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