Struct ConnectionPool

pub struct ConnectionPool<DB>
where
    DB: DbMarker,
{ /* private fields */ }

Pool of reusable database connections.

Implementations

impl<DB> ConnectionPool<DB>

where DB: DbMarker,

pub fn global_config() -> &'static GlobalConnectionPoolConfig

Returns a reference to the global configuration parameters applied for all DB pools. For consistency, these parameters should be changed early in the app life cycle.

pub async fn test_pool() -> ConnectionPool<DB>

Creates a test pool with a reasonably large number of connections.

Test pools trace their active connections. If acquiring a connection fails (e.g., with a timeout), the returned error will contain information on all active connections.

pub async fn constrained_test_pool(connections: u32) -> ConnectionPool<DB>

Same as Self::test_pool(), but with a configurable number of connections. This is useful to test behavior of components that rely on singleton / constrained pools in production.

pub fn builder( database_url: SensitiveUrl, max_pool_size: u32, ) -> ConnectionPoolBuilder<DB>

Initializes a builder for connection pools.

pub fn singleton(database_url: SensitiveUrl) -> ConnectionPoolBuilder<DB>

Initializes a builder for connection pools with a single connection. This is equivalent to calling Self::builder(db_url, 1).

pub fn database_url(&self) -> &SensitiveUrl

Returns database URL for this pool. It may include authentication info, so be mindful of outputting it into logs etc.

pub fn max_size(&self) -> u32

Returns the maximum number of connections in this pool specified during its creation. This number may be distinct from the current number of connections in the pool (including idle ones).

pub async fn connection(&self) -> Result<Connection<'_, DB>, DalError>

Creates a Connection entity over a recoverable connection. Upon a database outage connection will block the thread until it will be able to recover the connection (or, if connection cannot be restored after several retries, this will be considered as irrecoverable database error and result in panic).

This method is intended to be used in crucial contexts, where the database access is must-have (e.g. block committer).

pub fn connection_tagged( &self, requester: &'static str, ) -> impl Future<Output = Result<Connection<'_, DB>, DalError>>

A version of connection that would also expose the duration of the connection acquisition tagged to the requester name. It also tracks the caller location for the purposes of logging (e.g., long-living connections) and debugging (when used with a test connection pool).

WARN: This method should not be used if it will result in too many time series (e.g. from witness generators or provers), otherwise Prometheus won’t be able to handle it.

Trait Implementations

impl<DB> Clone for ConnectionPool<DB>

where DB: Clone + DbMarker,

fn clone(&self) -> ConnectionPool<DB>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<DB> Debug for ConnectionPool<DB>

where DB: DbMarker,

fn fmt(&self, formatter: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.