rippled/modules/ripple_app/misc/ripple_FeeVote.cpp

//------------------------------------------------------------------------------
/*
    Copyright (c) 2011-2013, OpenCoin, Inc.
*/
//==============================================================================

class Features;

//------------------------------------------------------------------------------

class FeeVote : public IFeeVote
{
private:
    // VFALCO TODO rename template parameter (wtf, looks like a macro)
    template <typename INT>
    class VotableInteger
    {
    public:
        VotableInteger (INT current, INT target) : mCurrent (current), mTarget (target)
        {
            ++mVoteMap[mTarget];                // Add our vote
        }

        bool mayVote ()
        {
            return mCurrent != mTarget;         // If we love the current setting, we will not vote
        }

        void addVote (INT vote)
        {
            ++mVoteMap[vote];
        }

        void noVote ()
        {
            addVote (mCurrent);
        }

        INT getVotes ()
        {
            INT ourVote = mCurrent;
            int weight = 0;

            typedef typename std::map<INT, int>::value_type mapVType;
            BOOST_FOREACH (const mapVType & value, mVoteMap)
            {
                // Take most voted value between current and target, inclusive
                if ((value.first <= std::max (mTarget, mCurrent)) &&
                        (value.first >= std::min (mTarget, mCurrent)) &&
                        (value.second > weight))
                {
                    ourVote = value.first;
                    weight = value.second;
                }
            }

            return ourVote;
        }

    private:
        INT                     mCurrent;       // The current setting
        INT                     mTarget;        // The setting we want
        std::map<INT, int>      mVoteMap;
    };
public:
    FeeVote (uint64 targetBaseFee, uint32 targetReserveBase, uint32 targetReserveIncrement)
        : mTargetBaseFee (targetBaseFee)
        , mTargetReserveBase (targetReserveBase)
        , mTargetReserveIncrement (targetReserveIncrement)
    {
    }

    //--------------------------------------------------------------------------

    void doValidation (Ledger::ref lastClosedLedger, STObject& baseValidation)
    {
        if (lastClosedLedger->getBaseFee () != mTargetBaseFee)
        {
            WriteLog (lsINFO, Features) << "Voting for base fee of " << mTargetBaseFee;
            baseValidation.setFieldU64 (sfBaseFee, mTargetBaseFee);
        }

        if (lastClosedLedger->getReserve (0) != mTargetReserveBase)
        {
            WriteLog (lsINFO, Features) << "Voting for base resrve of " << mTargetReserveBase;
            baseValidation.setFieldU32 (sfReserveBase, mTargetReserveBase);
        }

        if (lastClosedLedger->getReserveInc () != mTargetReserveIncrement)
        {
            WriteLog (lsINFO, Features) << "Voting for reserve increment of " << mTargetReserveIncrement;
            baseValidation.setFieldU32 (sfReserveIncrement, mTargetReserveIncrement);
        }
    }

    //--------------------------------------------------------------------------

    void doVoting (Ledger::ref lastClosedLedger, SHAMap::ref initialPosition)
    {
        // LCL must be flag ledger
        assert ((lastClosedLedger->getLedgerSeq () % 256) == 0);

        VotableInteger<uint64> baseFeeVote (lastClosedLedger->getBaseFee (), mTargetBaseFee);
        VotableInteger<uint32> baseReserveVote (lastClosedLedger->getReserve (0), mTargetReserveBase);
        VotableInteger<uint32> incReserveVote (lastClosedLedger->getReserveInc (), mTargetReserveIncrement);

        // get validations for ledger before flag
        ValidationSet set = getApp().getValidations ().getValidations (lastClosedLedger->getParentHash ());
        BOOST_FOREACH (ValidationSet::value_type const & value, set)
        {
            SerializedValidation const& val = *value.second;

            if (val.isTrusted ())
            {
                if (val.isFieldPresent (sfBaseFee))
                {
                    baseFeeVote.addVote (val.getFieldU64 (sfBaseFee));
                }
                else
                {
                    baseFeeVote.noVote ();
                }

                if (val.isFieldPresent (sfReserveBase))
                {
                    baseReserveVote.addVote (val.getFieldU32 (sfReserveBase));
                }
                else
                {
                    baseReserveVote.noVote ();
                }

                if (val.isFieldPresent (sfReserveIncrement))
                {
                    incReserveVote.addVote (val.getFieldU32 (sfReserveIncrement));
                }
                else
                {
                    incReserveVote.noVote ();
                }
            }
        }

        // choose our positions
        uint64 baseFee = baseFeeVote.getVotes ();
        uint32 baseReserve = baseReserveVote.getVotes ();
        uint32 incReserve = incReserveVote.getVotes ();

        // add transactions to our position
        if ((baseFee != lastClosedLedger->getBaseFee ()) ||
                (baseReserve != lastClosedLedger->getReserve (0)) ||
                (incReserve != lastClosedLedger->getReserveInc ()))
        {
            WriteLog (lsWARNING, Features) << "We are voting for a fee change: " << baseFee << "/" << baseReserve << "/" << incReserve;

            SerializedTransaction trans (ttFEE);
            trans.setFieldAccount (sfAccount, uint160 ());
            trans.setFieldU64 (sfBaseFee, baseFee);
            trans.setFieldU32 (sfReferenceFeeUnits, 10);
            trans.setFieldU32 (sfReserveBase, baseReserve);
            trans.setFieldU32 (sfReserveIncrement, incReserve);

            uint256 txID = trans.getTransactionID ();

            WriteLog (lsWARNING, Features) << "Vote: " << txID;

            Serializer s;
            trans.add (s, true);

            SHAMapItem::pointer tItem = boost::make_shared<SHAMapItem> (txID, s.peekData ());

            if (!initialPosition->addGiveItem (tItem, true, false))
            {
                WriteLog (lsWARNING, Features) << "Ledger already had fee change";
            }
        }
    }

private:
    uint64 mTargetBaseFee;
    uint32 mTargetReserveBase;
    uint32 mTargetReserveIncrement;
};

//------------------------------------------------------------------------------

IFeeVote* IFeeVote::New (uint64 targetBaseFee,
                         uint32 targetReserveBase,
                         uint32 targetReserveIncrement)
{
    return new FeeVote (targetBaseFee, targetReserveBase, targetReserveIncrement);
}

// vim:ts=4