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Merge #7796: [amount] Add support for negative fee rates

facf5a4 [amount] tests: Fix off-by-one mistake (MarcoFalke)
fa2da2c [amount] Add support for negative fee rates (MarcoFalke)
11114a6 [amount] test negative fee rates and full constructor (MarcoFalke)
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laanwj committed Apr 14, 2016
2 parents 8bb5d3d + facf5a4 commit 536b75e946fb61a7431f429820c95b8e434cb62a
Showing with 51 additions and 9 deletions.
  1. +15 −5 src/amount.cpp
  2. +7 −4 src/amount.h
  3. +29 −0 src/test/amount_tests.cpp
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@@ -9,20 +9,30 @@
const std::string CURRENCY_UNIT = "BTC";
CFeeRate::CFeeRate(const CAmount& nFeePaid, size_t nSize)
CFeeRate::CFeeRate(const CAmount& nFeePaid, size_t nBytes_)
{
assert(nBytes_ <= uint64_t(std::numeric_limits<int64_t>::max()));
int64_t nSize = int64_t(nBytes_);
if (nSize > 0)
nSatoshisPerK = nFeePaid*1000/nSize;
nSatoshisPerK = nFeePaid * 1000 / nSize;
else
nSatoshisPerK = 0;
}
CAmount CFeeRate::GetFee(size_t nSize) const
CAmount CFeeRate::GetFee(size_t nBytes_) const
{
assert(nBytes_ <= uint64_t(std::numeric_limits<int64_t>::max()));
int64_t nSize = int64_t(nBytes_);
CAmount nFee = nSatoshisPerK * nSize / 1000;
if (nFee == 0 && nSize != 0 && nSatoshisPerK > 0)
nFee = CAmount(1);
if (nFee == 0 && nSize != 0) {
if (nSatoshisPerK > 0)
nFee = CAmount(1);
if (nSatoshisPerK < 0)
nFee = CAmount(-1);
}
return nFee;
}
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@@ -11,6 +11,7 @@
#include <stdlib.h>
#include <string>
/** Amount in satoshis (Can be negative) */
typedef int64_t CAmount;
static const CAmount COIN = 100000000;
@@ -30,22 +31,24 @@ extern const std::string CURRENCY_UNIT;
static const CAmount MAX_MONEY = 21000000 * COIN;
inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
/** Type-safe wrapper class for fee rates
* (how much to pay based on transaction size)
/**
* Fee rate in satoshis per kilobyte: CAmount / kB
*/
class CFeeRate
{
private:
CAmount nSatoshisPerK; // unit is satoshis-per-1,000-bytes
public:
/** Fee rate of 0 satoshis per kB */
CFeeRate() : nSatoshisPerK(0) { }
explicit CFeeRate(const CAmount& _nSatoshisPerK): nSatoshisPerK(_nSatoshisPerK) { }
CFeeRate(const CAmount& nFeePaid, size_t nSize);
/** Constructor for a fee rate in satoshis per kB. The size in bytes must not exceed (2^63 - 1)*/
CFeeRate(const CAmount& nFeePaid, size_t nBytes);
CFeeRate(const CFeeRate& other) { nSatoshisPerK = other.nSatoshisPerK; }
/**
* Return the fee in satoshis for the given size in bytes.
*/
CAmount GetFee(size_t size) const;
CAmount GetFee(size_t nBytes) const;
/**
* Return the fee in satoshis for a size of 1000 bytes
*/
View
@@ -27,6 +27,15 @@ BOOST_AUTO_TEST_CASE(GetFeeTest)
BOOST_CHECK_EQUAL(feeRate.GetFee(1e3), 1e3);
BOOST_CHECK_EQUAL(feeRate.GetFee(9e3), 9e3);
feeRate = CFeeRate(-1000);
// Must always just return -1 * arg
BOOST_CHECK_EQUAL(feeRate.GetFee(0), 0);
BOOST_CHECK_EQUAL(feeRate.GetFee(1), -1);
BOOST_CHECK_EQUAL(feeRate.GetFee(121), -121);
BOOST_CHECK_EQUAL(feeRate.GetFee(999), -999);
BOOST_CHECK_EQUAL(feeRate.GetFee(1e3), -1e3);
BOOST_CHECK_EQUAL(feeRate.GetFee(9e3), -9e3);
feeRate = CFeeRate(123);
// Truncates the result, if not integer
BOOST_CHECK_EQUAL(feeRate.GetFee(0), 0);
@@ -37,6 +46,26 @@ BOOST_AUTO_TEST_CASE(GetFeeTest)
BOOST_CHECK_EQUAL(feeRate.GetFee(999), 122);
BOOST_CHECK_EQUAL(feeRate.GetFee(1e3), 123);
BOOST_CHECK_EQUAL(feeRate.GetFee(9e3), 1107);
feeRate = CFeeRate(-123);
// Truncates the result, if not integer
BOOST_CHECK_EQUAL(feeRate.GetFee(0), 0);
BOOST_CHECK_EQUAL(feeRate.GetFee(8), -1); // Special case: returns -1 instead of 0
BOOST_CHECK_EQUAL(feeRate.GetFee(9), -1);
// Check full constructor
// default value
BOOST_CHECK(CFeeRate(CAmount(-1), 1000) == CFeeRate(-1));
BOOST_CHECK(CFeeRate(CAmount(0), 1000) == CFeeRate(0));
BOOST_CHECK(CFeeRate(CAmount(1), 1000) == CFeeRate(1));
// lost precision (can only resolve satoshis per kB)
BOOST_CHECK(CFeeRate(CAmount(1), 1001) == CFeeRate(0));
BOOST_CHECK(CFeeRate(CAmount(2), 1001) == CFeeRate(1));
// some more integer checks
BOOST_CHECK(CFeeRate(CAmount(26), 789) == CFeeRate(32));
BOOST_CHECK(CFeeRate(CAmount(27), 789) == CFeeRate(34));
// Maximum size in bytes, should not crash
CFeeRate(MAX_MONEY, std::numeric_limits<size_t>::max() >> 1).GetFeePerK();
}
BOOST_AUTO_TEST_SUITE_END()

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