Higher precision interest per block info

src/masternodes/loan.cpp

@@ -1,6 +1,7 @@
 
 #include <chainparams.h>
 #include <masternodes/loan.h>
+#include <boost/multiprecision/cpp_int.hpp>
 
 std::unique_ptr<CLoanView::CLoanSetCollateralTokenImpl> CLoanView::GetLoanCollateralToken(uint256 const & txid) const
 {
@@ -478,3 +479,41 @@ CAmount CLoanView::GetLoanLiquidationPenalty()
 
     return 5 * COIN / 100;
 }
+
+std::string GetInterestPerBlockHighPrecisionString(base_uint<128> value) {
+    struct HighPrecisionInterestValue {
+        typedef boost::multiprecision::int128_t int128;
+        typedef int64_t int64;
+
+        int128 value;
+
+        HighPrecisionInterestValue(base_uint<128> val) {
+            value = int128("0x" + val.GetHex());
+        }
+
+        int64 GetInterestPerBlockSat() {
+            return int64(value / HIGH_PRECISION_SCALER);
+        }
+
+        int64 GetInterestPerBlockSubSat() {
+            return int64(value % HIGH_PRECISION_SCALER);
+        }
+
+        int64 GetInterestPerBlockMagnitude() {
+            return int64(value / HIGH_PRECISION_SCALER / COIN);
+        }
+
+        int128 GetInterestPerBlockDecimal() {
+            auto v = GetInterestPerBlockSat();
+            return v == 0 ? value : value % (int128(HIGH_PRECISION_SCALER) * COIN);
+        }
+
+        std::string GetInterestPerBlockString() {
+            std::ostringstream result;
+            result << GetInterestPerBlockMagnitude() << ".";
+            result << std::setw(24) << std::setfill('0') << GetInterestPerBlockDecimal();
+            return result.str();
+        }
+    };
+    return HighPrecisionInterestValue(value).GetInterestPerBlockString();
+}

src/masternodes/loan.h

@@ -11,6 +11,7 @@
 #include <masternodes/vault.h>
 #include <script/script.h>
 
+
 class CLoanSetCollateralToken
 {
 public:
@@ -265,6 +266,7 @@ CAmount TotalInterest(const CInterestRateV2& rate, uint32_t height);
 CAmount InterestPerBlock(const CInterestRateV2& rate, uint32_t height);
 base_uint<128> TotalInterestCalculation(const CInterestRateV2& rate, uint32_t height);
 CAmount CeilInterest(const base_uint<128>& value, uint32_t height);
+std::string GetInterestPerBlockHighPrecisionString(base_uint<128> value);
 
 class CLoanTakeLoanMessage
 {

src/masternodes/rpc_loan.cpp

@@ -1335,6 +1335,13 @@ UniValue getinterest(const JSONRPCRequest& request) {
                 RPCResult
                 {
                     "{...}     (object) Json object with interest information\n"
+                    "            - `interestPerBlock`: Interest per block is always ceiled\n"
+                    "               to the min. unit of fi (8 decimals), however interest\n"
+                    "               less than this will continue to accrue until actual utilization\n"
+                    "               (eg. - payback of the loan), or until sub-fi maturity."
+                    "             - `realizedInterestPerBlock`: The actual realized interest\n"
+                    "               per block. This is continues to accumulate until\n"
+                    "               the min. unit of the blockchain (fi) can be realized. \n"
                 },
                 RPCExamples{
                     HelpExampleCli("getinterest", "LOAN0001 TSLA")
@@ -1395,19 +1402,21 @@ UniValue getinterest(const JSONRPCRequest& request) {
     UniValue obj(UniValue::VOBJ);
     for (std::map<DCT_ID, std::pair<base_uint<128>, base_uint<128> > >::iterator it=interest.begin(); it!=interest.end(); ++it)
     {
-        auto token = pcustomcsview->GetToken(it->first);
-        obj.pushKV("token", token->CreateSymbolKey(it->first));
-        obj.pushKV("totalInterest", ValueFromAmount(CeilInterest(it->second.first, height)));
-        obj.pushKV("interestPerBlock", ValueFromAmount(CeilInterest(it->second.second, height)));
+        auto tokenId = it->first;
+        auto interestRate = it->second;
+        auto totalInterest = it->second.first;
+        auto interestPerBlock = it->second.second;
+
+        auto token = pcustomcsview->GetToken(tokenId);
+        obj.pushKV("token", token->CreateSymbolKey(tokenId));
+        obj.pushKV("totalInterest", ValueFromAmount(CeilInterest(totalInterest, height)));
+        obj.pushKV("interestPerBlock", ValueFromAmount(CeilInterest(interestPerBlock, height)));
         if (height >= Params().GetConsensus().FortCanningHillHeight)
         {
-            auto subSatoshiInterest = (it->second.second - ((it->second.second / HIGH_PRECISION_SCALER) * HIGH_PRECISION_SCALER)).GetLow64();
-            obj.pushKV("immatureInterest", UniValue(UniValue::VNUM, strprintf("%de-24", subSatoshiInterest)));
+            obj.pushKV("realizedInterestPerBlock", UniValue(UniValue::VNUM, GetInterestPerBlockHighPrecisionString(interestPerBlock)));
         }
-
         ret.push_back(obj);
     }
-
     return ret;
 }
 

src/test/loan_tests.cpp

@@ -74,6 +74,27 @@ extern std::vector<CAuctionBatch> CollectAuctionBatches(const CCollateralLoans&
 
 BOOST_FIXTURE_TEST_SUITE(loan_tests, TestChain100Setup)
 
+BOOST_AUTO_TEST_CASE(high_precision_interest_rate_tests)
+{
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(0)), "0.000000000000000000000000");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(1)), "0.000000000000000000000001");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(1)), "0.000000000000000000000001");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(42058)), "0.000000000000000000042058");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(95129375)), "0.000000000000000095129375");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(117009132)), "0.000000000000000117009132");
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(11700913242)), "0.000000000000011700913242");
+
+    base_uint<128> num;
+    num.SetHex("21012F95D4094B33"); // 2378234398782343987
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(num)), "0.000002378234398782343987");
+    num.SetHex("3CDC4CA64879921C03BF061156E455BC"); // 80897539693407360060932882613242451388
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(num)), "80897539693407.360060932882613242451388");
+    num.SetHex("10E5FBB8CA9E273D0B0353C23D90A6"); // 87741364994776235347880977943597222
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(num)), "87741364994.776235347880977943597222");
+    num.SetHex("2D5C78FF9C3FE70F9F0B0C7"); // 877413626032608048611111111
+    BOOST_CHECK_EQUAL(GetInterestPerBlockHighPrecisionString(base_uint<128>(num)), "877.413626032608048611111111");
+}
+
 BOOST_AUTO_TEST_CASE(loan_iterest_rate)
 {
     CCustomCSView mnview(*pcustomcsview);

test/lint/lint-includes.sh

@@ -82,6 +82,7 @@ EXPECTED_BOOST_INCLUDES=(
     boost/variant.hpp
     boost/variant/apply_visitor.hpp
     boost/variant/static_visitor.hpp
+    boost/multiprecision/cpp_int.hpp
 )
 
 for BOOST_INCLUDE in $(git grep '^#include <boost/' -- "*.cpp" "*.h" | cut -f2 -d: | cut -f2 -d'<' | cut -f1 -d'>' | sort -u); do