EthashAux.h

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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/>.
*/
#pragma once

#include <condition_variable>
#include <libethash/ethash.h>
#include <libdevcore/Log.h>
#include <libdevcore/Worker.h>
#include "EthashProofOfWork.h"
#include "Ethash.h"

namespace dev
{
namespace eth
{

struct DAGChannel: public LogChannel { static const char* name(); static const int verbosity = 1; };

class BlockHeader;

class EthashAux
{
public:
        ~EthashAux();

        static EthashAux* get();

        struct LightAllocation
        {
                LightAllocation(h256 const& _seedHash);
                ~LightAllocation();
                bytesConstRef data() const;
                EthashProofOfWork::Result compute(h256 const& _headerHash, Nonce const& _nonce) const;
                ethash_light_t light;
                uint64_t size;
        };

        struct FullAllocation
        {
                FullAllocation(ethash_light_t _light, ethash_callback_t _cb);
                ~FullAllocation();
                EthashProofOfWork::Result compute(h256 const& _headerHash, Nonce const& _nonce) const;
                bytesConstRef data() const;
                uint64_t size() const { return ethash_full_dag_size(full); }
                ethash_full_t full;
        };

        using LightType = std::shared_ptr<LightAllocation>;
        using FullType = std::shared_ptr<FullAllocation>;

        static h256 seedHash(unsigned _number);
        static uint64_t number(h256 const& _seedHash);
        static uint64_t cacheSize(BlockHeader const& _header);
        static uint64_t dataSize(uint64_t _blockNumber);

        static LightType light(h256 const& _seedHash);

        static const uint64_t NotGenerating = (uint64_t)-1;
        static unsigned computeFull(h256 const& _seedHash, bool _createIfMissing = true);
        static std::pair<uint64_t, unsigned> fullGeneratingProgress() { return std::make_pair(get()->m_generatingFullNumber, get()->m_fullProgress); }
        static FullType full(h256 const& _seedHash, bool _createIfMissing = false, std::function<int(unsigned)> const& _f = std::function<int(unsigned)>());

        static EthashProofOfWork::Result eval(h256 const& _seedHash, h256 const& _headerHash, Nonce const& _nonce);

private:
        EthashAux() {}


        void killCache(h256 const& _s);

        static EthashAux* s_this;

        SharedMutex x_lights;
        std::unordered_map<h256, std::shared_ptr<LightAllocation>> m_lights;

        Mutex x_fulls;
        std::condition_variable m_fullsChanged;
        std::unordered_map<h256, std::weak_ptr<FullAllocation>> m_fulls;
        FullType m_lastUsedFull;
        std::unique_ptr<std::thread> m_fullGenerator;
        uint64_t m_generatingFullNumber = NotGenerating;
        unsigned m_fullProgress;

        Mutex x_epochs;
        std::unordered_map<h256, unsigned> m_epochs;
        h256s m_seedHashes;
};

}
}