl);
  return handle_block_to_main_chain(bl, id, bvc);
}
//------------------------------------------------------------------
bool blockchain_storage::push_transaction_to_global_outs_index(const transaction& tx, const crypto::hash& tx_id, std::vector<uint64_t>& global_indexes)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  size_t i = 0;
  BOOST_FOREACH(const auto& ot, tx.vout)
  {
    outputs_container::mapped_type& amount_index = m_outputs[ot.amount];
    amount_index.push_back(std::pair<crypto::hash, size_t>(tx_id, i));
    global_indexes.push_back(amount_index.size()-1);
    ++i;
  }
  return true;
}
//------------------------------------------------------------------
size_t blockchain_storage::get_total_transactions()
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  return m_transactions.size();
}
//------------------------------------------------------------------
bool blockchain_storage::get_outs(uint64_t amount, std::list<crypto::public_key>& pkeys)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  auto it = m_outputs.find(amount);
  if(it == m_outputs.end())
    return true;

  BOOST_FOREACH(const auto& out_entry, it->second)
  {
    auto tx_it = m_transactions.find(out_entry.first);
    CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "transactions outs global index consistency broken: wrong tx id in index");
    CHECK_AND_ASSERT_MES(tx_it->second.tx.vout.size() > out_entry.second, false, "transactions outs global index consistency broken: index in tx_outx more then size");
    CHECK_AND_ASSERT_MES(tx_it->second.tx.vout[out_entry.second].target.type() == typeid(txout_to_key), false, "transactions outs global index consistency broken: index in tx_outx more then size");
    pkeys.push_back(boost::get<txout_to_key>(tx_it->second.tx.vout[out_entry.second].target).key);
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::pop_transaction_from_global_index(const transaction& tx, const crypto::hash& tx_id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  size_t i = tx.vout.size()-1;
  BOOST_REVERSE_FOREACH(const auto& ot, tx.vout)
  {
    auto it = m_outputs.find(ot.amount);
    CHECK_AND_ASSERT_MES(it != m_outputs.end(), false, "transactions outs global index consistency broken");
    CHECK_AND_ASSERT_MES(it->second.size(), false, "transactions outs global index: empty index for amount: " << ot.amount);
    CHECK_AND_ASSERT_MES(it->second.back().first == tx_id , false, "transactions outs global index consistency broken: tx id missmatch");
    CHECK_AND_ASSERT_MES(it->second.back().second == i, false, "transactions outs global index consistency broken: in transaction index missmatch");
    it->second.pop_back();
    --i;
  }
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::add_transaction_from_block(const transaction& tx, const crypto::hash& tx_id, const crypto::hash& bl_id, uint64_t bl_height)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  struct add_transaction_input_visitor: public boost::static_visitor<bool>
  {
    key_images_container& m_spent_keys;
    const crypto::hash& m_tx_id;
    const crypto::hash& m_bl_id;
    add_transaction_input_visitor(key_images_container& spent_keys, const crypto::hash& tx_id, const crypto::hash& bl_id):m_spent_keys(spent_keys), m_tx_id(tx_id), m_bl_id(bl_id)
    {}
    bool operator()(const txin_to_key& in) const
    {
      const crypto::key_image& ki = in.k_image;
      auto r = m_spent_keys.insert(ki);
      if(!r.second)
      {
        //double spend detected
        LOG_PRINT_L1("tx with id: " << m_tx_id << " in block id: " << m_bl_id << " has input marked as spent with key image: " << ki << ", block declined");
        return false;
      }
      return true;
    }

    bool operator()(const txin_gen& tx) const{return true;}
    bool operator()(const txin_to_script& tx) const{return false;}
    bool operator()(const txin_to_scripthash& tx) const{return false;}
  };

  BOOST_FOREACH(const txin_v& in, tx.vin)
  {
    if(!boost::apply_visitor(add_transaction_input_visitor(m_spent_keys, tx_id, bl_id), in))
    {
      LOG_PRINT_L1("critical internal error: add_transaction_input_visitor failed. but here key_images should be checked");
      purge_transaction_keyimages_from_blockchain(tx, false);
      return false;
    }
  }
  transaction_chain_entry ch_e;
  ch_e.m_keeper_block_height = bl_height;
  ch_e.tx = tx;
  auto i_r = m_transactions.insert(std::pair<crypto::hash, transaction_chain_entry>(tx_id, ch_e));
  if(!i_r.second)
  {
    LOG_PRINT_L1("tx with id: " << tx_id << " in block id: " << bl_id << " already in blockchain");
    return false;
  }
  bool r = push_transaction_to_global_outs_index(tx, tx_id, i_r.first->second.m_global_output_indexes);
  CHECK_AND_ASSERT_MES(r, false, "failed to return push_transaction_to_global_outs_index tx id " << tx_id);
  LOG_PRINT_L2("Added transaction to blockchain history:" << ENDL
    << "tx_id: " << tx_id << ENDL
    << "inputs: " << tx.vin.size() << ", outs: " << tx.vout.size() << ", spend money: " << print_money(get_outs_money_amount(tx)) << "(fee: " << (is_coinbase(tx) ? "0[coinbase]" : print_money(get_tx_fee(tx))) << ")");
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  auto it = m_transactions.find(tx_id);
  if(it == m_transactions.end())
  {
    LOG_PRINT_RED_L1("warning: get_tx_outputs_gindexs failed to find transaction with id = " << tx_id);
    return false;
  }

  CHECK_AND_ASSERT_MES(it->second.m_global_output_indexes.size(), false, "internal error: global indexes for transaction " << tx_id << " is empty");
  indexs = it->second.m_global_output_indexes;
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t& max_used_block_height, crypto::hash& max_used_block_id)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  bool res = check_tx_inputs(tx, &max_used_block_height);
  if(!res) return false;
  CHECK_AND_ASSERT_MES(max_used_block_height < m_blocks.size(), false,  "internal error: max used block index=" << max_used_block_height << " is not less then blockchain size = " << m_blocks.size());
  get_block_hash(m_blocks[max_used_block_height].bl, max_used_block_id);
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::have_tx_keyimges_as_spent(const transaction &tx)
{
  BOOST_FOREACH(const txin_v& in, tx.vin)
  {
    CHECKED_GET_SPECIFIC_VARIANT(in, const txin_to_key, in_to_key, true);
    if(have_tx_keyimg_as_spent(in_to_key.k_image))
      return true;
  }
  return false;
}
//------------------------------------------------------------------
bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height)
{
  crypto::hash tx_prefix_hash = get_transaction_prefix_hash(tx);
  return check_tx_inputs(tx, tx_prefix_hash, pmax_used_block_height);
}
//------------------------------------------------------------------
bool blockchain_storage::check_tx_inputs(const transaction& tx, const crypto::hash& tx_prefix_hash, uint64_t* pmax_used_block_height)
{
  size_t sig_index = 0;
  if(pmax_used_block_height)
    *pmax_used_block_height = 0;

  BOOST_FOREACH(const auto& txin,  tx.vin)
  {
    CHECK_AND_ASSERT_MES(txin.type() == typeid(txin_to_key), false, "wrong type id in tx input at blockchain_storage::check_tx_inputs");
    const txin_to_key& in_to_key = boost::get<txin_to_key>(txin);

    CHECK_AND_ASSERT_MES(in_to_key.key_offsets.size(), false, "empty in_to_key.key_offsets in transaction with id " << get_transaction_hash(tx));

    if(have_tx_keyimg_as_spent(in_to_key.k_image))
    {
      LOG_PRINT_L1("Key image already spent in blockchain: " << epee::string_tools::pod_to_hex(in_to_key.k_image));
      return false;
    }

    CHECK_AND_ASSERT_MES(sig_index < tx.signatures.size(), false, "wrong transaction: not signature entry for input with index= " << sig_index);
    if(!check_tx_input(in_to_key, tx_prefix_hash, tx.signatures[sig_index], pmax_used_block_height))
    {
      LOG_PRINT_L1("Failed to check ring signature for tx " << get_transaction_hash(tx));
      return false;
    }

    sig_index++;
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::is_tx_spendtime_unlocked(uint64_t unlock_time)
{
  if(unlock_time < CRYPTONOTE_MAX_BLOCK_NUMBER)
  {
    //interpret as block index
    if(get_current_blockchain_height()-1 + CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_BLOCKS >= unlock_time)
      return true;
    else
      return false;
  }else
  {
    //interpret as time
    uint64_t current_time = static_cast<uint64_t>(time(NULL));
    if(current_time + CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_SECONDS >= unlock_time)
      return true;
    else
      return false;
  }
  return false;
}
//------------------------------------------------------------------
bool blockchain_storage::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height)
{
  CRITICAL_REGION_LOCAL(m_blockchain_lock);

  struct outputs_visitor
  {
    std::vector<const crypto::public_key *>& m_results_collector;
    blockchain_storage& m_bch;
    outputs_visitor(std::vector<const crypto::public_key *>& results_collector, blockchain_storage& bch):m_results_collector(results_collector), m_bch(bch)
    {}
    bool handle_output(const transaction& tx, const tx_out& out)
    {
      //check tx unlock time
      if(!m_bch.is_tx_spendtime_unlocked(tx.unlock_time))
      {
        LOG_PRINT_L1("One of outputs for one of inputs has wrong tx.unlock_time = " << tx.unlock_time);
        return false;
      }

      if(out.target.type() != typeid(txout_to_key))
      {
        LOG_PRINT_L1("Output has wrong type id, which=" << out.target.which());
        return false;
      }

      m_results_collector.push_back(&boost::get<txout_to_key>(out.target).key);
      return true;
    }
  };

  //check ring signature
  std::vector<const crypto::public_key *> output_keys;
  outputs_visitor vi(output_keys, *this);
  if(!scan_outputkeys_for_indexes(txin, vi, pmax_related_block_height))
  {
    LOG_PRINT_L1("Failed to get output keys for tx with amount = " << print_money(txin.amount) << " and count indexes " << txin.key_offsets.size());
    return false;
  }

  if(txin.key_offsets.size() != output_keys.size())
  {
    LOG_PRINT_L1("Output keys for tx with amount = " << txin.amount << " and count indexes " << txin.key_offsets.size() << " returned wrong keys count " << output_keys.size());
    return false;
  }
  CHECK_AND_ASSERT_MES(sig.size() == output_keys.size(), false, "internal error: tx signatures count=" << sig.size() << " mismatch with outputs keys count for inputs=" << output_keys.size());
  if(m_is_in_checkpoint_zone)
    return true;
  return crypto::check_ring_signature(tx_prefix_hash, txin.k_image, output_keys, sig.data());
}
//------------------------------------------------------------------
uint64_t blockchain_storage::get_adjusted_time()
{
  //TODO: add collecting median time
  return time(NULL);
}
//------------------------------------------------------------------
bool blockchain_storage::check_block_timestamp_main(const block& b)
{
  if(b.timestamp > get_adjusted_time() + CRYPTONOTE_BLOCK_FUTURE_TIME_LIMIT)
  {
    LOG_PRINT_L1("Timestamp of block with id: " << get_block_hash(b) << ", " << b.timestamp << ", bigger than adjusted time + 2 hours");
    return false;
  }

  std::vector<uint64_t> timestamps;
  size_t offset = m_blocks.size() <= BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW ? 0: m_blocks.size()- BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW;
  for(;offset!= m_blocks.size(); ++offset)
    timestamps.push_back(m_blocks[offset].bl.timestamp);

  return check_block_timestamp(std::move(timestamps), b);
}
//------------------------------------------------------------------
bool blockchain_storage::check_block_timestamp(std::vector<uint64_t> timestamps, const block& b)
{
  if(timestamps.size() < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW)
    return true;

  uint64_t median_ts = epee::misc_utils::median(timestamps);

  if(b.timestamp < median_ts)
  {
    LOG_PRINT_L1("Timestamp of block with id: " << get_block_hash(b) << ", " << b.timestamp << ", less than median of last " << BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW << " blocks, " << median_ts);
    return false;
  }

  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypto::hash& id, block_verification_context& bvc)
{
  TIME_MEASURE_START(block_processing_time);
  CRITICAL_REGION_LOCAL(m_blockchain_lock);
  if(bl.prev_id != get_tail_id())
  {
    LOG_PRINT_L1("Block with id: " << id << ENDL
      << "has wrong prev_id: " << bl.prev_id << ENDL
      << "expected: " << get_tail_id());
    return false;
  }

  if(!check_block_timestamp_main(bl))
  {
    LOG_PRINT_L1("Block with id: " << id << ENDL
      << "has invalid timestamp: " << bl.timestamp);
    //add_block_as_invalid(bl, id);//do not add blocks to invalid storage befor proof of work check was passed
    bvc.m_verifivation_failed = true;
    return false;
  }

  //check proof of work
  TIME_MEASURE_START(target_calculating_time);
  difficulty_type current_diffic = get_difficulty_for_next_block();
  CHECK_AND_ASSERT_MES(current_diffic, false, "!!!!!!!!! difficulty overhead !!!!!!!!!");
  TIME_MEASURE_FINISH(target_calculating_time);
  TIME_MEASURE_START(longhash_calculating_time);
  crypto::hash proof_of_work = null_hash;

  // Formerly the code below contained an if loop with the following condition
  // !m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height())
  // however, this caused the daemon to not bother checking PoW for blocks
  // before checkpoints, which is very dangerous behaviour. We moved the PoW
  // validation out of the next chunk of code to make sure that we correctly
  // check PoW now.
  proof_of_work = get_block_longhash(bl, m_blocks.size());

  if(!check_hash(proof_of_work, current_diffic))
  {
    LOG_PRINT_L1("Block with id: " << id << ENDL
      << "does not have enough proof of work: " << proof_of_work << ENDL
      << "unexpected difficulty: " << current_diffic );
    bvc.m_verifivation_failed = true;
    return false;
  }

  // If we're at a checkpoint, ensure that our hardcoded checkpoint hash
  // is correct.
  if(m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height()))
  {
    if(!m_checkpoints.check_block(get_current_blockchain_height(), id))
    {
      LOG_ERROR("CHECKPOINT VALIDATION FAILED");
      bvc.m_verifivation_failed = true;
      return false;
    }
  }

  TIME_MEASURE_FINISH(longhash_calculating_time);

  if(!prevalidate_miner_transaction(bl, m_blocks.size()))
  {
    LOG_PRINT_L1("Block with id: " << id
      << " failed to pass prevalidation");
    bvc.m_verifivation_failed = true;
    return false;
  }
  size_t coinbase_blob_size = get_object_blobsize(bl.miner_tx);
  size_t cumulative_block_size = coinbase_blob_size;
  //process transactions
  if(!add_transaction_from_block(bl.miner_tx, get_transaction_hash(bl.miner_tx), id, get_current_blockchain_height()))
  {
    LOG_PRINT_L1("Block with id: " << id << " failed to add transaction to blockchain storage");
    bvc.m_verifivation_failed = true;
    return false;
  }
  size_t tx_processed_count = 0;
  uint64_t fee_summary = 0;
  BOOST_FOREACH(const crypto::hash& tx_id, bl.tx_hashes)
  {
    transaction tx;
    size_t blob_size = 0;
    uint64_t fee = 0;
    if(!m_tx_pool.take_tx(tx_id, tx, blob_size, fee))
    {
      LOG_PRINT_L1("Block with id: " << id  << "has at least one unknown transaction with id: " << tx_id);
      purge_block_data_from_blockchain(bl, tx_processed_count);
      //add_block_as_invalid(bl, id);
      bvc.m_verifivation_failed = true;
      return false;
    }
    if(!check_tx_inputs(tx))
    {
      LOG_PRINT_L1("Block with id: " << id  << "has at least one transaction (id: " << tx_id << ") with wrong inputs.");
      cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
      bool add_res = m_tx_pool.add_tx(tx, tvc, true);
      CHECK_AND_ASSERT_MES2(add_res, "handle_block_to_main_chain: failed to add transaction back to transaction pool");
      purge_block_data_from_blockchain(bl, tx_processed_count);
      add_block_as_invalid(bl, id);
      LOG_PRINT_L1("Block with id " << id << " added as invalid becouse of wrong inputs in transactions");
      bvc.m_verifivation_failed = true;
      return false;
    }

    if(!add_transaction_from_block(tx, tx_id, id, get_current_blockchain_height()))
    {
       LOG_PRINT_L1("Block with id: " << id << " failed to add transaction to blockchain storage");
       cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
       bool add_res = m_tx_pool.add_tx(tx, tvc, true);
       CHECK_AND_ASSERT_MES2(add_res, "handle_block_to_main_chain: failed to add transaction back to transaction pool");
       purge_block_data_from_blockchain(bl, tx_processed_count);
       bvc.m_verifivation_failed = true;
       return false;
    }
    fee_summary += fee;
    cumulative_block_size += blob_size;
    ++tx_processed_count;
  }
  uint64_t base_reward = 0;
  uint64_t already_generated_coins = m_blocks.size() ? m_blocks.back().already_generated_coins:0;
  if(!validate_miner_transaction(bl, cumulative_block_size, fee_summary, base_reward, already_generated_coins))
  {
    LOG_PRINT_L1("Block with id: " << id
      << " has incorrect miner transaction");
    purge_block_data_from_blockchain(bl, tx_processed_count);
    bvc.m_verifivation_failed = true;
    return false;
  }


  block_extended_info bei = boost::value_initialized<block_extended_info>();
  bei.bl = bl;
  bei.block_cumulative_size = cumulative_block_size;
  bei.cumulative_difficulty = current_diffic;
  bei.already_generated_coins = already_generated_coins + base_reward;
  if(m_blocks.size())
    bei.cumulative_difficulty += m_blocks.back().cumulative_difficulty;

  bei.height = m_blocks.size();

  auto ind_res = m_blocks_index.insert(std::pair<crypto::hash, size_t>(id, bei.height));
  if(!ind_res.second)
  {
    LOG_PRINT_L1("block with id: " << id << " already in block indexes");
    purge_block_data_from_blockchain(bl, tx_processed_count);
    bvc.m_verifivation_failed = true;
    return false;
  }

  m_blocks.push_back(bei);
  update_next_comulative_size_limit();
  TIME_MEASURE_FINISH(block_processing_time);
  LOG_PRINT_L1("+++++ BLOCK SUCCESSFULLY ADDED" << ENDL << "id:\t" << id
    << ENDL << "PoW:\t" << proof_of_work
    << ENDL << "HEIGHT " << bei.height << ", difficulty:\t" << current_diffic
    << ENDL << "block reward: " << print_money(fee_summary + base_reward) << "(" << print_money(base_reward) << " + " << print_money(fee_summary)
    << "), coinbase_blob_size: " << coinbase_blob_size << ", cumulative size: " << cumulative_block_size
    << ", " << block_processing_time << "("<< target_calculating_time << "/" << longhash_calculating_time << ")ms");

  bvc.m_added_to_main_chain = true;
  /*if(!m_orphanes_reorganize_in_work)
    review_orphaned_blocks_with_new_block_id(id, true);*/

  m_tx_pool.on_blockchain_inc(bei.height, id);
  //LOG_PRINT_L0("BLOCK: " << ENDL << "" << dump_obj_as_json(bei.bl));
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::update_next_comulative_size_limit()
{
  std::vector<size_t> sz;
  get_last_n_blocks_sizes(sz, CRYPTONOTE_REWARD_BLOCKS_WINDOW);

  uint64_t median = epee::misc_utils::median(sz);
  if(median <= CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE)
    median = CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE;

  m_current_block_cumul_sz_limit = median*2;
  return true;
}
//------------------------------------------------------------------
bool blockchain_storage::add_new_block(const block& bl_, block_verification_context& bvc)
{
  //copy block here to let modify block.target
  block bl = bl_;
  crypto::hash id = get_block_hash(bl);
  CRITICAL_REGION_LOCAL(m_tx_pool);//to avoid deadlock lets lock tx_pool for whole add/reorganize process
  CRITICAL_REGION_LOCAL1(m_blockchain_lock);
  if(have_block(id))
  {
    LOG_PRINT_L3("block with id = " << id << " already exists");
    bvc.m_already_exists = true;
    return false;
  }

  //check that block refers to chain tail
  if(!(bl.prev_id == get_tail_id()))
  {
    //chain switching or wrong block
    bvc.m_added_to_main_chain = false;
    return handle_alternative_block(bl, id, bvc);
    //never relay alternative blocks
  }

  return handle_block_to_main_chain(bl, id, bvc);
}
//------------------------------------------------------------------
void blockchain_storage::check_against_checkpoints(checkpoints& points, bool enforce)
{
  const auto& pts = points.get_points();

  for (const auto& pt : pts)
  {
    // if the checkpoint is for a block we don't have yet, move on
    if (pt.first >= m_blocks.size())
    {
      continue;
    }

    if (!points.check_block(pt.first, get_block_hash(m_blocks[pt.first].bl)))
    {
      // if asked to enforce checkpoints, roll back to a couple of blocks before the checkpoint
      if (enforce)
      {
	LOG_ERROR("Local blockchain failed to pass a checkpoint, rolling back!");
	std::list<block> empty;
	rollback_blockchain_switching(empty, pt.first - 2);
      }
      else
      {
	LOG_ERROR("WARNING: local blockchain failed to pass a MoneroPulse checkpoint, and you could be on a fork. You should either sync up from scratch, OR download a fresh blockchain bootstrap, OR enable checkpoint enforcing with the --enforce-dns-checkpointing command-line option");
      }
    }
  }
}
//------------------------------------------------------------------
// returns false if any of the checkpoints loading returns false.
// That should happen only if a checkpoint is added that conflicts
// with an existing checkpoint.
bool blockchain_storage::update_checkpoints(const std::string& file_path, bool check_dns)
{
  if (!cryptonote::load_checkpoints_from_json(m_checkpoints, file_path))
  {
    return false;
  }

  // if we're checking both dns and json, load checkpoints from dns.
  // if we're not hard-enforcing dns checkpoints, handle accordingly
  if (m_enforce_dns_checkpoints && check_dns)
  {
    if (!cryptonote::load_checkpoints_from_dns(m_checkpoints))
    {
      return false;
    }
  }
  else if (check_dns)
  {
    checkpoints dns_points;
    cryptonote::load_checkpoints_from_dns(dns_points, m_testnet);
    if (m_checkpoints.check_for_conflicts(dns_points))
    {
      check_against_checkpoints(dns_points, false);
    }
    else
    {
      LOG_PRINT_L0("One or more checkpoints fetched from DNS conflicted with existing checkpoints!");
    }
  }

  check_against_checkpoints(m_checkpoints, true);

  return true;
}
//------------------------------------------------------------------
void blockchain_storage::set_enforce_dns_checkpoints(bool enforce_checkpoints)
{
  m_enforce_dns_checkpoints = enforce_checkpoints;
}