Trait TransactionManager

pub trait TransactionManager<Conn: AsyncConnection>: Send {
    type TransactionStateData;

    // Required methods
    fn begin_transaction(
        conn: &mut Conn,
    ) -> impl Future<Output = QueryResult<()>> + Send;
    fn rollback_transaction(
        conn: &mut Conn,
    ) -> impl Future<Output = QueryResult<()>> + Send;
    fn commit_transaction(
        conn: &mut Conn,
    ) -> impl Future<Output = QueryResult<()>> + Send;

    // Provided method
    fn transaction<'a, 'conn, F, R, E>(
        conn: &'conn mut Conn,
        callback: F,
    ) -> impl Future<Output = Result<R, E>> + Send + 'conn
       where F: for<'r> FnOnce(&'r mut Conn) -> ScopedBoxFuture<'a, 'r, Result<R, E>> + Send + 'a,
             E: From<Error> + Send,
             R: Send,
             'a: 'conn { ... }
}

Manages the internal transaction state for a connection.

You will not need to interact with this trait, unless you are writing an implementation of AsyncConnection.

Required Associated Types

type TransactionStateData

Data stored as part of the connection implementation to track the current transaction state of a connection

Required Methods

fn begin_transaction( conn: &mut Conn, ) -> impl Future<Output = QueryResult<()>> + Send

Begin a new transaction or savepoint

If the transaction depth is greater than 0, this should create a savepoint instead. This function is expected to increment the transaction depth by 1.

fn rollback_transaction( conn: &mut Conn, ) -> impl Future<Output = QueryResult<()>> + Send

Rollback the inner-most transaction or savepoint

If the transaction depth is greater than 1, this should rollback to the most recent savepoint. This function is expected to decrement the transaction depth by 1.

fn commit_transaction( conn: &mut Conn, ) -> impl Future<Output = QueryResult<()>> + Send

Commit the inner-most transaction or savepoint

If the transaction depth is greater than 1, this should release the most recent savepoint. This function is expected to decrement the transaction depth by 1.

Provided Methods

fn transaction<'a, 'conn, F, R, E>( conn: &'conn mut Conn, callback: F, ) -> impl Future<Output = Result<R, E>> + Send + 'conn

where F: for<'r> FnOnce(&'r mut Conn) -> ScopedBoxFuture<'a, 'r, Result<R, E>> + Send + 'a, E: From<Error> + Send, R: Send, 'a: 'conn,

Executes the given function inside of a database transaction

Each implementation of this function needs to fulfill the documented behaviour of AsyncConnection::transaction

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.

Implementors

impl<Conn> TransactionManager<Conn> for AnsiTransactionManager

where Conn: AsyncConnection<TransactionManager = Self>,

type TransactionStateData = AnsiTransactionManager