mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
70 lines
1.7 KiB
C++
70 lines
1.7 KiB
C++
/*
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This file is part of cpp-ethereum.
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cpp-ethereum is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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cpp-ethereum is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
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*/
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/** @file SwarmHash.cpp
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*/
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#include <libdevcore/SwarmHash.h>
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#include <libdevcore/SHA3.h>
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using namespace std;
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using namespace dev;
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bytes toLittleEndian(size_t _size)
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{
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bytes encoded(8);
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for (size_t i = 0; i < 8; ++i)
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encoded[i] = (_size >> (8 * i)) & 0xff;
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return encoded;
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}
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h256 swarmHashSimple(bytesConstRef _data, size_t _size)
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{
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return keccak256(toLittleEndian(_size) + _data.toBytes());
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}
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h256 dev::swarmHash(bytes const& _input)
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{
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bytes data = _input;
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size_t lastChunkSize = 0;
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size_t level = 0;
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do
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{
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bytes innerNodes;
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size_t i = 0;
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do
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{
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size_t bytes = std::min<size_t>(0x1000, data.size() - i);
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size_t size = bytes << (7 * level);
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if (i + 0x1000 >= data.size())
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{
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// last node
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size = level == 0 ? bytes : ((bytes - 32) << (7 * level)) + lastChunkSize;
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lastChunkSize = size;
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}
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innerNodes += swarmHashSimple(bytesConstRef(_input.data() + i, bytes), size).asBytes();
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i += 0x1000;
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}
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while (i < data.size());
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data = std::move(innerNodes);
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level++;
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}
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while (data.size() > 32);
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return h256(data);
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}
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