Add new function CalcMinClaimTrieFee to calulate the fee required for claimtrie transactions

src/Makefile.test.include

@@ -63,6 +63,7 @@ BITCOIN_TESTS =\
   test/claimtrie_tests.cpp \
   test/claimtriecache_tests.cpp \
   test/claimtriebranching_tests.cpp \
+  test/nameclaim_tests.cpp \
   test/netbase_tests.cpp \
   test/pmt_tests.cpp \
   test/policyestimator_tests.cpp \

src/nameclaim.cpp

@@ -1,7 +1,9 @@
+#include <boost/foreach.hpp>
 #include "nameclaim.h"
 #include "hash.h"
 #include "util.h"
 
+
 std::vector<unsigned char> uint32_t_to_vch(uint32_t n)
 {
     std::vector<unsigned char> vchN;
@@ -173,3 +175,27 @@ size_t ClaimNameSize(const CScript& scriptIn)
         return vvchParams[0].size();
     }
 }
+
+CAmount CalcMinClaimTrieFee(const CTransaction& tx, const CAmount &minFeePerNameClaimChar)
+{
+    if (minFeePerNameClaimChar == 0)
+    {
+        return 0;
+    }
+
+    CAmount min_fee = 0;
+    BOOST_FOREACH(const CTxOut& txout, tx.vout)
+    {
+        int op;
+        std::vector<std::vector<unsigned char> > vvchParams;
+        if (DecodeClaimScript(txout.scriptPubKey, op, vvchParams))
+        {
+            if (op == OP_CLAIM_NAME)
+            {
+                int claim_name_size = vvchParams[0].size();
+                min_fee += claim_name_size*minFeePerNameClaimChar;
+            }
+        }
+    }
+    return min_fee;
+}

src/nameclaim.h

@@ -1,11 +1,22 @@
 #ifndef BITCOIN_NAMECLAIM_H
 #define BITCOIN_NAMECLAIM_H
 
+#include "amount.h"
 #include "script/script.h"
+#include "primitives/transaction.h"
 #include "uint256.h"
 
 #include <vector>
 
+// This is the minimum claim fee per character in the name of an OP_CLAIM_NAME command that must
+// be attached to transactions for it to be accepted into the memory pool.
+// Rationale: current implementation of the claim trie uses more memory for longer name claims
+// due to the fact that each chracater is assigned a trie node regardless of whether it contains
+// any claims or not. In the future, we can switch to a radix tree implementation where
+// empty nodes do not take up any memory and the minimum fee can be priced on a per claim
+// basis.
+#define MIN_FEE_PER_NAMECLAIM_CHAR 200000
+
 // This is the max claim script size in bytes, not including the script pubkey part of the script.
 // Scripts exceeding this size are rejected in CheckTransaction in main.cpp
 #define MAX_CLAIM_SCRIPT_SIZE 8192
@@ -28,6 +39,7 @@ uint32_t vch_to_uint32_t(std::vector<unsigned char>& vchN);
 size_t ClaimScriptSize(const CScript& scriptIn);
 // get size of the name in a claim script, returns 0 if scriptin is not a claimetrie transaction
 size_t ClaimNameSize(const CScript& scriptIn);
-
+// calculate the minimum fee (mempool rule) required for transaction
+CAmount CalcMinClaimTrieFee(const CTransaction& tx, const CAmount &minFeePerNameClaimChar);
 
 #endif // BITCOIN_NAMECLAIM_H

src/test/nameclaim_tests.cpp

@@ -0,0 +1,38 @@
+#include "nameclaim.h"
+#include "primitives/transaction.h"
+#include <boost/test/unit_test.hpp>
+#include "test/test_bitcoin.h"
+
+//BOOST_FIXTURE_TEST_SUITE(nameclaim_tests, BasicTestingSetup)
+
+BOOST_AUTO_TEST_CASE(calc_min_claimtrie_fee)
+{
+
+    CMutableTransaction tx;
+    tx.vout.resize(1);
+    tx.vout[0].scriptPubKey = ClaimNameScript("A","test");
+    BOOST_CHECK_EQUAL(CalcMinClaimTrieFee(tx, MIN_FEE_PER_NAMECLAIM_CHAR), MIN_FEE_PER_NAMECLAIM_CHAR);
+
+    // check that fee is adjusted based on name length
+    CMutableTransaction tx2;
+    tx2.vout.resize(1);
+    tx2.vout[0].scriptPubKey = ClaimNameScript("ABCDE","test");
+    BOOST_CHECK_EQUAL(CalcMinClaimTrieFee(tx2,MIN_FEE_PER_NAMECLAIM_CHAR), MIN_FEE_PER_NAMECLAIM_CHAR*5);
+
+    // check that multiple OP_CLAIM_NAME outputs are counted
+    CMutableTransaction tx3;
+    tx3.vout.resize(2);
+    tx3.vout[0].scriptPubKey = ClaimNameScript("A","test");
+    tx3.vout[1].scriptPubKey = ClaimNameScript("AB","test");
+    BOOST_CHECK_EQUAL(CalcMinClaimTrieFee(tx3,MIN_FEE_PER_NAMECLAIM_CHAR), MIN_FEE_PER_NAMECLAIM_CHAR*3);
+
+    // if tx has no claim minimum fee is 0
+    CMutableTransaction tx4;
+    tx4.vout.resize(1);
+    BOOST_CHECK_EQUAL(CalcMinClaimTrieFee(tx4,MIN_FEE_PER_NAMECLAIM_CHAR), 0);
+
+}
+
+
+
+//BOOST_AUTO_TEST_SUITE_END()