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 <common/args.h>
  8  #include <dbwrapper.h>
  9  #include <flatfile.h>
 10  #include <index/base.h>
 11  #include <index/disktxpos.h>
 12  #include <interfaces/chain.h>
 13  #include <logging.h>
 14  #include <node/blockstorage.h>
 15  #include <primitives/block.h>
 16  #include <primitives/transaction.h>
 17  #include <serialize.h>
 18  #include <streams.h>
 19  #include <uint256.h>
 20  #include <util/fs.h>
 21  #include <validation.h>
 22  
 23  #include <cassert>
 24  #include <cstdint>
 25  #include <cstdio>
 26  #include <exception>
 27  #include <iterator>
 28  #include <span>
 29  #include <string>
 30  #include <utility>
 31  #include <vector>
 32  
 33  constexpr uint8_t DB_TXINDEX{'t'};
 34  
 35  std::unique_ptr<TxIndex> g_txindex;
 36  
 37  
 38  /** Access to the txindex database (indexes/txindex/) */
 39  class TxIndex::DB : public BaseIndex::DB
 40  {
 41  public:
 42      explicit DB(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
 43  
 44      /// Read the disk location of the transaction data with the given hash. Returns false if the
 45      /// transaction hash is not indexed.
 46      bool ReadTxPos(const Txid& txid, CDiskTxPos& pos) const;
 47  
 48      /// Write a batch of transaction positions to the DB.
 49      void WriteTxs(const std::vector<std::pair<Txid, CDiskTxPos>>& v_pos);
 50  };
 51  
 52  TxIndex::DB::DB(size_t n_cache_size, bool f_memory, bool f_wipe) :
 53      BaseIndex::DB(gArgs.GetDataDirNet() / "indexes" / "txindex", n_cache_size, f_memory, f_wipe)
 54  {}
 55  
 56  bool TxIndex::DB::ReadTxPos(const Txid& txid, CDiskTxPos& pos) const
 57  {
 58      return Read(std::make_pair(DB_TXINDEX, txid.ToUint256()), pos);
 59  }
 60  
 61  void TxIndex::DB::WriteTxs(const std::vector<std::pair<Txid, CDiskTxPos>>& v_pos)
 62  {
 63      CDBBatch batch(*this);
 64      for (const auto& [txid, pos] : v_pos) {
 65          batch.Write(std::make_pair(DB_TXINDEX, txid.ToUint256()), pos);
 66      }
 67      WriteBatch(batch);
 68  }
 69  
 70  TxIndex::TxIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
 71      : BaseIndex(std::move(chain), "txindex"), m_db(std::make_unique<TxIndex::DB>(n_cache_size, f_memory, f_wipe))
 72  {}
 73  
 74  TxIndex::~TxIndex() = default;
 75  
 76  bool TxIndex::CustomAppend(const interfaces::BlockInfo& block)
 77  {
 78      // Exclude genesis block transaction because outputs are not spendable.
 79      if (block.height == 0) return true;
 80  
 81      assert(block.data);
 82      CDiskTxPos pos({block.file_number, block.data_pos}, GetSizeOfCompactSize(block.data->vtx.size()));
 83      std::vector<std::pair<Txid, CDiskTxPos>> vPos;
 84      vPos.reserve(block.data->vtx.size());
 85      for (const auto& tx : block.data->vtx) {
 86          vPos.emplace_back(tx->GetHash(), pos);
 87          pos.nTxOffset += ::GetSerializeSize(TX_WITH_WITNESS(*tx));
 88      }
 89      m_db->WriteTxs(vPos);
 90      return true;
 91  }
 92  
 93  BaseIndex::DB& TxIndex::GetDB() const { return *m_db; }
 94  
 95  bool TxIndex::FindTx(const Txid& tx_hash, uint256& block_hash, CTransactionRef& tx) const
 96  {
 97      CDiskTxPos postx;
 98      if (!m_db->ReadTxPos(tx_hash, postx)) {
 99          return false;
100      }
101  
102      AutoFile file{m_chainstate->m_blockman.OpenBlockFile(postx, true)};
103      if (file.IsNull()) {
104          LogError("OpenBlockFile failed");
105          return false;
106      }
107      CBlockHeader header;
108      try {
109          file >> header;
110          file.seek(postx.nTxOffset, SEEK_CUR);
111          file >> TX_WITH_WITNESS(tx);
112      } catch (const std::exception& e) {
113          LogError("Deserialize or I/O error - %s", e.what());
114          return false;
115      }
116      if (tx->GetHash() != tx_hash) {
117          LogError("txid mismatch");
118          return false;
119      }
120      block_hash = header.GetHash();
121      return true;
122  }