src/txdb.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifndef BITCOIN_TXDB_H
   7 #define BITCOIN_TXDB_H
   8
   9 #include "coins.h"
  10 #include "dbwrapper.h"
  11 #include "chain.h"
  12
  13 #include <map>
  14 #include <string>
  15 #include <utility>
  16 #include <vector>
  17
  18 class CBlockIndex;
  19 class CCoinsViewDBCursor;
  20 class uint256;
  21
  22 //! Compensate for extra memory peak (x1.5-x1.9) at flush time.
  23 static constexpr int DB_PEAK_USAGE_FACTOR = 2;
  24 //! No need to periodic flush if at least this much space still available.
  25 static constexpr int MAX_BLOCK_COINSDB_USAGE = 200 * DB_PEAK_USAGE_FACTOR;
  26 //! Always periodic flush if less than this much space still available.
  27 static constexpr int MIN_BLOCK_COINSDB_USAGE = 50 * DB_PEAK_USAGE_FACTOR;
  28 //! -dbcache default (MiB)
  29 static const int64_t nDefaultDbCache = 450;
  30 //! max. -dbcache (MiB)
  31 static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
  32 //! min. -dbcache (MiB)
  33 static const int64_t nMinDbCache = 4;
  34 //! Max memory allocated to block tree DB specific cache, if no -txindex (MiB)
  35 static const int64_t nMaxBlockDBCache = 2;
  36 //! Max memory allocated to block tree DB specific cache, if -txindex (MiB)
  37 // Unlike for the UTXO database, for the txindex scenario the leveldb cache make
  38 // a meaningful difference: https://github.com/bitcoin/bitcoin/pull/8273#issuecomment-229601991
  39 static const int64_t nMaxBlockDBAndTxIndexCache = 1024;
  40 //! Max memory allocated to coin DB specific cache (MiB)
  41 static const int64_t nMaxCoinsDBCache = 8;
  42
  43 struct CDiskTxPos : public CDiskBlockPos
  44 {
  45     unsigned int nTxOffset; // after header
  46
  47     ADD_SERIALIZE_METHODS;
  48
  49     template <typename Stream, typename Operation>
  50     inline void SerializationOp(Stream& s, Operation ser_action) {
  51         READWRITE(*(CDiskBlockPos*)this);
  52         READWRITE(VARINT(nTxOffset));
  53     }
  54
  55     CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
  56     }
  57
  58     CDiskTxPos() {
  59         SetNull();
  60     }
  61
  62     void SetNull() {
  63         CDiskBlockPos::SetNull();
  64         nTxOffset = 0;
  65     }
  66 };
  67
  68 /** CCoinsView backed by the coin database (chainstate/) */
  69 class CCoinsViewDB : public CCoinsView
  70 {
  71 protected:
  72     CDBWrapper db;
  73 public:
  74     CCoinsViewDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
  75
  76     bool GetCoins(const uint256 &txid, CCoins &coins) const;
  77     bool HaveCoins(const uint256 &txid) const;
  78     uint256 GetBestBlock() const;
  79     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
  80     CCoinsViewCursor *Cursor() const;
  81 };
  82
  83 /** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */
  84 class CCoinsViewDBCursor: public CCoinsViewCursor
  85 {
  86 public:
  87     ~CCoinsViewDBCursor() {}
  88
  89     bool GetKey(uint256 &key) const;
  90     bool GetValue(CCoins &coins) const;
  91     unsigned int GetValueSize() const;
  92
  93     bool Valid() const;
  94     void Next();
  95
  96 private:
  97     CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256 &hashBlockIn):
  98         CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {}
  99     std::unique_ptr<CDBIterator> pcursor;
 100     std::pair<char, uint256> keyTmp;
 101
 102     friend class CCoinsViewDB;
 103 };
 104
 105 /** Access to the block database (blocks/index/) */
 106 class CBlockTreeDB : public CDBWrapper
 107 {
 108 public:
 109     CBlockTreeDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
 110 private:
 111     CBlockTreeDB(const CBlockTreeDB&);
 112     void operator=(const CBlockTreeDB&);
 113 public:
 114     bool WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo);
 115     bool ReadBlockFileInfo(int nFile, CBlockFileInfo &fileinfo);
 116     bool ReadLastBlockFile(int &nFile);
 117     bool WriteReindexing(bool fReindex);
 118     bool ReadReindexing(bool &fReindex);
 119     bool ReadTxIndex(const uint256 &txid, CDiskTxPos &pos);
 120     bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> > &list);
 121     bool WriteFlag(const std::string &name, bool fValue);
 122     bool ReadFlag(const std::string &name, bool &fValue);
 123     bool LoadBlockIndexGuts(std::function<CBlockIndex*(const uint256&)> insertBlockIndex);
 124 };
 125
 126 #endif // BITCOIN_TXDB_H