4 files changed, 99 insertions, 0 deletions
diff --git a/src/policy/feerate.cpp b/src/policy/feerate.cpp
new file mode 100644
index 0000000000..a089c02284
--- /dev/null
+++ b/src/policy/feerate.cpp
@@ -0,0 +1,43 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "feerate.h"
+
+#include "tinyformat.h"
+
+const std::string CURRENCY_UNIT = "BTC";
+
+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;
+    else
+        nSatoshisPerK = 0;
+}
+
+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) {
+        if (nSatoshisPerK > 0)
+            nFee = CAmount(1);
+        if (nSatoshisPerK < 0)
+            nFee = CAmount(-1);
+    }
+
+    return nFee;
+}
+
+std::string CFeeRate::ToString() const
+{
+    return strprintf("%d.%08d %s/kB", nSatoshisPerK / COIN, nSatoshisPerK % COIN, CURRENCY_UNIT);
+}
diff --git a/src/policy/feerate.h b/src/policy/feerate.h
new file mode 100644
index 0000000000..e82268b095
--- /dev/null
+++ b/src/policy/feerate.h
@@ -0,0 +1,54 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2015 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_POLICY_FEERATE_H
+#define BITCOIN_POLICY_FEERATE_H
+
+#include "amount.h"
+#include "serialize.h"
+
+#include <string>
+
+extern const std::string CURRENCY_UNIT;
+
+/**
+ * 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) { }
+    /** 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 nBytes) const;
+    /**
+     * Return the fee in satoshis for a size of 1000 bytes
+     */
+    CAmount GetFeePerK() const { return GetFee(1000); }
+    friend bool operator<(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK < b.nSatoshisPerK; }
+    friend bool operator>(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK > b.nSatoshisPerK; }
+    friend bool operator==(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK == b.nSatoshisPerK; }
+    friend bool operator<=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK <= b.nSatoshisPerK; }
+    friend bool operator>=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK >= b.nSatoshisPerK; }
+    CFeeRate& operator+=(const CFeeRate& a) { nSatoshisPerK += a.nSatoshisPerK; return *this; }
+    std::string ToString() const;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(nSatoshisPerK);
+    }
+};
+
+#endif //  BITCOIN_POLICY_FEERATE_H
diff --git a/src/policy/fees.h b/src/policy/fees.h
index 34f07c7270..15876574d2 100644
--- a/src/policy/fees.h
+++ b/src/policy/fees.h
@@ -6,6 +6,7 @@
 #define BITCOIN_POLICYESTIMATOR_H
 
 #include "amount.h"
+#include "feerate.h"
 #include "uint256.h"
 #include "random.h"
 #include "sync.h"
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 24bf3fa5d7..2c2ea9d5b8 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -7,6 +7,7 @@
 #define BITCOIN_POLICY_POLICY_H
 
 #include "consensus/consensus.h"
+#include "feerate.h"
 #include "script/interpreter.h"
 #include "script/standard.h"