CreateOffer.cpp

#include <xrpld/app/ledger/OrderBookDB.h>
#include <xrpld/app/misc/PermissionedDEXHelpers.h>
#include <xrpld/app/paths/Flow.h>
#include <xrpld/app/tx/detail/CreateOffer.h>
 
#include <xrpl/basics/base_uint.h>
#include <xrpl/beast/utility/WrappedSink.h>
#include <xrpl/ledger/PaymentSandbox.h>
#include <xrpl/protocol/Feature.h>
#include <xrpl/protocol/STAmount.h>
#include <xrpl/protocol/TER.h>
#include <xrpl/protocol/TxFlags.h>
#include <xrpl/protocol/st.h>
 
namespace ripple {
TxConsequences
CreateOffer::makeTxConsequences(PreflightContext const& ctx)
{
    auto calculateMaxXRPSpend = [](STTx const& tx) -> XRPAmount {
        auto const& amount{tx[sfTakerGets]};
        return amount.native() ? amount.xrp() : beast::zero;
    };
 
    return TxConsequences{ctx.tx, calculateMaxXRPSpend(ctx.tx)};
}
 
bool
CreateOffer::checkExtraFeatures(PreflightContext const& ctx)
{
    if (ctx.tx.isFieldPresent(sfDomainID) &&
        !ctx.rules.enabled(featurePermissionedDEX))
        return false;
 
    return true;
}
 
std::uint32_t
CreateOffer::getFlagsMask(PreflightContext const& ctx)
{
    // The tfOfferCreateMask is built assuming that PermissionedDEX is
    // enabled
    if (ctx.rules.enabled(featurePermissionedDEX))
        return tfOfferCreateMask;
    // If PermissionedDEX is not enabled, add tfHybrid to the mask,
    // indicating it is not allowed.
    return tfOfferCreateMask | tfHybrid;
}
 
NotTEC
CreateOffer::preflight(PreflightContext const& ctx)
{
    auto& tx = ctx.tx;
    auto& j = ctx.j;
 
    std::uint32_t const uTxFlags = tx.getFlags();
 
    if (tx.isFlag(tfHybrid) && !tx.isFieldPresent(sfDomainID))
        return temINVALID_FLAG;
 
    bool const bImmediateOrCancel(uTxFlags & tfImmediateOrCancel);
    bool const bFillOrKill(uTxFlags & tfFillOrKill);
 
    if (bImmediateOrCancel && bFillOrKill)
    {
        JLOG(j.debug()) << "Malformed transaction: both IoC and FoK set.";
        return temINVALID_FLAG;
    }
 
    bool const bHaveExpiration(tx.isFieldPresent(sfExpiration));
 
    if (bHaveExpiration && (tx.getFieldU32(sfExpiration) == 0))
    {
        JLOG(j.debug()) << "Malformed offer: bad expiration";
        return temBAD_EXPIRATION;
    }
 
    if (auto const cancelSequence = tx[~sfOfferSequence];
        cancelSequence && *cancelSequence == 0)
    {
        JLOG(j.debug()) << "Malformed offer: bad cancel sequence";
        return temBAD_SEQUENCE;
    }
 
    STAmount saTakerPays = tx[sfTakerPays];
    STAmount saTakerGets = tx[sfTakerGets];
 
    if (!isLegalNet(saTakerPays) || !isLegalNet(saTakerGets))
        return temBAD_AMOUNT;
 
    if (saTakerPays.native() && saTakerGets.native())
    {
        JLOG(j.debug()) << "Malformed offer: redundant (XRP for XRP)";
        return temBAD_OFFER;
    }
    if (saTakerPays <= beast::zero || saTakerGets <= beast::zero)
    {
        JLOG(j.debug()) << "Malformed offer: bad amount";
        return temBAD_OFFER;
    }
 
    auto const& uPaysIssuerID = saTakerPays.getIssuer();
    auto const& uPaysCurrency = saTakerPays.getCurrency();
 
    auto const& uGetsIssuerID = saTakerGets.getIssuer();
    auto const& uGetsCurrency = saTakerGets.getCurrency();
 
    if (uPaysCurrency == uGetsCurrency && uPaysIssuerID == uGetsIssuerID)
    {
        JLOG(j.debug()) << "Malformed offer: redundant (IOU for IOU)";
        return temREDUNDANT;
    }
    // We don't allow a non-native currency to use the currency code XRP.
    if (badCurrency() == uPaysCurrency || badCurrency() == uGetsCurrency)
    {
        JLOG(j.debug()) << "Malformed offer: bad currency";
        return temBAD_CURRENCY;
    }
 
    if (saTakerPays.native() != !uPaysIssuerID ||
        saTakerGets.native() != !uGetsIssuerID)
    {
        JLOG(j.debug()) << "Malformed offer: bad issuer";
        return temBAD_ISSUER;
    }
 
    return tesSUCCESS;
}
 
TER
CreateOffer::preclaim(PreclaimContext const& ctx)
{
    auto const id = ctx.tx[sfAccount];
 
    auto saTakerPays = ctx.tx[sfTakerPays];
    auto saTakerGets = ctx.tx[sfTakerGets];
 
    auto const& uPaysIssuerID = saTakerPays.getIssuer();
    auto const& uPaysCurrency = saTakerPays.getCurrency();
 
    auto const& uGetsIssuerID = saTakerGets.getIssuer();
 
    auto const cancelSequence = ctx.tx[~sfOfferSequence];
 
    auto const sleCreator = ctx.view.read(keylet::account(id));
    if (!sleCreator)
        return terNO_ACCOUNT;
 
    std::uint32_t const uAccountSequence = sleCreator->getFieldU32(sfSequence);
 
    auto viewJ = ctx.app.journal("View");
 
    if (isGlobalFrozen(ctx.view, uPaysIssuerID) ||
        isGlobalFrozen(ctx.view, uGetsIssuerID))
    {
        JLOG(ctx.j.debug()) << "Offer involves frozen asset";
        return tecFROZEN;
    }
 
    if (accountFunds(ctx.view, id, saTakerGets, fhZERO_IF_FROZEN, viewJ) <=
        beast::zero)
    {
        JLOG(ctx.j.debug())
            << "delay: Offers must be at least partially funded.";
        return tecUNFUNDED_OFFER;
    }
 
    // This can probably be simplified to make sure that you cancel sequences
    // before the transaction sequence number.
    if (cancelSequence && (uAccountSequence <= *cancelSequence))
    {
        JLOG(ctx.j.debug()) << "uAccountSequenceNext=" << uAccountSequence
                            << " uOfferSequence=" << *cancelSequence;
        return temBAD_SEQUENCE;
    }
 
    if (hasExpired(ctx.view, ctx.tx[~sfExpiration]))
    {
        // Note that this will get checked again in applyGuts, but it saves
        // us a call to checkAcceptAsset and possible false negative.
        return tecEXPIRED;
    }
 
    // Make sure that we are authorized to hold what the taker will pay us.
    if (!saTakerPays.native())
    {
        auto result = checkAcceptAsset(
            ctx.view,
            ctx.flags,
            id,
            ctx.j,
            Issue(uPaysCurrency, uPaysIssuerID));
        if (result != tesSUCCESS)
            return result;
    }
 
    // if domain is specified, make sure that domain exists and the offer create
    // is part of the domain
    if (ctx.tx.isFieldPresent(sfDomainID))
    {
        if (!permissioned_dex::accountInDomain(
                ctx.view, id, ctx.tx[sfDomainID]))
            return tecNO_PERMISSION;
    }
 
    return tesSUCCESS;
}
 
TER
CreateOffer::checkAcceptAsset(
    ReadView const& view,
    ApplyFlags const flags,
    AccountID const id,
    beast::Journal const j,
    Issue const& issue)
{
    // Only valid for custom currencies
    XRPL_ASSERT(
        !isXRP(issue.currency),
        "ripple::CreateOffer::checkAcceptAsset : input is not XRP");
 
    auto const issuerAccount = view.read(keylet::account(issue.account));
 
    if (!issuerAccount)
    {
        JLOG(j.debug())
            << "delay: can't receive IOUs from non-existent issuer: "
            << to_string(issue.account);
 
        return (flags & tapRETRY) ? TER{terNO_ACCOUNT} : TER{tecNO_ISSUER};
    }
 
    if (issue.account == id)
        // An account can always accept its own issuance.
        return tesSUCCESS;
 
    if ((*issuerAccount)[sfFlags] & lsfRequireAuth)
    {
        auto const trustLine =
            view.read(keylet::line(id, issue.account, issue.currency));
 
        if (!trustLine)
        {
            return (flags & tapRETRY) ? TER{terNO_LINE} : TER{tecNO_LINE};
        }
 
        // Entries have a canonical representation, determined by a
        // lexicographical "greater than" comparison employing strict weak
        // ordering. Determine which entry we need to access.
        bool const canonical_gt(id > issue.account);
 
        bool const is_authorized(
            (*trustLine)[sfFlags] & (canonical_gt ? lsfLowAuth : lsfHighAuth));
 
        if (!is_authorized)
        {
            JLOG(j.debug())
                << "delay: can't receive IOUs from issuer without auth.";
 
            return (flags & tapRETRY) ? TER{terNO_AUTH} : TER{tecNO_AUTH};
        }
    }
 
    // An account can not create a trustline to itself, so no line can exist
    // to be frozen. Additionally, an issuer can always accept its own
    // issuance.
    if (issue.account == id)
    {
        return tesSUCCESS;
    }
 
    auto const trustLine =
        view.read(keylet::line(id, issue.account, issue.currency));
 
    if (!trustLine)
    {
        return tesSUCCESS;
    }
 
    // There's no difference which side enacted deep freeze, accepting
    // tokens shouldn't be possible.
    bool const deepFrozen =
        (*trustLine)[sfFlags] & (lsfLowDeepFreeze | lsfHighDeepFreeze);
 
    if (deepFrozen)
    {
        return tecFROZEN;
    }
 
    return tesSUCCESS;
}
 
std::pair<TER, Amounts>
CreateOffer::flowCross(
    PaymentSandbox& psb,
    PaymentSandbox& psbCancel,
    Amounts const& takerAmount,
    std::optional<uint256> const& domainID)
{
    try
    {
        // If the taker is unfunded before we begin crossing there's nothing
        // to do - just return an error.
        //
        // We check this in preclaim, but when selling XRP charged fees can
        // cause a user's available balance to go to 0 (by causing it to dip
        // below the reserve) so we check this case again.
        STAmount const inStartBalance =
            accountFunds(psb, account_, takerAmount.in, fhZERO_IF_FROZEN, j_);
        if (inStartBalance <= beast::zero)
        {
            // The account balance can't cover even part of the offer.
            JLOG(j_.debug()) << "Not crossing: taker is unfunded.";
            return {tecUNFUNDED_OFFER, takerAmount};
        }
 
        // If the gateway has a transfer rate, accommodate that.  The
        // gateway takes its cut without any special consent from the
        // offer taker.  Set sendMax to allow for the gateway's cut.
        Rate gatewayXferRate{QUALITY_ONE};
        STAmount sendMax = takerAmount.in;
        if (!sendMax.native() && (account_ != sendMax.getIssuer()))
        {
            gatewayXferRate = transferRate(psb, sendMax.getIssuer());
            if (gatewayXferRate.value != QUALITY_ONE)
            {
                sendMax = multiplyRound(
                    takerAmount.in,
                    gatewayXferRate,
                    takerAmount.in.issue(),
                    true);
            }
        }
 
        // Payment flow code compares quality after the transfer rate is
        // included.  Since transfer rate is incorporated compute threshold.
        Quality threshold{takerAmount.out, sendMax};
 
        // If we're creating a passive offer adjust the threshold so we only
        // cross offers that have a better quality than this one.
        std::uint32_t const txFlags = ctx_.tx.getFlags();
        if (txFlags & tfPassive)
            ++threshold;
 
        // Don't send more than our balance.
        if (sendMax > inStartBalance)
            sendMax = inStartBalance;
 
        // Always invoke flow() with the default path.  However if neither
        // of the takerAmount currencies are XRP then we cross through an
        // additional path with XRP as the intermediate between two books.
        // This second path we have to build ourselves.
        STPathSet paths;
        if (!takerAmount.in.native() && !takerAmount.out.native())
        {
            STPath path;
            path.emplace_back(std::nullopt, xrpCurrency(), std::nullopt);
            paths.emplace_back(std::move(path));
        }
        // Special handling for the tfSell flag.
        STAmount deliver = takerAmount.out;
        OfferCrossing offerCrossing = OfferCrossing::yes;
        if (txFlags & tfSell)
        {
            offerCrossing = OfferCrossing::sell;
            // We are selling, so we will accept *more* than the offer
            // specified.  Since we don't know how much they might offer,
            // we allow delivery of the largest possible amount.
            if (deliver.native())
                deliver = STAmount{STAmount::cMaxNative};
            else
                // We can't use the maximum possible currency here because
                // there might be a gateway transfer rate to account for.
                // Since the transfer rate cannot exceed 200%, we use 1/2
                // maxValue for our limit.
                deliver = STAmount{
                    takerAmount.out.issue(),
                    STAmount::cMaxValue / 2,
                    STAmount::cMaxOffset};
        }
 
        // Call the payment engine's flow() to do the actual work.
        auto const result = flow(
            psb,
            deliver,
            account_,
            account_,
            paths,
            true,                       // default path
            !(txFlags & tfFillOrKill),  // partial payment
            true,                       // owner pays transfer fee
            offerCrossing,
            threshold,
            sendMax,
            domainID,
            j_);
 
        // If stale offers were found remove them.
        for (auto const& toRemove : result.removableOffers)
        {
            if (auto otr = psb.peek(keylet::offer(toRemove)))
                offerDelete(psb, otr, j_);
            if (auto otr = psbCancel.peek(keylet::offer(toRemove)))
                offerDelete(psbCancel, otr, j_);
        }
 
        // Determine the size of the final offer after crossing.
        auto afterCross = takerAmount;  // If !tesSUCCESS offer unchanged
        if (isTesSuccess(result.result()))
        {
            STAmount const takerInBalance = accountFunds(
                psb, account_, takerAmount.in, fhZERO_IF_FROZEN, j_);
 
            if (takerInBalance <= beast::zero)
            {
                // If offer crossing exhausted the account's funds don't
                // create the offer.
                afterCross.in.clear();
                afterCross.out.clear();
            }
            else
            {
                STAmount const rate{
                    Quality{takerAmount.out, takerAmount.in}.rate()};
 
                if (txFlags & tfSell)
                {
                    // If selling then scale the new out amount based on how
                    // much we sold during crossing.  This preserves the offer
                    // Quality,
 
                    // Reduce the offer that is placed by the crossed amount.
                    // Note that we must ignore the portion of the
                    // actualAmountIn that may have been consumed by a
                    // gateway's transfer rate.
                    STAmount nonGatewayAmountIn = result.actualAmountIn;
                    if (gatewayXferRate.value != QUALITY_ONE)
                        nonGatewayAmountIn = divideRound(
                            result.actualAmountIn,
                            gatewayXferRate,
                            takerAmount.in.issue(),
                            true);
 
                    afterCross.in -= nonGatewayAmountIn;
 
                    // It's possible that the divRound will cause our subtract
                    // to go slightly negative.  So limit afterCross.in to zero.
                    if (afterCross.in < beast::zero)
                        // We should verify that the difference *is* small, but
                        // what is a good threshold to check?
                        afterCross.in.clear();
 
                    afterCross.out = divRoundStrict(
                        afterCross.in, rate, takerAmount.out.issue(), false);
                }
                else
                {
                    // If not selling, we scale the input based on the
                    // remaining output.  This too preserves the offer
                    // Quality.
                    afterCross.out -= result.actualAmountOut;
                    XRPL_ASSERT(
                        afterCross.out >= beast::zero,
                        "ripple::CreateOffer::flowCross : minimum offer");
                    if (afterCross.out < beast::zero)
                        afterCross.out.clear();
                    afterCross.in = mulRound(
                        afterCross.out, rate, takerAmount.in.issue(), true);
                }
            }
        }
 
        // Return how much of the offer is left.
        return {tesSUCCESS, afterCross};
    }
    catch (std::exception const& e)
    {
        JLOG(j_.error()) << "Exception during offer crossing: " << e.what();
    }
    return {tecINTERNAL, takerAmount};
}
 
std::string
CreateOffer::format_amount(STAmount const& amount)
{
    std::string txt = amount.getText();
    txt += "/";
    txt += to_string(amount.issue().currency);
    return txt;
}
 
TER
CreateOffer::applyHybrid(
    Sandbox& sb,
    std::shared_ptr<STLedgerEntry> sleOffer,
    Keylet const& offerKey,
    STAmount const& saTakerPays,
    STAmount const& saTakerGets,
    std::function<void(SLE::ref, std::optional<uint256>)> const& setDir)
{
    if (!sleOffer->isFieldPresent(sfDomainID))
        return tecINTERNAL;  // LCOV_EXCL_LINE
 
    // set hybrid flag
    sleOffer->setFlag(lsfHybrid);
 
    // if offer is hybrid, need to also place into open offer dir
    Book const book{saTakerPays.issue(), saTakerGets.issue(), std::nullopt};
 
    auto dir =
        keylet::quality(keylet::book(book), getRate(saTakerGets, saTakerPays));
    bool const bookExists = sb.exists(dir);
 
    auto const bookNode = sb.dirAppend(dir, offerKey, [&](SLE::ref sle) {
        // don't set domainID on the directory object since this directory is
        // for open book
        setDir(sle, std::nullopt);
    });
 
    if (!bookNode)
    {
        JLOG(j_.debug())
            << "final result: failed to add hybrid offer to open book";
        return tecDIR_FULL;  // LCOV_EXCL_LINE
    }
 
    STArray bookArr(sfAdditionalBooks, 1);
    auto bookInfo = STObject::makeInnerObject(sfBook);
    bookInfo.setFieldH256(sfBookDirectory, dir.key);
    bookInfo.setFieldU64(sfBookNode, *bookNode);
    bookArr.push_back(std::move(bookInfo));
 
    if (!bookExists)
        ctx_.app.getOrderBookDB().addOrderBook(book);
 
    sleOffer->setFieldArray(sfAdditionalBooks, bookArr);
    return tesSUCCESS;
}
 
std::pair<TER, bool>
CreateOffer::applyGuts(Sandbox& sb, Sandbox& sbCancel)
{
    using beast::zero;
 
    std::uint32_t const uTxFlags = ctx_.tx.getFlags();
 
    bool const bPassive(uTxFlags & tfPassive);
    bool const bImmediateOrCancel(uTxFlags & tfImmediateOrCancel);
    bool const bFillOrKill(uTxFlags & tfFillOrKill);
    bool const bSell(uTxFlags & tfSell);
    bool const bHybrid(uTxFlags & tfHybrid);
 
    auto saTakerPays = ctx_.tx[sfTakerPays];
    auto saTakerGets = ctx_.tx[sfTakerGets];
    auto const domainID = ctx_.tx[~sfDomainID];
 
    auto const cancelSequence = ctx_.tx[~sfOfferSequence];
 
    // Note that we we use the value from the sequence or ticket as the
    // offer sequence.  For more explanation see comments in SeqProxy.h.
    auto const offerSequence = ctx_.tx.getSeqValue();
 
    // This is the original rate of the offer, and is the rate at which
    // it will be placed, even if crossing offers change the amounts that
    // end up on the books.
    auto uRate = getRate(saTakerGets, saTakerPays);
 
    auto viewJ = ctx_.app.journal("View");
 
    TER result = tesSUCCESS;
 
    // Process a cancellation request that's passed along with an offer.
    if (cancelSequence)
    {
        auto const sleCancel =
            sb.peek(keylet::offer(account_, *cancelSequence));
 
        // It's not an error to not find the offer to cancel: it might have
        // been consumed or removed. If it is found, however, it's an error
        // to fail to delete it.
        if (sleCancel)
        {
            JLOG(j_.debug()) << "Create cancels order " << *cancelSequence;
            result = offerDelete(sb, sleCancel, viewJ);
        }
    }
 
    auto const expiration = ctx_.tx[~sfExpiration];
 
    if (hasExpired(sb, expiration))
    {
        // If the offer has expired, the transaction has successfully
        // done nothing, so short circuit from here.
        return {tecEXPIRED, true};
    }
 
    bool const bOpenLedger = sb.open();
    bool crossed = false;
 
    if (result == tesSUCCESS)
    {
        // If a tick size applies, round the offer to the tick size
        auto const& uPaysIssuerID = saTakerPays.getIssuer();
        auto const& uGetsIssuerID = saTakerGets.getIssuer();
 
        std::uint8_t uTickSize = Quality::maxTickSize;
        if (!isXRP(uPaysIssuerID))
        {
            auto const sle = sb.read(keylet::account(uPaysIssuerID));
            if (sle && sle->isFieldPresent(sfTickSize))
                uTickSize = std::min(uTickSize, (*sle)[sfTickSize]);
        }
        if (!isXRP(uGetsIssuerID))
        {
            auto const sle = sb.read(keylet::account(uGetsIssuerID));
            if (sle && sle->isFieldPresent(sfTickSize))
                uTickSize = std::min(uTickSize, (*sle)[sfTickSize]);
        }
        if (uTickSize < Quality::maxTickSize)
        {
            auto const rate =
                Quality{saTakerGets, saTakerPays}.round(uTickSize).rate();
 
            // We round the side that's not exact,
            // just as if the offer happened to execute
            // at a slightly better (for the placer) rate
            if (bSell)
            {
                // this is a sell, round taker pays
                saTakerPays = multiply(saTakerGets, rate, saTakerPays.issue());
            }
            else
            {
                // this is a buy, round taker gets
                saTakerGets = divide(saTakerPays, rate, saTakerGets.issue());
            }
            if (!saTakerGets || !saTakerPays)
            {
                JLOG(j_.debug()) << "Offer rounded to zero";
                return {result, true};
            }
 
            uRate = getRate(saTakerGets, saTakerPays);
        }
 
        // We reverse pays and gets because during crossing we are taking.
        Amounts const takerAmount(saTakerGets, saTakerPays);
 
        JLOG(j_.debug()) << "Attempting cross: "
                         << to_string(takerAmount.in.issue()) << " -> "
                         << to_string(takerAmount.out.issue());
 
        if (auto stream = j_.trace())
        {
            stream << "   mode: " << (bPassive ? "passive " : "")
                   << (bSell ? "sell" : "buy");
            stream << "     in: " << format_amount(takerAmount.in);
            stream << "    out: " << format_amount(takerAmount.out);
        }
 
        // The amount of the offer that is unfilled after crossing has been
        // performed. It may be equal to the original amount (didn't cross),
        // empty (fully crossed), or something in-between.
        Amounts place_offer;
        PaymentSandbox psbFlow{&sb};
        PaymentSandbox psbCancelFlow{&sbCancel};
 
        std::tie(result, place_offer) =
            flowCross(psbFlow, psbCancelFlow, takerAmount, domainID);
        psbFlow.apply(sb);
        psbCancelFlow.apply(sbCancel);
 
        // We expect the implementation of cross to succeed
        // or give a tec.
        XRPL_ASSERT(
            result == tesSUCCESS || isTecClaim(result),
            "ripple::CreateOffer::applyGuts : result is tesSUCCESS or "
            "tecCLAIM");
 
        if (auto stream = j_.trace())
        {
            stream << "Cross result: " << transToken(result);
            stream << "     in: " << format_amount(place_offer.in);
            stream << "    out: " << format_amount(place_offer.out);
        }
 
        if (result == tecFAILED_PROCESSING && bOpenLedger)
            result = telFAILED_PROCESSING;
 
        if (result != tesSUCCESS)
        {
            JLOG(j_.debug()) << "final result: " << transToken(result);
            return {result, true};
        }
 
        XRPL_ASSERT(
            saTakerGets.issue() == place_offer.in.issue(),
            "ripple::CreateOffer::applyGuts : taker gets issue match");
        XRPL_ASSERT(
            saTakerPays.issue() == place_offer.out.issue(),
            "ripple::CreateOffer::applyGuts : taker pays issue match");
 
        if (takerAmount != place_offer)
            crossed = true;
 
        // The offer that we need to place after offer crossing should
        // never be negative. If it is, something went very very wrong.
        if (place_offer.in < zero || place_offer.out < zero)
        {
            JLOG(j_.fatal()) << "Cross left offer negative!"
                             << "     in: " << format_amount(place_offer.in)
                             << "    out: " << format_amount(place_offer.out);
            return {tefINTERNAL, true};
        }
 
        if (place_offer.in == zero || place_offer.out == zero)
        {
            JLOG(j_.debug()) << "Offer fully crossed!";
            return {result, true};
        }
 
        // We now need to adjust the offer to reflect the amount left after
        // crossing. We reverse in and out here, since during crossing we
        // were the taker.
        saTakerPays = place_offer.out;
        saTakerGets = place_offer.in;
    }
 
    XRPL_ASSERT(
        saTakerPays > zero && saTakerGets > zero,
        "ripple::CreateOffer::applyGuts : taker pays and gets positive");
 
    if (result != tesSUCCESS)
    {
        JLOG(j_.debug()) << "final result: " << transToken(result);
        return {result, true};
    }
 
    if (auto stream = j_.trace())
    {
        stream << "Place" << (crossed ? " remaining " : " ") << "offer:";
        stream << "    Pays: " << saTakerPays.getFullText();
        stream << "    Gets: " << saTakerGets.getFullText();
    }
 
    // For 'fill or kill' offers, failure to fully cross means that the
    // entire operation should be aborted, with only fees paid.
    if (bFillOrKill)
    {
        JLOG(j_.trace()) << "Fill or Kill: offer killed";
        return {tecKILLED, false};
    }
 
    // For 'immediate or cancel' offers, the amount remaining doesn't get
    // placed - it gets canceled and the operation succeeds.
    if (bImmediateOrCancel)
    {
        JLOG(j_.trace()) << "Immediate or cancel: offer canceled";
        if (!crossed)
            // Any ImmediateOrCancel offer that transfers absolutely no funds
            // returns tecKILLED rather than tesSUCCESS.  Motivation for the
            // change is here: https://github.com/ripple/rippled/issues/4115
            return {tecKILLED, false};
        return {tesSUCCESS, true};
    }
 
    auto const sleCreator = sb.peek(keylet::account(account_));
    if (!sleCreator)
        return {tefINTERNAL, false};
 
    {
        XRPAmount reserve =
            sb.fees().accountReserve(sleCreator->getFieldU32(sfOwnerCount) + 1);
 
        if (mPriorBalance < reserve)
        {
            // If we are here, the signing account had an insufficient reserve
            // *prior* to our processing. If something actually crossed, then
            // we allow this; otherwise, we just claim a fee.
            if (!crossed)
                result = tecINSUF_RESERVE_OFFER;
 
            if (result != tesSUCCESS)
            {
                JLOG(j_.debug()) << "final result: " << transToken(result);
            }
 
            return {result, true};
        }
    }
 
    // We need to place the remainder of the offer into its order book.
    auto const offer_index = keylet::offer(account_, offerSequence);
 
    // Add offer to owner's directory.
    auto const ownerNode = sb.dirInsert(
        keylet::ownerDir(account_), offer_index, describeOwnerDir(account_));
 
    if (!ownerNode)
    {
        // LCOV_EXCL_START
        JLOG(j_.debug())
            << "final result: failed to add offer to owner's directory";
        return {tecDIR_FULL, true};
        // LCOV_EXCL_STOP
    }
 
    // Update owner count.
    adjustOwnerCount(sb, sleCreator, 1, viewJ);
 
    JLOG(j_.trace()) << "adding to book: " << to_string(saTakerPays.issue())
                     << " : " << to_string(saTakerGets.issue())
                     << (domainID ? (" : " + to_string(*domainID)) : "");
 
    Book const book{saTakerPays.issue(), saTakerGets.issue(), domainID};
 
    // Add offer to order book, using the original rate
    // before any crossing occured.
    //
    // Regular offer - BookDirectory points to open directory
    //
    // Domain offer (w/o hyrbid) - BookDirectory points to domain
    // directory
    //
    // Hybrid domain offer - BookDirectory points to domain directory,
    // and AdditionalBooks field stores one entry that points to the open
    // directory
    auto dir = keylet::quality(keylet::book(book), uRate);
    bool const bookExisted = static_cast<bool>(sb.peek(dir));
 
    auto setBookDir = [&](SLE::ref sle,
                          std::optional<uint256> const& maybeDomain) {
        sle->setFieldH160(sfTakerPaysCurrency, saTakerPays.issue().currency);
        sle->setFieldH160(sfTakerPaysIssuer, saTakerPays.issue().account);
        sle->setFieldH160(sfTakerGetsCurrency, saTakerGets.issue().currency);
        sle->setFieldH160(sfTakerGetsIssuer, saTakerGets.issue().account);
        sle->setFieldU64(sfExchangeRate, uRate);
        if (maybeDomain)
            sle->setFieldH256(sfDomainID, *maybeDomain);
    };
 
    auto const bookNode = sb.dirAppend(dir, offer_index, [&](SLE::ref sle) {
        // sets domainID on book directory if it's a domain offer
        setBookDir(sle, domainID);
    });
 
    if (!bookNode)
    {
        // LCOV_EXCL_START
        JLOG(j_.debug()) << "final result: failed to add offer to book";
        return {tecDIR_FULL, true};
        // LCOV_EXCL_STOP
    }
 
    auto sleOffer = std::make_shared<SLE>(offer_index);
    sleOffer->setAccountID(sfAccount, account_);
    sleOffer->setFieldU32(sfSequence, offerSequence);
    sleOffer->setFieldH256(sfBookDirectory, dir.key);
    sleOffer->setFieldAmount(sfTakerPays, saTakerPays);
    sleOffer->setFieldAmount(sfTakerGets, saTakerGets);
    sleOffer->setFieldU64(sfOwnerNode, *ownerNode);
    sleOffer->setFieldU64(sfBookNode, *bookNode);
    if (expiration)
        sleOffer->setFieldU32(sfExpiration, *expiration);
    if (bPassive)
        sleOffer->setFlag(lsfPassive);
    if (bSell)
        sleOffer->setFlag(lsfSell);
    if (domainID)
        sleOffer->setFieldH256(sfDomainID, *domainID);
 
    // if it's a hybrid offer, set hybrid flag, and create an open dir
    if (bHybrid)
    {
        auto const res = applyHybrid(
            sb, sleOffer, offer_index, saTakerPays, saTakerGets, setBookDir);
        if (res != tesSUCCESS)
            return {res, true};  // LCOV_EXCL_LINE
    }
 
    sb.insert(sleOffer);
 
    if (!bookExisted)
        ctx_.app.getOrderBookDB().addOrderBook(book);
 
    JLOG(j_.debug()) << "final result: success";
 
    return {tesSUCCESS, true};
}
 
TER
CreateOffer::doApply()
{
    // This is the ledger view that we work against. Transactions are applied
    // as we go on processing transactions.
    Sandbox sb(&ctx_.view());
 
    // This is a ledger with just the fees paid and any unfunded or expired
    // offers we encounter removed. It's used when handling Fill-or-Kill offers,
    // if the order isn't going to be placed, to avoid wasting the work we did.
    Sandbox sbCancel(&ctx_.view());
 
    auto const result = applyGuts(sb, sbCancel);
    if (result.second)
        sb.apply(ctx_.rawView());
    else
        sbCancel.apply(ctx_.rawView());
    return result.first;
}
 
}  // namespace ripple