Trait Database 

pub trait Database:
    Send
    + Sync
    + Debug {
    type TX: DbTx + Send + Sync + Debug + 'static;
    type TXMut: DbTxMut + DbTx + TableImporter + Send + Sync + Debug + 'static;

    // Required methods
    fn tx(&self) -> Result<Self::TX, DatabaseError>;
    fn tx_mut(&self) -> Result<Self::TXMut, DatabaseError>;
    fn path(&self) -> PathBuf;
    fn oldest_reader_txnid(&self) -> Option<u64>;
    fn last_txnid(&self) -> Option<u64>;

    // Provided methods
    fn view<T, F>(&self, f: F) -> Result<T, DatabaseError>
       where F: FnOnce(&mut Self::TX) -> T { ... }
    fn update<T, F>(&self, f: F) -> Result<T, DatabaseError>
       where F: FnOnce(&Self::TXMut) -> T { ... }
}

Main Database trait that can open read-only and read-write transactions.

Sealed trait which cannot be implemented by 3rd parties, exposed only for consumption.

Required Associated Types

type TX: DbTx + Send + Sync + Debug + 'static

Read-Only database transaction

type TXMut: DbTxMut + DbTx + TableImporter + Send + Sync + Debug + 'static

Read-Write database transaction

Required Methods

fn tx(&self) -> Result<Self::TX, DatabaseError>

Create read only transaction.

fn tx_mut(&self) -> Result<Self::TXMut, DatabaseError>

Create read write transaction only possible if database is open with write access.

fn path(&self) -> PathBuf

Returns the path to the database directory.

fn oldest_reader_txnid(&self) -> Option<u64>

Returns the transaction ID of the oldest active reader, if available.

This is the committed txnid of the snapshot the reader is pinned to, not a unique per-reader identifier, so multiple readers can report the same txnid.

Used to check whether stale readers from a previous write transaction have completed. Returns None if no readers are active or the backend does not support this query.

fn last_txnid(&self) -> Option<u64>

Returns the ID of the most recently committed transaction, if available.

Provided Methods

fn view<T, F>(&self, f: F) -> Result<T, DatabaseError>

where F: FnOnce(&mut Self::TX) -> T,

Takes a function and passes a read-only transaction into it, making sure it’s closed in the end of the execution.

fn update<T, F>(&self, f: F) -> Result<T, DatabaseError>

where F: FnOnce(&Self::TXMut) -> T,

Takes a function and passes a write-read transaction into it, making sure it’s committed in the end of the execution.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<DB> Database for &DB

where DB: Database,

type TX = <DB as Database>::TX

type TXMut = <DB as Database>::TXMut

fn tx(&self) -> Result<<&DB as Database>::TX, DatabaseError>

fn tx_mut(&self) -> Result<<&DB as Database>::TXMut, DatabaseError>

fn path(&self) -> PathBuf

fn oldest_reader_txnid(&self) -> Option<u64>

fn last_txnid(&self) -> Option<u64>

impl<DB> Database for Arc<DB>

where DB: Database,

type TX = <DB as Database>::TX

type TXMut = <DB as Database>::TXMut

fn tx(&self) -> Result<<Arc<DB> as Database>::TX, DatabaseError>

fn tx_mut(&self) -> Result<<Arc<DB> as Database>::TXMut, DatabaseError>

fn path(&self) -> PathBuf

fn oldest_reader_txnid(&self) -> Option<u64>

fn last_txnid(&self) -> Option<u64>

Implementors

impl Database for DatabaseEnv

Available on crate feature mdbx only.

type TX = Tx<RO>

type TXMut = Tx<RW>

impl Database for DatabaseMock

type TX = TxMock

type TXMut = TxMock

impl<DB: Database> Database for TempDatabase<DB>

Available on crate features test-utils only.

type TX = <DB as Database>::TX

type TXMut = <DB as Database>::TXMut