1  // Copyright (c) 2017-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/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 <node/blockstorage.h>
 14  #include <primitives/block.h>
 15  #include <primitives/transaction.h>
 16  #include <serialize.h>
 17  #include <streams.h>
 18  #include <uint256.h>
 19  #include <util/fs.h>
 20  #include <util/log.h>
 21  #include <validation.h>
 22  
 23  #include <cassert>
 24  #include <cstdint>
 25  #include <cstdio>
 26  #include <exception>
 27  #include <span>
 28  #include <string>
 29  #include <utility>
 30  #include <vector>
 31  
 32  constexpr uint8_t DB_TXINDEX{'t'};
 33  
 34  std::unique_ptr<TxIndex> g_txindex;
 35  
 36  
 37  /** Access to the txindex database (indexes/txindex/) */
 38  class TxIndex::DB : public BaseIndex::DB
 39  {
 40  public:
 41      explicit DB(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
 42  
 43      /// Read the disk location of the transaction data with the given hash. Returns false if the
 44      /// transaction hash is not indexed.
 45      bool ReadTxPos(const Txid& txid, CDiskTxPos& pos) const;
 46  
 47      /// Write a batch of transaction positions to the DB.
 48      void WriteTxs(const std::vector<std::pair<Txid, CDiskTxPos>>& v_pos);
 49  };
 50  
 51  TxIndex::DB::DB(size_t n_cache_size, bool f_memory, bool f_wipe) :
 52      BaseIndex::DB(gArgs.GetDataDirNet() / "indexes" / "txindex", n_cache_size, f_memory, f_wipe)
 53  {}
 54  
 55  bool TxIndex::DB::ReadTxPos(const Txid& txid, CDiskTxPos& pos) const
 56  {
 57      return Read(std::make_pair(DB_TXINDEX, txid.ToUint256()), pos);
 58  }
 59  
 60  void TxIndex::DB::WriteTxs(const std::vector<std::pair<Txid, CDiskTxPos>>& v_pos)
 61  {
 62      CDBBatch batch(*this);
 63      for (const auto& [txid, pos] : v_pos) {
 64          batch.Write(std::make_pair(DB_TXINDEX, txid.ToUint256()), pos);
 65      }
 66      WriteBatch(batch);
 67  }
 68  
 69  TxIndex::TxIndex(std::unique_ptr<interfaces::Chain> chain, size_t n_cache_size, bool f_memory, bool f_wipe)
 70      : BaseIndex(std::move(chain), "txindex"), m_db(std::make_unique<TxIndex::DB>(n_cache_size, f_memory, f_wipe))
 71  {}
 72  
 73  TxIndex::~TxIndex() = default;
 74  
 75  bool TxIndex::CustomAppend(const interfaces::BlockInfo& block)
 76  {
 77      // Exclude genesis block transaction because outputs are not spendable.
 78      if (block.height == 0) return true;
 79  
 80      assert(block.data);
 81      CDiskTxPos pos({block.file_number, block.data_pos}, GetSizeOfCompactSize(block.data->vtx.size()));
 82      std::vector<std::pair<Txid, CDiskTxPos>> vPos;
 83      vPos.reserve(block.data->vtx.size());
 84      for (const auto& tx : block.data->vtx) {
 85          vPos.emplace_back(tx->GetHash(), pos);
 86          pos.nTxOffset += ::GetSerializeSize(TX_WITH_WITNESS(*tx));
 87      }
 88      m_db->WriteTxs(vPos);
 89      return true;
 90  }
 91  
 92  BaseIndex::DB& TxIndex::GetDB() const { return *m_db; }
 93  
 94  bool TxIndex::FindTx(const Txid& tx_hash, uint256& block_hash, CTransactionRef& tx) const
 95  {
 96      CDiskTxPos postx;
 97      if (!m_db->ReadTxPos(tx_hash, postx)) {
 98          return false;
 99      }
100  
101      AutoFile file{m_chainstate->m_blockman.OpenBlockFile(postx, true)};
102      if (file.IsNull()) {
103          LogError("OpenBlockFile failed");
104          return false;
105      }
106      CBlockHeader header;
107      try {
108          file >> header;
109          file.seek(postx.nTxOffset, SEEK_CUR);
110          file >> TX_WITH_WITNESS(tx);
111      } catch (const std::exception& e) {
112          LogError("Deserialize or I/O error - %s", e.what());
113          return false;
114      }
115      if (tx->GetHash() != tx_hash) {
116          LogError("txid mismatch");
117          return false;
118      }
119      block_hash = header.GetHash();
120      return true;
121  }