Change count type used by gettxoutsetinfo

changing CAmount (is a int64_t) to arith_uint256 for nTotalAmount in CCoinsStats to prevent overflow

src/core_io.h

@@ -6,6 +6,7 @@
 #define BITCOIN_CORE_IO_H
 
 #include <amount.h>
+#include <arith_uint256.h>
 #include <attributes.h>
 
 #include <string>
@@ -40,6 +41,7 @@ int ParseSighashString(const UniValue& sighash);
 
 // core_write.cpp
 UniValue ValueFromAmount(const CAmount& amount);
+UniValue ValueFromAmount(const arith_uint256& amount);
 std::string FormatScript(const CScript& script);
 std::string EncodeHexTx(const CTransaction& tx, const int serializeFlags = 0);
 std::string SighashToStr(unsigned char sighash_type);

src/core_write.cpp

@@ -4,6 +4,7 @@
 
 #include <core_io.h>
 
+#include <arith_uint256.h>
 #include <consensus/consensus.h>
 #include <consensus/validation.h>
 #include <key_io.h>
@@ -25,6 +26,16 @@ UniValue ValueFromAmount(const CAmount& amount)
             strprintf("%s%d.%08d", sign ? "-" : "", quotient, remainder));
 }
 
+// Dogecoin: Added to support very large total coin values, although this has a limitation that it doesn't support above 2^64 Doge.
+UniValue ValueFromAmount(const arith_uint256& amount)
+{
+    // uint256 is unsigned, so we never worry about sign.
+    arith_uint256 quotient = amount / COIN;
+    arith_uint256 remainder = amount - (quotient * COIN);
+    return UniValue(UniValue::VNUM,
+            strprintf("%d.%08d", ArithToUint256(quotient).GetUint64(0), ArithToUint256(remainder).GetUint64(0)));
+}
+
 std::string FormatScript(const CScript& script)
 {
     std::string ret;

src/node/coinstats.h

@@ -7,6 +7,7 @@
 #define BITCOIN_NODE_COINSTATS_H
 
 #include <amount.h>
+#include <arith_uint256.h>
 #include <uint256.h>
 
 #include <cstdint>
@@ -28,7 +29,7 @@ struct CCoinsStats
     uint64_t nBogoSize{0};
     uint256 hashSerialized{};
     uint64_t nDiskSize{0};
-    CAmount nTotalAmount{0};
+    arith_uint256 nTotalAmount{0};
 
     //! The number of coins contained.
     uint64_t coins_count{0};

src/test/rpc_tests.cpp

@@ -176,6 +176,21 @@ BOOST_AUTO_TEST_CASE(rpc_format_monetary_values)
     BOOST_CHECK_EQUAL(ValueFromAmount(COIN/100000000).write(), "0.00000001");
 }
 
+// Dogecoin: Test the uint256 amount formatting
+BOOST_AUTO_TEST_CASE(rpc_format_monetary_values_uint256)
+{
+    // Verify the simple zero case
+    const arith_uint256 zero = UintToArith256(uint256S("0x0000000000000000000000000000000000000000000000000000000000000000"));
+    BOOST_CHECK_EQUAL(ValueFromAmount(zero).write(), "0.00000000");
+    // Verify a number greater than 2^64 to prove that works. This is (2 ^ 72) - 1 Koinu (as in, 1*10^-8)
+    const arith_uint256 largeQuantity = UintToArith256(uint256S("0x0000000000000000000000000000000000000000000000ffffffffffffffffff"));
+    BOOST_CHECK_EQUAL(ValueFromAmount(largeQuantity).write(), "47223664828696.45213695");
+
+    // Verify that if we calculate a negative number and store it in a uint type, we get a positive back.
+    const arith_uint256 negativeQuantity = zero - largeQuantity;
+    BOOST_CHECK_EQUAL(ValueFromAmount(negativeQuantity).write(), "6366458373880712194.84426241");
+}
+
 static UniValue ValueFromString(const std::string &str)
 {
     UniValue value;