onion-wownero-blockchain-explorer/src/MicroCore.cpp

//
// Created by mwo on 5/11/15.
//

#include "MicroCore.h"


namespace xmreg
{
/**
 * The constructor is interesting, as
 * m_mempool and m_blockchain_storage depend
 * on each other.
 *
 * So basically m_mempool is initialized with
 * reference to Blockchain (i.e., Blockchain&)
 * and m_blockchain_storage is initialized with
 * reference to m_mempool (i.e., tx_memory_pool&)
 *
 * The same is done in cryptonode::core.
 */
MicroCore::MicroCore():
        m_mempool(m_blockchain_storage),
        m_blockchain_storage(m_mempool)
{
    m_device = &hw::get_device("default");
}


/**
 * Initialized the MicroCore object.
 *
 * Create BlockchainLMDB on the heap.
 * Open database files located in blockchain_path.
 * Initialize m_blockchain_storage with the BlockchainLMDB object.
 */
bool
MicroCore::init(const string& _blockchain_path, network_type nt)
{
    int db_flags = 0;

    blockchain_path = _blockchain_path;

    nettype = nt;

    db_flags |= MDB_RDONLY;
    db_flags |= MDB_NOLOCK;

    BlockchainDB* db = nullptr;
    db = new BlockchainLMDB();

    try
    {
        // try opening lmdb database files
        db->open(blockchain_path, db_flags);
    }
    catch (const std::exception& e)
    {
        cerr << "Error opening database: " << e.what();
        return false;
    }

    // check if the blockchain database
    // is successful opened
    if(!db->is_open())
        return false;

    // initialize Blockchain object to manage
    // the database.
    return m_blockchain_storage.init(db, nettype);
}

/**
* Get m_blockchain_storage.
* Initialize m_blockchain_storage with the BlockchainLMDB object.
*/
Blockchain&
MicroCore::get_core()
{
    return m_blockchain_storage;
}

tx_memory_pool&
MicroCore::get_mempool()
{
    return m_mempool;
}

/**
 * Get block by its height
 *
 * returns true if success
 */
bool
MicroCore::get_block_by_height(const uint64_t& height, block& blk)
{
    try
    {
        blk = m_blockchain_storage.get_db().get_block_from_height(height);
    }
    catch (const BLOCK_DNE& e)
    {
        cerr << "Block of height " << height
             << " not found in the blockchain!"
             << e.what()
             << endl;

        return false;
    }
    catch (const DB_ERROR& e)
    {
        cerr << "Blockchain access error when getting block " << height
             << e.what()
             << endl;

        return false;
    }
    catch (...)
    {
        cerr << "Something went terribly wrong when getting block " << height
             << endl;

        return false;
    }

    return true;
}



/**
 * Get transaction tx from the blockchain using it hash
 */
bool
MicroCore::get_tx(const crypto::hash& tx_hash, transaction& tx)
{
    if (m_blockchain_storage.have_tx(tx_hash))
    {
        // get transaction with given hash
        try
        {
            tx = m_blockchain_storage.get_db().get_tx(tx_hash);
        }
        catch (TX_DNE const& e)
        {
            try 
            {
                // coinbase txs are not considered pruned
                tx = m_blockchain_storage.get_db().get_pruned_tx(tx_hash);
                return true;
            }
            catch (TX_DNE const& e)
            {
                cerr << "MicroCore::get_tx: " << e.what() << endl;
            }

            return false;
        }
    }
    else
    {
        cerr << "MicroCore::get_tx tx does not exist in blockchain: " << tx_hash << endl;
        return false;
    }     


    return true;
}

bool
MicroCore::get_tx(const string& tx_hash_str, transaction& tx)
{

    // parse tx hash string to hash object
    crypto::hash tx_hash;

    if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
    {
        cerr << "Cant parse tx hash: " << tx_hash_str << endl;
        return false;
    }


    if (!get_tx(tx_hash, tx))
    {
        return false;
    }


    return true;
}




/**
 * Find output with given public key in a given transaction
 */
bool
MicroCore::find_output_in_tx(const transaction& tx,
                             const public_key& output_pubkey,
                             tx_out& out,
                             size_t& output_index)
{

    size_t idx {0};


    // search in the ouputs for an output which
    // public key matches to what we want
    auto it = std::find_if(tx.vout.begin(), tx.vout.end(),
                           [&](const tx_out& o)
                           {
                               const txout_to_key& tx_in_to_key
                                       = boost::get<txout_to_key>(o.target);

                               ++idx;

                               return tx_in_to_key.key == output_pubkey;
                           });

    if (it != tx.vout.end())
    {
        // we found the desired public key
        out = *it;
        output_index = idx > 0 ? idx - 1 : idx;

        //cout << idx << " " << output_index << endl;

        return true;
    }

    return false;
}


uint64_t
MicroCore::get_blk_timestamp(uint64_t blk_height)
{
    cryptonote::block blk;

    if (!get_block_by_height(blk_height, blk))
    {
        cerr << "Cant get block by height: " << blk_height << endl;
        return 0;
    }

    return blk.timestamp;
}


/**
 * De-initialized Blockchain.
 *
 * since blockchain is opened as MDB_RDONLY
 * need to manually free memory taken on heap
 * by BlockchainLMDB
 */
MicroCore::~MicroCore()
{
    //m_blockchain_storage.get_db().close();
    delete &m_blockchain_storage.get_db();
}


bool
init_blockchain(const string& path,
                MicroCore& mcore,
                Blockchain*& core_storage,
                network_type nt)
{

    // initialize the core using the blockchain path
    if (!mcore.init(path, nt))
    {
        cerr << "Error accessing blockchain." << endl;
        return false;
    }

    // get the high level Blockchain object to interact
    // with the blockchain lmdb database
    core_storage = &(mcore.get_core());

    return true;
}


bool
MicroCore::get_block_complete_entry(block const& b, block_complete_entry& bce)
{
    bce.block = cryptonote::block_to_blob(b);

    for (const auto &tx_hash: b.tx_hashes)
    {
      transaction tx;

      if (!get_tx(tx_hash, tx))
        return false;

      cryptonote::blobdata txblob =  tx_to_blob(tx);

      bce.txs.push_back(txblob);
    }

    return true;
}


string
MicroCore::get_blkchain_path()
{
    return blockchain_path;
}

hw::device* const
MicroCore::get_device() const
{
    return m_device;
}

}