Beispiel #1
0
        public void BlockPolicyEstimates()
        {
            var       dateTimeSet = new DateTimeProviderSet();
            var       settings    = NodeSettings.Default();
            TxMempool mpool       = new TxMempool(DateTimeProvider.Default,
                                                  new BlockPolicyEstimator(new MempoolSettings(settings), settings.LoggerFactory, settings), settings.LoggerFactory, settings);
            TestMemPoolEntryHelper entry = new TestMemPoolEntryHelper();
            Money        basefee         = new Money(2000);
            Money        deltaFee        = new Money(100);
            List <Money> feeV            = new List <Money>();

            // Populate vectors of increasing fees
            for (int j = 0; j < 10; j++)
            {
                feeV.Add(basefee * (j + 1));
            }

            // Store the hashes of transactions that have been
            // added to the mempool by their associate fee
            // txHashes[j] is populated with transactions either of
            // fee = basefee * (j+1)
            List <uint256>[] txHashes = new List <uint256> [10];
            for (int i = 0; i < txHashes.Length; i++)
            {
                txHashes[i] = new List <uint256>();
            }

            // Create a transaction template
            Script garbage = new Script(Enumerable.Range(0, 128).Select(i => (byte)1).ToArray());

            Transaction txf = new Transaction();

            txf.AddInput(new TxIn(garbage));
            txf.AddOutput(new TxOut(0L, Script.Empty));
            FeeRate baseRate = new FeeRate(basefee, txf.GetVirtualSize());

            // Create a fake block
            List <Transaction> block = new List <Transaction>();
            int blocknum             = 0;
            int answerFound;

            // Loop through 200 blocks
            // At a decay .998 and 4 fee transactions per block
            // This makes the tx count about 1.33 per bucket, above the 1 threshold
            while (blocknum < 200)
            {
                for (int j = 0; j < 10; j++)
                {                                                                        // For each fee
                    for (int k = 0; k < 4; k++)
                    {                                                                    // add 4 fee txs
                        var tx = txf.Clone(false);
                        tx.Inputs[0].PrevOut.N = (uint)(10000 * blocknum + 100 * j + k); // make transaction unique
                        uint256 hash = tx.GetHash();
                        mpool.AddUnchecked(hash, entry.Fee(feeV[j]).Time(dateTimeSet.GetTime()).Priority(0).Height(blocknum).FromTx(tx, mpool));
                        txHashes[j].Add(hash);
                    }
                }
                //Create blocks where higher fee txs are included more often
                for (int h = 0; h <= blocknum % 10; h++)
                {
                    // 10/10 blocks add highest fee transactions
                    // 9/10 blocks add 2nd highest and so on until ...
                    // 1/10 blocks add lowest fee transactions
                    while (txHashes[9 - h].Count > 0)
                    {
                        var ptx = mpool.Get(txHashes[9 - h].Last());
                        if (ptx != null)
                        {
                            block.Add(ptx);
                        }
                        txHashes[9 - h].Remove(txHashes[9 - h].Last());
                    }
                }
                mpool.RemoveForBlock(block, ++blocknum);
                block.Clear();
                if (blocknum == 30)
                {
                    // At this point we should need to combine 5 buckets to get enough data points
                    // So estimateFee(1,2,3) should fail and estimateFee(4) should return somewhere around
                    // 8*baserate.  estimateFee(4) %'s are 100,100,100,100,90 = average 98%
                    Assert.True(mpool.EstimateFee(1) == new FeeRate(0));
                    Assert.True(mpool.EstimateFee(2) == new FeeRate(0));
                    Assert.True(mpool.EstimateFee(3) == new FeeRate(0));
                    Assert.True(mpool.EstimateFee(4).FeePerK < 8 * baseRate.FeePerK + deltaFee);
                    Assert.True(mpool.EstimateFee(4).FeePerK > 8 * baseRate.FeePerK - deltaFee);

                    Assert.True(mpool.EstimateSmartFee(1, out answerFound) == mpool.EstimateFee(4) && answerFound == 4);
                    Assert.True(mpool.EstimateSmartFee(3, out answerFound) == mpool.EstimateFee(4) && answerFound == 4);
                    Assert.True(mpool.EstimateSmartFee(4, out answerFound) == mpool.EstimateFee(4) && answerFound == 4);
                    Assert.True(mpool.EstimateSmartFee(8, out answerFound) == mpool.EstimateFee(8) && answerFound == 8);
                }
            }

            List <Money> origFeeEst = new List <Money>();

            // Highest feerate is 10*baseRate and gets in all blocks,
            // second highest feerate is 9*baseRate and gets in 9/10 blocks = 90%,
            // third highest feerate is 8*base rate, and gets in 8/10 blocks = 80%,
            // so estimateFee(1) would return 10*baseRate but is hardcoded to return failure
            // Second highest feerate has 100% chance of being included by 2 blocks,
            // so estimateFee(2) should return 9*baseRate etc...
            for (int i = 1; i < 10; i++)
            {
                origFeeEst.Add(mpool.EstimateFee(i).FeePerK);
                if (i > 2)
                { // Fee estimates should be monotonically decreasing
                    Assert.True(origFeeEst[i - 1] <= origFeeEst[i - 2]);
                }
                int mult = 11 - i;
                if (i > 1)
                {
                    Assert.True(origFeeEst[i - 1] < mult * baseRate.FeePerK + deltaFee);
                    Assert.True(origFeeEst[i - 1] > mult * baseRate.FeePerK - deltaFee);
                }
                else
                {
                    Assert.True(origFeeEst[i - 1] == new FeeRate(0).FeePerK);
                }
            }

            // Mine 50 more blocks with no transactions happening, estimates shouldn't change
            // We haven't decayed the moving average enough so we still have enough data points in every bucket
            while (blocknum < 250)
            {
                mpool.RemoveForBlock(block, ++blocknum);
            }

            Assert.True(mpool.EstimateFee(1) == new FeeRate(0));
            for (int i = 2; i < 10; i++)
            {
                Assert.True(mpool.EstimateFee(i).FeePerK < origFeeEst[i - 1] + deltaFee);
                Assert.True(mpool.EstimateFee(i).FeePerK > origFeeEst[i - 1] - deltaFee);
            }

            // Mine 15 more blocks with lots of transactions happening and not getting mined
            // Estimates should go up
            while (blocknum < 265)
            {
                for (int j = 0; j < 10; j++)
                {     // For each fee multiple
                    for (int k = 0; k < 4; k++)
                    { // add 4 fee txs
                        var tx = txf.Clone(false);
                        tx.Inputs[0].PrevOut.N = (uint)(10000 * blocknum + 100 * j + k);
                        uint256 hash = tx.GetHash();
                        mpool.AddUnchecked(hash, entry.Fee(feeV[j]).Time(dateTimeSet.GetTime()).Priority(0).Height(blocknum).FromTx(tx, mpool));
                        txHashes[j].Add(hash);
                    }
                }
                mpool.RemoveForBlock(block, ++blocknum);
            }

            for (int i = 1; i < 10; i++)
            {
                Assert.True(mpool.EstimateFee(i) == new FeeRate(0) || mpool.EstimateFee(i).FeePerK > origFeeEst[i - 1] - deltaFee);
                Assert.True(mpool.EstimateSmartFee(i, out answerFound).FeePerK > origFeeEst[answerFound - 1] - deltaFee);
            }

            // Mine all those transactions
            // Estimates should still not be below original
            for (int j = 0; j < 10; j++)
            {
                while (txHashes[j].Count > 0)
                {
                    var ptx = mpool.Get(txHashes[j].Last());
                    if (ptx != null)
                    {
                        block.Add(ptx);
                    }
                    txHashes[j].Remove(txHashes[j].Last());
                }
            }
            mpool.RemoveForBlock(block, 265);
            block.Clear();
            Assert.True(mpool.EstimateFee(1) == new FeeRate(0));
            for (int i = 2; i < 10; i++)
            {
                Assert.True(mpool.EstimateFee(i).FeePerK > origFeeEst[i - 1] - deltaFee);
            }

            // Mine 200 more blocks where everything is mined every block
            // Estimates should be below original estimates
            while (blocknum < 465)
            {
                for (int j = 0; j < 10; j++)
                {     // For each fee multiple
                    for (int k = 0; k < 4; k++)
                    { // add 4 fee txs
                        var tx = txf.Clone(false);
                        tx.Inputs[0].PrevOut.N = (uint)(10000 * blocknum + 100 * j + k);
                        uint256 hash = tx.GetHash();
                        mpool.AddUnchecked(hash, entry.Fee(feeV[j]).Time(dateTimeSet.GetTime()).Priority(0).Height(blocknum).FromTx(tx, mpool));
                        var ptx = mpool.Get(hash);
                        if (ptx != null)
                        {
                            block.Add(ptx);
                        }
                    }
                }
                mpool.RemoveForBlock(block, ++blocknum);
                block.Clear();
            }
            Assert.True(mpool.EstimateFee(1) == new FeeRate(0));
            for (int i = 2; i < 10; i++)
            {
                Assert.True(mpool.EstimateFee(i).FeePerK < origFeeEst[i - 1] - deltaFee);
            }

            // Test that if the mempool is limited, estimateSmartFee won't return a value below the mempool min fee
            // and that estimateSmartPriority returns essentially an infinite value
            mpool.AddUnchecked(txf.GetHash(), entry.Fee(feeV[5]).Time(dateTimeSet.GetTime()).Priority(0).Height(blocknum).FromTx(txf, mpool));
            // evict that transaction which should set a mempool min fee of minRelayTxFee + feeV[5]
            mpool.TrimToSize(1);
            Assert.True(mpool.GetMinFee(1).FeePerK > feeV[5]);
            for (int i = 1; i < 10; i++)
            {
                Assert.True(mpool.EstimateSmartFee(i, out answerFound).FeePerK >= mpool.EstimateFee(i).FeePerK);
                Assert.True(mpool.EstimateSmartFee(i, out answerFound).FeePerK >= mpool.GetMinFee(1).FeePerK);
                Assert.True(mpool.EstimateSmartPriority(i, out answerFound) == BlockPolicyEstimator.InfPriority);
            }
        }
        public void MempoolAncestorIndexingTest()
        {
            var settings = NodeSettings.Default();
            var pool     = new TxMempool(DateTimeProvider.Default, new BlockPolicyEstimator(new MempoolSettings(settings), settings.LoggerFactory, settings), settings.LoggerFactory, settings);
            var entry    = new TestMemPoolEntryHelper();

            /* 3rd highest fee */
            Transaction tx1 = new Transaction();

            tx1.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx1.GetHash(), entry.Fee(new Money(10000L)).Priority(10.0).FromTx(tx1));

            /* highest fee */
            Transaction tx2 = new Transaction();

            tx2.AddOutput(new TxOut(new Money(2 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx2.GetHash(), entry.Fee(new Money(20000L)).Priority(9.0).FromTx(tx2));
            var tx2Size = tx2.GetVirtualSize();

            /* lowest fee */
            Transaction tx3 = new Transaction();

            tx3.AddOutput(new TxOut(new Money(5 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx3.GetHash(), entry.Fee(new Money(0L)).Priority(100.0).FromTx(tx3));

            /* 2nd highest fee */
            Transaction tx4 = new Transaction();

            tx4.AddOutput(new TxOut(new Money(6 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx4.GetHash(), entry.Fee(new Money(15000L)).Priority(1.0).FromTx(tx4));

            /* equal fee rate to tx1, but newer */
            Transaction tx5 = new Transaction();

            tx5.AddOutput(new TxOut(new Money(11 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx5.GetHash(), entry.Fee(new Money(10000L)).Priority(1.0).FromTx(tx5));

            // assert size
            Assert.Equal(5, pool.Size);

            List <string> sortedOrder = new List <string>(5);

            sortedOrder.Insert(0, tx2.GetHash().ToString()); // 20000
            sortedOrder.Insert(1, tx4.GetHash().ToString()); // 15000

            // tx1 and tx5 are both 10000
            // Ties are broken by hash, not timestamp, so determine which
            // hash comes first.
            if (tx1.GetHash() < tx5.GetHash())
            {
                sortedOrder.Insert(2, tx1.GetHash().ToString());
                sortedOrder.Insert(3, tx5.GetHash().ToString());
            }
            else
            {
                sortedOrder.Insert(2, tx5.GetHash().ToString());
                sortedOrder.Insert(3, tx1.GetHash().ToString());
            }
            sortedOrder.Insert(4, tx3.GetHash().ToString()); // 0
            this.CheckSort(pool, pool.MapTx.AncestorScore.ToList(), sortedOrder);

            /* low fee parent with high fee child */
            /* tx6 (0) -> tx7 (high) */
            Transaction tx6 = new Transaction();

            tx6.AddOutput(new TxOut(new Money(20 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx6.GetHash(), entry.Fee(new Money(0L)).FromTx(tx6));
            var tx6Size = tx6.GetVirtualSize();

            Assert.Equal(6, pool.Size);
            // Ties are broken by hash
            if (tx3.GetHash() < tx6.GetHash())
            {
                sortedOrder.Add(tx6.GetHash().ToString());
            }
            else
            {
                sortedOrder.Insert(sortedOrder.Count - 1, tx6.GetHash().ToString());
            }
            this.CheckSort(pool, pool.MapTx.AncestorScore.ToList(), sortedOrder);

            Transaction tx7 = new Transaction();

            tx7.AddInput(new TxIn(new OutPoint(tx6.GetHash(), 0), new Script(OpcodeType.OP_11)));
            tx7.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            var   tx7Size = tx7.GetVirtualSize();
            Money fee     = (20000 / tx2Size) * (tx7Size + tx6Size) - 1;

            pool.AddUnchecked(tx7.GetHash(), entry.Fee(fee).FromTx(tx7));
            Assert.Equal(7, pool.Size);
            sortedOrder.Insert(1, tx7.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.AncestorScore.ToList(), sortedOrder);

            /* after tx6 is mined, tx7 should move up in the sort */
            List <Transaction> vtx = new List <Transaction>(new[] { tx6 });

            pool.RemoveForBlock(vtx, 1);

            sortedOrder.RemoveAt(1);
            // Ties are broken by hash
            if (tx3.GetHash() < tx6.GetHash())
            {
                sortedOrder.Remove(sortedOrder.Last());
            }
            else
            {
                sortedOrder.RemoveAt(sortedOrder.Count - 2);
            }
            sortedOrder.Insert(0, tx7.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.AncestorScore.ToList(), sortedOrder);
        }
        public void MempoolSizeLimitTest()
        {
            var settings    = NodeSettings.Default();
            var dateTimeSet = new DateTimeProviderSet();
            var pool        = new TxMempool(dateTimeSet, new BlockPolicyEstimator(new MempoolSettings(settings), settings.LoggerFactory, settings), settings.LoggerFactory, settings);
            var entry       = new TestMemPoolEntryHelper();

            entry.Priority(10.0);

            Transaction tx1 = new Transaction();

            tx1.AddInput(new TxIn(new Script(OpcodeType.OP_1)));
            tx1.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_1, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx1.GetHash(), entry.Fee(10000L).FromTx(tx1, pool));

            Transaction tx2 = new Transaction();

            tx2.AddInput(new TxIn(new Script(OpcodeType.OP_2)));
            tx2.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_2, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx2.GetHash(), entry.Fee(5000L).FromTx(tx2, pool));

            pool.TrimToSize(pool.DynamicMemoryUsage()); // should do nothing
            Assert.True(pool.Exists(tx1.GetHash()));
            Assert.True(pool.Exists(tx2.GetHash()));

            pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // should remove the lower-feerate transaction
            Assert.True(pool.Exists(tx1.GetHash()));
            Assert.True(!pool.Exists(tx2.GetHash()));

            pool.AddUnchecked(tx2.GetHash(), entry.FromTx(tx2, pool));
            Transaction tx3 = new Transaction();

            tx3.AddInput(new TxIn(new OutPoint(tx2.GetHash(), 0), new Script(OpcodeType.OP_2)));
            tx3.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_3, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx3.GetHash(), entry.Fee(20000L).FromTx(tx3, pool));

            pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // tx3 should pay for tx2 (CPFP)
            Assert.True(!pool.Exists(tx1.GetHash()));
            Assert.True(pool.Exists(tx2.GetHash()));
            Assert.True(pool.Exists(tx3.GetHash()));

            pool.TrimToSize(tx1.GetVirtualSize()); // mempool is limited to tx1's size in memory usage, so nothing fits
            Assert.True(!pool.Exists(tx1.GetHash()));
            Assert.True(!pool.Exists(tx2.GetHash()));
            Assert.True(!pool.Exists(tx3.GetHash()));

            FeeRate maxFeeRateRemoved = new FeeRate(25000, tx3.GetVirtualSize() + tx2.GetVirtualSize());

            Assert.Equal(pool.GetMinFee(1).FeePerK, maxFeeRateRemoved.FeePerK + 1000);

            Transaction tx4 = new Transaction();

            tx4.AddInput(new TxIn(new Script(OpcodeType.OP_4)));
            tx4.AddInput(new TxIn(new Script(OpcodeType.OP_4)));
            tx4.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_4, OpcodeType.OP_EQUAL)));
            tx4.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_4, OpcodeType.OP_EQUAL)));

            Transaction tx5 = new Transaction();

            tx5.AddInput(new TxIn(new OutPoint(tx4.GetHash(), 0), new Script(OpcodeType.OP_4)));
            tx5.AddInput(new TxIn(new Script(OpcodeType.OP_5)));
            tx5.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_5, OpcodeType.OP_EQUAL)));
            tx5.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_5, OpcodeType.OP_EQUAL)));

            Transaction tx6 = new Transaction();

            tx6.AddInput(new TxIn(new OutPoint(tx4.GetHash(), 0), new Script(OpcodeType.OP_4)));
            tx6.AddInput(new TxIn(new Script(OpcodeType.OP_6)));
            tx6.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_6, OpcodeType.OP_EQUAL)));
            tx6.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_6, OpcodeType.OP_EQUAL)));

            Transaction tx7 = new Transaction();

            tx7.AddInput(new TxIn(new OutPoint(tx5.GetHash(), 0), new Script(OpcodeType.OP_5)));
            tx7.AddInput(new TxIn(new OutPoint(tx6.GetHash(), 0), new Script(OpcodeType.OP_6)));
            tx7.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_7, OpcodeType.OP_EQUAL)));
            tx7.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_7, OpcodeType.OP_EQUAL)));

            pool.AddUnchecked(tx4.GetHash(), entry.Fee(7000L).FromTx(tx4, pool));
            pool.AddUnchecked(tx5.GetHash(), entry.Fee(1000L).FromTx(tx5, pool));
            pool.AddUnchecked(tx6.GetHash(), entry.Fee(1100L).FromTx(tx6, pool));
            pool.AddUnchecked(tx7.GetHash(), entry.Fee(9000L).FromTx(tx7, pool));

            // we only require this remove, at max, 2 txn, because its not clear what we're really optimizing for aside from that
            pool.TrimToSize(pool.DynamicMemoryUsage() - 1);
            Assert.True(pool.Exists(tx4.GetHash()));
            Assert.True(pool.Exists(tx6.GetHash()));
            Assert.True(!pool.Exists(tx7.GetHash()));

            if (!pool.Exists(tx5.GetHash()))
            {
                pool.AddUnchecked(tx5.GetHash(), entry.Fee(1000L).FromTx(tx5, pool));
            }
            pool.AddUnchecked(tx7.GetHash(), entry.Fee(9000L).FromTx(tx7, pool));

            pool.TrimToSize(pool.DynamicMemoryUsage() / 2); // should maximize mempool size by only removing 5/7
            Assert.True(pool.Exists(tx4.GetHash()));
            Assert.True(!pool.Exists(tx5.GetHash()));
            Assert.True(pool.Exists(tx6.GetHash()));
            Assert.True(!pool.Exists(tx7.GetHash()));

            pool.AddUnchecked(tx5.GetHash(), entry.Fee(1000L).FromTx(tx5, pool));
            pool.AddUnchecked(tx7.GetHash(), entry.Fee(9000L).FromTx(tx7, pool));

            List <Transaction> vtx = new List <Transaction>();

            dateTimeSet.time = 42 + TxMempool.RollingFeeHalflife;
            Assert.Equal(pool.GetMinFee(1).FeePerK.Satoshi, maxFeeRateRemoved.FeePerK.Satoshi + 1000);
            // ... we should keep the same min fee until we get a block
            pool.RemoveForBlock(vtx, 1);
            dateTimeSet.time = 42 + 2 * +TxMempool.RollingFeeHalflife;
            Assert.Equal(pool.GetMinFee(1).FeePerK.Satoshi, (maxFeeRateRemoved.FeePerK.Satoshi + 1000) / 2);
            // ... then feerate should drop 1/2 each halflife

            dateTimeSet.time = 42 + 2 * TxMempool.RollingFeeHalflife + TxMempool.RollingFeeHalflife / 2;
            Assert.Equal(pool.GetMinFee(pool.DynamicMemoryUsage() * 5 / 2).FeePerK.Satoshi, (maxFeeRateRemoved.FeePerK.Satoshi + 1000) / 4);
            // ... with a 1/2 halflife when mempool is < 1/2 its target size

            dateTimeSet.time = 42 + 2 * TxMempool.RollingFeeHalflife + TxMempool.RollingFeeHalflife / 2 + TxMempool.RollingFeeHalflife / 4;
            Assert.Equal(pool.GetMinFee(pool.DynamicMemoryUsage() * 9 / 2).FeePerK.Satoshi, (maxFeeRateRemoved.FeePerK.Satoshi + 1000) / 8);
            // ... with a 1/4 halflife when mempool is < 1/4 its target size

            dateTimeSet.time = 42 + 7 * TxMempool.RollingFeeHalflife + TxMempool.RollingFeeHalflife / 2 + TxMempool.RollingFeeHalflife / 4;
            Assert.Equal(1000, pool.GetMinFee(1).FeePerK.Satoshi);
            // ... but feerate should never drop below 1000

            dateTimeSet.time = 42 + 8 * TxMempool.RollingFeeHalflife + TxMempool.RollingFeeHalflife / 2 + TxMempool.RollingFeeHalflife / 4;
            Assert.Equal(0, pool.GetMinFee(1).FeePerK);
            // ... unless it has gone all the way to 0 (after getting past 1000/2)
        }
        public void MempoolIndexingTest()
        {
            var settings = NodeSettings.Default();
            var pool     = new TxMempool(DateTimeProvider.Default, new BlockPolicyEstimator(new MempoolSettings(settings), settings.LoggerFactory, settings), settings.LoggerFactory, settings);
            var entry    = new TestMemPoolEntryHelper();

            /* 3rd highest fee */
            Transaction tx1 = new Transaction();

            tx1.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx1.GetHash(), entry.Fee(new Money(10000L)).Priority(10.0).FromTx(tx1));

            /* highest fee */
            Transaction tx2 = new Transaction();

            tx2.AddOutput(new TxOut(new Money(2 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx2.GetHash(), entry.Fee(new Money(20000L)).Priority(9.0).FromTx(tx2));

            /* lowest fee */
            Transaction tx3 = new Transaction();

            tx3.AddOutput(new TxOut(new Money(5 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx3.GetHash(), entry.Fee(new Money(0L)).Priority(100.0).FromTx(tx3));

            /* 2nd highest fee */
            Transaction tx4 = new Transaction();

            tx4.AddOutput(new TxOut(new Money(6 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx4.GetHash(), entry.Fee(new Money(15000L)).Priority(1.0).FromTx(tx4));

            /* equal fee rate to tx1, but newer */
            Transaction tx5 = new Transaction();

            tx5.AddOutput(new TxOut(new Money(11 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx5.GetHash(), entry.Fee(new Money(10000L)).Priority(10.0).Time(1).FromTx(tx5));

            // assert size
            Assert.Equal(5, pool.Size);

            List <string> sortedOrder = new List <string>(5);

            sortedOrder.Insert(0, tx3.GetHash().ToString()); // 0
            sortedOrder.Insert(1, tx5.GetHash().ToString()); // 10000
            sortedOrder.Insert(2, tx1.GetHash().ToString()); // 10000
            sortedOrder.Insert(3, tx4.GetHash().ToString()); // 15000
            sortedOrder.Insert(4, tx2.GetHash().ToString()); // 20000
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            /* low fee but with high fee child */
            /* tx6 -> tx7 -> tx8, tx9 -> tx10 */
            Transaction tx6 = new Transaction();

            tx6.AddOutput(new TxOut(new Money(20 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx6.GetHash(), entry.Fee(new Money(0L)).FromTx(tx6));

            // assert size
            Assert.Equal(6, pool.Size);

            // Check that at this point, tx6 is sorted low
            sortedOrder.Insert(0, tx6.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            TxMempool.SetEntries setAncestors = new TxMempool.SetEntries();
            setAncestors.Add(pool.MapTx.TryGet(tx6.GetHash()));
            Transaction tx7 = new Transaction();

            tx7.AddInput(new TxIn(new OutPoint(tx6.GetHash(), 0), new Script(OpcodeType.OP_11)));
            tx7.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            tx7.AddOutput(new TxOut(new Money(1 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));

            TxMempool.SetEntries setAncestorsCalculated = new TxMempool.SetEntries();
            string dummy;

            Assert.True(pool.CalculateMemPoolAncestors(entry.Fee(2000000L).FromTx(tx7), setAncestorsCalculated, 100, 1000000, 1000, 1000000, out dummy));
            Assert.True(setAncestorsCalculated.Equals(setAncestors));

            pool.AddUnchecked(tx7.GetHash(), entry.FromTx(tx7), setAncestors);
            Assert.Equal(7, pool.Size);

            // Now tx6 should be sorted higher (high fee child): tx7, tx6, tx2, ...
            sortedOrder.RemoveAt(0);
            sortedOrder.Add(tx6.GetHash().ToString());
            sortedOrder.Add(tx7.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            /* low fee child of tx7 */
            Transaction tx8 = new Transaction();

            tx8.AddInput(new TxIn(new OutPoint(tx7.GetHash(), 0), new Script(OpcodeType.OP_11)));
            tx8.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            setAncestors.Add(pool.MapTx.TryGet(tx7.GetHash()));
            pool.AddUnchecked(tx8.GetHash(), entry.Fee(0L).Time(2).FromTx(tx8), setAncestors);

            // Now tx8 should be sorted low, but tx6/tx both high
            sortedOrder.Insert(0, tx8.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            /* low fee child of tx7 */
            Transaction tx9 = new Transaction();

            tx9.AddInput(new TxIn(new OutPoint(tx7.GetHash(), 1), new Script(OpcodeType.OP_11)));
            tx9.AddOutput(new TxOut(new Money(1 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));
            pool.AddUnchecked(tx9.GetHash(), entry.Fee(0L).Time(3).FromTx(tx9), setAncestors);

            // tx9 should be sorted low
            Assert.Equal(9, pool.Size);

            sortedOrder.Insert(0, tx9.GetHash().ToString());
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            List <string> snapshotOrder = sortedOrder.ToList();

            setAncestors.Add(pool.MapTx.TryGet(tx8.GetHash()));
            setAncestors.Add(pool.MapTx.TryGet(tx9.GetHash()));
            /* tx10 depends on tx8 and tx9 and has a high fee*/
            Transaction tx10 = new Transaction();

            tx10.AddInput(new TxIn(new OutPoint(tx8.GetHash(), 0), new Script(OpcodeType.OP_11)));
            tx10.AddInput(new TxIn(new OutPoint(tx9.GetHash(), 0), new Script(OpcodeType.OP_11)));
            tx10.AddOutput(new TxOut(new Money(10 * Money.COIN), new Script(OpcodeType.OP_11, OpcodeType.OP_EQUAL)));

            setAncestorsCalculated.Clear();
            Assert.True(pool.CalculateMemPoolAncestors(entry.Fee(200000L).Time(4).FromTx(tx10), setAncestorsCalculated, 100, 1000000, 1000, 1000000, out dummy));
            Assert.True(setAncestorsCalculated.Equals(setAncestors));

            pool.AddUnchecked(tx10.GetHash(), entry.FromTx(tx10), setAncestors);

            /**
             *  tx8 and tx9 should both now be sorted higher
             *  Final order after tx10 is added:
             *
             *  tx3 = 0 (1)
             *  tx5 = 10000 (1)
             *  tx1 = 10000 (1)
             *  tx4 = 15000 (1)
             *  tx2 = 20000 (1)
             *  tx9 = 200k (2 txs)
             *  tx8 = 200k (2 txs)
             *  tx10 = 200k (1 tx)
             *  tx6 = 2.2M (5 txs)
             *  tx7 = 2.2M (4 txs)
             */
            sortedOrder.RemoveRange(0, 2); // take out tx9, tx8 from the beginning
            sortedOrder.Insert(5, tx9.GetHash().ToString());
            sortedOrder.Insert(6, tx8.GetHash().ToString());
            sortedOrder.Insert(7, tx10.GetHash().ToString()); // tx10 is just before tx6
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), sortedOrder);

            // there should be 10 transactions in the mempool
            Assert.Equal(10, pool.Size);

            // Now try removing tx10 and verify the sort order returns to normal
            pool.RemoveRecursive(pool.MapTx.TryGet(tx10.GetHash()).Transaction);
            this.CheckSort(pool, pool.MapTx.DescendantScore.ToList(), snapshotOrder);

            pool.RemoveRecursive(pool.MapTx.TryGet(tx9.GetHash()).Transaction);
            pool.RemoveRecursive(pool.MapTx.TryGet(tx8.GetHash()).Transaction);

            /* Now check the sort on the mining score index.
             * Final order should be:
             *
             * tx7 (2M)
             * tx2 (20k)
             * tx4 (15000)
             * tx1/tx5 (10000)
             * tx3/6 (0)
             * (Ties resolved by hash)
             */
            sortedOrder.Clear();
            sortedOrder.Add(tx7.GetHash().ToString());
            sortedOrder.Add(tx2.GetHash().ToString());
            sortedOrder.Add(tx4.GetHash().ToString());
            if (tx1.GetHash() < tx5.GetHash())
            {
                sortedOrder.Add(tx5.GetHash().ToString());
                sortedOrder.Add(tx1.GetHash().ToString());
            }
            else
            {
                sortedOrder.Add(tx1.GetHash().ToString());
                sortedOrder.Add(tx5.GetHash().ToString());
            }
            if (tx3.GetHash() < tx6.GetHash())
            {
                sortedOrder.Add(tx6.GetHash().ToString());
                sortedOrder.Add(tx3.GetHash().ToString());
            }
            else
            {
                sortedOrder.Add(tx3.GetHash().ToString());
                sortedOrder.Add(tx6.GetHash().ToString());
            }
            this.CheckSort(pool, pool.MapTx.MiningScore.ToList(), sortedOrder);
        }