Merge branch 'bthomee/rename_binary' into bthomee/rename_namespace

include/xrpl/protocol/Protocol.h

@@ -3,6 +3,7 @@
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/Units.h>
 
 #include <cstdint>
 
@@ -65,6 +66,140 @@ std::size_t constexpr maxDeletableTokenOfferEntries = 500;
  */
 std::uint16_t constexpr maxTransferFee = 50000;
 
+/** There are 10,000 basis points (bips) in 100%.
+ *
+ * Basis points represent 0.01%.
+ *
+ * Given a value X, to find the amount for B bps,
+ * use X * B / bipsPerUnity
+ *
+ * Example: If a loan broker has 999 XRP of debt, and must maintain 1,000 bps of
+ * that debt as cover (10%), then the minimum cover amount is 999,000,000 drops
+ * * 1000 / bipsPerUnity = 99,900,00 drops or 99.9 XRP.
+ *
+ * Given a percentage P, to find the number of bps that percentage represents,
+ * use P * bipsPerUnity.
+ *
+ * Example: 50% is 0.50 * bipsPerUnity = 5,000 bps.
+ */
+Bips32 constexpr bipsPerUnity(100 * 100);
+static_assert(bipsPerUnity == Bips32{10'000});
+TenthBips32 constexpr tenthBipsPerUnity(bipsPerUnity.value() * 10);
+static_assert(tenthBipsPerUnity == TenthBips32(100'000));
+
+constexpr Bips32
+percentageToBips(std::uint32_t percentage)
+{
+    return Bips32(percentage * bipsPerUnity.value() / 100);
+}
+constexpr TenthBips32
+percentageToTenthBips(std::uint32_t percentage)
+{
+    return TenthBips32(percentage * tenthBipsPerUnity.value() / 100);
+}
+template <typename T, class TBips>
+constexpr T
+bipsOfValue(T value, Bips<TBips> bips)
+{
+    return value * bips.value() / bipsPerUnity.value();
+}
+template <typename T, class TBips>
+constexpr T
+tenthBipsOfValue(T value, TenthBips<TBips> bips)
+{
+    return value * bips.value() / tenthBipsPerUnity.value();
+}
+
+namespace Lending {
+/** The maximum management fee rate allowed by a loan broker in 1/10 bips.
+
+    Valid values are between 0 and 10% inclusive.
+*/
+TenthBips16 constexpr maxManagementFeeRate(
+    unsafe_cast<std::uint16_t>(percentageToTenthBips(10).value()));
+static_assert(maxManagementFeeRate == TenthBips16(std::uint16_t(10'000u)));
+
+/** The maximum coverage rate required of a loan broker in 1/10 bips.
+
+    Valid values are between 0 and 100% inclusive.
+*/
+TenthBips32 constexpr maxCoverRate = percentageToTenthBips(100);
+static_assert(maxCoverRate == TenthBips32(100'000u));
+
+/** The maximum overpayment fee on a loan in 1/10 bips.
+*
+    Valid values are between 0 and 100% inclusive.
+*/
+TenthBips32 constexpr maxOverpaymentFee = percentageToTenthBips(100);
+static_assert(maxOverpaymentFee == TenthBips32(100'000u));
+
+/** Annualized interest rate of the Loan in 1/10 bips.
+ *
+ * Valid values are between 0 and 100% inclusive.
+ */
+TenthBips32 constexpr maxInterestRate = percentageToTenthBips(100);
+static_assert(maxInterestRate == TenthBips32(100'000u));
+
+/** The maximum premium added to the interest rate for late payments on a loan
+ * in 1/10 bips.
+ *
+ * Valid values are between 0 and 100% inclusive.
+ */
+TenthBips32 constexpr maxLateInterestRate = percentageToTenthBips(100);
+static_assert(maxLateInterestRate == TenthBips32(100'000u));
+
+/** The maximum close interest rate charged for repaying a loan early in 1/10
+ * bips.
+ *
+ * Valid values are between 0 and 100% inclusive.
+ */
+TenthBips32 constexpr maxCloseInterestRate = percentageToTenthBips(100);
+static_assert(maxCloseInterestRate == TenthBips32(100'000u));
+
+/** The maximum overpayment interest rate charged on loan overpayments in 1/10
+ * bips.
+ *
+ * Valid values are between 0 and 100% inclusive.
+ */
+TenthBips32 constexpr maxOverpaymentInterestRate = percentageToTenthBips(100);
+static_assert(maxOverpaymentInterestRate == TenthBips32(100'000u));
+
+/** LoanPay transaction cost will be one base fee per X combined payments
+ *
+ * The number of payments is estimated based on the Amount paid and the Loan's
+ * Fixed Payment size. Overpayments (indicated with the tfLoanOverpayment flag)
+ * count as one more payment.
+ *
+ * This number was chosen arbitrarily, but should not be changed once released
+ * without an amendment
+ */
+static constexpr int loanPaymentsPerFeeIncrement = 5;
+
+/** Maximum number of combined payments that a LoanPay transaction will process
+ *
+ * This limit is enforced during the loan payment process, and thus is not
+ * estimated. If the limit is hit, no further payments or overpayments will be
+ * processed, no matter how much of the transation Amount is left, but the
+ * transaction will succeed with the payments that have been processed up to
+ * that point.
+ *
+ * This limit is independent of loanPaymentsPerFeeIncrement, so a transaction
+ * could potentially be charged for many more payments than actually get
+ * processed. Users should take care not to submit a transaction paying more
+ * than loanMaximumPaymentsPerTransaction * Loan.PeriodicPayment. Because
+ * overpayments are charged as a payment, if submitting
+ * loanMaximumPaymentsPerTransaction * Loan.PeriodicPayment, users should not
+ * set the tfLoanOverpayment flag.
+ *
+ * Even though they're independent, loanMaximumPaymentsPerTransaction should be
+ * a multiple of loanPaymentsPerFeeIncrement.
+ *
+ * This number was chosen arbitrarily, but should not be changed once released
+ * without an amendment
+ */
+static constexpr int loanMaximumPaymentsPerTransaction = 100;
+}  // namespace Lending
+
 /** The maximum length of a URI inside an NFT */
 std::size_t constexpr maxTokenURILength = 256;