StateImporter.cpp

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/*
    This file is part of cpp-ethereum.

    cpp-ethereum is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    cpp-ethereum is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "StateImporter.h"

#include <libdevcore/OverlayDB.h>
#include <libdevcore/RLP.h>
#include <libdevcore/TrieDB.h>

namespace dev
{
namespace eth
{

namespace
{

class StateImporter: public StateImporterFace
{
public:
    explicit StateImporter(OverlayDB& _stateDb): m_trie(&_stateDb) { m_trie.init(); }

    void importAccount(h256 const& _addressHash, u256 const& _nonce, u256 const& _balance, std::map<h256, bytes> const& _storage, h256 const& _codeHash) override
    {
        RLPStream s(4);
        s << _nonce << _balance;

        h256 const storageRoot = isAccountImported(_addressHash) ? accountStorageRoot(_addressHash) : EmptyTrie;
        if (_storage.empty())
            s.append(storageRoot);
        else
        {
            SpecificTrieDB<GenericTrieDB<OverlayDB>, h256> storageDB(m_trie.db(), storageRoot);
            for (auto const& hashAndValue: _storage)
                storageDB.insert(hashAndValue.first, hashAndValue.second);

            s.append(storageDB.root());
        }

        s << _codeHash;

        m_trie.insert(_addressHash, &s.out());
    }

    h256 importCode(bytesConstRef _code) override
    {
        h256 const hash = sha3(_code);
        m_trie.db()->insert(hash, _code);
        return hash;
    }

    void commitStateDatabase() override { m_trie.db()->commit(); }

    bool isAccountImported(h256 const& _addressHash) const override { return m_trie.contains(_addressHash); }

    h256 stateRoot() const override { return m_trie.root(); }

    std::string lookupCode(h256 const& _hash) const override { return m_trie.db()->lookup(_hash); }

private:
    // can be used only with already imported accounts
    h256 accountStorageRoot(h256 const& _addressHash) const
    {
        std::string const account = m_trie.at(_addressHash);
        assert(!account.empty());
        
        RLP accountRlp(account);
        if (accountRlp.itemCount() < 3)
            BOOST_THROW_EXCEPTION(InvalidAccountInTheDatabase());

        return accountRlp[2].toHash<h256>(RLP::VeryStrict);
    }

    SpecificTrieDB<GenericTrieDB<OverlayDB>, h256> m_trie;
};

}

std::unique_ptr<StateImporterFace> createStateImporter(OverlayDB& _stateDb)
{
    return std::unique_ptr<StateImporterFace>(new StateImporter(_stateDb));
}

}
}