1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present 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 <kernel/caches.h>
12#include <kernel/cs_main.h>
13#include <sync.h>
14#include <util/fs.h>
15
16#include <cstddef>
17#include <cstdint>
18#include <future>
19#include <memory>
20#include <optional>
21#include <string>
22#include <vector>
23
24class COutPoint;
25class uint256;
26
27//! User-controlled performance and debug options.
28struct CoinsViewOptions {
29    //! Maximum database write batch size in bytes.
30    uint64_t batch_write_bytes{DEFAULT_DB_CACHE_BATCH};
31    //! If non-zero, randomly exit when the database is flushed with (1/ratio) probability.
32    int simulate_crash_ratio{0};
33};
34
35/** CCoinsView backed by the coin database (chainstate/) */
36class CCoinsViewDB final : public CCoinsView
37{
38protected:
39    DBParams m_db_params;
40    CoinsViewOptions m_options;
41    //! Prevents CompactFull() from using m_db while ResizeCache() replaces it.
42    Mutex m_db_mutex;
43    std::unique_ptr<CDBWrapper> m_db;
44    std::shared_future<void> m_compaction;
45public:
46    explicit CCoinsViewDB(DBParams db_params, CoinsViewOptions options);
47    ~CCoinsViewDB() override;
48
49    std::optional<Coin> GetCoin(const COutPoint& outpoint) const override;
50    std::optional<Coin> PeekCoin(const COutPoint& outpoint) const override;
51    bool HaveCoin(const COutPoint& outpoint) const override;
52    uint256 GetBestBlock() const override;
53    std::vector<uint256> GetHeadBlocks() const override;
54    void BatchWrite(CoinsViewCacheCursor& cursor, const uint256& block_hash) override;
55    //! Get a cursor to iterate over the whole state.
56    std::unique_ptr<CCoinsViewCursor> Cursor() const;
57
58    //! Whether an unsupported database format is used.
59    bool NeedsUpgrade();
60    size_t EstimateSize() const override;
61
62    //! Dynamically alter the underlying leveldb cache size.
63    void ResizeCache(size_t new_cache_size) EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_db_mutex);
64
65    //! Perform a full compaction of the underlying LevelDB on a one-shot background thread.
66    std::shared_future<void> CompactFullAsync() EXCLUSIVE_LOCKS_REQUIRED(cs_main, !m_db_mutex);
67
68    //! Return an underlying LevelDB property value, if available.
69    std::optional<std::string> GetDBProperty(const std::string& property);
70};
71
72#endif // BITCOIN_TXDB_H
73