/ src / index / coinstatsindex.cpp
coinstatsindex.cpp
  1  // Copyright (c) 2020-present 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 <index/coinstatsindex.h>
  6  
  7  #include <arith_uint256.h>
  8  #include <chain.h>
  9  #include <chainparams.h>
 10  #include <coins.h>
 11  #include <common/args.h>
 12  #include <consensus/amount.h>
 13  #include <crypto/muhash.h>
 14  #include <dbwrapper.h>
 15  #include <index/base.h>
 16  #include <index/db_key.h>
 17  #include <interfaces/chain.h>
 18  #include <interfaces/types.h>
 19  #include <kernel/coinstats.h>
 20  #include <primitives/block.h>
 21  #include <primitives/transaction.h>
 22  #include <script/script.h>
 23  #include <serialize.h>
 24  #include <uint256.h>
 25  #include <undo.h>
 26  #include <util/check.h>
 27  #include <util/fs.h>
 28  #include <util/log.h>
 29  #include <validation.h>
 30  
 31  #include <compare>
 32  #include <limits>
 33  #include <string>
 34  #include <utility>
 35  #include <vector>
 36  
 37  using kernel::ApplyCoinHash;
 38  using kernel::CCoinsStats;
 39  using kernel::GetBogoSize;
 40  using kernel::RemoveCoinHash;
 41  
 42  static constexpr uint8_t DB_MUHASH{'M'};
 43  
 44  namespace {
 45  
 46  struct DBVal {
 47      uint256 muhash{uint256::ZERO};
 48      uint64_t transaction_output_count{0};
 49      uint64_t bogo_size{0};
 50      CAmount total_amount{0};
 51      CAmount total_subsidy{0};
 52      arith_uint256 total_prevout_spent_amount{0};
 53      arith_uint256 total_new_outputs_ex_coinbase_amount{0};
 54      arith_uint256 total_coinbase_amount{0};
 55      CAmount total_unspendables_genesis_block{0};
 56      CAmount total_unspendables_bip30{0};
 57      CAmount total_unspendables_scripts{0};
 58      CAmount total_unspendables_unclaimed_rewards{0};
 59  
 60      SERIALIZE_METHODS(DBVal, obj)
 61      {
 62          uint256 prevout_spent, new_outputs, coinbase;
 63          SER_WRITE(obj, prevout_spent = ArithToUint256(obj.total_prevout_spent_amount));
 64          SER_WRITE(obj, new_outputs = ArithToUint256(obj.total_new_outputs_ex_coinbase_amount));
 65          SER_WRITE(obj, coinbase = ArithToUint256(obj.total_coinbase_amount));
 66  
 67          READWRITE(obj.muhash);
 68          READWRITE(obj.transaction_output_count);
 69          READWRITE(obj.bogo_size);
 70          READWRITE(obj.total_amount);
 71          READWRITE(obj.total_subsidy);
 72          READWRITE(prevout_spent);
 73          READWRITE(new_outputs);
 74          READWRITE(coinbase);
 75          READWRITE(obj.total_unspendables_genesis_block);
 76          READWRITE(obj.total_unspendables_bip30);
 77          READWRITE(obj.total_unspendables_scripts);
 78          READWRITE(obj.total_unspendables_unclaimed_rewards);
 79  
 80          SER_READ(obj, obj.total_prevout_spent_amount = UintToArith256(prevout_spent));
 81          SER_READ(obj, obj.total_new_outputs_ex_coinbase_amount = UintToArith256(new_outputs));
 82          SER_READ(obj, obj.total_coinbase_amount = UintToArith256(coinbase));
 83      }
 84  };
 85  }; // namespace
 86  
 87  std::unique_ptr<CoinStatsIndex> g_coin_stats_index;
 88  
 89  CoinStatsIndex::CoinStatsIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
 90      : BaseIndex(std::move(chain), "coinstatsindex")
 91  {
 92      // An earlier version of the index used "indexes/coinstats" but it contained
 93      // a bug and is superseded by a fixed version at "indexes/coinstatsindex".
 94      // The original index is kept around until the next release in case users
 95      // decide to downgrade their node.
 96      auto old_path = gArgs.GetDataDirNet() / "indexes" / "coinstats";
 97      if (fs::exists(old_path)) {
 98          // TODO: Change this to deleting the old index with v31.
 99          LogWarning("Old version of coinstatsindex found at %s. This folder can be safely deleted unless you " \
100              "plan to downgrade your node to version 29 or lower.", fs::PathToString(old_path));
101      }
102      fs::path path{gArgs.GetDataDirNet() / "indexes" / "coinstatsindex"};
103      fs::create_directories(path);
104  
105      m_db = std::make_unique<CoinStatsIndex::DB>(path / "db", n_cache_size, f_memory, f_wipe);
106  }
107  
108  bool CoinStatsIndex::CustomAppend(const interfaces::BlockInfo& block)
109  {
110      const CAmount block_subsidy{GetBlockSubsidy(block.height, Params().GetConsensus())};
111      m_total_subsidy += block_subsidy;
112  
113      // Ignore genesis block
114      if (block.height > 0) {
115          uint256 expected_block_hash{*Assert(block.prev_hash)};
116          if (m_current_block_hash != expected_block_hash) {
117              LogError("previous block header belongs to unexpected block %s; expected %s",
118                        m_current_block_hash.ToString(), expected_block_hash.ToString());
119              return false;
120          }
121  
122          // Add the new utxos created from the block
123          assert(block.data);
124          for (size_t i = 0; i < block.data->vtx.size(); ++i) {
125              const auto& tx{block.data->vtx.at(i)};
126              const bool is_coinbase{tx->IsCoinBase()};
127  
128              // Skip duplicate txid coinbase transactions (BIP30).
129              if (is_coinbase && IsBIP30Unspendable(block.hash, block.height)) {
130                  m_total_unspendables_bip30 += block_subsidy;
131                  continue;
132              }
133  
134              for (uint32_t j = 0; j < tx->vout.size(); ++j) {
135                  const CTxOut& out{tx->vout[j]};
136                  const Coin coin{out, block.height, is_coinbase};
137                  const COutPoint outpoint{tx->GetHash(), j};
138  
139                  // Skip unspendable coins
140                  if (coin.out.scriptPubKey.IsUnspendable()) {
141                      m_total_unspendables_scripts += coin.out.nValue;
142                      continue;
143                  }
144  
145                  ApplyCoinHash(m_muhash, outpoint, coin);
146  
147                  if (is_coinbase) {
148                      m_total_coinbase_amount += coin.out.nValue;
149                  } else {
150                      m_total_new_outputs_ex_coinbase_amount += coin.out.nValue;
151                  }
152  
153                  ++m_transaction_output_count;
154                  m_total_amount += coin.out.nValue;
155                  m_bogo_size += GetBogoSize(coin.out.scriptPubKey);
156              }
157  
158              // The coinbase tx has no undo data since no former output is spent
159              if (!is_coinbase) {
160                  const auto& tx_undo{Assert(block.undo_data)->vtxundo.at(i - 1)};
161  
162                  for (size_t j = 0; j < tx_undo.vprevout.size(); ++j) {
163                      const Coin& coin{tx_undo.vprevout[j]};
164                      const COutPoint outpoint{tx->vin[j].prevout.hash, tx->vin[j].prevout.n};
165  
166                      RemoveCoinHash(m_muhash, outpoint, coin);
167  
168                      m_total_prevout_spent_amount += coin.out.nValue;
169  
170                      --m_transaction_output_count;
171                      m_total_amount -= coin.out.nValue;
172                      m_bogo_size -= GetBogoSize(coin.out.scriptPubKey);
173                  }
174              }
175          }
176      } else {
177          // genesis block
178          m_total_unspendables_genesis_block += block_subsidy;
179      }
180  
181      // If spent prevouts + block subsidy are still a higher amount than
182      // new outputs + coinbase + current unspendable amount this means
183      // the miner did not claim the full block reward. Unclaimed block
184      // rewards are also unspendable.
185      const CAmount temp_total_unspendable_amount{m_total_unspendables_genesis_block + m_total_unspendables_bip30 + m_total_unspendables_scripts + m_total_unspendables_unclaimed_rewards};
186      const arith_uint256 unclaimed_rewards{(m_total_prevout_spent_amount + m_total_subsidy) - (m_total_new_outputs_ex_coinbase_amount + m_total_coinbase_amount + temp_total_unspendable_amount)};
187      assert(unclaimed_rewards <= arith_uint256(std::numeric_limits<CAmount>::max()));
188      m_total_unspendables_unclaimed_rewards += static_cast<CAmount>(unclaimed_rewards.GetLow64());
189  
190      std::pair<uint256, DBVal> value;
191      value.first = block.hash;
192      value.second.transaction_output_count = m_transaction_output_count;
193      value.second.bogo_size = m_bogo_size;
194      value.second.total_amount = m_total_amount;
195      value.second.total_subsidy = m_total_subsidy;
196      value.second.total_prevout_spent_amount = m_total_prevout_spent_amount;
197      value.second.total_new_outputs_ex_coinbase_amount = m_total_new_outputs_ex_coinbase_amount;
198      value.second.total_coinbase_amount = m_total_coinbase_amount;
199      value.second.total_unspendables_genesis_block = m_total_unspendables_genesis_block;
200      value.second.total_unspendables_bip30 = m_total_unspendables_bip30;
201      value.second.total_unspendables_scripts = m_total_unspendables_scripts;
202      value.second.total_unspendables_unclaimed_rewards = m_total_unspendables_unclaimed_rewards;
203  
204      uint256 out;
205      m_muhash.Finalize(out);
206      value.second.muhash = out;
207  
208      m_current_block_hash = block.hash;
209  
210      // Intentionally do not update DB_MUHASH here so it stays in sync with
211      // DB_BEST_BLOCK, and the index is not corrupted if there is an unclean shutdown.
212      m_db->Write(index_util::DBHeightKey(block.height), value);
213      return true;
214  }
215  
216  bool CoinStatsIndex::CustomRemove(const interfaces::BlockInfo& block)
217  {
218      CDBBatch batch(*m_db);
219      std::unique_ptr<CDBIterator> db_it(m_db->NewIterator());
220  
221      // During a reorg, copy the block's hash digest from the height index to the hash index,
222      // ensuring it's still accessible after the height index entry is overwritten.
223      if (!index_util::CopyHeightIndexToHashIndex<DBVal>(*db_it, batch, m_name, block.height)) {
224          return false;
225      }
226  
227      m_db->WriteBatch(batch);
228  
229      if (!RevertBlock(block)) {
230          return false; // failure cause logged internally
231      }
232  
233      return true;
234  }
235  
236  std::optional<CCoinsStats> CoinStatsIndex::LookUpStats(const CBlockIndex& block_index) const
237  {
238      CCoinsStats stats{block_index.nHeight, block_index.GetBlockHash()};
239      stats.index_used = true;
240  
241      DBVal entry;
242      if (!index_util::LookUpOne(*m_db, {block_index.GetBlockHash(), block_index.nHeight}, entry)) {
243          return std::nullopt;
244      }
245  
246      stats.hashSerialized = entry.muhash;
247      stats.nTransactionOutputs = entry.transaction_output_count;
248      stats.nBogoSize = entry.bogo_size;
249      stats.total_amount = entry.total_amount;
250      stats.total_subsidy = entry.total_subsidy;
251      stats.total_prevout_spent_amount = entry.total_prevout_spent_amount;
252      stats.total_new_outputs_ex_coinbase_amount = entry.total_new_outputs_ex_coinbase_amount;
253      stats.total_coinbase_amount = entry.total_coinbase_amount;
254      stats.total_unspendables_genesis_block = entry.total_unspendables_genesis_block;
255      stats.total_unspendables_bip30 = entry.total_unspendables_bip30;
256      stats.total_unspendables_scripts = entry.total_unspendables_scripts;
257      stats.total_unspendables_unclaimed_rewards = entry.total_unspendables_unclaimed_rewards;
258  
259      return stats;
260  }
261  
262  bool CoinStatsIndex::CustomInit(const std::optional<interfaces::BlockRef>& block)
263  {
264      if (!m_db->Read(DB_MUHASH, m_muhash)) {
265          // Check that the cause of the read failure is that the key does not
266          // exist. Any other errors indicate database corruption or a disk
267          // failure, and starting the index would cause further corruption.
268          if (m_db->Exists(DB_MUHASH)) {
269              LogError("Cannot read current %s state; index may be corrupted",
270                        GetName());
271              return false;
272          }
273      }
274  
275      if (block) {
276          DBVal entry;
277          if (!index_util::LookUpOne(*m_db, *block, entry)) {
278              LogError("Cannot read current %s state; index may be corrupted",
279                        GetName());
280              return false;
281          }
282  
283          uint256 out;
284          m_muhash.Finalize(out);
285          if (entry.muhash != out) {
286              LogError("Cannot read current %s state; index may be corrupted",
287                        GetName());
288              return false;
289          }
290  
291          m_transaction_output_count = entry.transaction_output_count;
292          m_bogo_size = entry.bogo_size;
293          m_total_amount = entry.total_amount;
294          m_total_subsidy = entry.total_subsidy;
295          m_total_prevout_spent_amount = entry.total_prevout_spent_amount;
296          m_total_new_outputs_ex_coinbase_amount = entry.total_new_outputs_ex_coinbase_amount;
297          m_total_coinbase_amount = entry.total_coinbase_amount;
298          m_total_unspendables_genesis_block = entry.total_unspendables_genesis_block;
299          m_total_unspendables_bip30 = entry.total_unspendables_bip30;
300          m_total_unspendables_scripts = entry.total_unspendables_scripts;
301          m_total_unspendables_unclaimed_rewards = entry.total_unspendables_unclaimed_rewards;
302          m_current_block_hash = block->hash;
303      }
304  
305      return true;
306  }
307  
308  bool CoinStatsIndex::CustomCommit(CDBBatch& batch)
309  {
310      // DB_MUHASH should always be committed in a batch together with DB_BEST_BLOCK
311      // to prevent an inconsistent state of the DB.
312      batch.Write(DB_MUHASH, m_muhash);
313      return true;
314  }
315  
316  interfaces::Chain::NotifyOptions CoinStatsIndex::CustomOptions()
317  {
318      interfaces::Chain::NotifyOptions options;
319      options.connect_undo_data = true;
320      options.disconnect_data = true;
321      options.disconnect_undo_data = true;
322      return options;
323  }
324  
325  // Revert a single block as part of a reorg
326  bool CoinStatsIndex::RevertBlock(const interfaces::BlockInfo& block)
327  {
328      std::pair<uint256, DBVal> read_out;
329  
330      // Ignore genesis block
331      if (block.height > 0) {
332          if (!m_db->Read(index_util::DBHeightKey(block.height - 1), read_out)) {
333              return false;
334          }
335  
336          uint256 expected_block_hash{*block.prev_hash};
337          if (read_out.first != expected_block_hash) {
338              LogWarning("previous block header belongs to unexpected block %s; expected %s",
339                        read_out.first.ToString(), expected_block_hash.ToString());
340  
341              if (!m_db->Read(index_util::DBHashKey(expected_block_hash), read_out)) {
342                  LogError("previous block header not found; expected %s",
343                            expected_block_hash.ToString());
344                  return false;
345              }
346          }
347      }
348  
349      // Roll back muhash by removing the new UTXOs that were created by the
350      // block and reapplying the old UTXOs that were spent by the block
351      assert(block.data);
352      assert(block.undo_data);
353      for (size_t i = 0; i < block.data->vtx.size(); ++i) {
354          const auto& tx{block.data->vtx.at(i)};
355          const bool is_coinbase{tx->IsCoinBase()};
356  
357          if (is_coinbase && IsBIP30Unspendable(block.hash, block.height)) {
358              continue;
359          }
360  
361          for (uint32_t j = 0; j < tx->vout.size(); ++j) {
362              const CTxOut& out{tx->vout[j]};
363              const COutPoint outpoint{tx->GetHash(), j};
364              const Coin coin{out, block.height, is_coinbase};
365  
366              if (!coin.out.scriptPubKey.IsUnspendable()) {
367                  RemoveCoinHash(m_muhash, outpoint, coin);
368              }
369          }
370  
371          // The coinbase tx has no undo data since no former output is spent
372          if (!is_coinbase) {
373              const auto& tx_undo{block.undo_data->vtxundo.at(i - 1)};
374  
375              for (size_t j = 0; j < tx_undo.vprevout.size(); ++j) {
376                  const Coin& coin{tx_undo.vprevout[j]};
377                  const COutPoint outpoint{tx->vin[j].prevout.hash, tx->vin[j].prevout.n};
378                  ApplyCoinHash(m_muhash, outpoint, coin);
379              }
380          }
381      }
382  
383      // Check that the rolled back muhash is consistent with the DB read out
384      uint256 out;
385      m_muhash.Finalize(out);
386      Assert(read_out.second.muhash == out);
387  
388      // Apply the other values from the DB to the member variables
389      m_transaction_output_count = read_out.second.transaction_output_count;
390      m_total_amount = read_out.second.total_amount;
391      m_bogo_size = read_out.second.bogo_size;
392      m_total_subsidy = read_out.second.total_subsidy;
393      m_total_prevout_spent_amount = read_out.second.total_prevout_spent_amount;
394      m_total_new_outputs_ex_coinbase_amount = read_out.second.total_new_outputs_ex_coinbase_amount;
395      m_total_coinbase_amount = read_out.second.total_coinbase_amount;
396      m_total_unspendables_genesis_block = read_out.second.total_unspendables_genesis_block;
397      m_total_unspendables_bip30 = read_out.second.total_unspendables_bip30;
398      m_total_unspendables_scripts = read_out.second.total_unspendables_scripts;
399      m_total_unspendables_unclaimed_rewards = read_out.second.total_unspendables_unclaimed_rewards;
400      m_current_block_hash = *block.prev_hash;
401  
402      return true;
403  }