Crate deadpool_r2d2

Deadpool for R2D2 Managers

Deadpool is a dead simple async pool for connections and objects of any type.

This crate implements a deadpool manager for r2d2 managers.

Features

Feature	Description	Extra dependencies	Default
rt_tokio_1	Enable support for tokio crate	deadpool/rt_tokio_1	yes
rt_async-std_1	Enable support for async-std crate	deadpool/rt_async-std_1	no
serde	Enable support for serde crate	deadpool/serde	no
tracing	Enable support for tracing by propagating Spans in the interact() calls. Enable this if you use the tracing crate and you want to get useful traces from within interact() calls.	deadpool-sync/tracing, tracing	no

Example

use std::env;

use deadpool_r2d2::Runtime;
use r2d2_postgres::postgres::Error as PgError;

type PgManager = deadpool_r2d2::Manager<
    r2d2_postgres::PostgresConnectionManager<r2d2_postgres::postgres::NoTls>,
>;
type PgPool = deadpool_r2d2::Pool<PgManager>;

fn create_pool(max_size: usize) -> PgPool {
    let mut pg_config = r2d2_postgres::postgres::Config::new();
    pg_config.host(&env::var("PG__HOST").unwrap());
    pg_config.user(&env::var("PG__USER").unwrap());
    pg_config.password(&env::var("PG__PASSWORD").unwrap());
    pg_config.dbname(&env::var("PG__DBNAME").unwrap());
    let r2d2_manager =
        r2d2_postgres::PostgresConnectionManager::new(pg_config, r2d2_postgres::postgres::NoTls);
    let manager = PgManager::new(r2d2_manager, Runtime::Tokio1);
    let pool = PgPool::builder(manager)
        .max_size(max_size)
        .build()
        .unwrap();
    pool
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let pool = create_pool(2);
    let client = pool.get().await.unwrap();
    let answer: i32 = client
        .interact(|client| client.query_one("SELECT 42", &[]).map(|row| row.get(0)))
        .await??;
    assert_eq!(answer, 42);
    Ok(())
}

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Structs

• Manager
  Manager for use with r2d2 managers.
• Metrics
  Statistics regarding an object returned by the pool
• Pool
  Generic object and connection pool.
• PoolConfig
  Pool configuration.
• Status
  The current pool status.
• SyncGuard
  This guard is returned when calling SyncWrapper::lock or SyncWrapper::try_lock. This is basicly just a wrapper around a MutexGuard but hides some implementation details.
• SyncWrapper
  Wrapper for objects which only provides blocking functions that need to be called on a separate thread.
• Timeouts
  Timeouts when getting Objects from a Pool.

Enums

• InteractError
  Possible errors returned when SyncWrapper::interact() fails.
• PoolError
  Possible errors returned by Pool::get() method.
• Runtime
  Enumeration for picking a runtime implementation.