1  // Copyright (c) 2017-2022 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/txindex.h>
  6  
  7  #include <clientversion.h>
  8  #include <common/args.h>
  9  #include <index/disktxpos.h>
 10  #include <logging.h>
 11  #include <node/blockstorage.h>
 12  #include <validation.h>
 13  
 14  constexpr uint8_t DB_TXINDEX{'t'};
 15  
 16  std::unique_ptr<TxIndex> g_txindex;
 17  
 18  
 19  /** Access to the txindex database (indexes/txindex/) */
 20  class TxIndex::DB : public BaseIndex::DB
 21  {
 22  public:
 23      explicit DB(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
 24  
 25      /// Read the disk location of the transaction data with the given hash. Returns false if the
 26      /// transaction hash is not indexed.
 27      bool ReadTxPos(const uint256& txid, CDiskTxPos& pos) const;
 28  
 29      /// Write a batch of transaction positions to the DB.
 30      [[nodiscard]] bool WriteTxs(const std::vector<std::pair<uint256, CDiskTxPos>>& v_pos);
 31  };
 32  
 33  TxIndex::DB::DB(size_t n_cache_size, bool f_memory, bool f_wipe) :
 34      BaseIndex::DB(gArgs.GetDataDirNet() / "indexes" / "txindex", n_cache_size, f_memory, f_wipe)
 35  {}
 36  
 37  bool TxIndex::DB::ReadTxPos(const uint256 &txid, CDiskTxPos& pos) const
 38  {
 39      return Read(std::make_pair(DB_TXINDEX, txid), pos);
 40  }
 41  
 42  bool TxIndex::DB::WriteTxs(const std::vector<std::pair<uint256, CDiskTxPos>>& v_pos)
 43  {
 44      CDBBatch batch(*this);
 45      for (const auto& tuple : v_pos) {
 46          batch.Write(std::make_pair(DB_TXINDEX, tuple.first), tuple.second);
 47      }
 48      return WriteBatch(batch);
 49  }
 50  
 51  TxIndex::TxIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
 52      : BaseIndex(std::move(chain), "txindex"), m_db(std::make_unique<TxIndex::DB>(n_cache_size, f_memory, f_wipe))
 53  {}
 54  
 55  TxIndex::~TxIndex() = default;
 56  
 57  bool TxIndex::CustomAppend(const interfaces::BlockInfo& block)
 58  {
 59      // Exclude genesis block transaction because outputs are not spendable.
 60      if (block.height == 0) return true;
 61  
 62      assert(block.data);
 63      CDiskTxPos pos({block.file_number, block.data_pos}, GetSizeOfCompactSize(block.data->vtx.size()));
 64      std::vector<std::pair<uint256, CDiskTxPos>> vPos;
 65      vPos.reserve(block.data->vtx.size());
 66      for (const auto& tx : block.data->vtx) {
 67          vPos.emplace_back(tx->GetHash(), pos);
 68          pos.nTxOffset += ::GetSerializeSize(TX_WITH_WITNESS(*tx));
 69      }
 70      return m_db->WriteTxs(vPos);
 71  }
 72  
 73  BaseIndex::DB& TxIndex::GetDB() const { return *m_db; }
 74  
 75  bool TxIndex::FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRef& tx) const
 76  {
 77      CDiskTxPos postx;
 78      if (!m_db->ReadTxPos(tx_hash, postx)) {
 79          return false;
 80      }
 81  
 82      AutoFile file{m_chainstate->m_blockman.OpenBlockFile(postx, true)};
 83      if (file.IsNull()) {
 84          LogError("%s: OpenBlockFile failed\n", __func__);
 85          return false;
 86      }
 87      CBlockHeader header;
 88      try {
 89          file >> header;
 90          if (fseek(file.Get(), postx.nTxOffset, SEEK_CUR)) {
 91              LogError("%s: fseek(...) failed\n", __func__);
 92              return false;
 93          }
 94          file >> TX_WITH_WITNESS(tx);
 95      } catch (const std::exception& e) {
 96          LogError("%s: Deserialize or I/O error - %s\n", __func__, e.what());
 97          return false;
 98      }
 99      if (tx->GetHash() != tx_hash) {
100          LogError("%s: txid mismatch\n", __func__);
101          return false;
102      }
103      block_hash = header.GetHash();
104      return true;
105  }