reth_db_api/
database.rs

1use crate::{table::TableImporter, transaction::DbTx, DatabaseError};
2use std::{fmt::Debug, path::PathBuf, sync::Arc};
3
4/// Main Database trait that can open read-only and read-write transactions.
5///
6/// Sealed trait which cannot be implemented by 3rd parties, exposed only for consumption.
7pub trait Database: Send + Sync + Debug {
8    /// Read-Only database transaction
9    type TX: DbTx + Sync + 'static;
10    /// Read-Write database transaction
11    type TXMut: DbTx + TableImporter + Sync + 'static;
12
13    /// Create read only transaction.
14    #[track_caller]
15    fn tx(&self) -> Result<Self::TX, DatabaseError>;
16
17    /// Create read write transaction only possible if database is open with write access.
18    #[track_caller]
19    fn tx_mut(&self) -> Result<Self::TXMut, DatabaseError>;
20
21    /// Returns the path to the database directory.
22    fn path(&self) -> PathBuf;
23
24    /// Returns the transaction ID of the oldest active reader, if available.
25    ///
26    /// This is the committed txnid of the snapshot the reader is pinned to, not a unique per-reader
27    /// identifier, so multiple readers can report the same txnid.
28    ///
29    /// Used to check whether stale readers from a previous write transaction have completed.
30    /// Returns `None` if no readers are active or the backend does not support this query.
31    fn oldest_reader_txnid(&self) -> Option<u64>;
32
33    /// Returns the ID of the most recently committed transaction, if available.
34    fn last_txnid(&self) -> Option<u64>;
35
36    /// Takes a function and passes a read-only transaction into it, making sure it's closed in the
37    /// end of the execution.
38    fn view<T, F>(&self, f: F) -> Result<T, DatabaseError>
39    where
40        F: FnOnce(&mut Self::TX) -> T,
41    {
42        let mut tx = self.tx()?;
43
44        let res = f(&mut tx);
45        tx.commit()?;
46
47        Ok(res)
48    }
49
50    /// Takes a function and passes a write-read transaction into it, making sure it's committed in
51    /// the end of the execution.
52    fn update<T, F>(&self, f: F) -> Result<T, DatabaseError>
53    where
54        F: FnOnce(&Self::TXMut) -> T,
55    {
56        let tx = self.tx_mut()?;
57
58        let res = f(&tx);
59        tx.commit()?;
60
61        Ok(res)
62    }
63}
64
65impl<DB: Database> Database for Arc<DB> {
66    type TX = <DB as Database>::TX;
67    type TXMut = <DB as Database>::TXMut;
68
69    fn tx(&self) -> Result<Self::TX, DatabaseError> {
70        <DB as Database>::tx(self)
71    }
72
73    fn tx_mut(&self) -> Result<Self::TXMut, DatabaseError> {
74        <DB as Database>::tx_mut(self)
75    }
76
77    fn path(&self) -> PathBuf {
78        <DB as Database>::path(self)
79    }
80
81    fn oldest_reader_txnid(&self) -> Option<u64> {
82        <DB as Database>::oldest_reader_txnid(self)
83    }
84
85    fn last_txnid(&self) -> Option<u64> {
86        <DB as Database>::last_txnid(self)
87    }
88}
89
90impl<DB: Database> Database for &DB {
91    type TX = <DB as Database>::TX;
92    type TXMut = <DB as Database>::TXMut;
93
94    fn tx(&self) -> Result<Self::TX, DatabaseError> {
95        <DB as Database>::tx(self)
96    }
97
98    fn tx_mut(&self) -> Result<Self::TXMut, DatabaseError> {
99        <DB as Database>::tx_mut(self)
100    }
101
102    fn path(&self) -> PathBuf {
103        <DB as Database>::path(self)
104    }
105
106    fn oldest_reader_txnid(&self) -> Option<u64> {
107        <DB as Database>::oldest_reader_txnid(self)
108    }
109
110    fn last_txnid(&self) -> Option<u64> {
111        <DB as Database>::last_txnid(self)
112    }
113}
114
115/// Object-safe adapter for reader-txn tracking during unwind.
116pub trait ReaderTxnTracker: Send + Sync {
117    /// Waits until all readers older than the latest committed txnid have drained.
118    fn wait_for_pre_commit_readers(&self);
119}
120
121impl<DB: Database> ReaderTxnTracker for DB {
122    fn wait_for_pre_commit_readers(&self) {
123        if let Some(committed_txnid) = Database::last_txnid(self) {
124            while Database::oldest_reader_txnid(self).is_some_and(|oldest| oldest < committed_txnid)
125            {
126                std::thread::sleep(std::time::Duration::from_millis(10));
127            }
128        }
129    }
130}
reth_db_api/database.rs

reth_db_api/
database.rs
