// Take as much as possible. Adjusts account balances. Charges fees on top to taker.
// -->    uBookBase: The order book to take against.
// -->  saTakerPays: What the taker offers (w/ issuer)
// -->  saTakerGets: What the taker wanted (w/ issuer)
// <--  saTakerPaid: What taker could have paid including saved not including fees. To reduce an offer.
// <--   saTakerGot: What taker got not including fees. To reduce an offer.
// <--    terResult: tesSUCCESS, terNO_ACCOUNT, telFAILED_PROCESSING, or tecFAILED_PROCESSING
// <--    bUnfunded: if tesSUCCESS, consider offer unfunded after taking.
TER OfferCreateTransactor::takeOffers (
    const bool          bOpenLedger,
    const bool          bPassive,
    const bool          bSell,
    uint256 const&      uBookBase,
    const uint160&      uTakerAccountID,
    SLE::ref            sleTakerAccount,
    const STAmount&     saTakerPays,
    const STAmount&     saTakerGets,
    STAmount&           saTakerPaid,
    STAmount&           saTakerGot,
    bool&               bUnfunded)
{
    // The book has the most elements. Take the perspective of the book.
    // Book is ordered for taker: taker pays / taker gets (smaller is better)

    // The order is for the other books currencys for get and pays are opposites.
    // We want the same ratio for the respective currencies.
    // So we swap paid and gets for determing take quality.

    assert (saTakerPays && saTakerGets);

    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: bSell: " << bSell << ": against book: " << uBookBase.ToString ();

    LedgerEntrySet&         lesActive           = mEngine->getNodes ();
    uint256                 uTipIndex           = uBookBase;
    const uint256           uBookEnd            = Ledger::getQualityNext (uBookBase);
    const uint64            uTakeQuality        = STAmount::getRate (saTakerGets, saTakerPays);
    STAmount                saTakerRate         = STAmount::setRate (uTakeQuality);
    const uint160           uTakerPaysAccountID = saTakerPays.getIssuer ();
    const uint160           uTakerGetsAccountID = saTakerGets.getIssuer ();
    TER                     terResult           = temUNCERTAIN;

    boost::unordered_set<uint256>   usOfferUnfundedBecame;  // Offers that became unfunded.
    boost::unordered_set<uint160>   usAccountTouched;       // Accounts touched.

    saTakerPaid     = STAmount (saTakerPays.getCurrency (), saTakerPays.getIssuer ());
    saTakerGot      = STAmount (saTakerGets.getCurrency (), saTakerGets.getIssuer ());
    bUnfunded       = false;

    while (temUNCERTAIN == terResult)
    {
        SLE::pointer    sleOfferDir;
        uint64          uTipQuality     = 0;
        STAmount        saTakerFunds    = lesActive.accountFunds (uTakerAccountID, saTakerPays);
        STAmount        saSubTakerPays  = saTakerPays - saTakerPaid; // How much more to spend.
        STAmount        saSubTakerGets  = saTakerGets - saTakerGot; // How much more is wanted.

        // Figure out next offer to take, if needed.
        if (saTakerFunds.isPositive ()          // Taker has funds available.
                && saSubTakerPays.isPositive ()
                && saSubTakerGets.isPositive ())
        {
            sleOfferDir     = mEngine->entryCache (ltDIR_NODE, lesActive.getNextLedgerIndex (uTipIndex, uBookEnd));

            if (sleOfferDir)
            {
                uTipIndex       = sleOfferDir->getIndex ();
                uTipQuality     = Ledger::getQuality (uTipIndex);

                WriteLog (lsDEBUG, OfferCreateTransactor) << boost::str (boost::format ("takeOffers: possible counter offer found: uTipQuality=%d uTipIndex=%s")
                        % uTipQuality
                        % uTipIndex.ToString ());

            }
            else
            {
                WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: counter offer book is empty: "
                        << uTipIndex.ToString ()
                        << " ... "
                        << uBookEnd.ToString ();
            }
        }

        if (!saTakerFunds.isPositive ())                    // Taker has no funds.
        {
            // Done. Ran out of funds on previous round. As fees aren't calculated directly in this routine, funds are checked here.
            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: done: taker unfunded.";

            bUnfunded   = true;                             // Don't create an order.
            terResult   = tesSUCCESS;
        }
        else if (!sleOfferDir                               // No offer directory to take.
                 || uTakeQuality < uTipQuality                   // No offers of sufficient quality available.
                 || (bPassive && uTakeQuality == uTipQuality))
        {
            // Done.
            STAmount    saTipRate           = sleOfferDir ? STAmount::setRate (uTipQuality) : saTakerRate;

            WriteLog (lsDEBUG, OfferCreateTransactor) << boost::str (boost::format ("takeOffers: done: dir=%d uTakeQuality=%d %c uTipQuality=%d saTakerRate=%s %c saTipRate=%s bPassive=%d")
                    % !!sleOfferDir
                    % uTakeQuality
                    % (uTakeQuality == uTipQuality
                       ? '='
                       : uTakeQuality < uTipQuality
                       ? '<'
                       : '>')
                    % uTipQuality
                    % saTakerRate
                    % (saTakerRate == saTipRate
                       ? '='
                       : saTakerRate < saTipRate
                       ? '<'
                       : '>')
                    % saTipRate
                    % bPassive);

            terResult   = tesSUCCESS;
        }
        else
        {
            // Have an offer directory to consider.
            WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: considering dir: " << sleOfferDir->getJson (0);

            SLE::pointer    sleBookNode;
            unsigned int    uBookEntry;
            uint256         uOfferIndex;

            lesActive.dirFirst (uTipIndex, sleBookNode, uBookEntry, uOfferIndex);

            SLE::pointer    sleOffer        = mEngine->entryCache (ltOFFER, uOfferIndex);

            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: considering offer : " << sleOffer->getJson (0);

            const uint160   uOfferOwnerID   = sleOffer->getFieldAccount160 (sfAccount);
            STAmount        saOfferPays     = sleOffer->getFieldAmount (sfTakerGets);
            STAmount        saOfferGets     = sleOffer->getFieldAmount (sfTakerPays);

            STAmount        saOfferFunds;   // Funds of offer owner to payout.
            bool            bValid;

            bValid  =  bValidOffer (
                           sleOfferDir, uOfferIndex, uOfferOwnerID, saOfferPays, saOfferGets,
                           uTakerAccountID,
                           usOfferUnfundedFound, usOfferUnfundedBecame, usAccountTouched,
                           saOfferFunds);

            if (bValid)
            {
                STAmount    saSubTakerPaid;
                STAmount    saSubTakerGot;
                STAmount    saTakerIssuerFee;
                STAmount    saOfferIssuerFee;
                STAmount    saOfferRate = STAmount::setRate (uTipQuality);

                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPays: " << saTakerPays.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPaid: " << saTakerPaid.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:   saTakerFunds: " << saTakerFunds.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:   saOfferFunds: " << saOfferFunds.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferPays: " << saOfferPays.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferGets: " << saOfferGets.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferRate: " << saOfferRate.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerPays: " << saSubTakerPays.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerGets: " << saSubTakerGets.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPays: " << saTakerPays.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerGets: " << saTakerGets.getFullText ();

                bool    bOfferDelete    = STAmount::applyOffer (
                                              bSell,
                                              lesActive.rippleTransferRate (uTakerAccountID, uOfferOwnerID, uTakerPaysAccountID),
                                              lesActive.rippleTransferRate (uOfferOwnerID, uTakerAccountID, uTakerGetsAccountID),
                                              saOfferRate,
                                              saOfferFunds,
                                              saTakerFunds,
                                              saOfferPays,
                                              saOfferGets,
                                              saSubTakerPays,
                                              saSubTakerGets,
                                              saSubTakerPaid,
                                              saSubTakerGot,
                                              saTakerIssuerFee,
                                              saOfferIssuerFee);

                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerPaid: " << saSubTakerPaid.getFullText ();
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:  saSubTakerGot: " << saSubTakerGot.getFullText ();

                // Adjust offer

                // Offer owner will pay less.  Subtract what taker just got.
                sleOffer->setFieldAmount (sfTakerGets, saOfferPays -= saSubTakerGot);

                // Offer owner will get less.  Subtract what owner just paid.
                sleOffer->setFieldAmount (sfTakerPays, saOfferGets -= saSubTakerPaid);

                mEngine->entryModify (sleOffer);

                if (bOfferDelete)
                {
                    // Offer now fully claimed or now unfunded.
                    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: Offer claimed: Delete.";

                    usOfferUnfundedBecame.insert (uOfferIndex); // Delete unfunded offer on success.

                    // Offer owner's account is no longer pristine.
                    usAccountTouched.insert (uOfferOwnerID);
                }
                else if (saSubTakerGot)
                {
                    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: Offer partial claim.";

                    if (!saOfferPays.isPositive () || !saOfferGets.isPositive ())
                    {
                        WriteLog (lsWARNING, OfferCreateTransactor) << "takeOffers: ILLEGAL OFFER RESULT.";
                        bUnfunded   = true;
                        terResult   = bOpenLedger ? telFAILED_PROCESSING : tecFAILED_PROCESSING;
                    }
                }
                else
                {
                    // Taker got nothing, probably due to rounding. Consider taker unfunded.
                    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: No claim.";

                    bUnfunded   = true;
                    terResult   = tesSUCCESS;                   // Done.
                }

                assert (uTakerGetsAccountID == saSubTakerGot.getIssuer ());
                assert (uTakerPaysAccountID == saSubTakerPaid.getIssuer ());

                if (!bUnfunded)
                {
                    // Distribute funds. The sends charge appropriate fees which are implied by offer.

                    terResult   = lesActive.accountSend (uOfferOwnerID, uTakerAccountID, saSubTakerGot);            // Offer owner pays taker.

                    if (tesSUCCESS == terResult)
                        terResult   = lesActive.accountSend (uTakerAccountID, uOfferOwnerID, saSubTakerPaid);           // Taker pays offer owner.

                    if (!bSell)
                    {
                        // Buy semantics: Reduce amount considered paid by taker's rate. Not by actual cost which is lower.
                        // That is, take less as to just satify our buy requirement.
                        STAmount    saTakerCould    = saTakerPays - saTakerPaid;    // Taker could pay.

                        if (saTakerFunds < saTakerCould)
                            saTakerCould    = saTakerFunds;

                        STAmount    saTakerUsed = STAmount::multiply (saSubTakerGot, saTakerRate, saTakerPays);

                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:   saTakerCould: " << saTakerCould.getFullText ();
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:  saSubTakerGot: " << saSubTakerGot.getFullText ();
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerRate: " << saTakerRate.getFullText ();
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerUsed: " << saTakerUsed.getFullText ();

                        saSubTakerPaid  = std::min (saTakerCould, saTakerUsed);
                    }

                    saTakerPaid     += saSubTakerPaid;
                    saTakerGot      += saSubTakerGot;

                    if (tesSUCCESS == terResult)
                        terResult   = temUNCERTAIN;
                }
            }
        }
    }

    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: " << transToken (terResult);

    if (tesSUCCESS == terResult)
    {
        // On success, delete offers that became unfunded.
        BOOST_FOREACH (uint256 const & uOfferIndex, usOfferUnfundedBecame)
        {
            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: became unfunded: " << uOfferIndex.ToString ();

            terResult   = lesActive.offerDelete (uOfferIndex);

            if (tesSUCCESS != terResult)
                break;
        }
Example #2
0
    TER doApply () override
    {
        assert (mTxnAccount);

        // A ticket counts against the reserve of the issuing account, but we check
        // the starting balance because we want to allow dipping into the reserve to
        // pay fees.
        auto const accountReserve (mEngine->getLedger ()->getReserve (
            mTxnAccount->getFieldU32 (sfOwnerCount) + 1));

        if (mPriorBalance.getNValue () < accountReserve)
            return tecINSUFFICIENT_RESERVE;

        std::uint32_t expiration (0);

        if (mTxn.isFieldPresent (sfExpiration))
        {
            expiration = mTxn.getFieldU32 (sfExpiration);

            if (!expiration)
            {
                m_journal.warning <<
                    "Malformed ticket requestion: bad expiration";

                return temBAD_EXPIRATION;
            }

            if (mEngine->getLedger ()->getParentCloseTimeNC () >= expiration)
                return tesSUCCESS;
        }

        SLE::pointer sleTicket = mEngine->entryCreate (ltTICKET,
            Ledger::getTicketIndex (mTxnAccountID, mTxn.getSequence ()));

        sleTicket->setFieldAccount (sfAccount, mTxnAccountID);
        sleTicket->setFieldU32 (sfSequence, mTxn.getSequence ());

        if (expiration != 0)
            sleTicket->setFieldU32 (sfExpiration, expiration);

        if (mTxn.isFieldPresent (sfTarget))
        {
            Account const target_account (mTxn.getFieldAccount160 (sfTarget));

            SLE::pointer sleTarget = mEngine->entryCache (ltACCOUNT_ROOT,
                Ledger::getAccountRootIndex (target_account));

            // Destination account does not exist.
            if (!sleTarget)
                return tecNO_TARGET;

            // The issuing account is the default account to which the ticket
            // applies so don't bother saving it if that's what's specified.
            if (target_account != mTxnAccountID)
                sleTicket->setFieldAccount (sfTarget, target_account);
        }

        std::uint64_t hint;

        auto describer = [&](SLE::pointer p, bool b)
        {
            Ledger::ownerDirDescriber(p, b, mTxnAccountID);
        };
        TER result = mEngine->view ().dirAdd (
            hint,
            Ledger::getOwnerDirIndex (mTxnAccountID),
            sleTicket->getIndex (),
            describer);

        m_journal.trace <<
            "Creating ticket " << to_string (sleTicket->getIndex ()) <<
            ": " << transHuman (result);

        if (result != tesSUCCESS)
            return result;

        sleTicket->setFieldU64(sfOwnerNode, hint);

        // If we succeeded, the new entry counts agains the creator's reserve.
        mEngine->view ().incrementOwnerCount (mTxnAccount);

        return result;
    }
Example #3
0
// Take as much as possible. Adjusts account balances. Charges fees on top to taker.
// -->    uBookBase: The order book to take against.
// -->  saTakerPays: What the taker offers (w/ issuer)
// -->  saTakerGets: What the taker wanted (w/ issuer)
// <--  saTakerPaid: What taker could have paid including saved not including fees. To reduce an offer.
// <--   saTakerGot: What taker got not including fees. To reduce an offer.
// <--    terResult: tesSUCCESS, terNO_ACCOUNT, telFAILED_PROCESSING, or tecFAILED_PROCESSING
// <--    bUnfunded: if tesSUCCESS, consider offer unfunded after taking.
TER OfferCreateTransactor::takeOffers (
    const bool          bOpenLedger,
    const bool          bPassive,
    const bool          bSell,
    uint256 const&      uBookBase,
    const uint160&      uTakerAccountID,
    SLE::ref            sleTakerAccount,
    const STAmount&     saTakerPays,
    const STAmount&     saTakerGets,
    STAmount&           saTakerPaid,
    STAmount&           saTakerGot,
    bool&               bUnfunded)
{
    // The book has the most elements. Take the perspective of the book.
    // Book is ordered for taker: taker pays / taker gets (smaller is better)

    // The order is for the other books currencys for get and pays are opposites.
    // We want the same ratio for the respective currencies.
    // So we swap paid and gets for determing take quality.

    assert (saTakerPays && saTakerGets);

    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: bSell: " << bSell << ": against book: " << uBookBase.ToString ();

    LedgerEntrySet&         lesActive           = mEngine->getNodes ();
    const uint64            uTakeQuality        = STAmount::getRate (saTakerGets, saTakerPays);
    STAmount                saTakerRate         = STAmount::setRate (uTakeQuality);
    const uint160           uTakerPaysAccountID = saTakerPays.getIssuer ();
    const uint160           uTakerGetsAccountID = saTakerGets.getIssuer ();
    TER                     terResult           = temUNCERTAIN;

    boost::unordered_set<uint256>   usOfferUnfundedBecame;  // Offers that became unfunded.
    boost::unordered_set<uint160>   usAccountTouched;       // Accounts touched.

    saTakerPaid     = STAmount (saTakerPays.getCurrency (), saTakerPays.getIssuer ());
    saTakerGot      = STAmount (saTakerGets.getCurrency (), saTakerGets.getIssuer ());
    bUnfunded       = false;

    OrderBookIterator bookIterator (lesActive,
        saTakerPays.getCurrency(), saTakerPays.getIssuer(),
        saTakerGets.getCurrency(), saTakerGets.getIssuer());

    while ((temUNCERTAIN == terResult) && bookIterator.nextOffer())
    {
        STAmount        saTakerFunds    = lesActive.accountFunds (uTakerAccountID, saTakerPays);
        STAmount        saSubTakerPays  = saTakerPays - saTakerPaid; // How much more to spend.
        STAmount        saSubTakerGets  = saTakerGets - saTakerGot; // How much more is wanted.
        uint64          uTipQuality     = bookIterator.getCurrentQuality();

        if (!saTakerFunds.isPositive ())
        {
            // Taker is out of funds. Don't create the offer.
            bUnfunded = true;
            terResult = tesSUCCESS;
        }
        else if (!saSubTakerPays.isPositive() || !saSubTakerGets.isPositive())
        {
            // Offer is completely consumed
            terResult = tesSUCCESS;
        }
        else if ((uTakeQuality < uTipQuality)
                 || (bPassive && uTakeQuality == uTipQuality))
        {
            // Offer does not cross this offer
            STAmount    saTipRate           = STAmount::setRate (uTipQuality);

            WriteLog (lsDEBUG, OfferCreateTransactor) << boost::str (boost::format ("takeOffers: done: uTakeQuality=%d %c uTipQuality=%d saTakerRate=%s %c saTipRate=%s bPassive=%d")
                    % uTakeQuality
                    % (uTakeQuality == uTipQuality
                       ? '='
                       : uTakeQuality < uTipQuality
                       ? '<'
                       : '>')
                    % uTipQuality
                    % saTakerRate
                    % (saTakerRate == saTipRate
                       ? '='
                       : saTakerRate < saTipRate
                       ? '<'
                       : '>')
                    % saTipRate
                    % bPassive);

            terResult   = tesSUCCESS;
        }
        else
        {
            // We have a crossing offer to consider.

            SLE::pointer    sleOffer        = bookIterator.getCurrentOffer ();

            if (!sleOffer)
            { // offer is in directory but not in ledger
                uint256 offerIndex = bookIterator.getCurrentIndex ();
                WriteLog (lsWARNING, OfferCreateTransactor) << "takeOffers: offer not found : " << offerIndex;
                usMissingOffers.insert (missingOffer_t (
                    bookIterator.getCurrentIndex (), bookIterator.getCurrentDirectory ()));
            }
            else
            {
                WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: considering offer : " << sleOffer->getJson (0);

                const uint160&  uOfferOwnerID   = sleOffer->getFieldAccount160 (sfAccount);
                STAmount        saOfferPays     = sleOffer->getFieldAmount (sfTakerGets);
                STAmount        saOfferGets     = sleOffer->getFieldAmount (sfTakerPays);

                STAmount        saOfferFunds;   // Funds of offer owner to payout.
                bool            bValid;

                bValid  =  bValidOffer (
                               sleOffer, uOfferOwnerID, saOfferPays, saOfferGets,
                               uTakerAccountID,
                               usOfferUnfundedFound, usOfferUnfundedBecame, usAccountTouched,
                               saOfferFunds);

                if (bValid)
                {
                    STAmount    saSubTakerPaid;
                    STAmount    saSubTakerGot;
                    STAmount    saTakerIssuerFee;
                    STAmount    saOfferIssuerFee;
                    STAmount    saOfferRate = STAmount::setRate (uTipQuality);

                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPays: " << saTakerPays.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPaid: " << saTakerPaid.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:   saTakerFunds: " << saTakerFunds.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:   saOfferFunds: " << saOfferFunds.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferPays: " << saOfferPays.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferGets: " << saOfferGets.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saOfferRate: " << saOfferRate.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerPays: " << saSubTakerPays.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerGets: " << saSubTakerGets.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerPays: " << saTakerPays.getFullText ();
                    WriteLog (lsTRACE, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerGets: " << saTakerGets.getFullText ();

                    bool    bOfferDelete    = STAmount::applyOffer (
                                                  bSell,
                                                  lesActive.rippleTransferRate (uTakerAccountID, uOfferOwnerID, uTakerPaysAccountID),
                                                  lesActive.rippleTransferRate (uOfferOwnerID, uTakerAccountID, uTakerGetsAccountID),
                                                  saOfferRate,
                                                  saOfferFunds,
                                                  saTakerFunds,
                                                  saOfferPays,
                                                  saOfferGets,
                                                  saSubTakerPays,
                                                  saSubTakerGets,
                                                  saSubTakerPaid,
                                                  saSubTakerGot,
                                                  saTakerIssuerFee,
                                                  saOfferIssuerFee);

                    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer: saSubTakerPaid: " << saSubTakerPaid.getFullText ();
                    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:  saSubTakerGot: " << saSubTakerGot.getFullText ();

                    // Adjust offer

                    // Offer owner will pay less.  Subtract what taker just got.
                    sleOffer->setFieldAmount (sfTakerGets, saOfferPays -= saSubTakerGot);

                    // Offer owner will get less.  Subtract what owner just paid.
                    sleOffer->setFieldAmount (sfTakerPays, saOfferGets -= saSubTakerPaid);

                    mEngine->entryModify (sleOffer);

                    if (bOfferDelete)
                    {
                        // Offer now fully claimed or now unfunded.
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: Offer claimed: Delete.";

                        usOfferUnfundedBecame.insert (sleOffer->getIndex()); // Delete unfunded offer on success.

                        // Offer owner's account is no longer pristine.
                        usAccountTouched.insert (uOfferOwnerID);
                    }
                    else if (saSubTakerGot)
                    {
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: Offer partial claim.";

                        if (!saOfferPays.isPositive () || !saOfferGets.isPositive ())
                        {
                            WriteLog (lsWARNING, OfferCreateTransactor) << "takeOffers: ILLEGAL OFFER RESULT.";
                            bUnfunded   = true;
                            terResult   = bOpenLedger ? telFAILED_PROCESSING : tecFAILED_PROCESSING;
                        }
                    }
                    else
                    {
                        // Taker got nothing, probably due to rounding. Consider taker unfunded.
                        WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: No claim.";

                        bUnfunded   = true;
                        terResult   = tesSUCCESS;                   // Done.
                    }

                    assert (uTakerGetsAccountID == saSubTakerGot.getIssuer ());
                    assert (uTakerPaysAccountID == saSubTakerPaid.getIssuer ());

                    if (!bUnfunded)
                    {
                        // Distribute funds. The sends charge appropriate fees which are implied by offer.

                        terResult   = lesActive.accountSend (uOfferOwnerID, uTakerAccountID, saSubTakerGot);            // Offer owner pays taker.

                        if (tesSUCCESS == terResult)
                            terResult   = lesActive.accountSend (uTakerAccountID, uOfferOwnerID, saSubTakerPaid);           // Taker pays offer owner.

                        if (bSell)
                        {
                            // Sell semantics:
                            // Reduce amount considered received to original offer's rate.
                            // Not by crossing rate, which is higher.
                            STAmount saEffectiveGot = STAmount::divide(saSubTakerPaid, saTakerRate, saTakerGets);
                            saSubTakerGot = std::min(saEffectiveGot, saSubTakerGot);
                        }
                        else
                        {
                            // Buy semantics: Reduce amount considered paid by taker's rate. Not by actual cost which is lower.
                            // That is, take less as to just satify our buy requirement.
                            STAmount    saTakerCould    = saTakerPays - saTakerPaid;    // Taker could pay.

                            if (saTakerFunds < saTakerCould)
                                saTakerCould    = saTakerFunds;

                            STAmount    saTakerUsed = STAmount::multiply (saSubTakerGot, saTakerRate, saTakerPays);

                            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:   saTakerCould: " << saTakerCould.getFullText ();
                            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:  saSubTakerGot: " << saSubTakerGot.getFullText ();
                            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerRate: " << saTakerRate.getFullText ();
                            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: applyOffer:    saTakerUsed: " << saTakerUsed.getFullText ();

                            saSubTakerPaid  = std::min (saTakerCould, saTakerUsed);
                        }

                        saTakerPaid     += saSubTakerPaid;
                        saTakerGot      += saSubTakerGot;

                        if (tesSUCCESS == terResult)
                            terResult   = temUNCERTAIN;
                    }
                }
            }
        }
    }

    if (temUNCERTAIN == terResult)
        terResult = tesSUCCESS;

    WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: " << transToken (terResult);

    if (tesSUCCESS == terResult)
    {
        // On success, delete offers that became unfunded.
        BOOST_FOREACH (uint256 const & uOfferIndex, usOfferUnfundedBecame)
        {
            WriteLog (lsDEBUG, OfferCreateTransactor) << "takeOffers: became unfunded: " << uOfferIndex.ToString ();

            terResult   = lesActive.offerDelete (uOfferIndex);

            if (tesSUCCESS != terResult)
                break;
        }