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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/>.
*/
/** @file Ethasher.cpp
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#include <boost/detail/endian.hpp>
#include <boost/filesystem.hpp>
#include <chrono>
#include <array>
#include <random>
#include <thread>
#include <libdevcore/Guards.h>
#include <libdevcore/Log.h>
#include <libdevcrypto/CryptoPP.h>
#include <libdevcrypto/FileSystem.h>
#include <libdevcore/Common.h>
#include <libethash/ethash.h>
#include "BlockInfo.h"
#include "Ethasher.h"
using namespace std;
using namespace chrono;
using namespace dev;
using namespace eth;
Ethasher* dev::eth::Ethasher::s_this = nullptr;
bytes const& Ethasher::cache(BlockInfo const& _header)
{
RecursiveGuard l(x_this);
if (!m_caches.count(_header.seedHash))
{
try {
boost::filesystem::create_directories(getDataDir() + "/ethashcache");
} catch (...) {}
std::string memoFile = getDataDir() + "/ethashcache/" + toHex(_header.seedHash.ref().cropped(0, 4)) + ".cache";
m_caches[_header.seedHash] = contents(memoFile);
if (m_caches[_header.seedHash].empty())
{
ethash_params p = params((unsigned)_header.number);
m_caches[_header.seedHash].resize(p.cache_size);
ethash_prep_light(m_caches[_header.seedHash].data(), &p, _header.seedHash.data());
writeFile(memoFile, m_caches[_header.seedHash]);
}
}
return m_caches[_header.seedHash];
}
bytesConstRef Ethasher::full(BlockInfo const& _header)
{
RecursiveGuard l(x_this);
if (!m_fulls.count(_header.seedHash))
{
if (!m_fulls.empty())
{
delete [] m_fulls.begin()->second.data();
m_fulls.erase(m_fulls.begin());
}
std::string memoFile = getDataDir() + "/ethashcache/" + toHex(_header.seedHash.ref().cropped(0, 4)) + ".full";
m_fulls[_header.seedHash] = contentsNew(memoFile);
if (!m_fulls[_header.seedHash])
{
ethash_params p = params((unsigned)_header.number);
m_fulls[_header.seedHash] = bytesRef(new byte[p.full_size], p.full_size);
auto c = cache(_header);
ethash_prep_full(m_fulls[_header.seedHash].data(), &p, c.data());
writeFile(memoFile, m_fulls[_header.seedHash]);
}
}
return m_fulls[_header.seedHash];
}
ethash_params Ethasher::params(BlockInfo const& _header)
{
return params((unsigned)_header.number);
}
ethash_params Ethasher::params(unsigned _n)
{
ethash_params p;
p.cache_size = ethash_get_cachesize(_n);
p.full_size = ethash_get_datasize(_n);
return p;
}
bool Ethasher::verify(BlockInfo const& _header)
{
bigint boundary = (bigint(1) << 256) / _header.difficulty;
auto e = eval(_header, _header.nonce);
return (u256)e.value <= boundary && e.mixHash == _header.mixHash;
}
Ethasher::Result Ethasher::eval(BlockInfo const& _header, Nonce const& _nonce)
{
auto p = Ethasher::params(_header);
ethash_return_value r;
ethash_compute_light(&r, Ethasher::get()->cache(_header).data(), &p, _header.headerHash(WithoutNonce).data(), (uint64_t)(u64)_nonce);
return Result{h256(r.result, h256::ConstructFromPointer), h256(r.mix_hash, h256::ConstructFromPointer)};
}