/ 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 <span>
 34  #include <string>
 35  #include <utility>
 36  #include <vector>
 37  
 38  using kernel::ApplyCoinHash;
 39  using kernel::CCoinsStats;
 40  using kernel::GetBogoSize;
 41  using kernel::RemoveCoinHash;
 42  
 43  static constexpr uint8_t DB_MUHASH{'M'};
 44  
 45  namespace {
 46  
 47  struct DBVal {
 48      uint256 muhash{uint256::ZERO};
 49      uint64_t transaction_output_count{0};
 50      uint64_t bogo_size{0};
 51      CAmount total_amount{0};
 52      CAmount total_subsidy{0};
 53      arith_uint256 total_prevout_spent_amount{0};
 54      arith_uint256 total_new_outputs_ex_coinbase_amount{0};
 55      arith_uint256 total_coinbase_amount{0};
 56      CAmount total_unspendables_genesis_block{0};
 57      CAmount total_unspendables_bip30{0};
 58      CAmount total_unspendables_scripts{0};
 59      CAmount total_unspendables_unclaimed_rewards{0};
 60  
 61      SERIALIZE_METHODS(DBVal, obj)
 62      {
 63          uint256 prevout_spent, new_outputs, coinbase;
 64          SER_WRITE(obj, prevout_spent = ArithToUint256(obj.total_prevout_spent_amount));
 65          SER_WRITE(obj, new_outputs = ArithToUint256(obj.total_new_outputs_ex_coinbase_amount));
 66          SER_WRITE(obj, coinbase = ArithToUint256(obj.total_coinbase_amount));
 67  
 68          READWRITE(obj.muhash);
 69          READWRITE(obj.transaction_output_count);
 70          READWRITE(obj.bogo_size);
 71          READWRITE(obj.total_amount);
 72          READWRITE(obj.total_subsidy);
 73          READWRITE(prevout_spent);
 74          READWRITE(new_outputs);
 75          READWRITE(coinbase);
 76          READWRITE(obj.total_unspendables_genesis_block);
 77          READWRITE(obj.total_unspendables_bip30);
 78          READWRITE(obj.total_unspendables_scripts);
 79          READWRITE(obj.total_unspendables_unclaimed_rewards);
 80  
 81          SER_READ(obj, obj.total_prevout_spent_amount = UintToArith256(prevout_spent));
 82          SER_READ(obj, obj.total_new_outputs_ex_coinbase_amount = UintToArith256(new_outputs));
 83          SER_READ(obj, obj.total_coinbase_amount = UintToArith256(coinbase));
 84      }
 85  };
 86  }; // namespace
 87  
 88  std::unique_ptr<CoinStatsIndex> g_coin_stats_index;
 89  
 90  CoinStatsIndex::CoinStatsIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
 91      : BaseIndex(std::move(chain), "coinstatsindex")
 92  {
 93      // An earlier version of the index used "indexes/coinstats" but it contained
 94      // a bug and is superseded by a fixed version at "indexes/coinstatsindex".
 95      // The original index is kept around until the next release in case users
 96      // decide to downgrade their node.
 97      auto old_path = gArgs.GetDataDirNet() / "indexes" / "coinstats";
 98      if (fs::exists(old_path)) {
 99          // TODO: Change this to deleting the old index with v31.
100          LogWarning("Old version of coinstatsindex found at %s. This folder can be safely deleted unless you " \
101              "plan to downgrade your node to version 29 or lower.", fs::PathToString(old_path));
102      }
103      fs::path path{gArgs.GetDataDirNet() / "indexes" / "coinstatsindex"};
104      fs::create_directories(path);
105  
106      m_db = std::make_unique<CoinStatsIndex::DB>(path / "db", n_cache_size, f_memory, f_wipe);
107  }
108  
109  bool CoinStatsIndex::CustomAppend(const interfaces::BlockInfo& block)
110  {
111      const CAmount block_subsidy{GetBlockSubsidy(block.height, Params().GetConsensus())};
112      m_total_subsidy += block_subsidy;
113  
114      // Ignore genesis block
115      if (block.height > 0) {
116          uint256 expected_block_hash{*Assert(block.prev_hash)};
117          if (m_current_block_hash != expected_block_hash) {
118              LogError("previous block header belongs to unexpected block %s; expected %s",
119                        m_current_block_hash.ToString(), expected_block_hash.ToString());
120              return false;
121          }
122  
123          // Add the new utxos created from the block
124          assert(block.data);
125          for (size_t i = 0; i < block.data->vtx.size(); ++i) {
126              const auto& tx{block.data->vtx.at(i)};
127              const bool is_coinbase{tx->IsCoinBase()};
128  
129              // Skip duplicate txid coinbase transactions (BIP30).
130              if (is_coinbase && IsBIP30Unspendable(block.hash, block.height)) {
131                  m_total_unspendables_bip30 += block_subsidy;
132                  continue;
133              }
134  
135              for (uint32_t j = 0; j < tx->vout.size(); ++j) {
136                  const CTxOut& out{tx->vout[j]};
137                  const Coin coin{out, block.height, is_coinbase};
138                  const COutPoint outpoint{tx->GetHash(), j};
139  
140                  // Skip unspendable coins
141                  if (coin.out.scriptPubKey.IsUnspendable()) {
142                      m_total_unspendables_scripts += coin.out.nValue;
143                      continue;
144                  }
145  
146                  ApplyCoinHash(m_muhash, outpoint, coin);
147  
148                  if (is_coinbase) {
149                      m_total_coinbase_amount += coin.out.nValue;
150                  } else {
151                      m_total_new_outputs_ex_coinbase_amount += coin.out.nValue;
152                  }
153  
154                  ++m_transaction_output_count;
155                  m_total_amount += coin.out.nValue;
156                  m_bogo_size += GetBogoSize(coin.out.scriptPubKey);
157              }
158  
159              // The coinbase tx has no undo data since no former output is spent
160              if (!is_coinbase) {
161                  const auto& tx_undo{Assert(block.undo_data)->vtxundo.at(i - 1)};
162  
163                  for (size_t j = 0; j < tx_undo.vprevout.size(); ++j) {
164                      const Coin& coin{tx_undo.vprevout[j]};
165                      const COutPoint outpoint{tx->vin[j].prevout.hash, tx->vin[j].prevout.n};
166  
167                      RemoveCoinHash(m_muhash, outpoint, coin);
168  
169                      m_total_prevout_spent_amount += coin.out.nValue;
170  
171                      --m_transaction_output_count;
172                      m_total_amount -= coin.out.nValue;
173                      m_bogo_size -= GetBogoSize(coin.out.scriptPubKey);
174                  }
175              }
176          }
177      } else {
178          // genesis block
179          m_total_unspendables_genesis_block += block_subsidy;
180      }
181  
182      // If spent prevouts + block subsidy are still a higher amount than
183      // new outputs + coinbase + current unspendable amount this means
184      // the miner did not claim the full block reward. Unclaimed block
185      // rewards are also unspendable.
186      const CAmount temp_total_unspendable_amount{m_total_unspendables_genesis_block + m_total_unspendables_bip30 + m_total_unspendables_scripts + m_total_unspendables_unclaimed_rewards};
187      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)};
188      assert(unclaimed_rewards <= arith_uint256(std::numeric_limits<CAmount>::max()));
189      m_total_unspendables_unclaimed_rewards += static_cast<CAmount>(unclaimed_rewards.GetLow64());
190  
191      std::pair<uint256, DBVal> value;
192      value.first = block.hash;
193      value.second.transaction_output_count = m_transaction_output_count;
194      value.second.bogo_size = m_bogo_size;
195      value.second.total_amount = m_total_amount;
196      value.second.total_subsidy = m_total_subsidy;
197      value.second.total_prevout_spent_amount = m_total_prevout_spent_amount;
198      value.second.total_new_outputs_ex_coinbase_amount = m_total_new_outputs_ex_coinbase_amount;
199      value.second.total_coinbase_amount = m_total_coinbase_amount;
200      value.second.total_unspendables_genesis_block = m_total_unspendables_genesis_block;
201      value.second.total_unspendables_bip30 = m_total_unspendables_bip30;
202      value.second.total_unspendables_scripts = m_total_unspendables_scripts;
203      value.second.total_unspendables_unclaimed_rewards = m_total_unspendables_unclaimed_rewards;
204  
205      uint256 out;
206      m_muhash.Finalize(out);
207      value.second.muhash = out;
208  
209      m_current_block_hash = block.hash;
210  
211      // Intentionally do not update DB_MUHASH here so it stays in sync with
212      // DB_BEST_BLOCK, and the index is not corrupted if there is an unclean shutdown.
213      m_db->Write(index_util::DBHeightKey(block.height), value);
214      return true;
215  }
216  
217  bool CoinStatsIndex::CustomRemove(const interfaces::BlockInfo& block)
218  {
219      CDBBatch batch(*m_db);
220      std::unique_ptr<CDBIterator> db_it(m_db->NewIterator());
221  
222      // During a reorg, copy the block's hash digest from the height index to the hash index,
223      // ensuring it's still accessible after the height index entry is overwritten.
224      if (!index_util::CopyHeightIndexToHashIndex<DBVal>(*db_it, batch, m_name, block.height)) {
225          return false;
226      }
227  
228      m_db->WriteBatch(batch);
229  
230      if (!RevertBlock(block)) {
231          return false; // failure cause logged internally
232      }
233  
234      return true;
235  }
236  
237  std::optional<CCoinsStats> CoinStatsIndex::LookUpStats(const CBlockIndex& block_index) const
238  {
239      CCoinsStats stats{block_index.nHeight, block_index.GetBlockHash()};
240      stats.index_used = true;
241  
242      DBVal entry;
243      if (!index_util::LookUpOne(*m_db, {block_index.GetBlockHash(), block_index.nHeight}, entry)) {
244          return std::nullopt;
245      }
246  
247      stats.hashSerialized = entry.muhash;
248      stats.nTransactionOutputs = entry.transaction_output_count;
249      stats.nBogoSize = entry.bogo_size;
250      stats.total_amount = entry.total_amount;
251      stats.total_subsidy = entry.total_subsidy;
252      stats.total_prevout_spent_amount = entry.total_prevout_spent_amount;
253      stats.total_new_outputs_ex_coinbase_amount = entry.total_new_outputs_ex_coinbase_amount;
254      stats.total_coinbase_amount = entry.total_coinbase_amount;
255      stats.total_unspendables_genesis_block = entry.total_unspendables_genesis_block;
256      stats.total_unspendables_bip30 = entry.total_unspendables_bip30;
257      stats.total_unspendables_scripts = entry.total_unspendables_scripts;
258      stats.total_unspendables_unclaimed_rewards = entry.total_unspendables_unclaimed_rewards;
259  
260      return stats;
261  }
262  
263  bool CoinStatsIndex::CustomInit(const std::optional<interfaces::BlockRef>& block)
264  {
265      if (!m_db->Read(DB_MUHASH, m_muhash)) {
266          // Check that the cause of the read failure is that the key does not
267          // exist. Any other errors indicate database corruption or a disk
268          // failure, and starting the index would cause further corruption.
269          if (m_db->Exists(DB_MUHASH)) {
270              LogError("Cannot read current %s state; index may be corrupted",
271                        GetName());
272              return false;
273          }
274      }
275  
276      if (block) {
277          DBVal entry;
278          if (!index_util::LookUpOne(*m_db, *block, entry)) {
279              LogError("Cannot read current %s state; index may be corrupted",
280                        GetName());
281              return false;
282          }
283  
284          uint256 out;
285          m_muhash.Finalize(out);
286          if (entry.muhash != out) {
287              LogError("Cannot read current %s state; index may be corrupted",
288                        GetName());
289              return false;
290          }
291  
292          m_transaction_output_count = entry.transaction_output_count;
293          m_bogo_size = entry.bogo_size;
294          m_total_amount = entry.total_amount;
295          m_total_subsidy = entry.total_subsidy;
296          m_total_prevout_spent_amount = entry.total_prevout_spent_amount;
297          m_total_new_outputs_ex_coinbase_amount = entry.total_new_outputs_ex_coinbase_amount;
298          m_total_coinbase_amount = entry.total_coinbase_amount;
299          m_total_unspendables_genesis_block = entry.total_unspendables_genesis_block;
300          m_total_unspendables_bip30 = entry.total_unspendables_bip30;
301          m_total_unspendables_scripts = entry.total_unspendables_scripts;
302          m_total_unspendables_unclaimed_rewards = entry.total_unspendables_unclaimed_rewards;
303          m_current_block_hash = block->hash;
304      }
305  
306      return true;
307  }
308  
309  bool CoinStatsIndex::CustomCommit(CDBBatch& batch)
310  {
311      // DB_MUHASH should always be committed in a batch together with DB_BEST_BLOCK
312      // to prevent an inconsistent state of the DB.
313      batch.Write(DB_MUHASH, m_muhash);
314      return true;
315  }
316  
317  interfaces::Chain::NotifyOptions CoinStatsIndex::CustomOptions()
318  {
319      interfaces::Chain::NotifyOptions options;
320      options.connect_undo_data = true;
321      options.disconnect_data = true;
322      options.disconnect_undo_data = true;
323      return options;
324  }
325  
326  // Revert a single block as part of a reorg
327  bool CoinStatsIndex::RevertBlock(const interfaces::BlockInfo& block)
328  {
329      std::pair<uint256, DBVal> read_out;
330  
331      // Ignore genesis block
332      if (block.height > 0) {
333          if (!m_db->Read(index_util::DBHeightKey(block.height - 1), read_out)) {
334              return false;
335          }
336  
337          uint256 expected_block_hash{*block.prev_hash};
338          if (read_out.first != expected_block_hash) {
339              LogWarning("previous block header belongs to unexpected block %s; expected %s",
340                        read_out.first.ToString(), expected_block_hash.ToString());
341  
342              if (!m_db->Read(index_util::DBHashKey(expected_block_hash), read_out)) {
343                  LogError("previous block header not found; expected %s",
344                            expected_block_hash.ToString());
345                  return false;
346              }
347          }
348      }
349  
350      // Roll back muhash by removing the new UTXOs that were created by the
351      // block and reapplying the old UTXOs that were spent by the block
352      assert(block.data);
353      assert(block.undo_data);
354      for (size_t i = 0; i < block.data->vtx.size(); ++i) {
355          const auto& tx{block.data->vtx.at(i)};
356          const bool is_coinbase{tx->IsCoinBase()};
357  
358          if (is_coinbase && IsBIP30Unspendable(block.hash, block.height)) {
359              continue;
360          }
361  
362          for (uint32_t j = 0; j < tx->vout.size(); ++j) {
363              const CTxOut& out{tx->vout[j]};
364              const COutPoint outpoint{tx->GetHash(), j};
365              const Coin coin{out, block.height, is_coinbase};
366  
367              if (!coin.out.scriptPubKey.IsUnspendable()) {
368                  RemoveCoinHash(m_muhash, outpoint, coin);
369              }
370          }
371  
372          // The coinbase tx has no undo data since no former output is spent
373          if (!is_coinbase) {
374              const auto& tx_undo{block.undo_data->vtxundo.at(i - 1)};
375  
376              for (size_t j = 0; j < tx_undo.vprevout.size(); ++j) {
377                  const Coin& coin{tx_undo.vprevout[j]};
378                  const COutPoint outpoint{tx->vin[j].prevout.hash, tx->vin[j].prevout.n};
379                  ApplyCoinHash(m_muhash, outpoint, coin);
380              }
381          }
382      }
383  
384      // Check that the rolled back muhash is consistent with the DB read out
385      uint256 out;
386      m_muhash.Finalize(out);
387      Assert(read_out.second.muhash == out);
388  
389      // Apply the other values from the DB to the member variables
390      m_transaction_output_count = read_out.second.transaction_output_count;
391      m_total_amount = read_out.second.total_amount;
392      m_bogo_size = read_out.second.bogo_size;
393      m_total_subsidy = read_out.second.total_subsidy;
394      m_total_prevout_spent_amount = read_out.second.total_prevout_spent_amount;
395      m_total_new_outputs_ex_coinbase_amount = read_out.second.total_new_outputs_ex_coinbase_amount;
396      m_total_coinbase_amount = read_out.second.total_coinbase_amount;
397      m_total_unspendables_genesis_block = read_out.second.total_unspendables_genesis_block;
398      m_total_unspendables_bip30 = read_out.second.total_unspendables_bip30;
399      m_total_unspendables_scripts = read_out.second.total_unspendables_scripts;
400      m_total_unspendables_unclaimed_rewards = read_out.second.total_unspendables_unclaimed_rewards;
401      m_current_block_hash = *block.prev_hash;
402  
403      return true;
404  }