Trait warpgrapher::engine::database::DatabasePool
source · [−]pub trait DatabasePool: Clone + Sync + Send {
type TransactionType: Transaction;
fn read_transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>>
where
'life0: 'async_trait,
Self: 'async_trait;
fn transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>>
where
'life0: 'async_trait,
Self: 'async_trait;
}
Expand description
Trait for a database pool. Structs that implement this trait are created by a database endpoint and provide a way to get a transaction from the pool.
Associated Types
Required methods
fn read_transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>> where
'life0: 'async_trait,
Self: 'async_trait,
fn read_transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>> where
'life0: 'async_trait,
Self: 'async_trait,
Returns a Transaction
for the database for which this DatabasePool has connections. If
the database types offers specific read replicas, such as AWS Neptune, the connection is to
a read replica. If no separate read replicas are offered, the connection is to the same
endpoint that serves read/write requests.
Errors
Returns an Error
if the transaction cannot be created. The specific Error
variant
depends on the database back-end.
Examples
let endpoint = CypherEndpoint::from_env()?;
let pool = endpoint.pool().await?;
let transaction = pool.read_transaction().await?;
fn transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>> where
'life0: 'async_trait,
Self: 'async_trait,
fn transaction<'life0, 'async_trait>(
&'life0 self
) -> Pin<Box<dyn Future<Output = Result<Self::TransactionType, Error>> + Send + 'async_trait>> where
'life0: 'async_trait,
Self: 'async_trait,
Returns a Transaction
for the database for which this DatabasePool has connections
Errors
Returns an Error
if the transaction cannot be created. The specific Error
variant
depends on the database back-end.
Examples
let endpoint = CypherEndpoint::from_env()?;
let pool = endpoint.pool().await?;
let transaction = pool.transaction().await?;