C++ STAmount::clear方法代码示例

// To deliver from an order book, when computing
TER PathCursor::deliverNodeReverseImpl (
    AccountID const& uOutAccountID, // --> Output owner's account.
    STAmount const& saOutReq,       // --> Funds requested to be
                                    // delivered for an increment.
    STAmount& saOutAct,             // <-- Funds actually delivered for an
                                    // increment
    bool callerHasLiquidity
                                        ) const
{
    TER resultCode   = tesSUCCESS;

    // Accumulation of what the previous node must deliver.
    // Possible optimization: Note this gets zeroed on each increment, ideally
    // only on first increment, then it could be a limit on the forward pass.
    saOutAct.clear (saOutReq);

    JLOG (j_.trace())
        << "deliverNodeReverse>"
        << " saOutAct=" << saOutAct
        << " saOutReq=" << saOutReq
        << " saPrvDlvReq=" << previousNode().saRevDeliver;

    assert (saOutReq != zero);

    int loopCount = 0;
    auto viewJ = rippleCalc_.logs_.journal ("View");

    // While we did not deliver as much as requested:
    while (saOutAct < saOutReq)
    {
        if (++loopCount >
            (multiQuality_ ?
                CALC_NODE_DELIVER_MAX_LOOPS_MQ :
                CALC_NODE_DELIVER_MAX_LOOPS))
        {
            JLOG (j_.warn()) << "loop count exceeded";
            return telFAILED_PROCESSING;
        }

        resultCode = advanceNode (saOutAct, true, callerHasLiquidity);
        // If needed, advance to next funded offer.

        if (resultCode != tesSUCCESS || !node().offerIndex_)
            // Error or out of offers.
            break;

        auto const xferRate = effectiveRate (
            node().issue_,
            uOutAccountID,
            node().offerOwnerAccount_,
            node().transferRate_);

        JLOG (j_.trace())
            << "deliverNodeReverse:"
            << " offerOwnerAccount_=" << node().offerOwnerAccount_
            << " uOutAccountID=" << uOutAccountID
            << " node().issue_.account=" << node().issue_.account
            << " xferRate=" << xferRate;

        // Only use rate when not in multi-quality mode
        if (!multiQuality_)
        {
            if (!node().rateMax)
            {
                // Set initial rate.
                JLOG (j_.trace())
                    << "Set initial rate";

                node().rateMax = xferRate;
            }
            else if (xferRate > node().rateMax)
            {
                // Offer exceeds initial rate.
                JLOG (j_.trace())
                    << "Offer exceeds initial rate: " << *node().rateMax;

                break;  // Done. Don't bother looking for smaller transferRates.
            }
            else if (xferRate < node().rateMax)
            {
                // Reducing rate. Additional offers will only
                // be considered for this increment if they
                // are at least this good.
                //
                // At this point, the overall rate is reducing,
                // while the overall rate is not xferRate, it
                // would be wrong to add anything with a rate
                // above xferRate.
                //
                // The rate would be reduced if the current
                // offer was from the issuer and the previous
                // offer wasn't.

                JLOG (j_.trace())
                    << "Reducing rate: " << *node().rateMax;

                node().rateMax = xferRate;
            }
        }
//.........这里部分代码省略.........

TER PathCursor::deliverNodeForward (
    AccountID const& uInAccountID,    // --> Input owner's account.
    STAmount const& saInReq,        // --> Amount to deliver.
    STAmount& saInAct,              // <-- Amount delivered, this invocation.
    STAmount& saInFees,             // <-- Fees charged, this invocation.
    bool callerHasLiquidity) const
{
    TER resultCode   = tesSUCCESS;

    // Don't deliver more than wanted.
    // Zeroed in reverse pass.
    node().directory.restart(multiQuality_);

    saInAct.clear (saInReq);
    saInFees.clear (saInReq);

    int loopCount = 0;
    auto viewJ = rippleCalc_.logs_.journal ("View");

    // XXX Perhaps make sure do not exceed node().saRevDeliver as another way to
    // stop?
    while (resultCode == tesSUCCESS && saInAct + saInFees < saInReq)
    {
        // Did not spend all inbound deliver funds.
        if (++loopCount >
            (multiQuality_ ?
                CALC_NODE_DELIVER_MAX_LOOPS_MQ :
                CALC_NODE_DELIVER_MAX_LOOPS))
        {
            JLOG (j_.warn())
                << "deliverNodeForward: max loops cndf";
            return telFAILED_PROCESSING;
        }

        // Determine values for pass to adjust saInAct, saInFees, and
        // node().saFwdDeliver.
        advanceNode (saInAct, false, callerHasLiquidity);

        // If needed, advance to next funded offer.

        if (resultCode != tesSUCCESS)
        {
        }
        else if (!node().offerIndex_)
        {
            JLOG (j_.warn())
                << "deliverNodeForward: INTERNAL ERROR: Ran out of offers.";
            return telFAILED_PROCESSING;
        }
        else if (resultCode == tesSUCCESS)
        {
            auto const xferRate = effectiveRate (
                previousNode().issue_,
                uInAccountID,
                node().offerOwnerAccount_,
                previousNode().transferRate_);

            // First calculate assuming no output fees: saInPassAct,
            // saInPassFees, saOutPassAct.

            // Offer maximum out - limited by funds with out fees.
            auto saOutFunded = std::min (
                node().saOfferFunds, node().saTakerGets);

            // Offer maximum out - limit by most to deliver.
            auto saOutPassFunded = std::min (
                saOutFunded,
                node().saRevDeliver - node().saFwdDeliver);

            // Offer maximum in - Limited by by payout.
            auto saInFunded = mulRound (
                saOutPassFunded,
                node().saOfrRate,
                node().saTakerPays.issue (),
                true);

            // Offer maximum in with fees.
            auto saInTotal = multiplyRound (
                saInFunded, xferRate, true);
            auto saInRemaining = saInReq - saInAct - saInFees;

            if (saInRemaining < beast::zero)
                saInRemaining.clear();

            // In limited by remaining.
            auto saInSum = std::min (saInTotal, saInRemaining);

            // In without fees.
            auto saInPassAct = std::min (
                node().saTakerPays,
                divideRound (saInSum, xferRate, true));

            // Out limited by in remaining.
            auto outPass = divRound (
                saInPassAct, node().saOfrRate, node().saTakerGets.issue (), true);
            STAmount saOutPassMax    = std::min (saOutPassFunded, outPass);

            STAmount saInPassFeesMax = saInSum - saInPassAct;

            // Will be determined by next node().
//.........这里部分代码省略.........

// To deliver from an order book, when computing
TER PathCursor::deliverNodeReverse (
    Account const& uOutAccountID,  // --> Output owner's account.
    STAmount const& saOutReq,      // --> Funds requested to be
                                   // delivered for an increment.
    STAmount& saOutAct) const      // <-- Funds actually delivered for an
                                   // increment.
{
    TER resultCode   = tesSUCCESS;

    node().directory.restart(multiQuality_);

    // Accumulation of what the previous node must deliver.
    // Possible optimization: Note this gets zeroed on each increment, ideally
    // only on first increment, then it could be a limit on the forward pass.
    saOutAct.clear (saOutReq);

    WriteLog (lsTRACE, RippleCalc)
        << "deliverNodeReverse>"
        << " saOutAct=" << saOutAct
        << " saOutReq=" << saOutReq
        << " saPrvDlvReq=" << previousNode().saRevDeliver;

    assert (saOutReq != zero);

    int loopCount = 0;

    // While we did not deliver as much as requested:
    while (saOutAct < saOutReq)
    {
        if (++loopCount > CALC_NODE_DELIVER_MAX_LOOPS)
        {
            WriteLog (lsFATAL, RippleCalc) << "loop count exceeded";
            return telFAILED_PROCESSING;
        }

        resultCode = advanceNode (saOutAct, true);
        // If needed, advance to next funded offer.

        if (resultCode != tesSUCCESS || !node().offerIndex_)
            // Error or out of offers.
            break;

        auto const hasFee = node().offerOwnerAccount_ == node().issue_.account
            || uOutAccountID == node().issue_.account;
        // Issuer sending or receiving.

        const STAmount saOutFeeRate = hasFee
            ? saOne             // No fee.
            : node().transferRate_;   // Transfer rate of issuer.

        WriteLog (lsTRACE, RippleCalc)
            << "deliverNodeReverse:"
            << " offerOwnerAccount_="
            << node().offerOwnerAccount_
            << " uOutAccountID="
            << uOutAccountID
            << " node().issue_.account="
            << node().issue_.account
            << " node().transferRate_=" << node().transferRate_
            << " saOutFeeRate=" << saOutFeeRate;

        if (multiQuality_)
        {
            // In multi-quality mode, ignore rate.
        }
        else if (!node().saRateMax)
        {
            // Set initial rate.
            node().saRateMax = saOutFeeRate;

            WriteLog (lsTRACE, RippleCalc)
                << "deliverNodeReverse: Set initial rate:"
                << " node().saRateMax=" << node().saRateMax
                << " saOutFeeRate=" << saOutFeeRate;
        }
        else if (saOutFeeRate > node().saRateMax)
        {
            // Offer exceeds initial rate.
            WriteLog (lsTRACE, RippleCalc)
                << "deliverNodeReverse: Offer exceeds initial rate:"
                << " node().saRateMax=" << node().saRateMax
                << " saOutFeeRate=" << saOutFeeRate;

            break;  // Done. Don't bother looking for smaller transferRates.
        }
        else if (saOutFeeRate < node().saRateMax)
        {
            // Reducing rate. Additional offers will only considered for this
            // increment if they are at least this good.
            //
            // At this point, the overall rate is reducing, while the overall
            // rate is not saOutFeeRate, it would be wrong to add anything with
            // a rate above saOutFeeRate.
            //
            // The rate would be reduced if the current offer was from the
            // issuer and the previous offer wasn't.

            node().saRateMax   = saOutFeeRate;

//.........这里部分代码省略.........