Swim

A generic connection pool with Tokio support.

Inspired by a Mobc rewrite that never happened.

This connection pool is lock free and uses a single-thread event loop instead. It seems to have a much better performance.

Example

use swim::{Pool, PoolConfig};

#[tokio::main]
async fn main() {
    let manager = FooConnectionManager::new("foo://localhost:0000"); // Imaginary "foo" DB.
    let pool = Pool::new(manager, PoolConfig::default().max_open(50));

    for i in 0..20 {
        let pool = pool.clone();
        tokio::spawn(async move {
            let client = pool.get().await.unwrap();
            // use the connection
            // it will be returned to the pool when it falls out of scope.
        });
    }
}

Config

The config must be passed to the pool upon creation. It comes with default params that can be changed through a fluent API.

let config = PoolConfig::default()
  .max_open(20)
  .cleanup_rate(Duration::from_secs(5 * 60));

Param	Type	Description	Default
max_open	u16	Maximum number of connections managed by the pool. Defaults to 10.
max_idle	Option<u16>	Maximum idle connection count maintained by the pool.	None, meaning reuse forever
max_lifetime	Option<Duration>	Maximum lifetime of connections in the pool.	None, meaning reuse forever
idle_timeout	Option<Duration>	Maximum lifetime of idle connections in the pool.	5min
cleanup_rate	Duration	Rate at which a connection cleanup is scheduled.	60sec
test_on_check_out	bool	Check the connection before returning it to the client.	false
get_timeout	Duration	Maximum time to wait for a connection to become available before returning an error.	30sec