Autobridging:

Complete implementation of bridged offers crossings. While processing an offer
A:B we consider both the A:B order book and the combined A:XRP and XRP:B books
and pick the better offers. The net result is better liquidity and potentially
better rates.

* Rearchitect core::Taker to perform direct and bridged crossings.
* Compute bridged qualities.
* Implement a new Bridged OfferCreate transactor.
* Factor out common code from the Bridged and Direct OfferCreate transactors.
* Perform flow calculations without losing accuracy.
* Rename all transactors.
* Cleanups.

src/ripple/types/api/RippleAssets.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_TYPES_RIPPLEASSETS_H_INCLUDED
 #define RIPPLE_TYPES_RIPPLEASSETS_H_INCLUDED
 
+#include <cassert>
 #include <functional>
 #include <type_traits>
 
@@ -66,6 +67,9 @@ public:
         : currency (currency_)
         , issuer (issuer_)
     {
+        // Either XRP and (currency == zero && issuer == zero) or some custom
+        // currency and (currency != 0 && issuer != 0)
+        assert (currency.isZero () == issuer.isZero ());
     }
 
     template <bool OtherByValue>
@@ -87,6 +91,7 @@ public:
 
     bool is_xrp () const
     {
+        assert (currency.isZero () == issuer.isZero ());
         if (currency.isZero ())
             return true;
         return false;

src/ripple_app/book/Amount.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -191,18 +191,14 @@ public:
 
         if (sig == 0)
             return os << "0";
-        else if (sig < 0)
+        
+        if (sig < 0)
             os << "-";
-
         if (m_integral)
             return os << m_mantissa;
-
         if (m_exponent != 0 && (m_exponent < -25 || m_exponent > -5))
             return os << m_mantissa << "e" << m_exponent;
 
-        //if (m_exponent > 0)
-        //    return os <<
-
         return os;
     }
 };

src/ripple_app/book/Amounts.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -22,6 +22,8 @@
 
 #include "Amount.h"
 
+#include "../../beast/beast/utility/noexcept.h"
+
 namespace ripple {
 namespace core {
 

src/ripple_app/book/BookTip.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -25,8 +25,7 @@
 
 #include "../../beast/beast/utility/noexcept.h"
 
-#include <ostream>
+#include <functional>
-#include <utility>
 
 namespace ripple {
 namespace core {
@@ -54,15 +53,7 @@ private:
 
 public:
     /** Create the iterator. */
-    BookTip (LedgerView& view, BookRef book)
+    BookTip (LedgerView& view, BookRef book);
-        : m_view (view)
-        , m_valid (false)
-        , m_book (Ledger::getBookBase (
-            book.in.currency, book.in.issuer,
-            book.out.currency, book.out.issuer))
-        , m_end (Ledger::getQualityNext (m_book))
-    {
-    }
 
     uint256 const&
     dir() const noexcept
@@ -93,49 +84,7 @@ public:
         @return `true` if there is a next offer
     */
     bool
-    step ()
+    step ();
-    {
-        if (m_valid)
-        {
-            if (m_entry)
-            {
-                view().offerDelete (m_index);
-                m_entry = nullptr;
-            }
-        }
-
-        for(;;)
-        {
-            // See if there's an entry at or worse than current quality.
-            auto const page (
-                view().getNextLedgerIndex (m_book, m_end));
-
-            if (page.isZero())
-                return false;
-
-            unsigned int di (0);
-            SLE::pointer dir;
-            if (view().dirFirst (page, dir, di, m_index))
-            {
-                m_dir = dir->getIndex();
-                m_entry = view().entryCache (ltOFFER, m_index);
-                m_valid = true;
-
-                // Next query should start before this directory
-                m_book = page;
-
-                // The quality immediately before the next quality
-                --m_book; 
-
-                break;
-            }
-            // There should never be an empty directory but just in case,
-            // we handle that case by advancing to the next directory.
-            m_book = page;
-        }
-
-        return true;
-    }
 };
 
 }

src/ripple_app/book/Offer.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -27,6 +27,8 @@
 #include "../misc/SerializedLedger.h"
 #include "../../ripple_data/protocol/FieldNames.h"
 
+#include "../../beast/beast/utility/noexcept.h"
+
 #include <ostream>
 
 namespace ripple {
@@ -76,12 +78,23 @@ public:
         Some or all of the out amount may be unfunded.
     */
     Amounts const
-    amount() const noexcept
+    amount() const
     {
         return Amounts (m_entry->getFieldAmount (sfTakerPays),
             m_entry->getFieldAmount (sfTakerGets));
     }
 
+    /** Returns `true` if no more funds can flow through this offer. */
+    bool
+    fully_consumed() const
+    {
+        if (m_entry->getFieldAmount (sfTakerPays) <= zero)
+            return true;
+        if (m_entry->getFieldAmount (sfTakerGets) <= zero)
+            return true;
+        return false;
+    }
+
     /** Returns the ledger entry underlying the offer. */
     // AVOID USING THIS
     SLE::pointer

src/ripple_app/book/OfferStream.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -27,8 +27,7 @@
 
 #include "../../beast/beast/utility/noexcept.h"
 
-#include <ostream>
+#include <functional>
-#include <utility>
 
 namespace ripple {
 namespace core {
@@ -49,12 +48,10 @@ namespace core {
 
     When an offer is removed, it is removed from both views. This grooms the
     order book regardless of whether or not the transaction is successful.
-
-    TODO: Remove offers belonging to the taker
 */
 class OfferStream
 {
-protected:
+private:
     beast::Journal m_journal;
     std::reference_wrapper <LedgerView> m_view;
     std::reference_wrapper <LedgerView> m_view_cancel;
@@ -63,90 +60,37 @@ protected:
     BookTip m_tip;
     Offer m_offer;
 
-    // Handle the case where a directory item with no corresponding ledger entry
-    // is found. This shouldn't happen but if it does we clean it up.
     void
-    erase (LedgerView& view)
+    erase (LedgerView& view);
-    {
-        // VFALCO NOTE
-        //
-        //      This should be using LedgerView::dirDelete, which will
-        //      correctly remove the directory if its the last entry.
-        //      Unfortunately this is a protocol breaking change.
-
-        auto p (view.entryCache (ltDIR_NODE, m_tip.dir()));
-
-        if (p == nullptr)
-        {
-            if (m_journal.error) m_journal.error <<
-                "Missing directory " << m_tip.dir() <<
-                " for offer " << m_tip.index();
-            return;
-        }
-
-        auto v (p->getFieldV256 (sfIndexes));
-        auto& x (v.peekValue());
-        auto it (std::find (x.begin(), x.end(), m_tip.index()));
-
-        if (it == x.end())
-        {
-            if (m_journal.error) m_journal.error <<
-                "Missing offer " << m_tip.index() <<
-                " for directory " << m_tip.dir();
-            return;
-        }
-
-        x.erase (it);
-        p->setFieldV256 (sfIndexes, v);
-        view.entryModify (p);
-
-        if (m_journal.trace) m_journal.trace <<
-            "Missing offer " << m_tip.index() <<
-            " removed from directory " << m_tip.dir();
-    }
 
 public:
     OfferStream (LedgerView& view, LedgerView& view_cancel, BookRef book,
-        Clock::time_point when, beast::Journal journal)
+        Clock::time_point when, beast::Journal journal);
-        : m_journal (journal)
-        , m_view (view)
-        , m_view_cancel (view_cancel)
-        , m_book (book)
-        , m_when (when)
-        , m_tip (view, book)
-    {
-    }
 
     LedgerView&
-    view() noexcept
+    view () noexcept
     {
         return m_view;
     }
 
     LedgerView&
-    view_cancel() noexcept
+    view_cancel () noexcept
     {
         return m_view_cancel;
     }
 
     Book const&
-    book() const noexcept
+    book () const noexcept
     {
         return m_book;
     }
 
-uint256 const&
-dir() const noexcept
-{
-    return m_tip.dir();
-}
-
     /** Returns the offer at the tip of the order book.
         Offers are always presented in decreasing quality.
         Only valid if step() returned `true`.
     */
     Offer const&
-    tip() const
+    tip () const
     {
         return m_offer;
     }
@@ -159,166 +103,22 @@ dir() const noexcept
         @return `true` if there is a valid offer.
     */
     bool
-    step()
+    step ();
-    {
-        // Modifying the order or logic of these
-        // operations causes a protocol breaking change.
 
-        for(;;)
+    /** Advance to the next valid offer that is not from the specified account.
-        {
+        This automatically removes:
-            // BookTip::step deletes the current offer from the view before
+            - Offers with missing ledger entries
-            // advancing to the next (unless the ledger entry is missing).
+            - Offers found unfunded
-            if (! m_tip.step())
+            - Offers from the same account
-                return false;
+            - Expired offers
-
+        @return `true` if there is a valid offer.
-            SLE::pointer const& entry (m_tip.entry());
-
-            // Remove if missing
-            if (! entry)
-            {
-                erase (view());
-                erase (view_cancel());
-                continue;
-            }
-
-            // Remove if expired
-            if (entry->isFieldPresent (sfExpiration) &&
-                entry->getFieldU32 (sfExpiration) <= m_when)
-            {
-                view_cancel().offerDelete (entry->getIndex());
-                if (m_journal.trace) m_journal.trace <<
-                    "Removing expired offer " << entry->getIndex();
-                continue;
-            }
-
-            m_offer = Offer (entry, m_tip.quality());
-
-            Amounts const amount (m_offer.amount());
-
-            // Remove if either amount is zero
-            if (amount.empty())
-            {
-                view_cancel().offerDelete (entry->getIndex());
-                if (m_journal.warning) m_journal.warning <<
-                    "Removing bad offer " << entry->getIndex();
-                m_offer = Offer{};
-                continue;
-            }
-
-            // Calculate owner funds
-            // VFALCO NOTE The calling code also checks the funds,
-            //             how expensive is looking up the funds twice?
-            Amount const owner_funds (view().accountFunds (
-                m_offer.account(), m_offer.amount().out));
-
-            // Check for unfunded offer
-            if (owner_funds <= zero)
-            {
-                // If the owner's balance in the pristine view is the same,
-                // we haven't modified the balance and therefore the
-                // offer is "found unfunded" versus "became unfunded"
-                if (view_cancel().accountFunds (m_offer.account(),
-                    m_offer.amount().out) == owner_funds)
-                {
-                    view_cancel().offerDelete (entry->getIndex());
-                    if (m_journal.trace) m_journal.trace <<
-                        "Removing unfunded offer " << entry->getIndex();
-                }
-                else
-                {
-                    if (m_journal.trace) m_journal.trace <<
-                        "Removing became unfunded offer " << entry->getIndex();
-                }
-                m_offer = Offer{};
-                continue;
-            }
-
-#if 0
-            // Remove if its our own offer
-            //
-            // VFALCO NOTE We might not want this for payments
-            //
-            if (m_account == owner)
-            {
-                view_cancel().offerDelete (entry->getIndex());
-                if (m_journal.trace) m_journal.trace <<
-                    "Removing self offer " << entry->getIndex();
-                continue;
-            }
-#endif
-
-            break;
-        }
-
-        return true;
-    }
-
-    /** Updates the offer to reflect remaining funds.
-        The caller is responsible for following all the rounding rules.
-        The offer will be considered fully consumed if either the in
-        or the out amount is zero.
-        @return `true` If the offer had no funds remaining.
     */
     bool
-    fill (Amounts const& remaining_funds)
+    step_account (Account const& account);
-    {
-        // Erase the offer if it is fully consumed (in==0 || out==0)
-        // This is the same as becoming unfunded
-        return false;
-    }
 };
 
-//------------------------------------------------------------------------------
-
-/**
-  Does everything an OfferStream does, and:
-  - remove offers that became unfunded (if path is used)
-*/
-#if 0
-class PaymentOfferStream : public OfferStream
-{
-public:
-    PaymentOfferStream (LedgerView& view_base, BookRef book,
-        Clock::time_point when, beast::Journal journal)
-        : m_journal (journal)
-        , m_view (view_base.duplicate())
-        , m_view_apply (view_base.duplicate())
-        , m_book (book)
-        , m_when (when)
-    {
-    }
-};
-#endif
-
-//------------------------------------------------------------------------------
-
-/*
-TakerOfferStream
-  Does everything a PaymentOfferStream does, and:
-  - remove offers owned by the taker (if tx succeeds?)
-*/
-
-//------------------------------------------------------------------------------
-
-//------------------------------------------------------------------------------
-
 }
 }
 
-/*
-OfferStream
-  - remove offers with missing ledger entries (always)
-  - remove expired offers (always)
-  - remove offers found unfunded (always)
-
-PaymentOfferStream
-  Does everything an OfferStream does, and:
-  - remove offers that became unfunded (if path is used)
-
-TakerOfferStream
-  Does everything a PaymentOfferStream does, and:
-  - remove offers owned by the taker (if tx succeeds?)
-*/
-
 #endif
 

src/ripple_app/book/Quality.h

@@ -23,9 +23,7 @@
 #include "Amount.h"
 #include "Amounts.h"
 
-#include <cassert>
 #include <cstdint>
-#include <limits>
 #include <ostream>
 
 namespace ripple {
@@ -49,57 +47,53 @@ private:
 public:
     Quality() = default;
 
+    /** Create a quality from the integer encoding of an Amount */
     explicit
-    Quality (std::uint64_t value)
+    Quality (std::uint64_t value);
-        : m_value (value)
-    {
-    }
 
     /** Create a quality from the ratio of two amounts. */
     explicit
-    Quality (Amounts const& amount)
+    Quality (Amounts const& amount);
-        : m_value (Amount::getRate (amount.out, amount.in))
-    {
-    }
 
     /** Advances to the next higher quality level. */
     /** @{ */
     Quality&
-    operator++()
+    operator++();
-    {
-        assert (m_value > 0);
-        --m_value;
-        return *this;
-    }
 
     Quality
-    operator++ (int)
+    operator++ (int);
-    {
-        Quality prev (*this);
-        --*this;
-        return prev;
-    }
     /** @} */
 
     /** Advances to the next lower quality level. */
     /** @{ */
     Quality&
-    operator--()
+    operator--();
-    {
-        assert (m_value < std::numeric_limits<value_type>::max());
-        ++m_value;
-        return *this;
-    }
 
     Quality
-    operator-- (int)
+    operator-- (int);
-    {
-        Quality prev (*this);
-        ++*this;
-        return prev;
-    }
     /** @} */
 
+    /** Returns the quality as Amount. */
+    Amount
+    rate () const
+    {
+        return Amount::setRate (m_value);
+    }
+
+    /** Returns the scaled amount with in capped.
+        Math is avoided if the result is exact. The output is clamped
+        to prevent money creation.
+    */
+    Amounts
+    ceil_in (Amounts const& amount, Amount const& limit) const;
+
+    /** Returns the scaled amount with out capped.
+        Math is avoided if the result is exact. The input is clamped
+        to prevent money creation.
+    */
+    Amounts
+    ceil_out (Amounts const& amount, Amount const& limit) const;
+
     /** Returns `true` if lhs is lower quality than `rhs`.
         Lower quality means the taker receives a worse deal.
         Higher quality is better for the taker.
@@ -118,6 +112,13 @@ public:
         return lhs.m_value == rhs.m_value;
     }
 
+    friend
+    bool
+    operator!= (Quality const& lhs, Quality const& rhs) noexcept
+    {
+        return ! (lhs == rhs);
+    }
+
     friend
     std::ostream&
     operator<< (std::ostream& os, Quality const& quality)
@@ -125,72 +126,14 @@ public:
         os << quality.m_value;
         return os;
     }
-
-    /** Returns the quality as Amount. */
-    Amount
-    rate() const
-    {
-        return Amount::setRate (m_value);
-    }
-
-    /** Returns the scaled amount with in capped.
-        Math is avoided if the result is exact. The output is clamped
-        to prevent money creation.
-    */
-    Amounts
-    ceil_in (Amounts const& amount, Amount const& limit) const
-    {
-        if (amount.in > limit)
-        {
-            // VFALCO TODO make mulRound avoid math when v2==one
-#if 0
-            Amounts result (limit, Amount::mulRound (
-                limit, rate(), amount.out, true));
-#else
-            Amounts result (limit, Amount::divRound (
-                limit, rate(), amount.out, true));
-#endif
-            // Clamp out
-            if (result.out > amount.out)
-                result.out = amount.out;
-            return result;
-        }
-
-        return amount;
-    }
-
-    /** Returns the scaled amount with out capped.
-        Math is avoided if the result is exact. The input is clamped
-        to prevent money creation.
-    */
-    Amounts
-    ceil_out (Amounts const& amount, Amount const& limit) const
-    {
-        if (amount.out > limit)
-        {
-            // VFALCO TODO make divRound avoid math when v2==one
-#if 0
-            Amounts result (Amount::divRound (
-                limit, rate(), amount.in, true), limit);
-#else
-            Amounts result (Amount::mulRound (
-                limit, rate(), amount.in, true), limit);
-#endif
-            // Clamp in
-            if (result.in > amount.in)
-                result.in = amount.in;
-            return result;
-        }
-        return amount;
-    }
 };
 
-inline
+/** Calculate the quality of a two-hop path given the two hops.
-bool
+    @param lhs  The first leg of the path: input to intermediate.
-operator!= (Quality const& lhs, Quality const& rhs) noexcept
+    @param rhs  The second leg of the path: intermediate to output.
-{
+*/
-    return ! (lhs == rhs);
+Quality
-}
+composed_quality (Quality const& lhs, Quality const& rhs);
 
 }
 }

src/ripple_app/book/Taker.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -22,11 +22,14 @@
 
 #include "Amounts.h"
 #include "Quality.h"
+#include "Offer.h"
 #include "Types.h"
 
 #include "../../beast/beast/streams/debug_ostream.h"
+#include "../../beast/beast/utility/noexcept.h"
 
-#include <utility>
+#include <functional>
+//#include <utility>
 
 namespace ripple {
 namespace core {
@@ -37,7 +40,7 @@ class Taker
 public:
     struct Options
     {
-        Options() = default;
+        Options() = delete;
 
         explicit
         Options (std::uint32_t tx_flags)
@@ -56,99 +59,54 @@ public:
 
 private:
     std::reference_wrapper <LedgerView> m_view;
-    Book m_book;
     Account m_account;
     Options m_options;
     Quality m_quality;
     Quality m_threshold;
 
-    // The original in and out quantities
+    // The original in and out quantities.
-    Amounts m_amount;
+    Amounts const m_amount;
 
-    // Amount of input currency remaining.
+    // The amounts still left over for us to try and take.
-    Amount m_in;
+    Amounts m_remain;
 
-    // Amount of output currency we have received.
+private:
-    Amount m_out;
+    Amounts
+    flow (Amounts amount, Offer const& offer, Account const& taker);
 
-    // Returns the balance of the taker's input currency,
+    TER
-    Amount
+    fill (Offer const& offer, Amounts const& amount);
-    funds() const
+
-    {
+    TER
-        return view().accountFunds (account(), m_in);
+    fill (Offer const& leg1, Amounts const& amount1,
-    }
+        Offer const& leg2, Amounts const& amount2);
 
 public:
-    Taker (LedgerView& view, BookRef const& book,
+    Taker (LedgerView& view, Account const& account,
-        Account const& account, Amounts const& amount,
+        Amounts const& amount, Options const& options);
-            Options const& options)
-        : m_view (view)
-        , m_book (book)
-        , m_account (account)
-        , m_options (options)
-        , m_quality (amount)
-        , m_threshold (m_quality)
-        , m_amount (amount)
-        , m_in (amount.in)
-        , m_out (amount.out.getCurrency(), amount.out.getIssuer())
-    {
-        // If this is a passive order (tfPassive), this prevents
-        // offers at the same quality level from being consumed.
-        if (m_options.passive)
-            ++m_threshold;
-    }
 
     LedgerView&
-    view() const noexcept
+    view () const noexcept
     {
         return m_view;
     }
 
-    /** Returns the input and output asset pair identifier. */
+    /** Returns the amount remaining on the offer.
-    Book const&
+        This is the amount at which the offer should be placed. It may either
-    book() const noexcept
+        be for the full amount when there were no crossing offers, or for zero
-    {
+        when the offer fully crossed, or any amount in between.
-        return m_book;
+        It is always at the original offer quality (m_quality)
-    }
+    */
+    Amounts
+    remaining_offer () const;
 
     /** Returns the account identifier of the taker. */
     Account const&
-    account() const noexcept
+    account () const noexcept
     {
         return m_account;
     }
 
-    /** Returns `true` if order crossing should not continue.
-        Order processing is stopped if the taker's order quantities have
-        been reached, or if the taker has run out of input funds.
-    */
-    bool
-    done() const noexcept
-    {
-        if (m_options.sell)
-        {
-            // With the sell option, we are finished when
-            // we have consumed all the input currency.
-            if (m_in <= zero)
-                return true;
-        }
-        else if (m_out >= m_amount.out)
-        {
-            // With the buy option (!sell) we are finished when we
-            // have received the desired amount of output currency.
-            return true;
-        }
-
-        // We are finished if the taker is out of funds
-        return funds() <= zero;
-    }
-
-    Quality
-    threshold() const noexcept
-    {
-        return m_threshold;
-    }
-
     /** Returns `true` if the quality does not meet the taker's requirements. */
     bool
     reject (Quality const& quality) const noexcept
@@ -156,138 +114,26 @@ public:
         return quality < m_threshold;
     }
 
-    /** Calcualtes the result of applying the taker's funds to the offer.
+    /** Returns `true` if order crossing should not continue.
-        @return The flow and flag indicating if the order was consumed.
+        Order processing is stopped if the taker's order quantities have
+        been reached, or if the taker has run out of input funds.
     */
-    std::pair <Amounts, bool>
+    bool
-    fill (Offer const& offer) const
+    done () const;
-    {
-        // Best flow the owner can get.
-        // Start out assuming entire offer will flow.
-        Amounts owner_amount (offer.amount());
 
-        // Limit owner's output by available funds less fees
+    /** Perform direct crossing through given offer.
-
+        @return tesSUCCESS on success, error code otherwise.
-        // VFALCO TODO Rename accountFounds to make it clear that
-        //             it can return a clamped value.
-        Amount const owner_funds (view().accountFunds (
-            offer.account(), owner_amount.out));
-
-        // Get fee rate paid by owner
-        std::uint32_t const owner_charge_rate (view().rippleTransferRate (
-            offer.account(), account(), offer.entry()->getFieldAmount (
-                sfTakerGets).getIssuer()));
-        Amount const owner_charge (Amount::saFromRate (owner_charge_rate));
-
-        // VFALCO Make Amount::divide skip math if v2 == QUALITY_ONE
-        if (owner_charge_rate == QUALITY_ONE)
-        {
-            // Skip some math when there's no fee
-            owner_amount = offer.quality().ceil_out (
-                owner_amount, owner_funds);
-        }
-        else
-        {
-            owner_amount = offer.quality().ceil_out (owner_amount,
-                Amount::divide (owner_funds, owner_charge));
-        }
-
-        // Best flow the taker can get.
-        // Start out assuming entire offer will flow.
-        Amounts taker_amount (offer.amount());
-
-        // Limit taker's input by available funds less fees
-
-        Amount const taker_funds (view().accountFunds (account(), m_in));
-
-        // Get fee rate paid by taker
-        std::uint32_t const taker_charge_rate (view().rippleTransferRate (
-            account(), offer.account(), offer.entry()->getFieldAmount (
-                sfTakerPays).getIssuer()));
-        Amount const taker_charge (Amount::saFromRate (taker_charge_rate));
-
-        // VFALCO Make Amount::divide skip math if v2 == QUALITY_ONE
-        if (taker_charge_rate == QUALITY_ONE)
-        {
-            // Skip some math when there's no fee
-            taker_amount = offer.quality().ceil_in (
-                taker_amount, taker_funds);
-        }
-        else
-        {
-            taker_amount = offer.quality().ceil_in (taker_amount,
-                Amount::divide (taker_funds, taker_charge));
-        }
-
-        // Limit taker's input by options
-        if (! m_options.sell)
-        {
-            assert (m_out < m_amount.out);
-            taker_amount = offer.quality().ceil_out (
-                taker_amount, m_amount.out - m_out);
-            assert (taker_amount.in != zero);
-        }
-
-        // Calculate the amount that will flow through the offer
-        // This does not include the fees.
-        Amounts const flow ((owner_amount.in < taker_amount.in) ?
-            owner_amount : taker_amount);
-
-        bool const consumed (flow.out >= owner_amount.out);
-
-        return std::make_pair (flow, consumed);
-    }
-
-    /** Process the result of fee and funds calculation on the offer.    
-        
-        To protect the ledger, conditions which should never occur are
-        checked. If the invariants are broken, the processing fails.
-
-        If processing succeeds, the funds are distributed to the taker,
-        owner, and issuers.
-
-        @return `false` if processing failed (due to math errors).
     */
     TER
-    process (Amounts const& flow, Offer const& offer)
+    cross (Offer const& offer);
-    {
-        TER result (tesSUCCESS);
 
-        // VFALCO For the case of !sell, is it possible for the taker
+    /** Perform bridged crossing through given offers.
-        //        to get a tiny bit more than he asked for?
+        @return tesSUCCESS on success, error code otherwise.
-        // DAVIDS Can you verify?
+    */
-        assert (m_options.sell || flow.out <= m_amount.out);
+    TER
-
+    cross (Offer const& leg1, Offer const& leg2);
-        // Calculate remaining portion of offer
-        Amounts const remain (
-            offer.entry()->getFieldAmount (sfTakerPays) - flow.in,
-            offer.entry()->getFieldAmount (sfTakerGets) - flow.out);
-
-        offer.entry()->setFieldAmount (sfTakerPays, remain.in);
-        offer.entry()->setFieldAmount (sfTakerGets, remain.out);
-        view().entryModify (offer.entry());
-
-        // Pay the taker
-        result = view().accountSend (offer.account(), account(), flow.out);
-
-        if (result == tesSUCCESS)
-        {
-            m_out += flow.out;
-
-            // Pay the owner
-            result = view().accountSend (account(), offer.account(), flow.in);
-
-            if (result == tesSUCCESS)
-            {
-                m_in -= flow.in;
-            }
-        }
-
-        return result;
-    }
 };
 
-
 inline
 std::ostream&
 operator<< (std::ostream& os, Taker const& taker)
@@ -298,59 +144,4 @@ operator<< (std::ostream& os, Taker const& taker)
 }
 }
 
-/*
-
-// This code calculates the fees but then we discovered
-// that LedgerEntrySet::accountSend does it for you.
-
-Amounts fees;
-
-// Calculate taker fee
-if (taker_charge_rate == QUALITY_ONE)
-{
-    // No fee, skip math
-    fees.in = Amount (flow.in.getCurrency(),
-        flow.in.getIssuer());
-}
-else
-{
-    // VFALCO TODO Check the units (versus 4-arg version of mulRound)
-    Amount const in_plus_fees (Amount::mulRound (
-        flow.in, taker_charge, true));
-    // Make sure the taker has enough to pay the fee
-    if (in_plus_fees > taker_funds)
-    {
-        // Not enough funds, stiff the issuer
-        fees.in = taker_funds - flow.in;
-    }
-    else
-    {
-        fees.in = in_plus_fees - flow.in;
-    }
-}
-
-// Calculate owner fee
-if (owner_charge_rate == QUALITY_ONE)
-{
-    // No fee, skip math
-    fees.out = Amount (flow.out.getCurrency(),
-        flow.out.getIssuer());
-}
-else
-{
-    Amount const out_plus_fees (Amount::mulRound (
-        flow.out, owner_charge, true));
-    // Make sure the owner has enough to pay the fee
-    if (out_plus_fees > owner_funds)
-    {
-        // Not enough funds, stiff the issuer
-        fees.out = owner_funds - flow.out;
-    }
-    else
-    {
-        fees.out = out_plus_fees - flow.out;
-    }
-}
-*/
-
 #endif

src/ripple_app/book/Types.h

@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 /*
     This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2012, 2013 Ripple Labs Inc.
+    Copyright (c) 2014 Ripple Labs Inc.
 
     Permission to use, copy, modify, and/or distribute this software for any
     purpose  with  or without fee is hereby granted, provided that the above
@@ -22,7 +22,7 @@
 
 #include "../ledger/LedgerEntrySet.h"
 #include "../../ripple/types/api/RippleAssets.h"
-#include "../../ripple/types/api/UInt160.h"
+#include "../../ripple/types/api/base_uint.h"
 
 #include <chrono>
 #include <cstdint>

src/ripple_app/book/impl/BookTip.cpp

@@ -0,0 +1,81 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2014 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "../BookTip.h"
+
+namespace ripple {
+namespace core {
+
+BookTip::BookTip (LedgerView& view, BookRef book)
+    : m_view (view)
+    , m_valid (false)
+    , m_book (Ledger::getBookBase (
+        book.in.currency, book.in.issuer,
+        book.out.currency, book.out.issuer))
+    , m_end (Ledger::getQualityNext (m_book))
+{
+}
+
+bool
+BookTip::step ()
+{
+    if (m_valid)
+    {
+        if (m_entry)
+        {
+            view().offerDelete (m_index);
+            m_entry = nullptr;
+        }
+    }
+
+    for(;;)
+    {
+        // See if there's an entry at or worse than current quality.
+        auto const page (
+            view().getNextLedgerIndex (m_book, m_end));
+
+        if (page.isZero())
+            return false;
+
+        unsigned int di (0);
+        SLE::pointer dir;
+        if (view().dirFirst (page, dir, di, m_index))
+        {
+            m_dir = dir->getIndex();
+            m_entry = view().entryCache (ltOFFER, m_index);
+            m_valid = true;
+
+            // Next query should start before this directory
+            m_book = page;
+
+            // The quality immediately before the next quality
+            --m_book; 
+
+            break;
+        }
+        // There should never be an empty directory but just in case,
+        // we handle that case by advancing to the next directory.
+        m_book = page;
+    }
+
+    return true;
+}
+
+}
+}

src/ripple_app/book/impl/OfferStream.cpp

@@ -0,0 +1,170 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "../OfferStream.h"
+
+namespace ripple {
+namespace core {
+
+OfferStream::OfferStream (LedgerView& view, LedgerView& view_cancel,
+    BookRef book, Clock::time_point when, beast::Journal journal)
+    : m_journal (journal)
+    , m_view (view)
+    , m_view_cancel (view_cancel)
+    , m_book (book)
+    , m_when (when)
+    , m_tip (view, book)
+{
+}
+
+// Handle the case where a directory item with no corresponding ledger entry
+// is found. This shouldn't happen but if it does we clean it up.
+void
+OfferStream::erase (LedgerView& view)
+{
+    // NIKB NOTE This should be using LedgerView::dirDelete, which would
+    //           correctly remove the directory if its the last entry.
+    //           Unfortunately this is a protocol breaking change.
+
+    auto p (view.entryCache (ltDIR_NODE, m_tip.dir()));
+
+    if (p == nullptr)
+    {
+        if (m_journal.error) m_journal.error <<
+            "Missing directory " << m_tip.dir() <<
+            " for offer " << m_tip.index();
+        return;
+    }
+
+    auto v (p->getFieldV256 (sfIndexes));
+    auto& x (v.peekValue());
+    auto it (std::find (x.begin(), x.end(), m_tip.index()));
+
+    if (it == x.end())
+    {
+        if (m_journal.error) m_journal.error <<
+            "Missing offer " << m_tip.index() <<
+            " for directory " << m_tip.dir();
+        return;
+    }
+
+    x.erase (it);
+    p->setFieldV256 (sfIndexes, v);
+    view.entryModify (p);
+
+    if (m_journal.trace) m_journal.trace <<
+        "Missing offer " << m_tip.index() <<
+        " removed from directory " << m_tip.dir();
+}
+
+bool
+OfferStream::step ()
+{
+    // Modifying the order or logic of these
+    // operations causes a protocol breaking change.
+
+    for(;;)
+    {
+        // BookTip::step deletes the current offer from the view before
+        // advancing to the next (unless the ledger entry is missing).
+        if (! m_tip.step())
+            return false;
+
+        SLE::pointer const& entry (m_tip.entry());
+
+        // Remove if missing
+        if (! entry)
+        {
+            erase (view());
+            erase (view_cancel());
+            continue;
+        }
+
+        // Remove if expired
+        if (entry->isFieldPresent (sfExpiration) &&
+            entry->getFieldU32 (sfExpiration) <= m_when)
+        {
+            view_cancel().offerDelete (entry->getIndex());
+            if (m_journal.trace) m_journal.trace <<
+                "Removing expired offer " << entry->getIndex();
+            continue;
+        }
+
+        m_offer = Offer (entry, m_tip.quality());
+
+        Amounts const amount (m_offer.amount());
+
+        // Remove if either amount is zero
+        if (amount.empty())
+        {
+            view_cancel().offerDelete (entry->getIndex());
+            if (m_journal.warning) m_journal.warning <<
+                "Removing bad offer " << entry->getIndex();
+            m_offer = Offer{};
+            continue;
+        }
+
+        // Calculate owner funds
+        // NIKB NOTE The calling code also checks the funds, how expensive is
+        //           looking up the funds twice?
+        Amount const owner_funds (view().accountFunds (
+            m_offer.account(), m_offer.amount().out));
+
+        // Check for unfunded offer
+        if (owner_funds <= zero)
+        {
+            // If the owner's balance in the pristine view is the same,
+            // we haven't modified the balance and therefore the
+            // offer is "found unfunded" versus "became unfunded"
+            if (view_cancel().accountFunds (m_offer.account(),
+                m_offer.amount().out) == owner_funds)
+            {
+                view_cancel().offerDelete (entry->getIndex());
+                if (m_journal.trace) m_journal.trace <<
+                    "Removing unfunded offer " << entry->getIndex();
+            }
+            else
+            {
+                if (m_journal.trace) m_journal.trace <<
+                    "Removing became unfunded offer " << entry->getIndex();
+            }
+            m_offer = Offer{};
+            continue;
+        }
+
+        break;
+    }
+
+    return true;
+}
+
+bool
+OfferStream::step_account (Account const& account)
+{
+    while (step ())
+    {
+        if (tip ().account () != account)
+            return true;
+    }
+
+    return false;
+}
+
+}
+}

src/ripple_app/book/impl/Quality.cpp

@@ -0,0 +1,120 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "../Quality.h"
+
+#include <cassert>
+#include <limits>
+
+namespace ripple {
+namespace core {
+
+Quality::Quality (std::uint64_t value)
+    : m_value (value)
+{
+}
+
+Quality::Quality (Amounts const& amount)
+    : m_value (Amount::getRate (amount.out, amount.in))
+{
+}
+
+Quality&
+Quality::operator++()
+{
+    assert (m_value > 0);
+    --m_value;
+    return *this;
+}
+
+Quality
+Quality::operator++ (int)
+{
+    Quality prev (*this);
+    --*this;
+    return prev;
+}
+
+Quality&
+Quality::operator--()
+{
+    assert (m_value < std::numeric_limits<value_type>::max());
+    ++m_value;
+    return *this;
+}
+
+Quality
+Quality::operator-- (int)
+{
+    Quality prev (*this);
+    ++*this;
+    return prev;
+}
+
+Amounts
+Quality::ceil_in (Amounts const& amount, Amount const& limit) const
+{
+    if (amount.in > limit)
+    {
+        Amounts result (limit, Amount::divRound (
+            limit, rate(), amount.out, true));
+        // Clamp out
+        if (result.out > amount.out)
+            result.out = amount.out;
+        return result;
+    }
+    return amount;
+}
+
+Amounts
+Quality::ceil_out (Amounts const& amount, Amount const& limit) const
+{
+    if (amount.out > limit)
+    {
+        Amounts result (Amount::mulRound (
+            limit, rate(), amount.in, true), limit);
+        // Clamp in
+        if (result.in > amount.in)
+            result.in = amount.in;
+        return result;
+    }
+    return amount;
+}
+
+Quality
+composed_quality (Quality const& lhs, Quality const& rhs)
+{
+    Amount const lhs_rate (lhs.rate ());
+    assert (lhs_rate != zero);
+
+    Amount const rhs_rate (rhs.rate ());
+    assert (rhs_rate != zero);
+
+    Amount const rate (Amount::mulRound (lhs_rate, rhs_rate, true));
+
+    std::uint64_t const stored_exponent (rate.getExponent () + 100);
+    std::uint64_t const stored_mantissa (rate.getMantissa ());
+
+    assert ((stored_exponent >= 0) && (stored_exponent <= 255));
+
+    return Quality ((stored_exponent << (64 - 8)) | stored_mantissa);
+}
+
+}
+}

src/ripple_app/book/impl/Taker.cpp

@@ -0,0 +1,281 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2014 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "../Taker.h"
+
+//#include <utility>
+
+namespace ripple {
+namespace core {
+
+Taker::Taker (LedgerView& view, Account const& account,
+    Amounts const& amount, Options const& options)
+    : m_view (view)
+    , m_account (account)
+    , m_options (options)
+    , m_quality (amount)
+    , m_threshold (m_quality)
+    , m_amount (amount)
+    , m_remain (amount)
+{
+    // If this is a passive order (tfPassive), this prevents
+    // offers at the same quality level from being consumed.
+    if (m_options.passive)
+        ++m_threshold;
+}
+
+Amounts
+Taker::remaining_offer () const
+{
+    // If the taker is done, then there's no offer to place.
+    if (done ())
+    {
+        return Amounts (
+            Amount (m_amount.in.getCurrency (), m_amount.in.getIssuer ()),
+            Amount (m_amount.out.getCurrency (), m_amount.out.getIssuer ()));
+    }
+
+    // Avoid math altogether if we didn't cross.
+   if (m_amount == m_remain)
+       return m_amount;
+
+    if (m_options.sell)
+    {
+        assert (m_remain.in > zero);
+
+        // We scale the output based on the remaining input:
+        return Amounts (m_remain.in, Amount::divRound (
+            m_remain.in, m_quality.rate (), m_remain.out, true));
+    }
+
+    assert (m_remain.out > zero);
+
+    // We scale the input based on the remaining output:
+    return Amounts (Amount::mulRound (
+        m_remain.out, m_quality.rate (), m_remain.in, true), m_remain.out);
+}
+
+// Calculate the amount particular user could get through an offer.
+//   @param amount the maximum flow that is available to the taker.
+//   @param offer the offer to flow through.
+//   @param taker the person taking the offer.
+//   @return the maximum amount that can flow through this offer.
+Amounts
+Taker::flow (Amounts amount, Offer const& offer, Account const& taker)
+{
+    // Limit taker's input by available funds less fees
+    Amount const taker_funds (view ().accountFunds (taker, amount.in));
+
+    // Get fee rate paid by taker
+    std::uint32_t const taker_charge_rate (view ().rippleTransferRate (
+        taker, offer.account (), amount.in.getIssuer()));
+
+    // Skip some math when there's no fee
+    if (taker_charge_rate == QUALITY_ONE)
+    {
+        amount = offer.quality ().ceil_in (amount, taker_funds);
+    }
+    else
+    {
+        Amount const taker_charge (Amount::saFromRate (taker_charge_rate));
+        amount = offer.quality ().ceil_in (amount,
+            Amount::divide (taker_funds, taker_charge));
+    }
+
+    // Best flow the owner can get.
+    // Start out assuming entire offer will flow.
+    Amounts owner_amount (amount);
+
+    // Limit owner's output by available funds less fees
+    Amount const owner_funds (view ().accountFunds (
+        offer.account (), owner_amount.out));
+
+    // Get fee rate paid by owner
+    std::uint32_t const owner_charge_rate (view ().rippleTransferRate (
+        offer.account (), taker, amount.out.getIssuer()));
+
+    if (owner_charge_rate == QUALITY_ONE)
+    {
+        // Skip some math when there's no fee
+        owner_amount = offer.quality ().ceil_out (owner_amount, owner_funds);
+    }
+    else
+    {
+        Amount const owner_charge (Amount::saFromRate (owner_charge_rate));
+        owner_amount = offer.quality ().ceil_out (owner_amount,
+            Amount::divide (owner_funds, owner_charge));
+    }
+
+    // Calculate the amount that will flow through the offer
+    // This does not include the fees.
+    return (owner_amount.in < amount.in)
+        ? owner_amount
+        : amount;
+}
+
+// Fill a direct offer.
+//   @param offer the offer we are going to use.
+//   @param amount the amount to flow through the offer.
+//   @returns: tesSUCCESS if successful, or an error code otherwise.
+TER
+Taker::fill (Offer const& offer, Amounts const& amount)
+{
+    TER result (tesSUCCESS);
+    
+    Amounts const remain (
+        offer.entry ()->getFieldAmount (sfTakerPays) - amount.in,
+        offer.entry ()->getFieldAmount (sfTakerGets) - amount.out);
+
+    offer.entry ()->setFieldAmount (sfTakerPays, remain.in);
+    offer.entry ()->setFieldAmount (sfTakerGets, remain.out);
+    view ().entryModify (offer.entry());
+
+    // Pay the taker, then the owner
+    result = view ().accountSend (offer.account(), account(), amount.out);
+
+    if (result == tesSUCCESS)
+        result = view ().accountSend (account(), offer.account(), amount.in);
+
+    return result;
+}
+
+// Fill a bridged offer.
+//   @param leg1 the first leg we are going to use.
+//   @param amount1 the amount to flow through the first leg of the offer.
+//   @param leg2 the second leg we are going to use.
+//   @param amount2 the amount to flow through the second leg of the offer.
+//   @return tesSUCCESS if successful, or an error code otherwise.
+TER
+Taker::fill (
+    Offer const& leg1, Amounts const& amount1,
+    Offer const& leg2, Amounts const& amount2)
+{
+    assert (amount1.out == amount2.in);
+
+    TER result (tesSUCCESS);
+
+    Amounts const remain1 (
+        leg1.entry ()->getFieldAmount (sfTakerPays) - amount1.in,
+        leg1.entry ()->getFieldAmount (sfTakerGets) - amount1.out);
+
+    leg1.entry ()->setFieldAmount (sfTakerPays, remain1.in);
+    leg1.entry ()->setFieldAmount (sfTakerGets, remain1.out);
+    view ().entryModify (leg1.entry());
+
+    Amounts const remain2 (
+        leg2.entry ()->getFieldAmount (sfTakerPays) - amount2.in,
+        leg2.entry ()->getFieldAmount (sfTakerGets) - amount2.out);
+    view ().entryModify (leg2.entry ());
+
+    // Execute the payments in order:
+    // Taker pays Leg1 (amount1.in - A currency)
+    // Leg1 pays Leg2 (amount1.out == amount2.in, XRP)
+    // Leg2 pays Taker (amount2.out - B currency)
+
+    result = view ().accountSend (m_account, leg1.account (), amount1.in);
+
+    if (result == tesSUCCESS)
+        result = view ().accountSend (leg1.account (), leg2.account (), amount1.out);
+
+    if (result == tesSUCCESS)
+        result = view ().accountSend (leg2.account (), m_account, amount2.out);
+
+    return result;
+}
+
+bool
+Taker::done () const
+{
+    if (m_options.sell)
+    {
+        // With the sell option, we are finished when
+        // we have consumed all the input currency.
+        if (m_remain.in <= zero)
+            return true;
+    }
+    else if (m_remain.out <= zero)
+    {
+        // With the buy option (!sell) we are finished when we
+        // have received the desired amount of output currency.
+        return true;
+    }
+
+    // We are finished if the taker is out of funds
+    return view().accountFunds (account(), m_remain.in) <= zero;
+}
+
+TER
+Taker::cross (Offer const& offer)
+{
+    assert (!done ());
+    Amounts limit (offer.amount());
+    if (m_options.sell)
+        limit = offer.quality().ceil_in (limit, m_remain.in);
+    else
+        limit = offer.quality ().ceil_out (limit, m_remain.out);
+
+    assert (limit.out <= offer.amount().out);
+    assert (limit.in <= offer.amount().in);
+
+    Amounts const amount (flow (limit, offer, account ()));
+    m_remain.out -= amount.out;
+    m_remain.in -= amount.in;
+    assert (m_remain.in >= zero);
+    return fill (offer, amount);
+}
+
+TER
+Taker::cross (Offer const& leg1, Offer const& leg2)
+{
+    assert (!done ());
+
+    assert (leg1.amount ().out.isNative ());
+    assert (leg2.amount ().in.isNative ());
+
+    Amounts amount1 (leg1.amount());
+    Amounts amount2 (leg2.amount());
+
+    if (m_options.sell)
+        amount1 = leg1.quality().ceil_in (amount1, m_remain.in);
+    else
+        amount2 = leg2.quality().ceil_out (amount2, m_remain.out);
+
+    if (amount1.out <= amount2.in)
+        amount2 = leg2.quality().ceil_in (amount2, amount1.out);
+    else
+        amount1 = leg1.quality().ceil_out (amount1, amount2.in);
+
+    assert (amount1.out == amount2.in);
+
+    // As written, flow can't handle a 3-party transfer, but this works for
+    // us because the output of leg1 and the input leg2 are XRP.
+    Amounts flow1 (flow (amount1, leg1, m_account));
+
+    amount2 = leg2.quality().ceil_in (amount2, flow1.out);
+    
+    Amounts flow2 (flow (amount2, leg2, m_account));
+
+    m_remain.out -= amount2.out;
+    m_remain.in -= amount1.in;
+
+    return fill (leg1, flow1, leg2, flow2);
+}
+
+}
+}

src/ripple_app/consensus/LedgerConsensus.cpp

@@ -1384,8 +1384,8 @@ private:
                 return resultSuccess;
             }
 
-            if (isTefFailure (result) || isTemMalformed
+            if (isTefFailure (result) || isTemMalformed (result) || 
-                (result) || isTelLocal (result))
+                isTelLocal (result))
             {
                 // failure
                 WriteLog (lsDEBUG, LedgerConsensus)

src/ripple_app/ripple_app_pt9.unity.cpp

@@ -21,6 +21,11 @@
 
 #include "ripple_app.h"
 
+#include "book/impl/Taker.cpp"
+#include "book/impl/BookTip.cpp"
+#include "book/impl/OfferStream.cpp"
+#include "book/impl/Quality.cpp"
+
 #include "transactors/Transactor.cpp"
 
 #include "transactors/Change.cpp"

src/ripple_app/transactors/AddWallet.cpp

@@ -19,7 +19,7 @@
 
 namespace ripple {
 
-TER WalletAddTransactor::doApply ()
+TER AddWallet::doApply ()
 {
     std::uint32_t const uTxFlags = mTxn.getFlags ();
 

src/ripple_app/transactors/AddWallet.h

@@ -22,20 +22,20 @@
 
 namespace ripple {
 
-class WalletAddTransactorLog;
+class AddWalletLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <WalletAddTransactorLog> ()
+LogPartition::getPartitionName <AddWalletLog> ()
 {
     return "Tx/WalletAdd";
 }
 
-class WalletAddTransactor
+class AddWallet
     : public Transactor
 {
 public:
-    WalletAddTransactor (
+    AddWallet (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine) 
@@ -43,13 +43,23 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <WalletAddTransactorLog> ())
+            LogPartition::getJournal <AddWalletLog> ())
     {
     }
 
     TER doApply ();
 };
 
+inline
+std::unique_ptr <Transactor>
+make_AddWallet (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <AddWallet> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/CancelOffer.cpp

@@ -20,7 +20,7 @@
 namespace ripple {
 
 
-TER OfferCancelTransactor::doApply ()
+TER CancelOffer::doApply ()
 {
     std::uint32_t const uOfferSequence = mTxn.getFieldU32 (sfOfferSequence);
     std::uint32_t const uAccountSequenceNext = mTxnAccount->getFieldU32 (sfSequence);

src/ripple_app/transactors/CancelOffer.h

@@ -22,20 +22,20 @@
 
 namespace ripple {
 
-class OfferCancelTransactorLog;
+class CancelOfferLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <OfferCancelTransactorLog> ()
+LogPartition::getPartitionName <CancelOfferLog> ()
 {
     return "Tx/OfferCancel";
 }
 
-class OfferCancelTransactor
+class CancelOffer
     : public Transactor
 {
 public:
-    OfferCancelTransactor (
+    CancelOffer (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -43,7 +43,7 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <OfferCancelTransactorLog> ())
+            LogPartition::getJournal <CancelOfferLog> ())
     {
 
     }
@@ -51,6 +51,16 @@ public:
     TER doApply () override;
 };
 
+inline
+std::unique_ptr <Transactor>
+make_CancelOffer (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <CancelOffer> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/Change.cpp

@@ -19,7 +19,7 @@
 
 namespace ripple {
 
-TER ChangeTransactor::doApply ()
+TER Change::doApply ()
 {
     if (mTxn.getTxnType () == ttAMENDMENT)
         return applyAmendment ();
@@ -30,7 +30,7 @@ TER ChangeTransactor::doApply ()
     return temUNKNOWN;
 }
 
-TER ChangeTransactor::checkSig ()
+TER Change::checkSig ()
 {
     if (mTxn.getFieldAccount160 (sfAccount).isNonZero ())
     {
@@ -47,7 +47,7 @@ TER ChangeTransactor::checkSig ()
     return tesSUCCESS;
 }
 
-TER ChangeTransactor::checkSeq ()
+TER Change::checkSeq ()
 {
     if ((mTxn.getSequence () != 0) || mTxn.isFieldPresent (sfPreviousTxnID))
     {
@@ -58,7 +58,7 @@ TER ChangeTransactor::checkSeq ()
     return tesSUCCESS;
 }
 
-TER ChangeTransactor::payFee ()
+TER Change::payFee ()
 {
     if (mTxn.getTransactionFee () != STAmount ())
     {
@@ -69,7 +69,7 @@ TER ChangeTransactor::payFee ()
     return tesSUCCESS;
 }
 
-TER ChangeTransactor::preCheck ()
+TER Change::preCheck ()
 {
     mTxnAccountID   = mTxn.getSourceAccount ().getAccountID ();
 
@@ -89,7 +89,7 @@ TER ChangeTransactor::preCheck ()
     return tesSUCCESS;
 }
 
-TER ChangeTransactor::applyAmendment ()
+TER Change::applyAmendment ()
 {
     uint256 amendment (mTxn.getFieldH256 (sfAmendment));
 
@@ -119,7 +119,7 @@ TER ChangeTransactor::applyAmendment ()
     return tesSUCCESS;
 }
 
-TER ChangeTransactor::applyFee ()
+TER Change::applyFee ()
 {
 
     SLE::pointer feeObject = mEngine->entryCache (

src/ripple_app/transactors/Change.h

@@ -22,20 +22,20 @@
 
 namespace ripple {
 
-class ChangeTransactorLog;
+class ChangeLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <ChangeTransactorLog> ()
+LogPartition::getPartitionName <ChangeLog> ()
 {
     return "Tx/Change";
 }
 
-class ChangeTransactor
+class Change
     : public Transactor
 {
 public:
-    ChangeTransactor (
+    Change (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -43,7 +43,7 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <ChangeTransactorLog> ())
+            LogPartition::getJournal <ChangeLog> ())
     {
     }
 
@@ -64,6 +64,16 @@ private:
     }
 };
 
+inline
+std::unique_ptr <Transactor>
+make_Change (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <Change> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/CreateOffer.cpp

@@ -26,10 +26,11 @@
 
 #include "../book/OfferStream.h"
 #include "../book/Taker.h"
+#include "../book/Types.h"
 
 namespace ripple {
 
-OfferCreateTransactor::OfferCreateTransactor (
+CreateOffer::CreateOffer (
     SerializedTransaction const& txn,
     TransactionEngineParams params,
     TransactionEngine* engine)
@@ -37,31 +38,495 @@ OfferCreateTransactor::OfferCreateTransactor (
         txn,
         params,
         engine,
-        LogPartition::getJournal <OfferCreateTransactorLog> ())
+        LogPartition::getJournal <CreateOfferLog> ())
 {
 
 }
 
-std::unique_ptr <Transactor> make_OfferCreateTransactor (
+TER
+CreateOffer::checkAcceptAsset(core::AssetRef asset) const
+{
+    /* Only valid for custom currencies */
+    assert (!asset.is_xrp ());
+
+    SLE::pointer const issuerAccount = mEngine->entryCache (
+        ltACCOUNT_ROOT, Ledger::getAccountRootIndex (asset.issuer));
+
+    if (!issuerAccount)
+    {
+        if (m_journal.warning) m_journal.warning <<
+            "delay: can't receive IOUs from non-existent issuer: " <<
+            RippleAddress::createHumanAccountID (asset.issuer);
+
+        return is_bit_set (mParams, tapRETRY)
+            ? terNO_ACCOUNT
+            : tecNO_ISSUER;
+    }
+
+    if (is_bit_set (issuerAccount->getFieldU32 (sfFlags), lsfRequireAuth))
+    {
+        SLE::pointer const trustLine (mEngine->entryCache (
+            ltRIPPLE_STATE, Ledger::getRippleStateIndex (
+                mTxnAccountID, asset.issuer, asset.currency)));
+
+        if (!trustLine)
+        {
+            return is_bit_set (mParams, tapRETRY)
+                ? terNO_LINE
+                : 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 (mTxnAccountID > asset.issuer);
+
+        bool const need_auth (is_bit_set (
+            trustLine->getFieldU32 (sfFlags),
+            (canonical_gt ? lsfLowAuth : lsfHighAuth)));
+
+        if (need_auth)
+        {
+            if (m_journal.debug) m_journal.debug <<
+                "delay: can't receive IOUs from issuer without auth.";
+
+            return is_bit_set (mParams, tapRETRY)
+                ? terNO_AUTH
+                : tecNO_AUTH;
+        }
+    }
+
+    return tesSUCCESS;
+}
+
+TER
+CreateOffer::doApply ()
+{
+    if (m_journal.debug) m_journal.debug <<
+        "OfferCreate> " << mTxn.getJson (0);
+
+    std::uint32_t const uTxFlags = mTxn.getFlags ();
+
+    bool const bPassive = is_bit_set (uTxFlags, tfPassive);
+    bool const bImmediateOrCancel = is_bit_set (uTxFlags, tfImmediateOrCancel);
+    bool const bFillOrKill = is_bit_set (uTxFlags, tfFillOrKill);
+    bool const bSell = is_bit_set (uTxFlags, tfSell);
+
+    STAmount saTakerPays = mTxn.getFieldAmount (sfTakerPays);
+    STAmount saTakerGets = mTxn.getFieldAmount (sfTakerGets);
+
+    if (!saTakerPays.isLegalNet () || !saTakerGets.isLegalNet ())
+        return temBAD_AMOUNT;
+
+    uint160 const& uPaysIssuerID = saTakerPays.getIssuer ();
+    uint160 const& uPaysCurrency = saTakerPays.getCurrency ();
+
+    uint160 const& uGetsIssuerID = saTakerGets.getIssuer ();
+    uint160 const& uGetsCurrency = saTakerGets.getCurrency ();
+
+    bool const bHaveExpiration (mTxn.isFieldPresent (sfExpiration));
+    bool const bHaveCancel (mTxn.isFieldPresent (sfOfferSequence));
+
+    std::uint32_t const uExpiration = mTxn.getFieldU32 (sfExpiration);
+    std::uint32_t const uCancelSequence = mTxn.getFieldU32 (sfOfferSequence);
+
+    // FIXME understand why we use SequenceNext instead of current transaction
+    //       sequence to determine the transaction. Why is the offer seuqnce
+    //       number insufficient?
+
+    std::uint32_t const uAccountSequenceNext = mTxnAccount->getFieldU32 (sfSequence);
+    std::uint32_t const uSequence = mTxn.getSequence ();
+
+    const uint256 uLedgerIndex = Ledger::getOfferIndex (mTxnAccountID, uSequence);
+
+    if (m_journal.debug)
+    {
+        m_journal.debug <<
+            "Creating offer node: " << to_string (uLedgerIndex) <<
+            " uSequence=" << uSequence;
+
+        if (bImmediateOrCancel)
+            m_journal.debug << "Transaction: IoC set.";
+
+        if (bFillOrKill)
+            m_journal.debug << "Transaction: FoK set.";
+    }
+
+    // This is the original rate of this offer, and is the rate at which it will
+    // be placed, even if crossing offers change the amounts.
+    std::uint64_t const uRate = STAmount::getRate (saTakerGets, saTakerPays);
+
+    TER terResult (tesSUCCESS);
+    uint256 uDirectory;
+    std::uint64_t uOwnerNode;
+    std::uint64_t uBookNode;
+
+    // This is the ledger view that we work against. Transactions are applied
+    // as we go on processing transactions.
+    core::LedgerView& view (mEngine->view ());
+
+    // This is a checkpoint with just the fees paid. If something goes wrong
+    // with this transaction, we roll back to this ledger.
+    core::LedgerView view_checkpoint (view);
+
+    view.bumpSeq (); // Begin ledger variance.
+
+    SLE::pointer sleCreator = mEngine->entryCache (
+        ltACCOUNT_ROOT, Ledger::getAccountRootIndex (mTxnAccountID));
+
+    if (uTxFlags & tfOfferCreateMask)
+    {
+        if (m_journal.debug) m_journal.debug <<
+            "Malformed transaction: Invalid flags set.";
+
+        terResult = temINVALID_FLAG;
+    }
+    else if (bImmediateOrCancel && bFillOrKill)
+    {
+        if (m_journal.debug) m_journal.debug <<
+            "Malformed transaction: both IoC and FoK set.";
+
+        terResult = temINVALID_FLAG;
+    }
+    else if (bHaveExpiration && !uExpiration)
+    {
+        m_journal.warning <<
+            "Malformed offer: bad expiration";
+
+        terResult = temBAD_EXPIRATION;
+    }
+    else if (saTakerPays.isNative () && saTakerGets.isNative ())
+    {
+        m_journal.warning <<
+            "Malformed offer: XRP for XRP";
+
+        terResult   = temBAD_OFFER;
+    }
+    else if (saTakerPays <= zero || saTakerGets <= zero)
+    {
+        m_journal.warning <<
+            "Malformed offer: bad amount";
+
+        terResult   = temBAD_OFFER;
+    }
+    else if (uPaysCurrency == uGetsCurrency && uPaysIssuerID == uGetsIssuerID)
+    {
+        m_journal.warning <<
+            "Malformed offer: redundant offer";
+
+        terResult = temREDUNDANT;
+    }
+    // We don't allow a non-native currency to use the currency code XRP.
+    else if (CURRENCY_BAD == uPaysCurrency || CURRENCY_BAD == uGetsCurrency)
+    {
+        m_journal.warning <<
+            "Malformed offer: Bad currency.";
+
+        terResult = temBAD_CURRENCY;
+    }
+    else if (saTakerPays.isNative () != !uPaysIssuerID ||
+             saTakerGets.isNative () != !uGetsIssuerID)
+    {
+        m_journal.warning <<
+            "Malformed offer: bad issuer";
+
+        terResult = temBAD_ISSUER;
+    }
+    else if (view.accountFunds (mTxnAccountID, saTakerGets) <= zero)
+    {
+        m_journal.warning <<
+            "delay: Offers must be at least partially funded.";
+
+        terResult = tecUNFUNDED_OFFER;
+    }
+    // This can probably be simplified to make sure that you cancel sequences
+    // before the transaction sequence number.
+    else if (bHaveCancel && (!uCancelSequence || uAccountSequenceNext - 1 <= uCancelSequence))
+    {
+        if (m_journal.debug) m_journal.debug <<
+            "uAccountSequenceNext=" << uAccountSequenceNext <<
+            " uOfferSequence=" << uCancelSequence;
+
+        terResult = temBAD_SEQUENCE;
+    }
+
+    if (terResult != tesSUCCESS)
+    {
+        if (m_journal.debug) m_journal.debug <<
+            "final terResult=" << transToken (terResult);
+
+        return terResult;
+    }
+
+    // Process a cancellation request that's passed along with an offer.
+    if ((terResult == tesSUCCESS) && bHaveCancel)
+    {
+        uint256 const uCancelIndex (
+            Ledger::getOfferIndex (mTxnAccountID, uCancelSequence));
+        SLE::pointer sleCancel = mEngine->entryCache (ltOFFER, uCancelIndex);
+
+        // It's not an error to not find the offer to cancel: it might have
+        // been consumed or removed as we are processing.
+        if (sleCancel)
+        {
+            m_journal.warning <<
+                "Cancelling order with sequence " << uCancelSequence;
+
+            terResult = view.offerDelete (sleCancel);
+        }
+    }
+
+    // Expiration is defined in terms of the close time of the parent ledger,
+    // because we definitively know the time that it closed but we do not
+    // know the closing time of the ledger that is under construction.
+    if (bHaveExpiration &&
+        (mEngine->getLedger ()->getParentCloseTimeNC () >= uExpiration))
+    {
+        return tesSUCCESS;
+    }
+
+    // Make sure that we are authorized to hold what the taker will pay us.
+    if (terResult == tesSUCCESS && !saTakerPays.isNative ())
+        terResult = checkAcceptAsset (core::Asset (uPaysCurrency, uPaysIssuerID));
+
+    bool crossed = false;
+    bool const bOpenLedger = is_bit_set (mParams, tapOPEN_LEDGER);
+
+    if (terResult == tesSUCCESS)
+    {
+        // We reverse gets and pays because during offer crossing we are taking.
+        core::Amounts const taker_amount (saTakerGets, saTakerPays);
+        
+        // The amount of the offer that we will need to place, after we finish
+        // offer crossing processing. It may be equal to the original amount,
+        // empty (fully crossed), or something in-between.
+        core::Amounts place_offer;
+
+        std::tie(terResult, place_offer) = crossOffers (view, taker_amount);
+
+        if (terResult == tecFAILED_PROCESSING && bOpenLedger)
+            terResult = telFAILED_PROCESSING;
+
+        if (terResult == tesSUCCESS)
+        {
+            // We now need to reduce the offer by the cross flow. We reverse
+            // in and out here, since during crossing we were takers.
+            assert (saTakerPays.getCurrency () == place_offer.out.getCurrency ());
+            assert (saTakerPays.getIssuer () == place_offer.out.getIssuer ());
+            assert (saTakerGets.getCurrency () == place_offer.in.getCurrency ());
+            assert (saTakerGets.getIssuer () == place_offer.in.getIssuer ());
+
+            if (taker_amount != place_offer)
+                crossed = true;
+
+            if (m_journal.debug)
+            {
+                m_journal.debug << "Offer Crossing: " << transToken (terResult);
+
+                if (terResult == tesSUCCESS)
+                {
+                    m_journal.debug << 
+                        "    takerPays: " << saTakerPays.getFullText () <<
+                        " -> " << place_offer.out.getFullText ();
+                    m_journal.debug << 
+                        "    takerGets: " << saTakerGets.getFullText () <<
+                        " -> " << place_offer.in.getFullText ();
+                }
+            }
+
+            saTakerPays = place_offer.out;
+            saTakerGets = place_offer.in;
+        }
+    }
+
+    if (terResult != tesSUCCESS)
+    {
+        m_journal.debug <<
+            "final terResult=" << transToken (terResult);
+
+        return terResult;
+    }
+
+    if (m_journal.debug)
+    {
+        m_journal.debug <<
+            "takeOffers: saTakerPays=" <<saTakerPays.getFullText ();
+        m_journal.debug <<
+            "takeOffers: saTakerGets=" << saTakerGets.getFullText ();
+        m_journal.debug <<
+            "takeOffers: mTxnAccountID=" <<
+            RippleAddress::createHumanAccountID (mTxnAccountID);
+        m_journal.debug <<
+            "takeOffers:         FUNDS=" <<
+            view.accountFunds (mTxnAccountID, saTakerGets).getFullText ();
+    }
+
+    if (bFillOrKill && (saTakerPays != zero || saTakerGets != zero))
+    {
+        // Fill or kill and have leftovers.
+        view.swapWith (view_checkpoint); // Restore with just fees paid.
+        return tesSUCCESS;
+    }
+
+    // What the reserve would be if this offer was placed.
+    auto const accountReserve (mEngine->getLedger ()->getReserve (
+        sleCreator->getFieldU32 (sfOwnerCount) + 1));
+
+    if (saTakerPays <= zero ||                // Wants nothing more.
+        saTakerGets <= zero ||                // Offering nothing more.
+        bImmediateOrCancel)                   // Do not persist.
+    {
+        // Complete as is.
+        nothing ();
+    }
+    else if (mPriorBalance.getNValue () < accountReserve)
+    {
+        // If we are here, the signing account had an insufficient reserve
+        // *prior* to our processing. We use the prior balance to simplify
+        // client writing and make the user experience better.
+
+        if (bOpenLedger) // Ledger is not final, can vote no.
+        {
+            // Hope for more reserve to come in or more offers to consume. If we
+            // specified a local error this transaction will not be retried, so
+            // specify a tec to distribute the transaction and allow it to be
+            // retried. In particular, it may have been successful to a
+            // degree (partially filled) and if it hasn't, it might succeed.
+            terResult = tecINSUF_RESERVE_OFFER;
+        }
+        else if (!crossed)
+        {
+            // Ledger is final, insufficent reserve to create offer, processed
+            // nothing.
+            terResult = tecINSUF_RESERVE_OFFER;
+        }
+        else
+        {
+            // Ledger is final, insufficent reserve to create offer, processed
+            // something.
+
+            // Consider the offer unfunded. Treat as tesSUCCESS.
+            nothing ();
+        }
+    }
+    else
+    {
+        // We need to place the remainder of the offer into its order book.
+        if (m_journal.debug) m_journal.debug <<
+            "offer not fully consumed:" <<
+            " saTakerPays=" << saTakerPays.getFullText () <<
+            " saTakerGets=" << saTakerGets.getFullText ();
+
+        // Add offer to owner's directory.
+        terResult   = view.dirAdd (uOwnerNode,
+            Ledger::getOwnerDirIndex (mTxnAccountID), uLedgerIndex,
+            std::bind (&Ledger::ownerDirDescriber, std::placeholders::_1,
+                       std::placeholders::_2, mTxnAccountID));
+
+        if (tesSUCCESS == terResult)
+        {
+            // Update owner count.
+            view.ownerCountAdjust (mTxnAccountID, 1, sleCreator);
+
+            uint256 uBookBase = Ledger::getBookBase (
+                uPaysCurrency, uPaysIssuerID,
+                uGetsCurrency, uGetsIssuerID);
+
+            if (m_journal.debug) m_journal.debug <<
+                "adding to book: " << to_string (uBookBase) <<
+                " : " << saTakerPays.getHumanCurrency () <<
+                "/" << RippleAddress::createHumanAccountID (saTakerPays.getIssuer ()) <<
+                " -> " << saTakerGets.getHumanCurrency () <<
+                "/" << RippleAddress::createHumanAccountID (saTakerGets.getIssuer ());
+
+            // We use the original rate to place the offer.
+            uDirectory = Ledger::getQualityIndex (uBookBase, uRate);
+
+            // Add offer to order book.
+            terResult = view.dirAdd (uBookNode, uDirectory, uLedgerIndex,
+                std::bind (&Ledger::qualityDirDescriber, std::placeholders::_1,
+                           std::placeholders::_2, saTakerPays.getCurrency (),
+                           uPaysIssuerID, saTakerGets.getCurrency (),
+                           uGetsIssuerID, uRate));
+        }
+
+        if (tesSUCCESS == terResult)
+        {
+            if (m_journal.debug)
+            {
+                m_journal.debug <<
+                    "sfAccount=" <<
+                    RippleAddress::createHumanAccountID (mTxnAccountID);
+                m_journal.debug <<
+                    "uPaysIssuerID=" <<
+                    RippleAddress::createHumanAccountID (uPaysIssuerID);
+                m_journal.debug <<
+                    "uGetsIssuerID=" <<
+                    RippleAddress::createHumanAccountID (uGetsIssuerID);
+                m_journal.debug <<
+                    "saTakerPays.isNative()=" <<
+                    saTakerPays.isNative ();
+                m_journal.debug <<
+                    "saTakerGets.isNative()=" <<
+                    saTakerGets.isNative ();
+                m_journal.debug <<
+                    "uPaysCurrency=" <<
+                    saTakerPays.getHumanCurrency ();
+                m_journal.debug <<
+                    "uGetsCurrency=" <<
+                    saTakerGets.getHumanCurrency ();
+            }
+
+            SLE::pointer sleOffer (mEngine->entryCreate (ltOFFER, uLedgerIndex));
+
+            sleOffer->setFieldAccount (sfAccount, mTxnAccountID);
+            sleOffer->setFieldU32 (sfSequence, uSequence);
+            sleOffer->setFieldH256 (sfBookDirectory, uDirectory);
+            sleOffer->setFieldAmount (sfTakerPays, saTakerPays);
+            sleOffer->setFieldAmount (sfTakerGets, saTakerGets);
+            sleOffer->setFieldU64 (sfOwnerNode, uOwnerNode);
+            sleOffer->setFieldU64 (sfBookNode, uBookNode);
+
+            if (uExpiration)
+                sleOffer->setFieldU32 (sfExpiration, uExpiration);
+
+            if (bPassive)
+                sleOffer->setFlag (lsfPassive);
+
+            if (bSell)
+                sleOffer->setFlag (lsfSell);
+
+            if (m_journal.debug) m_journal.debug <<
+                "final terResult=" << transToken (terResult) <<
+                " sleOffer=" << sleOffer->getJson (0);
+        }
+    }
+
+    if (terResult != tesSUCCESS)
+    {
+        m_journal.debug <<
+            "final terResult=" << transToken (terResult);
+    }
+
+    return terResult;
+}
+
+std::unique_ptr <Transactor> make_CreateOffer (
     SerializedTransaction const& txn,
     TransactionEngineParams params,
     TransactionEngine* engine)
 {
 #if RIPPLE_USE_OLD_CREATE_TRANSACTOR
-    return std::make_unique <ClassicOfferCreateTransactor> (txn, params, engine);
+    return std::make_unique <CreateOfferLegacy> (txn, params, engine);
 #else
     STAmount const& amount_in = txn.getFieldAmount (sfTakerPays);
     STAmount const& amount_out = txn.getFieldAmount (sfTakerGets);
     
     // Autobridging is only in effect when an offer does not involve XRP
     if (!amount_in.isNative() && !amount_out.isNative ())
-    {
+        return std::make_unique <CreateOfferBridged> (txn, params, engine);
-        // no autobridging transactor exists yet - we create a regular, direct
-        // transactor for now.
-        return std::make_unique <DirectOfferCreateTransactor> (txn, params, engine);
-    }
     
-    return std::make_unique <DirectOfferCreateTransactor> (txn, params, engine);
+    return std::make_unique <CreateOfferDirect> (txn, params, engine);
 #endif
 }
 

src/ripple_app/transactors/CreateOffer.h

@@ -20,45 +20,53 @@
 #ifndef RIPPLE_TX_OFFERCREATE_H_INCLUDED
 #define RIPPLE_TX_OFFERCREATE_H_INCLUDED
 
+#include "../book/Amounts.h"
+#include "../book/Types.h"
+
 #include "../../beast/beast/cxx14/memory.h"
 
 namespace ripple {
 
-class OfferCreateTransactorLog;
+class CreateOfferLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <OfferCreateTransactorLog> ()
+LogPartition::getPartitionName <CreateOfferLog> ()
 {
     return "Tx/OfferCreate";
 }
 
-class OfferCreateTransactor
+class CreateOffer
     : public Transactor
 {
-private:
+protected:
-    template <class T>
+    /** Determine if we are authorized to hold the asset we want to get */
-    static std::string
+    TER checkAcceptAsset(core::AssetRef asset) const;
-    get_compare_sign (T const& lhs, T const& rhs)
-    {
-        if (lhs > rhs)
-            return ">";
 
-        if (rhs > lhs)
+    /** Fill offer as much as possible by consuming offers already on the books.
-            return "<";
+        We adjusts account balances and charges fees on top to taker.
 
-        // If neither is bigger than the other, they must be equal
+        @param taker_amount.in How much the taker offers
-        return "=";
+        @param taker_amount.out How much the taker wants
-    }
+
+        @return result.first crossing operation success/failure indicator.
+                result.second amount of offer left unfilled - only meaningful
+                              if result.first is tesSUCCESS.
+    */
+    virtual std::pair<TER, core::Amounts> crossOffers (
+        core::LedgerView& view,
+        core::Amounts const& taker_amount) = 0;
 
 public:
-    OfferCreateTransactor (
+    CreateOffer (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine);
+
+    TER doApply () override;
 };
 
-std::unique_ptr <Transactor> make_OfferCreateTransactor (
+std::unique_ptr <Transactor> make_CreateOffer (
     SerializedTransaction const& txn,
     TransactionEngineParams params,
     TransactionEngine* engine);

src/ripple_app/transactors/CreateOfferBridged.cpp

@@ -17,3 +17,175 @@
 */
 //==============================================================================
 
+#include "../book/OfferStream.h"
+#include "../book/Taker.h"
+#include "../book/Quality.h"
+#include "../../beast/beast/streams/debug_ostream.h"
+
+namespace ripple {
+
+std::pair<TER, core::Amounts>
+CreateOfferBridged::crossOffers (
+    core::LedgerView& view,
+    core::Amounts const& taker_amount)
+{
+    assert (!taker_amount.in.isNative () && !taker_amount.out.isNative ());
+
+    if (taker_amount.in.isNative () || taker_amount.out.isNative ())
+        return std::make_pair (tefINTERNAL, core::Amounts ());
+
+    core::Clock::time_point const when (
+        mEngine->getLedger ()->getParentCloseTimeNC ());
+
+    core::Taker::Options const options (mTxn.getFlags());
+
+    core::LedgerView view_cancel (view.duplicate());
+
+    core::AssetRef const asset_in (
+        taker_amount.in.getCurrency(), taker_amount.in.getIssuer());
+
+    core::AssetRef const asset_out (
+        taker_amount.out.getCurrency(), taker_amount.out.getIssuer());
+
+    core::OfferStream offers_direct (view, view_cancel,
+        core::Book (asset_in, asset_out), when, m_journal);
+
+    core::OfferStream offers_leg1 (view, view_cancel,
+        core::Book (asset_in, xrp_asset ()), when, m_journal);
+    
+    core::OfferStream offers_leg2 (view, view_cancel,
+        core::Book (xrp_asset (), asset_out), when, m_journal);
+
+    core::Taker taker (view, mTxnAccountID, taker_amount, options);
+
+    if (m_journal.debug) m_journal.debug <<
+        "process_order: " <<
+        (options.sell? "sell" : "buy") << " " <<
+        (options.passive? "passive" : "") << std::endl <<
+        "     taker: " << taker.account() << std::endl <<
+        "  balances: " <<
+            view.accountFunds (taker.account(), taker_amount.in) << ", " <<
+            view.accountFunds (taker.account(), taker_amount.out);
+
+    TER cross_result (tesSUCCESS);
+
+    bool have_bridged (
+        offers_leg1.step_account (taker.account()) &&
+        offers_leg2.step_account (taker.account()));
+    bool have_direct (offers_direct.step_account (taker.account()));
+    bool place_order (true);
+
+    while (have_direct || have_bridged)
+    {
+        core::Quality quality;
+        bool use_direct;
+        bool leg1_consumed(false);
+        bool leg2_consumed(false);
+        bool direct_consumed(false);
+
+        // Logic:
+        // We calculate the qualities of any direct and bridged offers at the
+        // tip of the order book, and choose the best one of the two.
+        
+        if (have_direct)
+        {
+            core::Quality const direct_quality (offers_direct.tip ().quality ());
+
+            if (have_bridged)
+            {
+                core::Quality const bridged_quality (core::composed_quality (
+                    offers_leg1.tip ().quality (),
+                    offers_leg2.tip ().quality ()));
+
+                if (bridged_quality < direct_quality)
+                {
+                    use_direct = true;
+                    quality = direct_quality;
+                }
+                else
+                {
+                    use_direct = false;
+                    quality = bridged_quality;
+                }
+            }
+            else
+            {
+                use_direct = true;
+                quality = offers_direct.tip ().quality ();
+            }
+        }
+        else
+        {
+            use_direct = false;
+            quality = core::composed_quality (
+                    offers_leg1.tip ().quality (),
+                    offers_leg2.tip ().quality ());
+        }
+
+        // We are always looking at the best quality available, so if we reject
+        // that, we know that we are done.
+        if (taker.reject(quality))
+            break;
+
+        if (use_direct)
+        {
+            if (m_journal.debug) m_journal.debug <<
+                "  Offer: " << offers_direct.tip () << std::endl <<
+                "         " << offers_direct.tip ().amount().in <<
+                " : " << offers_direct.tip ().amount ().out;
+
+            cross_result = taker.cross(offers_direct.tip ());
+
+            if (offers_direct.tip ().fully_consumed ())
+            {
+                direct_consumed = true;
+                have_direct = offers_direct.step_account (taker.account());
+            }
+        }
+        else
+        {
+            if (m_journal.debug) m_journal.debug <<
+                " Offer1: " << offers_leg1.tip () << std::endl <<
+                "         " << offers_leg1.tip ().amount().in <<
+                " : " << offers_leg1.tip ().amount ().out << std::endl <<
+                " Offer2: " << offers_leg2.tip () << std::endl <<
+                "         " << offers_leg2.tip ().amount ().in <<
+                " : " << offers_leg2.tip ().amount ().out;
+
+            cross_result = taker.cross(offers_leg1.tip (), offers_leg2.tip ());
+
+            if (offers_leg1.tip ().fully_consumed ())
+            {
+                leg1_consumed = true;
+                have_bridged = offers_leg1.step_account (taker.account ());
+            }
+            if (have_bridged && offers_leg2.tip ().fully_consumed ())
+            {
+                leg2_consumed = true;
+                have_bridged = offers_leg2.step_account (taker.account ());
+            }
+        }
+
+        if (cross_result != tesSUCCESS)
+        {
+            cross_result = tecFAILED_PROCESSING;
+            break;
+        }
+
+        if (taker.done())
+        {
+            m_journal.debug << "The taker reports he's done during crossing!";
+            place_order = false;
+            break;
+        }
+
+        // Postcondition: If we aren't done, then we must have consumed at
+        //                least one offer fully.
+        assert (direct_consumed || leg1_consumed || leg2_consumed);
+    }
+
+    return std::make_pair(cross_result, taker.remaining_offer ());
+}
+
+}
+

src/ripple_app/transactors/CreateOfferBridged.h

@@ -20,4 +20,34 @@
 #ifndef RIPPLE_TX_BRIDGE_OFFERCREATE_H_INCLUDED
 #define RIPPLE_TX_BRIDGE_OFFERCREATE_H_INCLUDED
 
+#include "../book/Amounts.h"
+
+#include <unordered_set>
+
+namespace ripple {
+
+class CreateOfferBridged
+    : public CreateOffer
+{
+public:
+    CreateOfferBridged (
+        SerializedTransaction const& txn,
+        TransactionEngineParams params,
+        TransactionEngine* engine)
+        : CreateOffer (
+            txn,
+            params,
+            engine)
+    {
+
+    }
+
+private:
+    std::pair<TER, core::Amounts> crossOffers (
+        core::LedgerView& view,
+        core::Amounts const& taker_amount) override;
+};
+
+}
+
 #endif

src/ripple_app/transactors/CreateOfferDirect.cpp

@@ -23,38 +23,38 @@
 
 namespace ripple {
 
-//------------------------------------------------------------------------------
+/** Fill offer as much as possible by consuming offers already on the books.
+    We adjusts account balances and charges fees on top to taker.
 
-// NIKB Move this in the right place
+    @param taker_amount.in How much the taker offers
-std::pair<TER,bool>
+    @param taker_amount.out How much the taker wants
-process_order (
+    @param taker_flow.in    What the taker actually paid, not including fees.
+    @param taker_flow.out   What the taker actually got, not including fees.
+
+    @return tesSUCCESS, terNO_ACCOUNT, telFAILED_PROCESSING, or
+            tecFAILED_PROCESSING
+*/
+std::pair<TER, core::Amounts>
+CreateOfferDirect::crossOffers (
     core::LedgerView& view,
-    core::BookRef const book,
+    core::Amounts const& taker_amount)
-    core::Account const& account,
-    core::Amounts const& amount,
-    core::Amounts& cross_flow,
-    core::Taker::Options const options,
-    core::Clock::time_point const when,
-    beast::Journal& journal)
 {
-    TER result (tesSUCCESS);
+    core::Taker::Options const options (mTxn.getFlags());
+
+    core::Clock::time_point const when (
+        mEngine->getLedger ()->getParentCloseTimeNC ());
+
     core::LedgerView view_cancel (view.duplicate());
-    core::OfferStream offers (view, view_cancel, book, when, journal);
+    core::OfferStream offers (view, view_cancel, 
-    core::Taker taker (offers.view(), book, account, amount, options);
+        core::Book (
+            core::AssetRef (
+                taker_amount.in.getCurrency(), taker_amount.in.getIssuer()), 
+            core::AssetRef (
+                taker_amount.out.getCurrency(), taker_amount.out.getIssuer())), 
+        when, m_journal);
+    core::Taker taker (offers.view(), mTxnAccountID, taker_amount, options);
 
-    if (journal.debug) journal.debug <<
+    TER cross_result (tesSUCCESS);
-        "process_order: " <<
-        (options.sell? "sell" : "buy") << " " <<
-        (options.passive? "passive" : "") << std::endl <<
-        "     taker: " << taker.account() << std::endl <<
-        "  balances: " <<
-            view.accountFunds (taker.account(), amount.in) << ", " <<
-            view.accountFunds (taker.account(), amount.out);
-
-    cross_flow.in.clear (amount.in);
-    cross_flow.out.clear (amount.out);
-
-    bool place_order (true);
 
     while (true)
     {
@@ -67,27 +67,22 @@ process_order (
 
         if (taker.done())
         {
-            journal.debug << "The taker reports he's done during crossing!";
+            m_journal.debug << "The taker reports he's done during crossing!";
-            place_order = false;
             break;
         }
 
-        if (! offers.step())
+        // NIKB CHECKME Investigate whether we can use offer.step_account() here
+        //              or whether doing so would cause a protocol-breaking
+        //             change.
+        if (! offers.step ())
         {
             // Place the order since there are no
             // more offers and the order has a balance.
-            journal.debug << "No more offers to consider during crossing!";
+            m_journal.debug << "No more offers to consider during crossing!";
             break;
         }
 
-        auto const offer (offers.tip());
+        auto const& offer (offers.tip());
-
-        if (journal.debug) journal.debug <<
-            "Considering offer: " << std::endl <<
-            "  Id: " << offer.entry()->getIndex() << std::endl <<
-            "  In: " << offer.amount().in << std::endl <<
-            " Out: " << offer.amount().out << std::endl <<
-            "  By: " << offer.account();
 
         if (taker.reject (offer.quality()))
         {
@@ -98,592 +93,25 @@ process_order (
 
         if (offer.account() == taker.account())
         {
-            if (journal.debug) journal.debug <<
+            // Skip offer from self. The offer will be considered expired and
-                " skipping self-offer " << offer.entry()->getIndex() << std::endl <<
+            // will get deleted.
-                "  pays/gets " << offer.amount().in << ", " << offer.amount().out << std::endl <<
-                " during cross for " << std::endl <<
-                "   pays/gets " << amount.in << ", " << amount.out;
-                ;
-
-            // Skip offer from self.
-            // (Offer will be considered expired, and get deleted)
             continue;
         }
 
-        if (journal.debug) journal.debug <<
+        if (m_journal.debug) m_journal.debug <<
-            "   offer " << offer.entry()->getIndex() << std::endl <<
+                "  Offer: " << offer.entry()->getIndex() << std::endl <<
-            "  pays/gets " << offer.amount().in << ", " << offer.amount().out
+                "         " << offer.amount().in << " : " << offer.amount().out;
-            ;
 
-        core::Amounts flow;
+        cross_result = taker.cross (offer);
-        bool consumed;
-        std::tie (flow, consumed) = taker.fill (offer);
 
-        result = taker.process (flow, offer);
+        if (cross_result != tesSUCCESS)
-
-        if (journal.debug) journal.debug <<
-            "       flow " <<
-                flow.in << ", " << flow.out << std::endl <<
-            "   balances " <<
-                view.accountFunds (taker.account(), amount.in) << ", " <<
-                view.accountFunds (taker.account(), amount.out)
-            ;
-
-        if (result != tesSUCCESS)
         {
-            // VFALCO TODO Return the tec and let a caller higher
+            cross_result = tecFAILED_PROCESSING;
-            //             up convert the error if the ledger is open.
-            //result = bOpenLedger ?
-            //    telFAILED_PROCESSING : tecFAILED_PROCESSING;
-            result = tecFAILED_PROCESSING;
             break;
         }
-
-        cross_flow.in += flow.in;
-        cross_flow.out += flow.out;
     }
 
-    if (result == tesSUCCESS)
+    return std::make_pair(cross_result, taker.remaining_offer ());
-    {
-        // No point in placing an offer for a fill-or-kill offer - the offer
-        // will not succeed, since it wasn't filled.
-        if (options.fill_or_kill)
-            place_order = false;
-
-        // An immediate or cancel order will fill however much it is possible
-        // to fill and the remainder is not filled.
-        if (options.immediate_or_cancel)
-            place_order = false;
-    }
-
-    if (result == tesSUCCESS)
-    {
-        if (place_order)
-        {
-
-        }
-    }
-    else
-    {
-
-    }
-
-    return std::make_pair(result,place_order);
-}
-
-/** Take as much as possible.
-    We adjusts account balances and charges fees on top to taker.
-
-    @param saTakerPays What the taker offers (w/ issuer)
-    @param saTakerGets What the taker wanted (w/ issuer)
-    @param saTakerPaid What taker could have paid including saved not including
-                       fees. To reduce an offer.
-    @param saTakerGot What taker got not including fees. To reduce an offer.
-    @return tesSUCCESS, terNO_ACCOUNT, telFAILED_PROCESSING, or
-            tecFAILED_PROCESSING
-*/
-std::pair<TER,bool> DirectOfferCreateTransactor::crossOffers (
-    core::LedgerView& view,
-    const STAmount&     saTakerPays,
-    const STAmount&     saTakerGets,
-    STAmount&           saTakerPaid,
-    STAmount&           saTakerGot)
-{
-    if (m_journal.debug) m_journal.debug << "takeOffers: ";
-
-    core::Book book (
-        core::AssetRef (
-            saTakerPays.getCurrency(), saTakerPays.getIssuer()),
-        core::AssetRef (
-            saTakerGets.getCurrency(), saTakerGets.getIssuer()));
-
-    core::Amounts cross_flow (
-        core::Amount (saTakerPays.getCurrency(), saTakerPays.getIssuer()),
-        core::Amount (saTakerGets.getCurrency(), saTakerGets.getIssuer()));
-
-    auto const result (process_order (
-        view, book, mTxnAccountID,
-        core::Amounts (saTakerPays, saTakerGets), cross_flow,
-        core::Taker::Options (mTxn.getFlags()),
-        mEngine->getLedger ()->getParentCloseTimeNC (),
-        m_journal));
-
-    core::Amounts const funds (
-        view.accountFunds (mTxnAccountID, saTakerPays),
-        view.accountFunds (mTxnAccountID, saTakerGets));
-
-    if (m_journal.debug) m_journal.debug << " cross_flow: " <<
-            cross_flow.in << ", " << cross_flow.out;
-
-    if (m_journal.debug) m_journal.debug << "   balances: " <<
-        funds.in << ", " << funds.out;
-
-    saTakerPaid = cross_flow.in;
-    saTakerGot = cross_flow.out;
-
-    if (m_journal.debug) m_journal.debug <<
-        "        result: " << transToken (result.first) <<
-        (result.second ? " (consumed)" : "");
-
-    return result;
-}
-
-TER DirectOfferCreateTransactor::doApply ()
-{
-    if (m_journal.debug) m_journal.debug <<
-        "OfferCreate> " << mTxn.getJson (0);
-
-    std::uint32_t const uTxFlags = mTxn.getFlags ();
-
-    bool const bPassive = is_bit_set (uTxFlags, tfPassive);
-    bool const bImmediateOrCancel = is_bit_set (uTxFlags, tfImmediateOrCancel);
-    bool const bFillOrKill = is_bit_set (uTxFlags, tfFillOrKill);
-    bool const bSell = is_bit_set (uTxFlags, tfSell);
-
-    STAmount saTakerPays = mTxn.getFieldAmount (sfTakerPays);
-    STAmount saTakerGets = mTxn.getFieldAmount (sfTakerGets);
-
-    if (!saTakerPays.isLegalNet () || !saTakerGets.isLegalNet ())
-        return temBAD_AMOUNT;
-
-    uint160 const uPaysIssuerID = saTakerPays.getIssuer ();
-    uint160 const uGetsIssuerID = saTakerGets.getIssuer ();
-
-    bool const bHaveExpiration (mTxn.isFieldPresent (sfExpiration));
-    bool const bHaveCancel (mTxn.isFieldPresent (sfOfferSequence));
-
-    std::uint32_t const uExpiration = mTxn.getFieldU32 (sfExpiration);
-    std::uint32_t const uCancelSequence = mTxn.getFieldU32 (sfOfferSequence);
-
-    // FIXME understand why we use SequenceNext instead of current transaction
-    //       sequence to determine the transaction. Why is the offer seuqnce
-    //       number insufficient?
-
-    std::uint32_t const uAccountSequenceNext = mTxnAccount->getFieldU32 (sfSequence);
-    std::uint32_t const uSequence = mTxn.getSequence ();
-
-    const uint256 uLedgerIndex = Ledger::getOfferIndex (mTxnAccountID, uSequence);
-
-    if (m_journal.debug)
-    {
-        m_journal.debug <<
-            "Creating offer node: " << to_string (uLedgerIndex) <<
-            " uSequence=" << uSequence;
-
-        if (bImmediateOrCancel)
-            m_journal.debug << "Transaction: IoC set.";
-
-        if (bFillOrKill)
-            m_journal.debug << "Transaction: FoK set.";
-    }
-
-    uint160 const uPaysCurrency = saTakerPays.getCurrency ();
-    uint160 const uGetsCurrency = saTakerGets.getCurrency ();
-    std::uint64_t const uRate = STAmount::getRate (saTakerGets, saTakerPays);
-
-    TER terResult (tesSUCCESS);
-    uint256 uDirectory; // Delete hints.
-    std::uint64_t uOwnerNode;
-    std::uint64_t uBookNode;
-
-    // This is the ledger view that we work against. Transactions are applied
-    // as we go on processing transactions.
-    core::LedgerView& view (mEngine->view ());
-
-    // This is a checkpoint with just the fees paid. If something goes wrong
-    // with this transaction, we roll back to this ledger.
-    core::LedgerView view_checkpoint (view);
-
-    view.bumpSeq (); // Begin ledger variance.
-
-    SLE::pointer sleCreator = mEngine->entryCache (
-        ltACCOUNT_ROOT, Ledger::getAccountRootIndex (mTxnAccountID));
-
-    if (uTxFlags & tfOfferCreateMask)
-    {
-        if (m_journal.debug) m_journal.debug <<
-            "Malformed transaction: Invalid flags set.";
-
-        return temINVALID_FLAG;
-    }
-    else if (bImmediateOrCancel && bFillOrKill)
-    {
-        if (m_journal.debug) m_journal.debug <<
-            "Malformed transaction: both IoC and FoK set.";
-
-        return temINVALID_FLAG;
-    }
-    else if (bHaveExpiration && !uExpiration)
-    {
-        m_journal.warning <<
-            "Malformed offer: bad expiration";
-
-        terResult = temBAD_EXPIRATION;
-    }
-    else if (saTakerPays.isNative () && saTakerGets.isNative ())
-    {
-        m_journal.warning <<
-            "Malformed offer: XRP for XRP";
-
-        terResult   = temBAD_OFFER;
-    }
-    else if (saTakerPays <= zero || saTakerGets <= zero)
-    {
-        m_journal.warning <<
-            "Malformed offer: bad amount";
-
-        terResult   = temBAD_OFFER;
-    }
-    else if (uPaysCurrency == uGetsCurrency && uPaysIssuerID == uGetsIssuerID)
-    {
-        m_journal.warning <<
-            "Malformed offer: redundant offer";
-
-        terResult = temREDUNDANT;
-    }
-    // We don't allow a non-native currency to use the currency code XRP.
-    else if (CURRENCY_BAD == uPaysCurrency || CURRENCY_BAD == uGetsCurrency)
-    {
-        m_journal.warning <<
-            "Malformed offer: Bad currency.";
-
-        terResult = temBAD_CURRENCY;
-    }
-    else if (saTakerPays.isNative () != !uPaysIssuerID || saTakerGets.isNative () != !uGetsIssuerID)
-    {
-        m_journal.warning <<
-            "Malformed offer: bad issuer";
-
-        terResult = temBAD_ISSUER;
-    }
-    else if (view.accountFunds (mTxnAccountID, saTakerGets) <= zero)
-    {
-        m_journal.warning <<
-            "delay: Offers must be at least partially funded.";
-
-        terResult = tecUNFUNDED_OFFER;
-    }
-    // This can probably be simplified to make sure that you cancel sequences
-    // before the transaction sequence number.
-    else if (bHaveCancel && (!uCancelSequence || uAccountSequenceNext - 1 <= uCancelSequence))
-    {
-        if (m_journal.debug) m_journal.debug <<
-            "uAccountSequenceNext=" << uAccountSequenceNext <<
-            " uOfferSequence=" << uCancelSequence;
-
-        terResult = temBAD_SEQUENCE;
-    }
-
-    if (tesSUCCESS != terResult)
-    {
-        if (m_journal.debug) m_journal.debug <<
-            "final terResult=" << transToken (terResult);
-
-        return terResult;
-    }
-
-    // Process a cancellation request that's passed along with an offer.
-    if ((tesSUCCESS == terResult) && bHaveCancel)
-    {
-        uint256 const uCancelIndex (
-            Ledger::getOfferIndex (mTxnAccountID, uCancelSequence));
-        SLE::pointer sleCancel = mEngine->entryCache (ltOFFER, uCancelIndex);
-
-        // It's not an error to not find the offer to cancel: it might have
-        // been consumed or removed as we are processing. Additionally, it
-        // might not even have been an offer - we don't care.
-        if (sleCancel)
-        {
-            m_journal.warning <<
-                "Cancelling order with sequence " << uCancelSequence;
-
-            terResult = view.offerDelete (sleCancel);
-        }
-    }
-
-    // Expiration is defined in terms of the close time of the parent ledger,
-    // because we definitively know the time that it closed but we do not
-    // know the closing time of the ledger that is under construction.
-    if (bHaveExpiration &&
-        (mEngine->getLedger ()->getParentCloseTimeNC () >= uExpiration))
-    {
-        return tesSUCCESS;
-    }
-
-    // If all is well and this isn't an offer to XRP, then we make sure we are
-    // authorized to hold what the taker will pay.
-    if (tesSUCCESS == terResult && !saTakerPays.isNative ())
-    {
-        SLE::pointer sleTakerPays = mEngine->entryCache (
-            ltACCOUNT_ROOT, Ledger::getAccountRootIndex (uPaysIssuerID));
-
-        if (!sleTakerPays)
-        {
-            m_journal.warning <<
-                "delay: can't receive IOUs from non-existent issuer: " <<
-                RippleAddress::createHumanAccountID (uPaysIssuerID);
-
-            return is_bit_set (mParams, tapRETRY)
-                ? terNO_ACCOUNT
-                : tecNO_ISSUER;
-        }
-
-        if (is_bit_set (sleTakerPays->getFieldU32 (sfFlags), lsfRequireAuth))
-        {
-            SLE::pointer sleRippleState (mEngine->entryCache (
-                ltRIPPLE_STATE,
-                Ledger::getRippleStateIndex (
-                    mTxnAccountID, uPaysIssuerID, uPaysCurrency)));
-
-            if (!sleRippleState)
-            {
-                return is_bit_set (mParams, tapRETRY)
-                    ? terNO_LINE
-                    : 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 (mTxnAccountID > uPaysIssuerID);
-
-            bool const need_auth (is_bit_set (
-                sleRippleState->getFieldU32 (sfFlags),
-                (canonical_gt ? lsfLowAuth : lsfHighAuth)));
-
-            if (need_auth)
-            {
-                if (m_journal.debug) m_journal.debug <<
-                    "delay: can't receive IOUs from issuer without auth.";
-
-                return is_bit_set (mParams, tapRETRY)
-                    ? terNO_AUTH
-                    : tecNO_AUTH;
-            }
-        }
-    }
-
-    STAmount saPaid;
-    STAmount saGot;
-    bool const bOpenLedger = is_bit_set (mParams, tapOPEN_LEDGER);
-    bool const placeOffer = true;
-
-    if (tesSUCCESS == terResult)
-    {
-        // Take using the parameters of the offer.
-        if (m_journal.debug) m_journal.debug <<
-            "takeOffers: BEFORE saTakerGets=" << saTakerGets.getFullText ();
-
-        auto ret = crossOffers (
-            view,
-            saTakerGets,  // Reverse as we are the taker for taking.
-            saTakerPays,
-            saPaid,       // Buy semantics: how much would have sold at full price. Sell semantics: how much was sold.
-            saGot);       // How much was got.
-
-        terResult = ret.first;
-
-        if (terResult == tecFAILED_PROCESSING && bOpenLedger)
-            terResult = telFAILED_PROCESSING;
-
-        if (m_journal.debug)
-        {
-            m_journal.debug << "takeOffers=" << terResult;
-            m_journal.debug << "takeOffers: saPaid=" << saPaid.getFullText ();
-            m_journal.debug << "takeOffers:  saGot=" << saGot.getFullText ();
-        }
-
-        if (tesSUCCESS == terResult)
-        {
-            // Reduce pay in from takers by what offer just got.
-            saTakerPays -= saGot;
-
-            // Reduce pay out to takers by what srcAccount just paid.
-            saTakerGets -= saPaid;
-
-            if (m_journal.debug)
-            {
-                m_journal.debug <<
-                    "takeOffers: AFTER saTakerPays=" <<
-                    saTakerPays.getFullText ();
-                m_journal.debug <<
-                    "takeOffers: AFTER saTakerGets=" <<
-                    saTakerGets.getFullText ();
-            }
-        }
-    }
-
-    if (m_journal.debug)
-    {
-        m_journal.debug <<
-            "takeOffers: saTakerPays=" <<saTakerPays.getFullText ();
-        m_journal.debug <<
-            "takeOffers: saTakerGets=" << saTakerGets.getFullText ();
-        m_journal.debug <<
-            "takeOffers: mTxnAccountID=" <<
-            RippleAddress::createHumanAccountID (mTxnAccountID);
-        m_journal.debug <<
-            "takeOffers:         FUNDS=" <<
-            view.accountFunds (mTxnAccountID, saTakerGets).getFullText ();
-    }
-
-    if (tesSUCCESS != terResult)
-    {
-        m_journal.debug <<
-            "final terResult=" << transToken (terResult);
-
-        return terResult;
-    }
-
-    if (bFillOrKill && (saTakerPays || saTakerGets))
-    {
-        // Fill or kill and have leftovers.
-        view.swapWith (view_checkpoint); // Restore with just fees paid.
-        return tesSUCCESS;
-    }
-
-    if (!placeOffer
-        || saTakerPays <= zero                                          // Wants nothing more.
-        || saTakerGets <= zero                                          // Offering nothing more.
-        || bImmediateOrCancel                                           // Do not persist.
-        || view.accountFunds (mTxnAccountID, saTakerGets) <= zero)      // Not funded.
-    {
-        // Complete as is.
-        nothing ();
-    }
-    else if (mPriorBalance.getNValue () < mEngine->getLedger ()->getReserve (sleCreator->getFieldU32 (sfOwnerCount) + 1))
-    {
-        // If we are here, the signing account had an insufficient reserve
-        // *prior* to our processing. We use the prior balance to simplify
-        // client writing and make the user experience better.
-
-        if (bOpenLedger) // Ledger is not final, can vote no.
-        {
-            // Hope for more reserve to come in or more offers to consume. If we
-            // specified a local error this transaction will not be retried, so
-            // specify a tec to distribute the transaction and allow it to be
-            // retried. In particular, it may have been successful to a
-            // degree (partially filled) and if it hasn't, it might succeed.
-            terResult = tecINSUF_RESERVE_OFFER;
-        }
-        else if (!saPaid && !saGot)
-        {
-            // Ledger is final, insufficent reserve to create offer, processed
-            // nothing.
-
-            terResult = tecINSUF_RESERVE_OFFER;
-        }
-        else
-        {
-            // Ledger is final, insufficent reserve to create offer, processed
-            // something.
-
-            // Consider the offer unfunded. Treat as tesSUCCESS.
-            nothing ();
-        }
-    }
-    else
-    {
-        // We need to place the remainder of the offer into its order book.
-        if (m_journal.debug) m_journal.debug <<
-            "offer not fully consumed:" <<
-            " saTakerPays=" << saTakerPays.getFullText () <<
-            " saTakerGets=" << saTakerGets.getFullText ();
-
-        // Add offer to owner's directory.
-        terResult   = view.dirAdd (uOwnerNode,
-            Ledger::getOwnerDirIndex (mTxnAccountID), uLedgerIndex,
-            std::bind (&Ledger::ownerDirDescriber, std::placeholders::_1,
-                       std::placeholders::_2, mTxnAccountID));
-
-        if (tesSUCCESS == terResult)
-        {
-            // Update owner count.
-            view.ownerCountAdjust (mTxnAccountID, 1, sleCreator);
-
-            uint256 uBookBase   = Ledger::getBookBase (
-                uPaysCurrency,
-                uPaysIssuerID,
-                uGetsCurrency,
-                uGetsIssuerID);
-
-            if (m_journal.debug) m_journal.debug <<
-                "adding to book: " << to_string (uBookBase) <<
-                " : " << saTakerPays.getHumanCurrency () <<
-                "/" << RippleAddress::createHumanAccountID (saTakerPays.getIssuer ()) <<
-                " -> " << saTakerGets.getHumanCurrency () <<
-                "/" << RippleAddress::createHumanAccountID (saTakerGets.getIssuer ());
-
-            // We use the original rate to place the offer.
-            uDirectory = Ledger::getQualityIndex (uBookBase, uRate);
-
-            // Add offer to order book.
-            terResult = view.dirAdd (uBookNode, uDirectory, uLedgerIndex,
-                std::bind (&Ledger::qualityDirDescriber, std::placeholders::_1,
-                           std::placeholders::_2, saTakerPays.getCurrency (),
-                           uPaysIssuerID, saTakerGets.getCurrency (),
-                           uGetsIssuerID, uRate));
-        }
-
-        if (tesSUCCESS == terResult)
-        {
-            if (m_journal.debug)
-            {
-                m_journal.debug <<
-                    "sfAccount=" <<
-                    RippleAddress::createHumanAccountID (mTxnAccountID);
-                m_journal.debug <<
-                    "uPaysIssuerID=" <<
-                    RippleAddress::createHumanAccountID (uPaysIssuerID);
-                m_journal.debug <<
-                    "uGetsIssuerID=" <<
-                    RippleAddress::createHumanAccountID (uGetsIssuerID);
-                m_journal.debug <<
-                    "saTakerPays.isNative()=" <<
-                    saTakerPays.isNative ();
-                m_journal.debug <<
-                    "saTakerGets.isNative()=" <<
-                    saTakerGets.isNative ();
-                m_journal.debug <<
-                    "uPaysCurrency=" <<
-                    saTakerPays.getHumanCurrency ();
-                m_journal.debug <<
-                    "uGetsCurrency=" <<
-                    saTakerGets.getHumanCurrency ();
-            }
-
-            SLE::pointer sleOffer (mEngine->entryCreate (ltOFFER, uLedgerIndex));
-
-            sleOffer->setFieldAccount (sfAccount, mTxnAccountID);
-            sleOffer->setFieldU32 (sfSequence, uSequence);
-            sleOffer->setFieldH256 (sfBookDirectory, uDirectory);
-            sleOffer->setFieldAmount (sfTakerPays, saTakerPays);
-            sleOffer->setFieldAmount (sfTakerGets, saTakerGets);
-            sleOffer->setFieldU64 (sfOwnerNode, uOwnerNode);
-            sleOffer->setFieldU64 (sfBookNode, uBookNode);
-
-            if (uExpiration)
-                sleOffer->setFieldU32 (sfExpiration, uExpiration);
-
-            if (bPassive)
-                sleOffer->setFlag (lsfPassive);
-
-            if (bSell)
-                sleOffer->setFlag (lsfSell);
-
-            if (m_journal.debug) m_journal.debug <<
-                "final terResult=" << transToken (terResult) <<
-                " sleOffer=" << sleOffer->getJson (0);
-        }
-    }
-
-    if (tesSUCCESS != terResult)
-    {
-        m_journal.debug <<
-            "final terResult=" << transToken (terResult);
-    }
-
-    return terResult;
 }
 
 }

src/ripple_app/transactors/CreateOfferDirect.h

@@ -20,22 +20,21 @@
 #ifndef RIPPLE_TX_DIRECT_OFFERCREATE_H_INCLUDED
 #define RIPPLE_TX_DIRECT_OFFERCREATE_H_INCLUDED
 
-#include "../book/OfferStream.h"
+#include "../book/Amounts.h"
-#include "../book/Taker.h"
+
-    
 #include <unordered_set>
 
 namespace ripple {
 
-class DirectOfferCreateTransactor
+class CreateOfferDirect
-    : public OfferCreateTransactor
+    : public CreateOffer
 {
 public:
-    DirectOfferCreateTransactor (
+    CreateOfferDirect (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
-        : OfferCreateTransactor (
+        : CreateOffer (
             txn,
             params,
             engine)
@@ -43,15 +42,10 @@ public:
 
     }
 
-    TER doApply () override;
-
 private:
-    std::pair<TER,bool> crossOffers (
+    std::pair<TER, core::Amounts> crossOffers (
         core::LedgerView& view,
-        STAmount const&     saTakerPays,
+        core::Amounts const& taker_amount) override;
-        STAmount const&     saTakerGets,
-        STAmount&           saTakerPaid,
-        STAmount&           saTakerGot);
 };
 
 }

src/ripple_app/transactors/CreateOfferLegacy.cpp

@@ -22,7 +22,7 @@ namespace ripple {
 /** Determine if an order is still valid
     If the order is not valid it will be marked as unfunded.
 */
-bool ClassicOfferCreateTransactor::isValidOffer (
+bool CreateOfferLegacy::isValidOffer (
     SLE::ref sleOffer,
     uint160 const& uOfferOwnerID,
     STAmount const& saOfferPays,
@@ -97,7 +97,7 @@ bool ClassicOfferCreateTransactor::isValidOffer (
 
 /**
 */
-bool ClassicOfferCreateTransactor::canCross (
+bool CreateOfferLegacy::canCross (
     STAmount const& saTakerFunds,
     STAmount const& saSubTakerPays,
     STAmount const& saSubTakerGets,
@@ -189,7 +189,7 @@ bool ClassicOfferCreateTransactor::canCross (
     books as: "give 0.57 BTC for 400 USD" which is what is left to sell at the
     original rate.
 */
-bool ClassicOfferCreateTransactor::applyOffer (
+bool CreateOfferLegacy::applyOffer (
     const bool bSell,
     const std::uint32_t uTakerPaysRate, const std::uint32_t uOfferPaysRate,
     const STAmount& saOfferRate,
@@ -327,7 +327,7 @@ bool ClassicOfferCreateTransactor::applyOffer (
     @return tesSUCCESS, terNO_ACCOUNT, telFAILED_PROCESSING, or
             tecFAILED_PROCESSING
 */
-TER ClassicOfferCreateTransactor::takeOffers (
+TER CreateOfferLegacy::takeOffers (
     const bool          bOpenLedger,
     const bool          bPassive,
     const bool          bSell,
@@ -671,7 +671,7 @@ TER ClassicOfferCreateTransactor::takeOffers (
     return terResult;
 }
 
-TER ClassicOfferCreateTransactor::doApply ()
+TER CreateOfferLegacy::doApply ()
 {
     if (m_journal.debug) m_journal.debug <<
         "OfferCreate> " << mTxn.getJson (0);

src/ripple_app/transactors/CreateOfferLegacy.h

@@ -24,30 +24,15 @@
 
 namespace ripple {
 
-class ClassicOfferCreateTransactor
+class CreateOfferLegacy
-    : public OfferCreateTransactor
+    : public CreateOffer
 {
-private:
-    template <class T>
-    static std::string
-    get_compare_sign (T const& lhs, T const& rhs)
-    {
-        if (lhs > rhs)
-            return ">";
-
-        if (rhs > lhs)
-            return "<";
-
-        // If neither is bigger than the other, they must be equal
-        return "=";
-    }
-
 public:
-    ClassicOfferCreateTransactor (
+    CreateOfferLegacy (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
-        : OfferCreateTransactor (
+        : CreateOffer (
             txn,
             params,
             engine)
@@ -57,6 +42,13 @@ public:
 
     TER doApply () override;
 
+    virtual std::pair<TER, core::Amounts> crossOffers (
+        core::LedgerView& view,
+        core::Amounts const& taker_amount)
+    {
+        return std::make_pair (tesSUCCESS, core::Amounts ());
+    }
+
 private:
     bool isValidOffer (
         SLE::ref            sleOfferDir,

src/ripple_app/transactors/Payment.cpp

@@ -21,7 +21,7 @@ namespace ripple {
 
 // See https://ripple.com/wiki/Transaction_Format#Payment_.280.29
 
-TER PaymentTransactor::doApply ()
+TER Payment::doApply ()
 {
     // Ripple if source or destination is non-native or if there are paths.
     std::uint32_t const uTxFlags = mTxn.getFlags ();

src/ripple_app/transactors/Payment.h

@@ -22,23 +22,23 @@
 
 namespace ripple {
 
-class PaymentTransactorLog;
+class PaymentLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <PaymentTransactorLog> ()
+LogPartition::getPartitionName <PaymentLog> ()
 {
     return "Tx/Payment";
 }
 
-class PaymentTransactor 
+class Payment 
     : public Transactor
 {
     /* The largest number of paths we allow */
     static std::size_t const MaxPathSize = 6;
 
 public:
-    PaymentTransactor (
+    Payment (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -46,7 +46,7 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <PaymentTransactorLog> ())
+            LogPartition::getJournal <PaymentLog> ())
     {
 
     }
@@ -54,6 +54,16 @@ public:
     TER doApply ();
 };
 
+inline
+std::unique_ptr <Transactor>
+make_Payment (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <Payment> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/SetAccount.cpp

@@ -19,7 +19,7 @@
 
 namespace ripple {
 
-TER AccountSetTransactor::doApply ()
+TER SetAccount::doApply ()
 {
     std::uint32_t const uTxFlags = mTxn.getFlags ();
 

src/ripple_app/transactors/SetAccount.h

@@ -22,20 +22,20 @@
 
 namespace ripple {
 
-class AccountSetTransactorLog;
+class SetAccountLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <AccountSetTransactorLog> ()
+LogPartition::getPartitionName <SetAccountLog> ()
 {
     return "Tx/AccountSet";
 }
 
-class AccountSetTransactor
+class SetAccount
     : public Transactor
 {
 public:
-    AccountSetTransactor (
+    SetAccount (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -43,7 +43,7 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <AccountSetTransactorLog> ())
+            LogPartition::getJournal <SetAccountLog> ())
     {
 
     }
@@ -51,6 +51,16 @@ public:
     TER doApply () override;
 };
 
+inline
+std::unique_ptr <Transactor>
+make_SetAccount (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <SetAccount> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/SetRegularKey.cpp

@@ -19,7 +19,7 @@
 
 namespace ripple {
 
-std::uint64_t RegularKeySetTransactor::calculateBaseFee ()
+std::uint64_t SetRegularKey::calculateBaseFee ()
 {
     if ( mTxnAccount
             && (! (mTxnAccount->getFlags () & lsfPasswordSpent))
@@ -33,7 +33,7 @@ std::uint64_t RegularKeySetTransactor::calculateBaseFee ()
 }
 
 
-TER RegularKeySetTransactor::doApply ()
+TER SetRegularKey::doApply ()
 {
     std::uint32_t const uTxFlags = mTxn.getFlags ();
 

src/ripple_app/transactors/SetRegularKey.h

@@ -22,22 +22,22 @@
 
 namespace ripple {
 
-class RegularKeySetTransactorLog;
+class SetRegularKeyLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <RegularKeySetTransactorLog> ()
+LogPartition::getPartitionName <SetRegularKeyLog> ()
 {
     return "Tx/RegularKeySet";
 }
 
-class RegularKeySetTransactor
+class SetRegularKey
     : public Transactor
 {
     std::uint64_t calculateBaseFee ();
 
 public:
-    RegularKeySetTransactor (
+    SetRegularKey (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -45,7 +45,7 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <RegularKeySetTransactorLog> ())
+            LogPartition::getJournal <SetRegularKeyLog> ())
     {
 
     }
@@ -54,6 +54,16 @@ public:
     TER doApply ();
 };
 
+inline
+std::unique_ptr <Transactor>
+make_SetRegularKey (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <SetRegularKey> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/SetTrust.cpp

@@ -19,7 +19,7 @@
 
 namespace ripple {
 
-TER TrustSetTransactor::doApply ()
+TER SetTrust::doApply ()
 {
     TER terResult = tesSUCCESS;
 

src/ripple_app/transactors/SetTrust.h

@@ -22,20 +22,20 @@
 
 namespace ripple {
 
-class TrustSetTransactorLog;
+class SetTrustLog;
 
 template <>
 char const*
-LogPartition::getPartitionName <TrustSetTransactorLog> ()
+LogPartition::getPartitionName <SetTrustLog> ()
 {
     return "Tx/TrustSet";
 }
 
-class TrustSetTransactor
+class SetTrust
     : public Transactor
 {
 public:
-    TrustSetTransactor (
+    SetTrust (
         SerializedTransaction const& txn,
         TransactionEngineParams params,
         TransactionEngine* engine)
@@ -43,13 +43,23 @@ public:
             txn,
             params,
             engine,
-            LogPartition::getJournal <TrustSetTransactorLog> ())
+            LogPartition::getJournal <SetTrustLog> ())
     {
     }
 
     TER doApply ();
 };
 
+inline
+std::unique_ptr <Transactor>
+make_SetTrust (
+    SerializedTransaction const& txn,
+    TransactionEngineParams params,
+    TransactionEngine* engine)
+{
+    return std::make_unique <SetTrust> (txn, params, engine);
+}
+
 }
 
 #endif

src/ripple_app/transactors/Transactor.cpp

@@ -37,36 +37,29 @@ std::unique_ptr<Transactor> Transactor::makeTransactor (
     switch (txn.getTxnType ())
     {
     case ttPAYMENT:
-        return std::unique_ptr<Transactor> (
+        return make_Payment (txn, params, engine);
-            new PaymentTransactor (txn, params, engine));
 
     case ttACCOUNT_SET:
-        return std::unique_ptr<Transactor> (
+        return make_SetAccount (txn, params, engine);
-            new AccountSetTransactor (txn, params, engine));
 
     case ttREGULAR_KEY_SET:
-        return std::unique_ptr<Transactor> (
+        return make_SetRegularKey (txn, params, engine);
-            new RegularKeySetTransactor (txn, params, engine));
 
     case ttTRUST_SET:
-        return std::unique_ptr<Transactor> (
+        return make_SetTrust (txn, params, engine);
-            new TrustSetTransactor (txn, params, engine));
 
     case ttOFFER_CREATE:
-        return make_OfferCreateTransactor (txn, params, engine);
+        return make_CreateOffer (txn, params, engine);
 
     case ttOFFER_CANCEL:
-        return std::unique_ptr<Transactor> (
+        return make_CancelOffer (txn, params, engine);
-            new OfferCancelTransactor (txn, params, engine));
 
     case ttWALLET_ADD:
-        return std::unique_ptr<Transactor> (
+        return make_AddWallet (txn, params, engine);
-            new WalletAddTransactor (txn, params, engine));
 
     case ttAMENDMENT:
     case ttFEE:
-        return std::unique_ptr<Transactor> (
+        return make_Change (txn, params, engine);
-            new ChangeTransactor (txn, params, engine));
 
     default:
         return std::unique_ptr<Transactor> ();
@@ -229,11 +222,12 @@ TER Transactor::preCheck ()
     }
 
     // Extract signing key
-    // Transactions contain a signing key.  This allows us to trivially verify a transaction has at least been properly signed
+    // Transactions contain a signing key.  This allows us to trivially verify a
-    // without going to disk.  Each transaction also notes a source account id.  This is used to verify that the signing key is
+    // transaction has at least been properly signed without going to disk.
-    // associated with the account.
+    // Each transaction also notes a source account id. This is used to verify
+    // that the signing key is associated with the account.
     // XXX This could be a lot cleaner to prevent unnecessary copying.
-    mSigningPubKey  = RippleAddress::createAccountPublic (mTxn.getSigningPubKey ());
+    mSigningPubKey = RippleAddress::createAccountPublic (mTxn.getSigningPubKey ());
 
     // Consistency: really signed.
     if (!mTxn.isKnownGood ())

src/ripple_basics/utility/StringUtilities.cpp

@@ -262,25 +262,6 @@ bool parseUrl (const std::string& strUrl, std::string& strScheme, std::string& s
     return bMatch;
 }
 
-//
-// Quality parsing
-// - integers as is.
-// - floats multiplied by a billion
-bool parseQuality (const std::string& strSource, std::uint32_t& uQuality)
-{
-    uQuality    = beast::lexicalCast <std::uint32_t> (strSource);
-
-    if (!uQuality)
-    {
-        float   fQuality    = beast::lexicalCast <float> (strSource);
-
-        if (fQuality)
-            uQuality    = (std::uint32_t) (QUALITY_ONE * fQuality);
-    }
-
-    return !!uQuality;
-}
-
 beast::StringPairArray parseDelimitedKeyValueString (beast::String parameters,
                                                    beast::beast_wchar delimiter)
 {

src/ripple_basics/utility/StringUtilities.h

@@ -111,7 +111,6 @@ Blob strCopy (const std::string& strSrc);
 std::string strCopy (Blob const& vucSrc);
 
 bool parseIpPort (const std::string& strSource, std::string& strIP, int& iPort);
-bool parseQuality (const std::string& strSource, std::uint32_t& uQuality);
 
 inline std::string strGetEnv (const std::string& strKey)
 {

src/ripple_data/protocol/STAmount.cpp

@@ -920,6 +920,7 @@ STAmount operator- (const STAmount& v1, const STAmount& v2)
         return STAmount (v1.getFName (), v1.mCurrency, v1.mIssuer, -fv, ov1, true);
 }
 
+// NIKB TODO Make Amount::divide skip math if den == QUALITY_ONE
 STAmount STAmount::divide (const STAmount& num, const STAmount& den, const uint160& uCurrencyID, const uint160& uIssuerID)
 {
     if (den == zero)