A trait which provides connection-specific functionality.
type Connection: Send + 'static
The connection type this manager deals with.
The error type returned by
fn connect(&self) -> Result<Self::Connection, Self::Error>
Attempts to create a new connection.
fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error>
Determines if the connection is still connected to the database.
A standard implementation would check if a simple query like
fn has_broken(&self, conn: &mut Self::Connection) -> bool
Quickly determines if the connection is no longer usable.
This will be called synchronously every time a connection is returned
to the pool, so it should not block. If it returns
connection will be discarded.
For example, an implementation might check if the underlying TCP socket
has disconnected. Implementations that do not support this kind of
fast health check may simply return