bool
AllowTrustOpFrame::doApply(LedgerDelta& delta, LedgerManager& ledgerManager)
{
    if (!(mSourceAccount->getAccount().flags & AUTH_REQUIRED_FLAG))
    { // this account doesn't require authorization to hold credit
        innerResult().code(ALLOW_TRUST_TRUST_NOT_REQUIRED);
        return false;
    }

    if (!(mSourceAccount->getAccount().flags & AUTH_REVOCABLE_FLAG) &&
        !mAllowTrust.authorize)
    {
        innerResult().code(ALLOW_TRUST_CANT_REVOKE);
        return false;
    }

    Currency ci;
    ci.type(CURRENCY_TYPE_ALPHANUM);
    ci.alphaNum().currencyCode = mAllowTrust.currency.currencyCode();
    ci.alphaNum().issuer = getSourceID();

    Database& db = ledgerManager.getDatabase();
    TrustFrame::pointer trustLine;
    trustLine = TrustFrame::loadTrustLine(mAllowTrust.trustor, ci, db);

    if (!trustLine)
    {
        innerResult().code(ALLOW_TRUST_NO_TRUST_LINE);
        return false;
    }

    innerResult().code(ALLOW_TRUST_SUCCESS);

    trustLine->setAuthorized(mAllowTrust.authorize);

    trustLine->storeChange(delta, db);

    return true;
}
bool
PathPaymentOpFrame::doApply(medida::MetricsRegistry& metrics,
                            LedgerDelta& delta, LedgerManager& ledgerManager)
{
    Database& db = ledgerManager.getDatabase();

    innerResult().code(PATH_PAYMENT_SUCCESS);

    // tracks the last amount that was traded
    int64_t curBReceived = mPathPayment.destAmount;
    Asset curB = mPathPayment.destAsset;

    // update balances, walks backwards

    // build the full path to the destination, starting with sendAsset
    std::vector<Asset> fullPath;
    fullPath.emplace_back(mPathPayment.sendAsset);
    fullPath.insert(fullPath.end(), mPathPayment.path.begin(),
                    mPathPayment.path.end());

    bool bypassIssuerCheck = false;

    // if the payment doesn't involve intermediate accounts
    // and the destination is the issuer we don't bother
    // checking if the destination account even exist
    // so that it's always possible to send credits back to its issuer
    bypassIssuerCheck = (curB.type() != ASSET_TYPE_NATIVE) &&
                        (fullPath.size() == 1) &&
                        (mPathPayment.sendAsset == mPathPayment.destAsset) &&
                        (getIssuer(curB) == mPathPayment.destination);

    AccountFrame::pointer destination;

    if (!bypassIssuerCheck)
    {
        destination = AccountFrame::loadAccount(mPathPayment.destination, db);

        if (!destination)
        {
            metrics.NewMeter({"op-path-payment", "failure", "no-destination"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_NO_DESTINATION);
            return false;
        }
    }

    // update last balance in the chain
    if (curB.type() == ASSET_TYPE_NATIVE)
    {
        destination->getAccount().balance += curBReceived;
        destination->storeChange(delta, db);
    }
    else
    {
        TrustFrame::pointer destLine;

        if (bypassIssuerCheck)
        {
            destLine =
                TrustFrame::loadTrustLine(mPathPayment.destination, curB, db);
        }
        else
        {
            auto tlI = TrustFrame::loadTrustLineIssuer(mPathPayment.destination,
                                                       curB, db);
            if (!tlI.second)
            {
                metrics.NewMeter({"op-path-payment", "failure", "no-issuer"},
                                 "operation").Mark();
                innerResult().code(PATH_PAYMENT_NO_ISSUER);
                innerResult().noIssuer() = curB;
                return false;
            }
            destLine = tlI.first;
        }

        if (!destLine)
        {
            metrics.NewMeter({"op-path-payment", "failure", "no-trust"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_NO_TRUST);
            return false;
        }

        if (!destLine->isAuthorized())
        {
            metrics.NewMeter({"op-path-payment", "failure", "not-authorized"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_NOT_AUTHORIZED);
            return false;
        }

        if (!destLine->addBalance(curBReceived))
        {
            metrics.NewMeter({"op-path-payment", "failure", "line-full"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_LINE_FULL);
            return false;
        }

        destLine->storeChange(delta, db);
    }

    innerResult().success().last =
        SimplePaymentResult(mPathPayment.destination, curB, curBReceived);

    // now, walk the path backwards
    for (int i = (int)fullPath.size() - 1; i >= 0; i--)
    {
        int64_t curASent, actualCurBReceived;
        Asset const& curA = fullPath[i];

        if (curA == curB)
        {
            continue;
        }

        if (curA.type() != ASSET_TYPE_NATIVE)
        {
            if (!AccountFrame::loadAccount(getIssuer(curA), db))
            {
                metrics.NewMeter({"op-path-payment", "failure", "no-issuer"},
                                 "operation").Mark();
                innerResult().code(PATH_PAYMENT_NO_ISSUER);
                innerResult().noIssuer() = curA;
                return false;
            }
        }

        OfferExchange oe(delta, ledgerManager);

        // curA -> curB
        OfferExchange::ConvertResult r = oe.convertWithOffers(
            curA, INT64_MAX, curASent, curB, curBReceived, actualCurBReceived,
            [this, &metrics](OfferFrame const& o)
            {
                if (o.getSellerID() == getSourceID())
                {
                    // we are crossing our own offer, potentially invalidating
                    // mSourceAccount (balance or numSubEntries)
                    metrics.NewMeter({"op-path-payment", "failure",
                                      "offer-cross-self"},
                                     "operation").Mark();
                    innerResult().code(PATH_PAYMENT_OFFER_CROSS_SELF);
                    return OfferExchange::eStop;
                }
                return OfferExchange::eKeep;
            });
        switch (r)
        {
        case OfferExchange::eFilterStop:
            return false;
        case OfferExchange::eOK:
            if (curBReceived == actualCurBReceived)
            {
                break;
            }
        // fall through
        case OfferExchange::ePartial:
            metrics.NewMeter({"op-path-payment", "failure", "too-few-offers"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_TOO_FEW_OFFERS);
            return false;
        }
        assert(curBReceived == actualCurBReceived);
        curBReceived = curASent; // next round, we need to send enough
        curB = curA;

        // add offers that got taken on the way
        // insert in front to match the path's order
        auto& offers = innerResult().success().offers;
        offers.insert(offers.begin(), oe.getOfferTrail().begin(),
                      oe.getOfferTrail().end());
    }

    // last step: we've reached the first account in the chain, update its
    // balance

    int64_t curBSent;

    curBSent = curBReceived;

    if (curBSent > mPathPayment.sendMax)
    { // make sure not over the max
        metrics.NewMeter({"op-path-payment", "failure", "over-send-max"},
                         "operation").Mark();
        innerResult().code(PATH_PAYMENT_OVER_SENDMAX);
        return false;
    }

    if (curB.type() == ASSET_TYPE_NATIVE)
    {
        int64_t minBalance = mSourceAccount->getMinimumBalance(ledgerManager);

        if ((mSourceAccount->getAccount().balance - curBSent) < minBalance)
        { // they don't have enough to send
            metrics.NewMeter({"op-path-payment", "failure", "underfunded"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_UNDERFUNDED);
            return false;
        }

        mSourceAccount->getAccount().balance -= curBSent;
        mSourceAccount->storeChange(delta, db);
    }
    else
    {
        TrustFrame::pointer sourceLineFrame;
        if (bypassIssuerCheck)
        {
            sourceLineFrame =
                TrustFrame::loadTrustLine(getSourceID(), curB, db);
        }
        else
        {
            auto tlI = TrustFrame::loadTrustLineIssuer(getSourceID(), curB, db);

            if (!tlI.second)
            {
                metrics.NewMeter({"op-path-payment", "failure", "no-issuer"},
                                 "operation").Mark();
                innerResult().code(PATH_PAYMENT_NO_ISSUER);
                innerResult().noIssuer() = curB;
                return false;
            }
            sourceLineFrame = tlI.first;
        }

        if (!sourceLineFrame)
        {
            metrics.NewMeter({"op-path-payment", "failure", "src-no-trust"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_SRC_NO_TRUST);
            return false;
        }

        if (!sourceLineFrame->isAuthorized())
        {
            metrics.NewMeter(
                        {"op-path-payment", "failure", "src-not-authorized"},
                        "operation").Mark();
            innerResult().code(PATH_PAYMENT_SRC_NOT_AUTHORIZED);
            return false;
        }

        if (!sourceLineFrame->addBalance(-curBSent))
        {
            metrics.NewMeter({"op-path-payment", "failure", "underfunded"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_UNDERFUNDED);
            return false;
        }

        sourceLineFrame->storeChange(delta, db);
    }

    metrics.NewMeter({"op-path-payment", "success", "apply"}, "operation")
        .Mark();

    return true;
}
OfferExchange::CrossOfferResult
OfferExchange::crossOffer(OfferFrame& sellingWheatOffer,
                          int64_t maxWheatReceived, int64_t& numWheatReceived,
                          int64_t maxSheepSend, int64_t& numSheepSend)
{
    Asset& sheep = sellingWheatOffer.getOffer().buying;
    Asset& wheat = sellingWheatOffer.getOffer().selling;
    AccountID& accountBID = sellingWheatOffer.getOffer().sellerID;

    Database& db = mLedgerManager.getDatabase();

    AccountFrame::pointer accountB;
    accountB = AccountFrame::loadAccount(accountBID, db);
    if (!accountB)
    {
        throw std::runtime_error(
            "invalid database state: offer must have matching account");
    }

    TrustFrame::pointer wheatLineAccountB;
    if (wheat.type() != ASSET_TYPE_NATIVE)
    {
        wheatLineAccountB = TrustFrame::loadTrustLine(accountBID, wheat, db);
        if (!wheatLineAccountB)
        {
            throw std::runtime_error(
                "invalid database state: offer must have matching trust line");
        }
    }

    TrustFrame::pointer sheepLineAccountB;

    if (sheep.type() == ASSET_TYPE_NATIVE)
    {
        numWheatReceived = INT64_MAX;
    }
    else
    {
        sheepLineAccountB = TrustFrame::loadTrustLine(accountBID, sheep, db);
        if (!sheepLineAccountB)
        {
            throw std::runtime_error(
                "invalid database state: offer must have matching trust line");
        }

        // compute numWheatReceived based on what the account can receive
        int64_t sellerMaxSheep = sheepLineAccountB->getMaxAmountReceive();

        if (!bigDivide(numWheatReceived, sellerMaxSheep,
                       sellingWheatOffer.getOffer().price.d,
                       sellingWheatOffer.getOffer().price.n))
        {
            numWheatReceived = INT64_MAX;
        }
    }

    // adjust numWheatReceived with what the seller has
    {
        int64_t wheatCanSell;
        if (wheat.type() == ASSET_TYPE_NATIVE)
        {
            // can only send above the minimum balance
            wheatCanSell = accountB->getBalanceAboveReserve(mLedgerManager);
        }
        else
        {
            if (wheatLineAccountB->isAuthorized())
            {
                wheatCanSell = wheatLineAccountB->getBalance();
            }
            else
            {
                wheatCanSell = 0;
            }
        }
        if (numWheatReceived > wheatCanSell)
        {
            numWheatReceived = wheatCanSell;
        }
    }
    // you can receive the lesser of the amount of wheat offered or
    // the amount the guy has

    if (numWheatReceived >= sellingWheatOffer.getOffer().amount)
    {
        numWheatReceived = sellingWheatOffer.getOffer().amount;
    }
    else
    {
        // update the offer based on the balance (to determine if it should be
        // deleted or not)
        // note that we don't need to write into the db at this point as the
        // actual update
        // is done further down
        sellingWheatOffer.getOffer().amount = numWheatReceived;
    }

    bool reducedOffer = false;

    if (numWheatReceived > maxWheatReceived)
    {
        numWheatReceived = maxWheatReceived;
        reducedOffer = true;
    }

    // this guy can get X wheat to you. How many sheep does that get him?
    if (!bigDivide(numSheepSend, numWheatReceived,
                   sellingWheatOffer.getOffer().price.n,
                   sellingWheatOffer.getOffer().price.d))
    {
        numSheepSend = INT64_MAX;
    }

    if (numSheepSend > maxSheepSend)
    {
        // reduce the number even more if there is a limit on Sheep
        numSheepSend = maxSheepSend;
        reducedOffer = true;
    }

    // bias towards seller (this cannot overflow at this point)
    numWheatReceived =
        bigDivide(numSheepSend, sellingWheatOffer.getOffer().price.d,
                  sellingWheatOffer.getOffer().price.n);

    bool offerTaken = false;

    if (numWheatReceived == 0 || numSheepSend == 0)
    {
        if (reducedOffer)
        {
            return eOfferCantConvert;
        }
        else
        {
            // force delete the offer as it represents a bogus offer
            numWheatReceived = 0;
            numSheepSend = 0;
            offerTaken = true;
        }
    }

    offerTaken =
        offerTaken || sellingWheatOffer.getOffer().amount <= numWheatReceived;
    if (offerTaken)
    {   // entire offer is taken
        sellingWheatOffer.storeDelete(mDelta, db);

        accountB->addNumEntries(-1, mLedgerManager);
        accountB->storeChange(mDelta, db);
    }
    else
    {
        sellingWheatOffer.getOffer().amount -= numWheatReceived;
        sellingWheatOffer.storeChange(mDelta, db);
    }

    // Adjust balances
    if (sheep.type() == ASSET_TYPE_NATIVE)
    {
        accountB->getAccount().balance += numSheepSend;
        accountB->storeChange(mDelta, db);
    }
    else
    {
        if (!sheepLineAccountB->addBalance(numSheepSend))
        {
            return eOfferCantConvert;
        }
        sheepLineAccountB->storeChange(mDelta, db);
    }

    if (wheat.type() == ASSET_TYPE_NATIVE)
    {
        accountB->getAccount().balance -= numWheatReceived;
        accountB->storeChange(mDelta, db);
    }
    else
    {
        if (!wheatLineAccountB->addBalance(-numWheatReceived))
        {
            return eOfferCantConvert;
        }
        wheatLineAccountB->storeChange(mDelta, db);
    }

    mOfferTrail.push_back(
        ClaimOfferAtom(accountB->getID(), sellingWheatOffer.getOfferID(), wheat,
                       numWheatReceived, sheep, numSheepSend));

    return offerTaken ? eOfferTaken : eOfferPartial;
}
// you are selling sheep for wheat
// need to check the counter offers selling wheat for sheep
// see if this is modifying an old offer
// see if this offer crosses any existing offers
bool
ManageOfferOpFrame::doApply(medida::MetricsRegistry& metrics,
                            LedgerDelta& delta, LedgerManager& ledgerManager)
{
    Database& db = ledgerManager.getDatabase();

    if (!checkOfferValid(metrics, db))
    {
        return false;
    }

    Asset const& sheep = mManageOffer.selling;
    Asset const& wheat = mManageOffer.buying;

    bool creatingNewOffer = false;
    uint64_t offerID = mManageOffer.offerID;

    if (offerID)
    { // modifying an old offer
        mSellSheepOffer = OfferFrame::loadOffer(getSourceID(), offerID, db);

        if (mSellSheepOffer)
        {
            // make sure the currencies are the same
            if (!compareAsset(mManageOffer.selling,
                              mSellSheepOffer->getOffer().selling) ||
                !compareAsset(mManageOffer.buying,
                              mSellSheepOffer->getOffer().buying))
            {
                metrics.NewMeter({"op-manage-offer", "invalid", "mismatch"},
                                 "operation").Mark();
                innerResult().code(MANAGE_OFFER_MISMATCH);
                return false;
            }
            mPassive = mSellSheepOffer->getFlags() & PASSIVE_FLAG;
        }
        else
        {
            metrics.NewMeter({"op-manage-offer", "invalid", "not-found"},
                             "operation").Mark();
            innerResult().code(MANAGE_OFFER_NOT_FOUND);
            return false;
        }
    }
    else
    { // creating a new Offer
        creatingNewOffer = true;
        mSellSheepOffer = OfferFrame::from(getSourceID(), mManageOffer);
        if (mPassive)
            mSellSheepOffer->mEntry.data.offer().flags = PASSIVE_FLAG;
    }

    int64_t maxSheepSend = mManageOffer.amount;

    int64_t maxAmountOfSheepCanSell;
    if (sheep.type() == ASSET_TYPE_NATIVE)
    {
        maxAmountOfSheepCanSell =
            mSourceAccount->getBalanceAboveReserve(ledgerManager);
    }
    else
    {
        maxAmountOfSheepCanSell = mSheepLineA->getBalance();
    }

    // the maximum is defined by how much wheat it can receive
    int64_t maxWheatCanSell;
    if (wheat.type() == ASSET_TYPE_NATIVE)
    {
        maxWheatCanSell = INT64_MAX;
    }
    else
    {
        maxWheatCanSell = mWheatLineA->getMaxAmountReceive();
        if (maxWheatCanSell == 0)
        {
            metrics.NewMeter({"op-manage-offer", "invalid", "line-full"},
                             "operation").Mark();
            innerResult().code(MANAGE_OFFER_LINE_FULL);
            return false;
        }
    }

    {
        int64_t maxSheepBasedOnWheat;
        if (!bigDivide(maxSheepBasedOnWheat, maxWheatCanSell,
                       mManageOffer.price.d, mManageOffer.price.n))
        {
            maxSheepBasedOnWheat = INT64_MAX;
        }

        if (maxAmountOfSheepCanSell > maxSheepBasedOnWheat)
        {
            maxAmountOfSheepCanSell = maxSheepBasedOnWheat;
        }
    }

    // amount of sheep for sale is the lesser of amount we can sell and amount
    // put in the offer
    if (maxAmountOfSheepCanSell < maxSheepSend)
    {
        maxSheepSend = maxAmountOfSheepCanSell;
    }

    Price sheepPrice = mManageOffer.price;

    innerResult().code(MANAGE_OFFER_SUCCESS);

    {
        soci::transaction sqlTx(db.getSession());
        LedgerDelta tempDelta(delta);

        int64_t sheepSent, wheatReceived;

        OfferExchange oe(tempDelta, ledgerManager);

        Price maxWheatPrice(sheepPrice.d, sheepPrice.n);

        OfferExchange::ConvertResult r = oe.convertWithOffers(
            sheep, maxSheepSend, sheepSent, wheat, maxWheatCanSell,
            wheatReceived, [this, maxWheatPrice](OfferFrame const& o)
            {
                if ((mPassive && (o.getPrice() >= maxWheatPrice)) ||
                    (o.getPrice() > maxWheatPrice))
                {
                    return OfferExchange::eStop;
                }
                if (o.getSellerID() == getSourceID())
                {
                    // we are crossing our own offer
                    innerResult().code(MANAGE_OFFER_CROSS_SELF);
                    return OfferExchange::eStop;
                }
                return OfferExchange::eKeep;
            });

        bool offerIsValid = false;

        switch (r)
        {
        case OfferExchange::eOK:
        case OfferExchange::ePartial:
            offerIsValid = true;
            break;
        case OfferExchange::eFilterStop:
            if (innerResult().code() != MANAGE_OFFER_SUCCESS)
            {
                return false;
            }
            offerIsValid = true;
            break;
        }

        // updates the result with the offers that got taken on the way

        for (auto const& oatom : oe.getOfferTrail())
        {
            innerResult().success().offersClaimed.push_back(oatom);
        }

        if (wheatReceived > 0)
        {
            if (wheat.type() == ASSET_TYPE_NATIVE)
            {
                mSourceAccount->getAccount().balance += wheatReceived;
                mSourceAccount->storeChange(delta, db);
            }
            else
            {
                TrustFrame::pointer wheatLineSigningAccount;
                wheatLineSigningAccount =
                    TrustFrame::loadTrustLine(getSourceID(), wheat, db);
                if (!wheatLineSigningAccount)
                {
                    throw std::runtime_error("invalid database state: must "
                                             "have matching trust line");
                }
                if (!wheatLineSigningAccount->addBalance(wheatReceived))
                {
                    // this would indicate a bug in OfferExchange
                    throw std::runtime_error("offer claimed over limit");
                }

                wheatLineSigningAccount->storeChange(delta, db);
            }

            if (sheep.type() == ASSET_TYPE_NATIVE)
            {
                mSourceAccount->getAccount().balance -= sheepSent;
                mSourceAccount->storeChange(delta, db);
            }
            else
            {
                if (!mSheepLineA->addBalance(-sheepSent))
                {
                    // this would indicate a bug in OfferExchange
                    throw std::runtime_error("offer sold more than balance");
                }
                mSheepLineA->storeChange(delta, db);
            }
        }

        // recomputes the amount of sheep for sale
        mSellSheepOffer->getOffer().amount = maxSheepSend - sheepSent;

        if (offerIsValid && mSellSheepOffer->getOffer().amount > 0)
        { // we still have sheep to sell so leave an offer

            if (creatingNewOffer)
            {
                // make sure we don't allow us to add offers when we don't have
                // the minbalance
                if (!mSourceAccount->addNumEntries(1, ledgerManager))
                {
                    metrics.NewMeter(
                                {"op-manage-offer", "invalid", "low reserve"},
                                "operation").Mark();
                    innerResult().code(MANAGE_OFFER_LOW_RESERVE);
                    return false;
                }
                mSellSheepOffer->mEntry.data.offer().offerID =
                    tempDelta.getHeaderFrame().generateID();
                innerResult().success().offer.effect(MANAGE_OFFER_CREATED);
                mSellSheepOffer->storeAdd(tempDelta, db);
                mSourceAccount->storeChange(tempDelta, db);
            }
            else
            {
                innerResult().success().offer.effect(MANAGE_OFFER_UPDATED);
                mSellSheepOffer->storeChange(tempDelta, db);
            }
            innerResult().success().offer.offer() = mSellSheepOffer->getOffer();
        }
        else
        {
            innerResult().success().offer.effect(MANAGE_OFFER_DELETED);

            if (!creatingNewOffer)
            {
                mSellSheepOffer->storeDelete(tempDelta, db);
                mSourceAccount->addNumEntries(-1, ledgerManager);
                mSourceAccount->storeChange(tempDelta, db);
            }
        }

        sqlTx.commit();
        tempDelta.commit();
    }
    metrics.NewMeter({"op-create-offer", "success", "apply"}, "operation")
        .Mark();
    return true;
}
bool
AllowTrustOpFrame::doApply(Application& app, LedgerDelta& delta,
                           LedgerManager& ledgerManager)
{
    if (ledgerManager.getCurrentLedgerVersion() > 2)
    {
        if (mAllowTrust.trustor == getSourceID())
        { // since version 3 it is not
            // allowed to use ALLOW_TRUST on
            // self
            app.getMetrics()
                .NewMeter({"op-allow-trust", "failure", "trust-self"},
                          "operation")
                .Mark();
            innerResult().code(ALLOW_TRUST_SELF_NOT_ALLOWED);
            return false;
        }
    }

    if (!(mSourceAccount->getAccount().flags & AUTH_REQUIRED_FLAG))
    { // this account doesn't require authorization to
        // hold credit
        app.getMetrics()
            .NewMeter({"op-allow-trust", "failure", "not-required"},
                      "operation")
            .Mark();
        innerResult().code(ALLOW_TRUST_TRUST_NOT_REQUIRED);
        return false;
    }

    if (!(mSourceAccount->getAccount().flags & AUTH_REVOCABLE_FLAG) &&
        !mAllowTrust.authorize)
    {
        app.getMetrics()
            .NewMeter({"op-allow-trust", "failure", "cant-revoke"}, "operation")
            .Mark();
        innerResult().code(ALLOW_TRUST_CANT_REVOKE);
        return false;
    }

    Asset ci;
    ci.type(mAllowTrust.asset.type());
    if (mAllowTrust.asset.type() == ASSET_TYPE_CREDIT_ALPHANUM4)
    {
        ci.alphaNum4().assetCode = mAllowTrust.asset.assetCode4();
        ci.alphaNum4().issuer = getSourceID();
    }
    else if (mAllowTrust.asset.type() == ASSET_TYPE_CREDIT_ALPHANUM12)
    {
        ci.alphaNum12().assetCode = mAllowTrust.asset.assetCode12();
        ci.alphaNum12().issuer = getSourceID();
    }

    Database& db = ledgerManager.getDatabase();
    TrustFrame::pointer trustLine;
    trustLine = TrustFrame::loadTrustLine(mAllowTrust.trustor, ci, db, &delta);

    if (!trustLine)
    {
        app.getMetrics()
            .NewMeter({"op-allow-trust", "failure", "no-trust-line"},
                      "operation")
            .Mark();
        innerResult().code(ALLOW_TRUST_NO_TRUST_LINE);
        return false;
    }

    app.getMetrics()
        .NewMeter({"op-allow-trust", "success", "apply"}, "operation")
        .Mark();
    innerResult().code(ALLOW_TRUST_SUCCESS);

    trustLine->setAuthorized(mAllowTrust.authorize);

    trustLine->storeChange(delta, db);

    return true;
}
bool
PathPaymentOpFrame::doApply(medida::MetricsRegistry& metrics,
                            LedgerDelta& delta, LedgerManager& ledgerManager)
{
    AccountFrame::pointer destination;

    Database& db = ledgerManager.getDatabase();

    destination = AccountFrame::loadAccount(mPathPayment.destination, db);

    if (!destination)
    {
        metrics.NewMeter({"op-path-payment", "failure", "no-destination"},
                         "operation").Mark();
        innerResult().code(PATH_PAYMENT_NO_DESTINATION);
        return false;
    }

    innerResult().code(PATH_PAYMENT_SUCCESS);

    // tracks the last amount that was traded
    int64_t curBReceived = mPathPayment.destAmount;
    Asset curB = mPathPayment.destAsset;

    // update balances, walks backwards

    // build the full path to the destination, starting with sendAsset
    std::vector<Asset> fullPath;
    fullPath.emplace_back(mPathPayment.sendAsset);
    fullPath.insert(fullPath.end(), mPathPayment.path.begin(),
                    mPathPayment.path.end());

    // update last balance in the chain
    {
        if (curB.type() == ASSET_TYPE_NATIVE)
        {
            destination->getAccount().balance += curBReceived;
            destination->storeChange(delta, db);
        }
        else
        {
            TrustFrame::pointer destLine;

            destLine =
                TrustFrame::loadTrustLine(destination->getID(), curB, db);
            if (!destLine)
            {
                metrics.NewMeter({"op-path-payment", "failure", "no-trust"},
                                 "operation").Mark();
                innerResult().code(PATH_PAYMENT_NO_TRUST);
                return false;
            }

            if (!destLine->isAuthorized())
            {
                metrics.NewMeter(
                            {"op-path-payment", "failure", "not-authorized"},
                            "operation").Mark();
                innerResult().code(PATH_PAYMENT_NOT_AUTHORIZED);
                return false;
            }

            if (!destLine->addBalance(curBReceived))
            {
                metrics.NewMeter({"op-path-payment", "failure", "line-full"},
                                 "operation").Mark();
                innerResult().code(PATH_PAYMENT_LINE_FULL);
                return false;
            }

            destLine->storeChange(delta, db);
        }

        innerResult().success().last =
            SimplePaymentResult(destination->getID(), curB, curBReceived);
    }

    // now, walk the path backwards
    for (int i = (int)fullPath.size() - 1; i >= 0; i--)
    {
        int64_t curASent, actualCurBReceived;
        Asset const& curA = fullPath[i];

        if (curA == curB)
        {
            continue;
        }

        OfferExchange oe(delta, ledgerManager);

        // curA -> curB
        OfferExchange::ConvertResult r =
            oe.convertWithOffers(curA, INT64_MAX, curASent, curB, curBReceived,
                                 actualCurBReceived, nullptr);
        switch (r)
        {
        case OfferExchange::eFilterStop:
            assert(false); // no filter -> should not happen
            break;
        case OfferExchange::eOK:
            if (curBReceived == actualCurBReceived)
            {
                break;
            }
        // fall through
        case OfferExchange::ePartial:
            metrics.NewMeter({"op-path-payment", "failure", "too-few-offers"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_TOO_FEW_OFFERS);
            return false;
        }
        assert(curBReceived == actualCurBReceived);
        curBReceived = curASent; // next round, we need to send enough
        curB = curA;

        // add offers that got taken on the way
        // insert in front to match the path's order
        auto& offers = innerResult().success().offers;
        offers.insert(offers.begin(), oe.getOfferTrail().begin(),
                      oe.getOfferTrail().end());
    }

    // last step: we've reached the first account in the chain, update its
    // balance

    int64_t curBSent;

    curBSent = curBReceived;

    if (curBSent > mPathPayment.sendMax)
    { // make sure not over the max
        metrics.NewMeter({"op-path-payment", "failure", "over-send-max"},
                         "operation").Mark();
        innerResult().code(PATH_PAYMENT_OVER_SENDMAX);
        return false;
    }

    if (curB.type() == ASSET_TYPE_NATIVE)
    {
        int64_t minBalance = mSourceAccount->getMinimumBalance(ledgerManager);

        if ((mSourceAccount->getAccount().balance - curBSent) < minBalance)
        { // they don't have enough to send
            metrics.NewMeter({"op-path-payment", "failure", "underfunded"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_UNDERFUNDED);
            return false;
        }

        mSourceAccount->getAccount().balance -= curBSent;
        mSourceAccount->storeChange(delta, db);
    }
    else
    {
        AccountFrame::pointer issuer;
        if(curB.type()==ASSET_TYPE_CREDIT_ALPHANUM4)
            issuer = AccountFrame::loadAccount(curB.alphaNum4().issuer, db);
        else if(curB.type()==ASSET_TYPE_CREDIT_ALPHANUM12)
            issuer = AccountFrame::loadAccount(curB.alphaNum12().issuer, db);

        if (!issuer)
        {
            metrics.NewMeter({"op-path-payment", "failure", "no-issuer"},
                             "operation").Mark();
            throw std::runtime_error("sendCredit Issuer not found");
        }

        TrustFrame::pointer sourceLineFrame;
        sourceLineFrame = TrustFrame::loadTrustLine(getSourceID(), curB, db);
        if (!sourceLineFrame)
        {
            metrics.NewMeter({"op-path-payment", "failure", "src-no-trust"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_SRC_NO_TRUST);
            return false;
        }

        if (!sourceLineFrame->isAuthorized())
        {
            metrics.NewMeter(
                        {"op-path-payment", "failure", "src-not-authorized"},
                        "operation").Mark();
            innerResult().code(PATH_PAYMENT_SRC_NOT_AUTHORIZED);
            return false;
        }

        if (!sourceLineFrame->addBalance(-curBSent))
        {
            metrics.NewMeter({"op-path-payment", "failure", "underfunded"},
                             "operation").Mark();
            innerResult().code(PATH_PAYMENT_UNDERFUNDED);
            return false;
        }

        sourceLineFrame->storeChange(delta, db);
    }

    metrics.NewMeter({"op-path-payment", "success", "apply"}, "operation")
        .Mark();

    return true;
}