LogFilter.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 "LogFilter.h"
 
#include <libdevcore/SHA3.h>
#include "Block.h"
using namespace std;
using namespace dev;
using namespace dev::eth;
 
std::ostream& dev::eth::operator<<(std::ostream& _out, LogFilter const& _s)
{
    // TODO
    _out << "(@" << _s.m_addresses << "#" << _s.m_topics << ">" << _s.m_earliest << "-" << _s.m_latest << "< )";
    return _out;
}
 
void LogFilter::streamRLP(RLPStream& _s) const
{
    _s.appendList(4) << m_addresses << m_topics << m_earliest << m_latest;
}
 
h256 LogFilter::sha3() const
{
    RLPStream s;
    streamRLP(s);
    return dev::sha3(s.out());
}
 
bool LogFilter::isRangeFilter() const
{
    if (m_addresses.size())
        return false;
 
    for (auto const& t: m_topics)
        if (t.size())
            return false;
 
    return true;
}
 
bool LogFilter::matches(LogBloom _bloom) const
{
    if (m_addresses.size())
    {
        for (auto const& i: m_addresses)
            if (_bloom.containsBloom<3>(dev::sha3(i)))
                goto OK1;
        return false;
    }
    OK1:
    for (auto const& t: m_topics)
        if (t.size())
        {
            for (auto const& i: t)
                if (_bloom.containsBloom<3>(dev::sha3(i)))
                    goto OK2;
            return false;
            OK2:;
        }
    return true;
}
 
bool LogFilter::matches(Block const& _s, unsigned _i) const
{
    return matches(_s.receipt(_i)).size() > 0;
}
 
vector<LogBloom> LogFilter::bloomPossibilities() const
{
    // return combination of each of the addresses/topics
    vector<LogBloom> ret;
 
    // | every address with every topic
    for (auto const& i: m_addresses)
    {
        // 1st case, there are addresses and topics
        //
        // m_addresses = [a0, a1];
        // m_topics = [[t0], [t1a, t1b], [], []];
        //
        // blooms = [
        // a0 | t0, a0 | t1a | t1b,
        // a1 | t0, a1 | t1a | t1b
        // ]
        //
        for (auto const& t: m_topics)
            if (t.size())
            {
                LogBloom b = LogBloom().shiftBloom<3>(dev::sha3(i));
                for (auto const &j: t)
                    b = b.shiftBloom<3>(dev::sha3(j));
                ret.push_back(b);
            }
    }
 
    // 2nd case, there are no topics
    //
    // m_addresses = [a0, a1];
    // m_topics = [[t0], [t1a, t1b], [], []];
    //
    // blooms = [a0, a1];
    //
    if (!ret.size())
        for (auto const& i: m_addresses)
            ret.push_back(LogBloom().shiftBloom<3>(dev::sha3(i)));
 
    // 3rd case, there are no addresses, at least create blooms from topics
    //
    // m_addresses = [];
    // m_topics = [[t0], [t1a, t1b], [], []];
    //
    // blooms = [t0, t1a | t1b];
    //
    if (!m_addresses.size())
        for (auto const& t: m_topics)
            if (t.size())
            {
                LogBloom b;
                for (auto const &j: t)
                    b = b.shiftBloom<3>(dev::sha3(j));
                ret.push_back(b);
            }
 
    return ret;
}
 
LogEntries LogFilter::matches(TransactionReceipt const& _m) const
{
    // there are no addresses or topics to filter
    if (isRangeFilter())
        return _m.log();
 
    LogEntries ret;
    if (matches(_m.bloom()))
        for (LogEntry const& e: _m.log())
        {
            if (!m_addresses.empty() && !m_addresses.count(e.address))
                goto continue2;
            for (unsigned i = 0; i < 4; ++i)
                if (!m_topics[i].empty() && (e.topics.size() < i || !m_topics[i].count(e.topics[i])))
                    goto continue2;
            ret.push_back(e);
            continue2:;
        }
    return ret;
}