cpp-ethereum/libdevcore/RLP.cpp at develop · cheny56/cpp-ethereum · GitHub

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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 RLP.cpp

* @author Gav Wood <i@gavwood.com>

* @date 2014

#include "RLP.h"

using namespace std;

using namespace dev;

bytes dev::RLPNull = rlp("");

bytes dev::RLPEmptyList = rlpList();

RLP::RLP(bytesConstRef _d, Strictness _s):

m_data(_d)

{

if ((_s & FailIfTooBig) && actualSize() < _d.size())

{

if (_s & ThrowOnFail)

BOOST_THROW_EXCEPTION(OversizeRLP());

else

m_data.reset();

}

if ((_s & FailIfTooSmall) && actualSize() > _d.size())

{

if (_s & ThrowOnFail)

BOOST_THROW_EXCEPTION(UndersizeRLP());

else

m_data.reset();

}

RLP::iterator& RLP::iterator::operator++()

{

if (m_remaining)

{

m_currentItem.retarget(m_currentItem.next().data(), m_remaining);

m_currentItem = m_currentItem.cropped(0, sizeAsEncoded(m_currentItem));

m_remaining -= std::min<size_t>(m_remaining, m_currentItem.size());

}

else

m_currentItem.retarget(m_currentItem.next().data(), 0);

return *this;

}

RLP::iterator::iterator(RLP const& _parent, bool _begin)

{

if (_begin && _parent.isList())

{

auto pl = _parent.payload();

m_currentItem = pl.cropped(0, sizeAsEncoded(pl));

m_remaining = pl.size() - m_currentItem.size();

}

else

{

m_currentItem = _parent.data().cropped(_parent.data().size());

m_remaining = 0;

}

RLP RLP::operator[](size_t _i) const

{

if (_i < m_lastIndex)

{

m_lastEnd = sizeAsEncoded(payload());

m_lastItem = payload().cropped(0, m_lastEnd);

m_lastIndex = 0;

}

for (; m_lastIndex < _i && m_lastItem.size(); ++m_lastIndex)

{

m_lastItem = payload().cropped(m_lastEnd);

m_lastItem = m_lastItem.cropped(0, sizeAsEncoded(m_lastItem));

m_lastEnd += m_lastItem.size();

}

return RLP(m_lastItem, ThrowOnFail | FailIfTooSmall);

}

RLPs RLP::toList(int _flags) const

{

RLPs ret;

if (!isList())

{

if (_flags & ThrowOnFail)

BOOST_THROW_EXCEPTION(BadCast());

else

return ret;

}

for (auto const& i: *this)

ret.push_back(i);

return ret;

}

size_t RLP::actualSize() const

{

if (isNull())

return 0;

if (isSingleByte())

return 1;

if (isData() || isList())

return payloadOffset() + length();

return 0;

}

void RLP::requireGood() const

{

if (isNull())

BOOST_THROW_EXCEPTION(BadRLP());

byte n = m_data[0];

if (n != c_rlpDataImmLenStart + 1)

return;

if (m_data.size() < 2)

BOOST_THROW_EXCEPTION(BadRLP());

if (m_data[1] < c_rlpDataImmLenStart)

BOOST_THROW_EXCEPTION(BadRLP());

}

bool RLP::isInt() const

{

if (isNull())

return false;

requireGood();

byte n = m_data[0];

if (n < c_rlpDataImmLenStart)

return !!n;

else if (n == c_rlpDataImmLenStart)

return true;

else if (n <= c_rlpDataIndLenZero)

{

if (m_data.size() <= 1)

BOOST_THROW_EXCEPTION(BadRLP());

return m_data[1] != 0;

}

else if (n < c_rlpListStart)

{

if (m_data.size() <= size_t(1 + n - c_rlpDataIndLenZero))

BOOST_THROW_EXCEPTION(BadRLP());

return m_data[1 + n - c_rlpDataIndLenZero] != 0;

}

else

return false;

}

size_t RLP::length() const

{

if (isNull())

return 0;

requireGood();

size_t ret = 0;

byte const n = m_data[0];

if (n < c_rlpDataImmLenStart)

return 1;

else if (n <= c_rlpDataIndLenZero)

return n - c_rlpDataImmLenStart;

else if (n < c_rlpListStart)

{

if (m_data.size() <= size_t(n - c_rlpDataIndLenZero))

BOOST_THROW_EXCEPTION(BadRLP());

if (m_data.size() > 1)

if (m_data[1] == 0)

BOOST_THROW_EXCEPTION(BadRLP());

unsigned lengthSize = n - c_rlpDataIndLenZero;

if (lengthSize > sizeof(ret))

// We did not check, but would most probably not fit in our memory.

BOOST_THROW_EXCEPTION(UndersizeRLP());

// No leading zeroes.

if (!m_data[1])

BOOST_THROW_EXCEPTION(BadRLP());

for (unsigned i = 0; i < lengthSize; ++i)

ret = (ret << 8) | m_data[i + 1];

// Must be greater than the limit.

if (ret < c_rlpListStart - c_rlpDataImmLenStart - c_rlpMaxLengthBytes)

BOOST_THROW_EXCEPTION(BadRLP());

}

else if (n <= c_rlpListIndLenZero)

return n - c_rlpListStart;

else

{

unsigned lengthSize = n - c_rlpListIndLenZero;

if (m_data.size() <= lengthSize)

BOOST_THROW_EXCEPTION(BadRLP());

if (m_data.size() > 1)

if (m_data[1] == 0)

BOOST_THROW_EXCEPTION(BadRLP());

if (lengthSize > sizeof(ret))

// We did not check, but would most probably not fit in our memory.

BOOST_THROW_EXCEPTION(UndersizeRLP());

if (!m_data[1])

BOOST_THROW_EXCEPTION(BadRLP());

for (unsigned i = 0; i < lengthSize; ++i)

ret = (ret << 8) | m_data[i + 1];

if (ret < 0x100 - c_rlpListStart - c_rlpMaxLengthBytes)

BOOST_THROW_EXCEPTION(BadRLP());

}

// We have to be able to add payloadOffset to length without overflow.

// This rejects roughly 4GB-sized RLPs on some platforms.

if (ret >= std::numeric_limits<size_t>::max() - 0x100)

BOOST_THROW_EXCEPTION(UndersizeRLP());

return ret;

}

size_t RLP::items() const

{

if (isList())

{

bytesConstRef d = payload();

size_t i = 0;

for (; d.size(); ++i)

d = d.cropped(sizeAsEncoded(d));

return i;

}

return 0;

}

RLPStream& RLPStream::appendRaw(bytesConstRef _s, size_t _itemCount)

{

m_out.insert(m_out.end(), _s.begin(), _s.end());

noteAppended(_itemCount);

return *this;

}

void RLPStream::noteAppended(size_t _itemCount)

{

if (!_itemCount)

return;

// cdebug << "noteAppended(" << _itemCount << ")";

while (m_listStack.size())

{

if (m_listStack.back().first < _itemCount)

BOOST_THROW_EXCEPTION(RLPException() << errinfo_comment("itemCount too large") << RequirementError((bigint)m_listStack.back().first, (bigint)_itemCount));

m_listStack.back().first -= _itemCount;

if (m_listStack.back().first)

break;

else

{

auto p = m_listStack.back().second;

m_listStack.pop_back();

size_t s = m_out.size() - p; // list size

auto brs = bytesRequired(s);

unsigned encodeSize = s < c_rlpListImmLenCount ? 1 : (1 + brs);

// cdebug << "s: " << s << ", p: " << p << ", m_out.size(): " << m_out.size() << ", encodeSize: " << encodeSize << " (br: " << brs << ")";

auto os = m_out.size();

m_out.resize(os + encodeSize);

memmove(m_out.data() + p + encodeSize, m_out.data() + p, os - p);

if (s < c_rlpListImmLenCount)

m_out[p] = (byte)(c_rlpListStart + s);

else if (c_rlpListIndLenZero + brs <= 0xff)

{

m_out[p] = (byte)(c_rlpListIndLenZero + brs);

byte* b = &(m_out[p + brs]);

for (; s; s >>= 8)

*(b--) = (byte)s;

}

else

BOOST_THROW_EXCEPTION(RLPException() << errinfo_comment("itemCount too large for RLP"));

}

_itemCount = 1; // for all following iterations, we've effectively appended a single item only since we completed a list.

}

RLPStream& RLPStream::appendList(size_t _items)

{

// cdebug << "appendList(" << _items << ")";

if (_items)

m_listStack.push_back(std::make_pair(_items, m_out.size()));

else

appendList(bytes());

return *this;

}

RLPStream& RLPStream::appendList(bytesConstRef _rlp)

{

if (_rlp.size() < c_rlpListImmLenCount)

m_out.push_back((byte)(_rlp.size() + c_rlpListStart));

else

pushCount(_rlp.size(), c_rlpListIndLenZero);

appendRaw(_rlp, 1);

return *this;

}

RLPStream& RLPStream::append(bytesConstRef _s, bool _compact)

{

size_t s = _s.size();

byte const* d = _s.data();

if (_compact)

for (size_t i = 0; i < _s.size() && !*d; ++i, --s, ++d) {}

if (s == 1 && *d < c_rlpDataImmLenStart)

m_out.push_back(*d);

else

{

if (s < c_rlpDataImmLenCount)

m_out.push_back((byte)(s + c_rlpDataImmLenStart));

else

pushCount(s, c_rlpDataIndLenZero);

appendRaw(bytesConstRef(d, s), 0);

}

noteAppended();

return *this;

}

RLPStream& RLPStream::append(bigint _i)

{

if (!_i)

m_out.push_back(c_rlpDataImmLenStart);

else if (_i < c_rlpDataImmLenStart)

m_out.push_back((byte)_i);

else

{

unsigned br = bytesRequired(_i);

if (br < c_rlpDataImmLenCount)

m_out.push_back((byte)(br + c_rlpDataImmLenStart));

else

{

auto brbr = bytesRequired(br);

if (c_rlpDataIndLenZero + brbr > 0xff)

BOOST_THROW_EXCEPTION(RLPException() << errinfo_comment("Number too large for RLP"));

m_out.push_back((byte)(c_rlpDataIndLenZero + brbr));

pushInt(br, brbr);

}

pushInt(_i, br);

}

noteAppended();

return *this;

}

void RLPStream::pushCount(size_t _count, byte _base)

{

auto br = bytesRequired(_count);

if (int(br) + _base > 0xff)

BOOST_THROW_EXCEPTION(RLPException() << errinfo_comment("Count too large for RLP"));

m_out.push_back((byte)(br + _base)); // max 8 bytes.

pushInt(_count, br);

}

static void streamOut(std::ostream& _out, dev::RLP const& _d, unsigned _depth = 0)

{

if (_depth > 64)

_out << "<max-depth-reached>";

else if (_d.isNull())

_out << "null";

else if (_d.isInt())

_out << std::showbase << std::hex << std::nouppercase << _d.toInt<bigint>(RLP::LaissezFaire) << dec;

else if (_d.isData())

_out << escaped(_d.toString(), false);

else if (_d.isList())

{

_out << "[";

int j = 0;

for (auto i: _d)

{

_out << (j++ ? ", " : " ");

streamOut(_out, i, _depth + 1);

}

_out << " ]";

}

std::ostream& dev::operator<<(std::ostream& _out, RLP const& _d)

{

streamOut(_out, _d);

return _out;

}

cpp-ethereum/libdevcore/RLP.cpp at develop · cheny56/cpp-ethereum · GitHub

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