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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 TrieCommon.cpp
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#include "TrieCommon.h"
namespace dev
{
/*
* Hex-prefix Notation. First nibble has flags: oddness = 2^0 & termination = 2^1
* NOTE: the "termination marker" and "leaf-node" specifier are completely equivalent.
* [0,0,1,2,3,4,5] 0x10012345
* [0,1,2,3,4,5] 0x00012345
* [1,2,3,4,5] 0x112345
* [0,0,1,2,3,4] 0x00001234
* [0,1,2,3,4] 0x101234
* [1,2,3,4] 0x001234
* [0,0,1,2,3,4,5,T] 0x30012345
* [0,0,1,2,3,4,T] 0x20001234
* [0,1,2,3,4,5,T] 0x20012345
* [1,2,3,4,5,T] 0x312345
* [1,2,3,4,T] 0x201234
*/
std::string hexPrefixEncode(bytes const& _hexVector, bool _leaf, int _begin, int _end)
{
unsigned begin = _begin;
unsigned end = _end < 0 ? _hexVector.size() + 1 + _end : _end;
bool odd = ((end - begin) % 2) != 0;
std::string ret(1, ((_leaf ? 2 : 0) | (odd ? 1 : 0)) * 16);
if (odd)
{
ret[0] |= _hexVector[begin];
++begin;
}
for (unsigned i = begin; i < end; i += 2)
ret += _hexVector[i] * 16 + _hexVector[i + 1];
return ret;
}
std::string hexPrefixEncode(bytesConstRef _data, bool _leaf, int _beginNibble, int _endNibble, unsigned _offset)
{
unsigned begin = _beginNibble + _offset;
unsigned end = (_endNibble < 0 ? ((int)(_data.size() * 2 - _offset) + 1) + _endNibble : _endNibble) + _offset;
bool odd = (end - begin) & 1;
std::string ret(1, ((_leaf ? 2 : 0) | (odd ? 1 : 0)) * 16);
ret.reserve((end - begin) / 2 + 1);
unsigned d = odd ? 1 : 2;
for (auto i = begin; i < end; ++i, ++d)
{
byte n = nibble(_data, i);
if (d & 1) // odd
ret.back() |= n; // or the nibble onto the back
else
ret.push_back(n << 4); // push the nibble on to the back << 4
}
return ret;
}
std::string hexPrefixEncode(bytesConstRef _d1, unsigned _o1, bytesConstRef _d2, unsigned _o2, bool _leaf)
{
unsigned begin1 = _o1;
unsigned end1 = _d1.size() * 2;
unsigned begin2 = _o2;
unsigned end2 = _d2.size() * 2;
bool odd = (end1 - begin1 + end2 - begin2) & 1;
std::string ret(1, ((_leaf ? 2 : 0) | (odd ? 1 : 0)) * 16);
ret.reserve((end1 - begin1 + end2 - begin2) / 2 + 1);
unsigned d = odd ? 1 : 2;
for (auto i = begin1; i < end1; ++i, ++d)
{
byte n = nibble(_d1, i);
if (d & 1) // odd
ret.back() |= n; // or the nibble onto the back
else
ret.push_back(n << 4); // push the nibble on to the back << 4
}
for (auto i = begin2; i < end2; ++i, ++d)
{
byte n = nibble(_d2, i);
if (d & 1) // odd
ret.back() |= n; // or the nibble onto the back
else
ret.push_back(n << 4); // push the nibble on to the back << 4
}
return ret;
}
byte uniqueInUse(RLP const& _orig, byte except)
{
byte used = 255;
for (unsigned i = 0; i < 17; ++i)
if (i != except && !_orig[i].isEmpty())
{
if (used == 255)
used = (byte)i;
else
return 255;
}
return used;
}
}