src/test/mempool_tests.cpp

   1 // Copyright (c) 2011-2016 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include "policy/policy.h"
   6 #include "txmempool.h"
   7 #include "util.h"
   8
   9 #include "test/test_bitcoin.h"
  10
  11 #include <boost/test/unit_test.hpp>
  12 #include <list>
  13 #include <vector>
  14
  15 BOOST_FIXTURE_TEST_SUITE(mempool_tests, TestingSetup)
  16
  17 BOOST_AUTO_TEST_CASE(MempoolRemoveTest)
  18 {
  19     // Test CTxMemPool::remove functionality
  20
  21     TestMemPoolEntryHelper entry;
  22     // Parent transaction with three children,
  23     // and three grand-children:
  24     CMutableTransaction txParent;
  25     txParent.vin.resize(1);
  26     txParent.vin[0].scriptSig = CScript() << OP_11;
  27     txParent.vout.resize(3);
  28     for (int i = 0; i < 3; i++)
  29     {
  30         txParent.vout[i].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
  31         txParent.vout[i].nValue = 33000LL;
  32     }
  33     CMutableTransaction txChild[3];
  34     for (int i = 0; i < 3; i++)
  35     {
  36         txChild[i].vin.resize(1);
  37         txChild[i].vin[0].scriptSig = CScript() << OP_11;
  38         txChild[i].vin[0].prevout.hash = txParent.GetHash();
  39         txChild[i].vin[0].prevout.n = i;
  40         txChild[i].vout.resize(1);
  41         txChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
  42         txChild[i].vout[0].nValue = 11000LL;
  43     }
  44     CMutableTransaction txGrandChild[3];
  45     for (int i = 0; i < 3; i++)
  46     {
  47         txGrandChild[i].vin.resize(1);
  48         txGrandChild[i].vin[0].scriptSig = CScript() << OP_11;
  49         txGrandChild[i].vin[0].prevout.hash = txChild[i].GetHash();
  50         txGrandChild[i].vin[0].prevout.n = 0;
  51         txGrandChild[i].vout.resize(1);
  52         txGrandChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
  53         txGrandChild[i].vout[0].nValue = 11000LL;
  54     }
  55
  56
  57     CTxMemPool testPool;
  58
  59     // Nothing in pool, remove should do nothing:
  60     unsigned int poolSize = testPool.size();
  61     testPool.removeRecursive(txParent);
  62     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
  63
  64     // Just the parent:
  65     testPool.addUnchecked(txParent.GetHash(), entry.FromTx(txParent));
  66     poolSize = testPool.size();
  67     testPool.removeRecursive(txParent);
  68     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 1);
  69
  70     // Parent, children, grandchildren:
  71     testPool.addUnchecked(txParent.GetHash(), entry.FromTx(txParent));
  72     for (int i = 0; i < 3; i++)
  73     {
  74         testPool.addUnchecked(txChild[i].GetHash(), entry.FromTx(txChild[i]));
  75         testPool.addUnchecked(txGrandChild[i].GetHash(), entry.FromTx(txGrandChild[i]));
  76     }
  77     // Remove Child[0], GrandChild[0] should be removed:
  78     poolSize = testPool.size();
  79     testPool.removeRecursive(txChild[0]);
  80     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 2);
  81     // ... make sure grandchild and child are gone:
  82     poolSize = testPool.size();
  83     testPool.removeRecursive(txGrandChild[0]);
  84     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
  85     poolSize = testPool.size();
  86     testPool.removeRecursive(txChild[0]);
  87     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
  88     // Remove parent, all children/grandchildren should go:
  89     poolSize = testPool.size();
  90     testPool.removeRecursive(txParent);
  91     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 5);
  92     BOOST_CHECK_EQUAL(testPool.size(), 0);
  93
  94     // Add children and grandchildren, but NOT the parent (simulate the parent being in a block)
  95     for (int i = 0; i < 3; i++)
  96     {
  97         testPool.addUnchecked(txChild[i].GetHash(), entry.FromTx(txChild[i]));
  98         testPool.addUnchecked(txGrandChild[i].GetHash(), entry.FromTx(txGrandChild[i]));
  99     }
 100     // Now remove the parent, as might happen if a block-re-org occurs but the parent cannot be
 101     // put into the mempool (maybe because it is non-standard):
 102     poolSize = testPool.size();
 103     testPool.removeRecursive(txParent);
 104     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 6);
 105     BOOST_CHECK_EQUAL(testPool.size(), 0);
 106 }
 107
 108 template<typename name>
 109 void CheckSort(CTxMemPool &pool, std::vector<std::string> &sortedOrder)
 110 {
 111     BOOST_CHECK_EQUAL(pool.size(), sortedOrder.size());
 112     typename CTxMemPool::indexed_transaction_set::index<name>::type::iterator it = pool.mapTx.get<name>().begin();
 113     int count=0;
 114     for (; it != pool.mapTx.get<name>().end(); ++it, ++count) {
 115         BOOST_CHECK_EQUAL(it->GetTx().GetHash().ToString(), sortedOrder[count]);
 116     }
 117 }
 118
 119 BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
 120 {
 121     CTxMemPool pool;
 122     TestMemPoolEntryHelper entry;
 123
 124     /* 3rd highest fee */
 125     CMutableTransaction tx1 = CMutableTransaction();
 126     tx1.vout.resize(1);
 127     tx1.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 128     tx1.vout[0].nValue = 10 * COIN;
 129     pool.addUnchecked(tx1.GetHash(), entry.Fee(10000LL).FromTx(tx1));
 130
 131     /* highest fee */
 132     CMutableTransaction tx2 = CMutableTransaction();
 133     tx2.vout.resize(1);
 134     tx2.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 135     tx2.vout[0].nValue = 2 * COIN;
 136     pool.addUnchecked(tx2.GetHash(), entry.Fee(20000LL).FromTx(tx2));
 137
 138     /* lowest fee */
 139     CMutableTransaction tx3 = CMutableTransaction();
 140     tx3.vout.resize(1);
 141     tx3.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 142     tx3.vout[0].nValue = 5 * COIN;
 143     pool.addUnchecked(tx3.GetHash(), entry.Fee(0LL).FromTx(tx3));
 144
 145     /* 2nd highest fee */
 146     CMutableTransaction tx4 = CMutableTransaction();
 147     tx4.vout.resize(1);
 148     tx4.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 149     tx4.vout[0].nValue = 6 * COIN;
 150     pool.addUnchecked(tx4.GetHash(), entry.Fee(15000LL).FromTx(tx4));
 151
 152     /* equal fee rate to tx1, but newer */
 153     CMutableTransaction tx5 = CMutableTransaction();
 154     tx5.vout.resize(1);
 155     tx5.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 156     tx5.vout[0].nValue = 11 * COIN;
 157     entry.nTime = 1;
 158     pool.addUnchecked(tx5.GetHash(), entry.Fee(10000LL).FromTx(tx5));
 159     BOOST_CHECK_EQUAL(pool.size(), 5);
 160
 161     std::vector<std::string> sortedOrder;
 162     sortedOrder.resize(5);
 163     sortedOrder[0] = tx3.GetHash().ToString(); // 0
 164     sortedOrder[1] = tx5.GetHash().ToString(); // 10000
 165     sortedOrder[2] = tx1.GetHash().ToString(); // 10000
 166     sortedOrder[3] = tx4.GetHash().ToString(); // 15000
 167     sortedOrder[4] = tx2.GetHash().ToString(); // 20000
 168     CheckSort<descendant_score>(pool, sortedOrder);
 169
 170     /* low fee but with high fee child */
 171     /* tx6 -> tx7 -> tx8, tx9 -> tx10 */
 172     CMutableTransaction tx6 = CMutableTransaction();
 173     tx6.vout.resize(1);
 174     tx6.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 175     tx6.vout[0].nValue = 20 * COIN;
 176     pool.addUnchecked(tx6.GetHash(), entry.Fee(0LL).FromTx(tx6));
 177     BOOST_CHECK_EQUAL(pool.size(), 6);
 178     // Check that at this point, tx6 is sorted low
 179     sortedOrder.insert(sortedOrder.begin(), tx6.GetHash().ToString());
 180     CheckSort<descendant_score>(pool, sortedOrder);
 181
 182     CTxMemPool::setEntries setAncestors;
 183     setAncestors.insert(pool.mapTx.find(tx6.GetHash()));
 184     CMutableTransaction tx7 = CMutableTransaction();
 185     tx7.vin.resize(1);
 186     tx7.vin[0].prevout = COutPoint(tx6.GetHash(), 0);
 187     tx7.vin[0].scriptSig = CScript() << OP_11;
 188     tx7.vout.resize(2);
 189     tx7.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 190     tx7.vout[0].nValue = 10 * COIN;
 191     tx7.vout[1].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 192     tx7.vout[1].nValue = 1 * COIN;
 193
 194     CTxMemPool::setEntries setAncestorsCalculated;
 195     std::string dummy;
 196     BOOST_CHECK_EQUAL(pool.CalculateMemPoolAncestors(entry.Fee(2000000LL).FromTx(tx7), setAncestorsCalculated, 100, 1000000, 1000, 1000000, dummy), true);
 197     BOOST_CHECK(setAncestorsCalculated == setAncestors);
 198
 199     pool.addUnchecked(tx7.GetHash(), entry.FromTx(tx7), setAncestors);
 200     BOOST_CHECK_EQUAL(pool.size(), 7);
 201
 202     // Now tx6 should be sorted higher (high fee child): tx7, tx6, tx2, ...
 203     sortedOrder.erase(sortedOrder.begin());
 204     sortedOrder.push_back(tx6.GetHash().ToString());
 205     sortedOrder.push_back(tx7.GetHash().ToString());
 206     CheckSort<descendant_score>(pool, sortedOrder);
 207
 208     /* low fee child of tx7 */
 209     CMutableTransaction tx8 = CMutableTransaction();
 210     tx8.vin.resize(1);
 211     tx8.vin[0].prevout = COutPoint(tx7.GetHash(), 0);
 212     tx8.vin[0].scriptSig = CScript() << OP_11;
 213     tx8.vout.resize(1);
 214     tx8.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 215     tx8.vout[0].nValue = 10 * COIN;
 216     setAncestors.insert(pool.mapTx.find(tx7.GetHash()));
 217     pool.addUnchecked(tx8.GetHash(), entry.Fee(0LL).Time(2).FromTx(tx8), setAncestors);
 218
 219     // Now tx8 should be sorted low, but tx6/tx both high
 220     sortedOrder.insert(sortedOrder.begin(), tx8.GetHash().ToString());
 221     CheckSort<descendant_score>(pool, sortedOrder);
 222
 223     /* low fee child of tx7 */
 224     CMutableTransaction tx9 = CMutableTransaction();
 225     tx9.vin.resize(1);
 226     tx9.vin[0].prevout = COutPoint(tx7.GetHash(), 1);
 227     tx9.vin[0].scriptSig = CScript() << OP_11;
 228     tx9.vout.resize(1);
 229     tx9.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 230     tx9.vout[0].nValue = 1 * COIN;
 231     pool.addUnchecked(tx9.GetHash(), entry.Fee(0LL).Time(3).FromTx(tx9), setAncestors);
 232
 233     // tx9 should be sorted low
 234     BOOST_CHECK_EQUAL(pool.size(), 9);
 235     sortedOrder.insert(sortedOrder.begin(), tx9.GetHash().ToString());
 236     CheckSort<descendant_score>(pool, sortedOrder);
 237
 238     std::vector<std::string> snapshotOrder = sortedOrder;
 239
 240     setAncestors.insert(pool.mapTx.find(tx8.GetHash()));
 241     setAncestors.insert(pool.mapTx.find(tx9.GetHash()));
 242     /* tx10 depends on tx8 and tx9 and has a high fee*/
 243     CMutableTransaction tx10 = CMutableTransaction();
 244     tx10.vin.resize(2);
 245     tx10.vin[0].prevout = COutPoint(tx8.GetHash(), 0);
 246     tx10.vin[0].scriptSig = CScript() << OP_11;
 247     tx10.vin[1].prevout = COutPoint(tx9.GetHash(), 0);
 248     tx10.vin[1].scriptSig = CScript() << OP_11;
 249     tx10.vout.resize(1);
 250     tx10.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 251     tx10.vout[0].nValue = 10 * COIN;
 252
 253     setAncestorsCalculated.clear();
 254     BOOST_CHECK_EQUAL(pool.CalculateMemPoolAncestors(entry.Fee(200000LL).Time(4).FromTx(tx10), setAncestorsCalculated, 100, 1000000, 1000, 1000000, dummy), true);
 255     BOOST_CHECK(setAncestorsCalculated == setAncestors);
 256
 257     pool.addUnchecked(tx10.GetHash(), entry.FromTx(tx10), setAncestors);
 258
 259     /**
 260      *  tx8 and tx9 should both now be sorted higher
 261      *  Final order after tx10 is added:
 262      *
 263      *  tx3 = 0 (1)
 264      *  tx5 = 10000 (1)
 265      *  tx1 = 10000 (1)
 266      *  tx4 = 15000 (1)
 267      *  tx2 = 20000 (1)
 268      *  tx9 = 200k (2 txs)
 269      *  tx8 = 200k (2 txs)
 270      *  tx10 = 200k (1 tx)
 271      *  tx6 = 2.2M (5 txs)
 272      *  tx7 = 2.2M (4 txs)
 273      */
 274     sortedOrder.erase(sortedOrder.begin(), sortedOrder.begin()+2); // take out tx9, tx8 from the beginning
 275     sortedOrder.insert(sortedOrder.begin()+5, tx9.GetHash().ToString());
 276     sortedOrder.insert(sortedOrder.begin()+6, tx8.GetHash().ToString());
 277     sortedOrder.insert(sortedOrder.begin()+7, tx10.GetHash().ToString()); // tx10 is just before tx6
 278     CheckSort<descendant_score>(pool, sortedOrder);
 279
 280     // there should be 10 transactions in the mempool
 281     BOOST_CHECK_EQUAL(pool.size(), 10);
 282
 283     // Now try removing tx10 and verify the sort order returns to normal
 284     pool.removeRecursive(pool.mapTx.find(tx10.GetHash())->GetTx());
 285     CheckSort<descendant_score>(pool, snapshotOrder);
 286
 287     pool.removeRecursive(pool.mapTx.find(tx9.GetHash())->GetTx());
 288     pool.removeRecursive(pool.mapTx.find(tx8.GetHash())->GetTx());
 289     /* Now check the sort on the mining score index.
 290      * Final order should be:
 291      *
 292      * tx7 (2M)
 293      * tx2 (20k)
 294      * tx4 (15000)
 295      * tx1/tx5 (10000)
 296      * tx3/6 (0)
 297      * (Ties resolved by hash)
 298      */
 299     sortedOrder.clear();
 300     sortedOrder.push_back(tx7.GetHash().ToString());
 301     sortedOrder.push_back(tx2.GetHash().ToString());
 302     sortedOrder.push_back(tx4.GetHash().ToString());
 303     if (tx1.GetHash() < tx5.GetHash()) {
 304         sortedOrder.push_back(tx5.GetHash().ToString());
 305         sortedOrder.push_back(tx1.GetHash().ToString());
 306     } else {
 307         sortedOrder.push_back(tx1.GetHash().ToString());
 308         sortedOrder.push_back(tx5.GetHash().ToString());
 309     }
 310     if (tx3.GetHash() < tx6.GetHash()) {
 311         sortedOrder.push_back(tx6.GetHash().ToString());
 312         sortedOrder.push_back(tx3.GetHash().ToString());
 313     } else {
 314         sortedOrder.push_back(tx3.GetHash().ToString());
 315         sortedOrder.push_back(tx6.GetHash().ToString());
 316     }
 317     CheckSort<mining_score>(pool, sortedOrder);
 318 }
 319
 320 BOOST_AUTO_TEST_CASE(MempoolAncestorIndexingTest)
 321 {
 322     CTxMemPool pool;
 323     TestMemPoolEntryHelper entry;
 324
 325     /* 3rd highest fee */
 326     CMutableTransaction tx1 = CMutableTransaction();
 327     tx1.vout.resize(1);
 328     tx1.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 329     tx1.vout[0].nValue = 10 * COIN;
 330     pool.addUnchecked(tx1.GetHash(), entry.Fee(10000LL).FromTx(tx1));
 331
 332     /* highest fee */
 333     CMutableTransaction tx2 = CMutableTransaction();
 334     tx2.vout.resize(1);
 335     tx2.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 336     tx2.vout[0].nValue = 2 * COIN;
 337     pool.addUnchecked(tx2.GetHash(), entry.Fee(20000LL).FromTx(tx2));
 338     uint64_t tx2Size = GetVirtualTransactionSize(tx2);
 339
 340     /* lowest fee */
 341     CMutableTransaction tx3 = CMutableTransaction();
 342     tx3.vout.resize(1);
 343     tx3.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 344     tx3.vout[0].nValue = 5 * COIN;
 345     pool.addUnchecked(tx3.GetHash(), entry.Fee(0LL).FromTx(tx3));
 346
 347     /* 2nd highest fee */
 348     CMutableTransaction tx4 = CMutableTransaction();
 349     tx4.vout.resize(1);
 350     tx4.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 351     tx4.vout[0].nValue = 6 * COIN;
 352     pool.addUnchecked(tx4.GetHash(), entry.Fee(15000LL).FromTx(tx4));
 353
 354     /* equal fee rate to tx1, but newer */
 355     CMutableTransaction tx5 = CMutableTransaction();
 356     tx5.vout.resize(1);
 357     tx5.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 358     tx5.vout[0].nValue = 11 * COIN;
 359     pool.addUnchecked(tx5.GetHash(), entry.Fee(10000LL).FromTx(tx5));
 360     BOOST_CHECK_EQUAL(pool.size(), 5);
 361
 362     std::vector<std::string> sortedOrder;
 363     sortedOrder.resize(5);
 364     sortedOrder[0] = tx2.GetHash().ToString(); // 20000
 365     sortedOrder[1] = tx4.GetHash().ToString(); // 15000
 366     // tx1 and tx5 are both 10000
 367     // Ties are broken by hash, not timestamp, so determine which
 368     // hash comes first.
 369     if (tx1.GetHash() < tx5.GetHash()) {
 370         sortedOrder[2] = tx1.GetHash().ToString();
 371         sortedOrder[3] = tx5.GetHash().ToString();
 372     } else {
 373         sortedOrder[2] = tx5.GetHash().ToString();
 374         sortedOrder[3] = tx1.GetHash().ToString();
 375     }
 376     sortedOrder[4] = tx3.GetHash().ToString(); // 0
 377
 378     CheckSort<ancestor_score>(pool, sortedOrder);
 379
 380     /* low fee parent with high fee child */
 381     /* tx6 (0) -> tx7 (high) */
 382     CMutableTransaction tx6 = CMutableTransaction();
 383     tx6.vout.resize(1);
 384     tx6.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 385     tx6.vout[0].nValue = 20 * COIN;
 386     uint64_t tx6Size = GetVirtualTransactionSize(tx6);
 387
 388     pool.addUnchecked(tx6.GetHash(), entry.Fee(0LL).FromTx(tx6));
 389     BOOST_CHECK_EQUAL(pool.size(), 6);
 390     // Ties are broken by hash
 391     if (tx3.GetHash() < tx6.GetHash())
 392         sortedOrder.push_back(tx6.GetHash().ToString());
 393     else
 394         sortedOrder.insert(sortedOrder.end()-1,tx6.GetHash().ToString());
 395
 396     CheckSort<ancestor_score>(pool, sortedOrder);
 397
 398     CMutableTransaction tx7 = CMutableTransaction();
 399     tx7.vin.resize(1);
 400     tx7.vin[0].prevout = COutPoint(tx6.GetHash(), 0);
 401     tx7.vin[0].scriptSig = CScript() << OP_11;
 402     tx7.vout.resize(1);
 403     tx7.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
 404     tx7.vout[0].nValue = 10 * COIN;
 405     uint64_t tx7Size = GetVirtualTransactionSize(tx7);
 406
 407     /* set the fee to just below tx2's feerate when including ancestor */
 408     CAmount fee = (20000/tx2Size)*(tx7Size + tx6Size) - 1;
 409
 410     pool.addUnchecked(tx7.GetHash(), entry.Fee(fee).FromTx(tx7));
 411     BOOST_CHECK_EQUAL(pool.size(), 7);
 412     sortedOrder.insert(sortedOrder.begin()+1, tx7.GetHash().ToString());
 413     CheckSort<ancestor_score>(pool, sortedOrder);
 414
 415     /* after tx6 is mined, tx7 should move up in the sort */
 416     std::vector<CTransactionRef> vtx;
 417     vtx.push_back(MakeTransactionRef(tx6));
 418     pool.removeForBlock(vtx, 1);
 419
 420     sortedOrder.erase(sortedOrder.begin()+1);
 421     // Ties are broken by hash
 422     if (tx3.GetHash() < tx6.GetHash())
 423         sortedOrder.pop_back();
 424     else
 425         sortedOrder.erase(sortedOrder.end()-2);
 426     sortedOrder.insert(sortedOrder.begin(), tx7.GetHash().ToString());
 427     CheckSort<ancestor_score>(pool, sortedOrder);
 428 }
 429
 430
 431 BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest)
 432 {
 433     CTxMemPool pool;
 434     TestMemPoolEntryHelper entry;
 435
 436     CMutableTransaction tx1 = CMutableTransaction();
 437     tx1.vin.resize(1);
 438     tx1.vin[0].scriptSig = CScript() << OP_1;
 439     tx1.vout.resize(1);
 440     tx1.vout[0].scriptPubKey = CScript() << OP_1 << OP_EQUAL;
 441     tx1.vout[0].nValue = 10 * COIN;
 442     pool.addUnchecked(tx1.GetHash(), entry.Fee(10000LL).FromTx(tx1));
 443
 444     CMutableTransaction tx2 = CMutableTransaction();
 445     tx2.vin.resize(1);
 446     tx2.vin[0].scriptSig = CScript() << OP_2;
 447     tx2.vout.resize(1);
 448     tx2.vout[0].scriptPubKey = CScript() << OP_2 << OP_EQUAL;
 449     tx2.vout[0].nValue = 10 * COIN;
 450     pool.addUnchecked(tx2.GetHash(), entry.Fee(5000LL).FromTx(tx2));
 451
 452     pool.TrimToSize(pool.DynamicMemoryUsage()); // should do nothing
 453     BOOST_CHECK(pool.exists(tx1.GetHash()));
 454     BOOST_CHECK(pool.exists(tx2.GetHash()));
 455
 456     pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // should remove the lower-feerate transaction
 457     BOOST_CHECK(pool.exists(tx1.GetHash()));
 458     BOOST_CHECK(!pool.exists(tx2.GetHash()));
 459
 460     pool.addUnchecked(tx2.GetHash(), entry.FromTx(tx2));
 461     CMutableTransaction tx3 = CMutableTransaction();
 462     tx3.vin.resize(1);
 463     tx3.vin[0].prevout = COutPoint(tx2.GetHash(), 0);
 464     tx3.vin[0].scriptSig = CScript() << OP_2;
 465     tx3.vout.resize(1);
 466     tx3.vout[0].scriptPubKey = CScript() << OP_3 << OP_EQUAL;
 467     tx3.vout[0].nValue = 10 * COIN;
 468     pool.addUnchecked(tx3.GetHash(), entry.Fee(20000LL).FromTx(tx3));
 469
 470     pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // tx3 should pay for tx2 (CPFP)
 471     BOOST_CHECK(!pool.exists(tx1.GetHash()));
 472     BOOST_CHECK(pool.exists(tx2.GetHash()));
 473     BOOST_CHECK(pool.exists(tx3.GetHash()));
 474
 475     pool.TrimToSize(GetVirtualTransactionSize(tx1)); // mempool is limited to tx1's size in memory usage, so nothing fits
 476     BOOST_CHECK(!pool.exists(tx1.GetHash()));
 477     BOOST_CHECK(!pool.exists(tx2.GetHash()));
 478     BOOST_CHECK(!pool.exists(tx3.GetHash()));
 479
 480     CFeeRate maxFeeRateRemoved(25000, GetVirtualTransactionSize(tx3) + GetVirtualTransactionSize(tx2));
 481     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
 482
 483     CMutableTransaction tx4 = CMutableTransaction();
 484     tx4.vin.resize(2);
 485     tx4.vin[0].prevout.SetNull();
 486     tx4.vin[0].scriptSig = CScript() << OP_4;
 487     tx4.vin[1].prevout.SetNull();
 488     tx4.vin[1].scriptSig = CScript() << OP_4;
 489     tx4.vout.resize(2);
 490     tx4.vout[0].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
 491     tx4.vout[0].nValue = 10 * COIN;
 492     tx4.vout[1].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
 493     tx4.vout[1].nValue = 10 * COIN;
 494
 495     CMutableTransaction tx5 = CMutableTransaction();
 496     tx5.vin.resize(2);
 497     tx5.vin[0].prevout = COutPoint(tx4.GetHash(), 0);
 498     tx5.vin[0].scriptSig = CScript() << OP_4;
 499     tx5.vin[1].prevout.SetNull();
 500     tx5.vin[1].scriptSig = CScript() << OP_5;
 501     tx5.vout.resize(2);
 502     tx5.vout[0].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
 503     tx5.vout[0].nValue = 10 * COIN;
 504     tx5.vout[1].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
 505     tx5.vout[1].nValue = 10 * COIN;
 506
 507     CMutableTransaction tx6 = CMutableTransaction();
 508     tx6.vin.resize(2);
 509     tx6.vin[0].prevout = COutPoint(tx4.GetHash(), 1);
 510     tx6.vin[0].scriptSig = CScript() << OP_4;
 511     tx6.vin[1].prevout.SetNull();
 512     tx6.vin[1].scriptSig = CScript() << OP_6;
 513     tx6.vout.resize(2);
 514     tx6.vout[0].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
 515     tx6.vout[0].nValue = 10 * COIN;
 516     tx6.vout[1].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
 517     tx6.vout[1].nValue = 10 * COIN;
 518
 519     CMutableTransaction tx7 = CMutableTransaction();
 520     tx7.vin.resize(2);
 521     tx7.vin[0].prevout = COutPoint(tx5.GetHash(), 0);
 522     tx7.vin[0].scriptSig = CScript() << OP_5;
 523     tx7.vin[1].prevout = COutPoint(tx6.GetHash(), 0);
 524     tx7.vin[1].scriptSig = CScript() << OP_6;
 525     tx7.vout.resize(2);
 526     tx7.vout[0].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
 527     tx7.vout[0].nValue = 10 * COIN;
 528     tx7.vout[1].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
 529     tx7.vout[1].nValue = 10 * COIN;
 530
 531     pool.addUnchecked(tx4.GetHash(), entry.Fee(7000LL).FromTx(tx4));
 532     pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5));
 533     pool.addUnchecked(tx6.GetHash(), entry.Fee(1100LL).FromTx(tx6));
 534     pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7));
 535
 536     // we only require this remove, at max, 2 txn, because its not clear what we're really optimizing for aside from that
 537     pool.TrimToSize(pool.DynamicMemoryUsage() - 1);
 538     BOOST_CHECK(pool.exists(tx4.GetHash()));
 539     BOOST_CHECK(pool.exists(tx6.GetHash()));
 540     BOOST_CHECK(!pool.exists(tx7.GetHash()));
 541
 542     if (!pool.exists(tx5.GetHash()))
 543         pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5));
 544     pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7));
 545
 546     pool.TrimToSize(pool.DynamicMemoryUsage() / 2); // should maximize mempool size by only removing 5/7
 547     BOOST_CHECK(pool.exists(tx4.GetHash()));
 548     BOOST_CHECK(!pool.exists(tx5.GetHash()));
 549     BOOST_CHECK(pool.exists(tx6.GetHash()));
 550     BOOST_CHECK(!pool.exists(tx7.GetHash()));
 551
 552     pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5));
 553     pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7));
 554
 555     std::vector<CTransactionRef> vtx;
 556     SetMockTime(42);
 557     SetMockTime(42 + CTxMemPool::ROLLING_FEE_HALFLIFE);
 558     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
 559     // ... we should keep the same min fee until we get a block
 560     pool.removeForBlock(vtx, 1);
 561     SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE);
 562     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), llround((maxFeeRateRemoved.GetFeePerK() + 1000)/2.0));
 563     // ... then feerate should drop 1/2 each halflife
 564
 565     SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2);
 566     BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 5 / 2).GetFeePerK(), llround((maxFeeRateRemoved.GetFeePerK() + 1000)/4.0));
 567     // ... with a 1/2 halflife when mempool is < 1/2 its target size
 568
 569     SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
 570     BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 9 / 2).GetFeePerK(), llround((maxFeeRateRemoved.GetFeePerK() + 1000)/8.0));
 571     // ... with a 1/4 halflife when mempool is < 1/4 its target size
 572
 573     SetMockTime(42 + 7*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
 574     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 1000);
 575     // ... but feerate should never drop below 1000
 576
 577     SetMockTime(42 + 8*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
 578     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 0);
 579     // ... unless it has gone all the way to 0 (after getting past 1000/2)
 580
 581     SetMockTime(0);
 582 }
 583
 584 BOOST_AUTO_TEST_SUITE_END()