Rearrange sources (#4997)

2025-11-27 06:25:51 +00:00 · 2024-06-20 09:22:15 -05:00
parent 2e902dee53
commit e416ee72ca
994 changed files with 0 additions and 0 deletions
--- a/include/xrpl/protocol/QualityFunction.h
+++ b/include/xrpl/protocol/QualityFunction.h
@@ -0,0 +1,107 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 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.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_PROTOCOL_QUALITYFUNCTION_H_INCLUDED
+#define RIPPLE_PROTOCOL_QUALITYFUNCTION_H_INCLUDED
+
+#include <ripple/basics/Number.h>
+#include <ripple/protocol/AMMCore.h>
+#include <ripple/protocol/Quality.h>
+
+namespace ripple {
+
+/** Average quality of a path as a function of `out`: q(out) = m * out + b,
+ * where m = -1 / poolGets, b = poolPays / poolGets. If CLOB offer then
+ * `m` is equal to 0 `b` is equal to the offer's quality. The function
+ * is derived by substituting `in` in q = out / in with the swap out formula
+ * for `in`:
+ * in = [(poolGets * poolPays) / (poolGets - out) - poolPays] / (1 - tfee)
+ * and combining the function for multiple steps. The function is used
+ * to limit required output amount when quality limit is provided in one
+ * path optimization.
+ */
+class QualityFunction
+{
+private:
+    // slope
+    Number m_;
+    // intercept
+    Number b_;
+    // seated if QF is for CLOB offer.
+    std::optional<Quality> quality_;
+
+public:
+    struct AMMTag
+    {
+    };
+    // AMMOffer for multi-path is like CLOB, i.e. the offer size
+    // changes proportionally to its quality.
+    struct CLOBLikeTag
+    {
+    };
+    QualityFunction(Quality const& quality, CLOBLikeTag);
+    template <typename TIn, typename TOut>
+    QualityFunction(
+        TAmounts<TIn, TOut> const& amounts,
+        std::uint32_t tfee,
+        AMMTag);
+
+    /** Combines QF with the next step QF
+     */
+    void
+    combine(QualityFunction const& qf);
+
+    /** Find output to produce the requested
+     * average quality.
+     * @param quality requested average quality (quality limit)
+     */
+    std::optional<Number>
+    outFromAvgQ(Quality const& quality);
+
+    /** Return true if the quality function is constant
+     */
+    bool
+    isConst() const
+    {
+        return quality_.has_value();
+    }
+
+    std::optional<Quality> const&
+    quality() const
+    {
+        return quality_;
+    }
+};
+
+template <typename TIn, typename TOut>
+QualityFunction::QualityFunction(
+    TAmounts<TIn, TOut> const& amounts,
+    std::uint32_t tfee,
+    QualityFunction::AMMTag)
+{
+    if (amounts.in <= beast::zero || amounts.out <= beast::zero)
+        Throw<std::runtime_error>("QualityFunction amounts are 0.");
+    Number const cfee = feeMult(tfee);
+    m_ = -cfee / amounts.in;
+    b_ = amounts.out * cfee / amounts.in;
+}
+
+}  // namespace ripple
+
+#endif  // RIPPLE_PROTOCOL_QUALITYFUNCTION_H_INCLUDED