use crate::connection::ConnectionRef;
use crate::{Error, IsolationLevel, Transaction};
/// A builder for database transactions.
pub struct TransactionBuilder<'a> {
connection: ConnectionRef<'a>,
builder: tokio_postgres::TransactionBuilder<'a>,
}
impl<'a> TransactionBuilder<'a> {
pub(crate) fn new(
connection: ConnectionRef<'a>,
builder: tokio_postgres::TransactionBuilder<'a>,
) -> TransactionBuilder<'a> {
TransactionBuilder {
connection,
builder,
}
}
/// Sets the isolation level of the transaction.
pub fn isolation_level(mut self, isolation_level: IsolationLevel) -> Self {
self.builder = self.builder.isolation_level(isolation_level);
self
}
/// Sets the access mode of the transaction.
pub fn read_only(mut self, read_only: bool) -> Self {
self.builder = self.builder.read_only(read_only);
self
}
/// Sets the deferrability of the transaction.
///
/// If the transaction is also serializable and read only, creation of the transaction may block, but when it
/// completes the transaction is able to run with less overhead and a guarantee that it will not be aborted due to
/// serialization failure.
pub fn deferrable(mut self, deferrable: bool) -> Self {
self.builder = self.builder.deferrable(deferrable);
self
}
/// Begins the transaction.
///
/// The transaction will roll back by default - use the `commit` method to commit it.
pub fn start(mut self) -> Result<Transaction<'a>, Error> {
let transaction = self.connection.block_on(self.builder.start())?;
Ok(Transaction::new(self.connection, transaction))
}
}