Common.cpp

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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/>.
*/
#include "Common.h"
#include <libdevcore/SHA3.h>
#include "Message.h"
#include "BloomFilter.h"

using namespace std;
using namespace dev;
using namespace dev::p2p;
using namespace dev::shh;

AbridgedTopic dev::shh::abridge(Topic const& _p)
{
        return AbridgedTopic(sha3(_p));
}

AbridgedTopics dev::shh::abridge(Topics const& _topics)
{
        AbridgedTopics ret;
        ret.reserve(_topics.size());
        for (auto const& t: _topics)
                ret.push_back(abridge(t));
        return ret;
}

AbridgedTopics BuildTopic::toAbridgedTopics() const
{
        AbridgedTopics ret;
        ret.reserve(m_parts.size());
        for (auto const& h: m_parts)
                ret.push_back(abridge(h));
        return ret;
}

BuildTopic& BuildTopic::shiftBytes(bytes const& _b)
{
        m_parts.push_back(dev::sha3(_b));
        return *this;
}

h256 TopicFilter::sha3() const
{
        RLPStream s;
        streamRLP(s);
        return dev::sha3(s.out());
}

bool TopicFilter::matches(Envelope const& _e) const
{
        for (TopicMask const& t: m_topicMasks)
        {
                for (unsigned i = 0; i < t.size(); ++i)
                {
                        for (auto et: _e.topic())
                                if (((t[i].first ^ et) & t[i].second) == AbridgedTopic())
                                        goto NEXT_TOPICPART;
                        // failed to match topicmask against any topics: move on to next mask
                        goto NEXT_TOPICMASK;
                        NEXT_TOPICPART:;
                }
                // all topicmasks matched.
                return true;
                NEXT_TOPICMASK:;
        }
        return false;
}

TopicFilter::TopicFilter(RLP const& _r)
{
        for (RLP const& i: _r)
        {
                m_topicMasks.push_back(TopicMask());
                for (RLP const& j: i)
                        m_topicMasks.back().push_back(j.toPair<FixedHash<4>, FixedHash<4>>());
        }
}

TopicBloomFilterHash TopicFilter::exportBloom() const
{
        TopicBloomFilterHash ret;
        for (TopicMask const& t: m_topicMasks)
                for (auto const& i: t)
                        ret |= TopicBloomFilter::bloom(i.first);
                
        return ret;
}

TopicMask BuildTopicMask::toTopicMask() const
{
        TopicMask ret;
        ret.reserve(m_parts.size());
        for (auto const& h: m_parts)
                ret.push_back(make_pair(abridge(h), ~AbridgedTopic()));
        return ret;
}

/*
web3.shh.watch({}).arrived(function(m) { env.note("New message:\n"+JSON.stringify(m)); })
k = web3.shh.newIdentity()
web3.shh.post({from: k, topic: web3.fromAscii("test"), payload: web3.fromAscii("Hello world!")})
*/