diesel_async/pooled_connection/
mobc.rs

1//! A pool implementation for `diesel-async` based on [`mobc`]
2//!
3//! ```rust
4//! # include!("../doctest_setup.rs");
5//! use diesel::result::Error;
6//! use futures_util::FutureExt;
7//! use diesel_async::pooled_connection::AsyncDieselConnectionManager;
8//! use diesel_async::pooled_connection::mobc::Pool;
9//! use diesel_async::{RunQueryDsl, AsyncConnection};
10//!
11//! # #[tokio::main(flavor = "current_thread")]
12//! # async fn main() {
13//! #     run_test().await.unwrap();
14//! # }
15//! #
16//! # #[cfg(feature = "postgres")]
17//! # fn get_config() -> AsyncDieselConnectionManager<diesel_async::AsyncPgConnection> {
18//! #     let db_url = database_url_from_env("PG_DATABASE_URL");
19//! let config = AsyncDieselConnectionManager::<diesel_async::AsyncPgConnection>::new(db_url);
20//! #     config
21//! #  }
22//! #
23//! # #[cfg(feature = "mysql")]
24//! # fn get_config() -> AsyncDieselConnectionManager<diesel_async::AsyncMysqlConnection> {
25//! #     let db_url = database_url_from_env("MYSQL_DATABASE_URL");
26//! #    let config = AsyncDieselConnectionManager::<diesel_async::AsyncMysqlConnection>::new(db_url);
27//! #     config
28//! #  }
29//! #
30//! # #[cfg(feature = "sqlite")]
31//! # fn get_config() -> AsyncDieselConnectionManager<diesel_async::sync_connection_wrapper::SyncConnectionWrapper<diesel::SqliteConnection>> {
32//! #     let db_url = database_url_from_env("SQLITE_DATABASE_URL");
33//! #     let config = AsyncDieselConnectionManager::<diesel_async::sync_connection_wrapper::SyncConnectionWrapper<diesel::SqliteConnection>>::new(db_url);
34//! #     config
35//! # }
36//! #
37//! # async fn run_test() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
38//! #     use schema::users::dsl::*;
39//! #     let config = get_config();
40//! # #[cfg(feature = "postgres")]
41//! let pool: Pool<AsyncPgConnection> = Pool::new(config);
42//! # #[cfg(not(feature = "postgres"))]
43//! # let pool = Pool::new(config);
44//! let mut conn = pool.get().await?;
45//! # conn.begin_test_transaction();
46//! # create_tables(&mut conn).await;
47//! # conn.begin_test_transaction();
48//! let res = users.load::<(i32, String)>(&mut conn).await?;
49//! #     Ok(())
50//! # }
51//! ```
52use super::{AsyncDieselConnectionManager, PoolError, PoolableConnection};
53use diesel::query_builder::QueryFragment;
54use mobc::Manager;
55
56/// Type alias for using [`mobc::Pool`] with [`diesel-async`]
57///
58///
59/// This is **not** equal to [`mobc::Pool`]. It already uses the correct
60/// connection manager and expects only the connection type as generic argument
61pub type Pool<C> = mobc::Pool<AsyncDieselConnectionManager<C>>;
62
63/// Type alias for using [`mobc::Connection`] with [`diesel-async`]
64pub type PooledConnection<C> = mobc::Connection<AsyncDieselConnectionManager<C>>;
65
66/// Type alias for using [`mobc::Builder`] with [`diesel-async`]
67pub type Builder<C> = mobc::Builder<AsyncDieselConnectionManager<C>>;
68
69#[async_trait::async_trait]
70impl<C> Manager for AsyncDieselConnectionManager<C>
71where
72    C: PoolableConnection + 'static,
73    diesel::dsl::select<diesel::dsl::AsExprOf<i32, diesel::sql_types::Integer>>:
74        crate::methods::ExecuteDsl<C>,
75    diesel::query_builder::SqlQuery: QueryFragment<C::Backend>,
76{
77    type Connection = C;
78
79    type Error = PoolError;
80
81    async fn connect(&self) -> Result<Self::Connection, Self::Error> {
82        (self.manager_config.custom_setup)(&self.connection_url)
83            .await
84            .map_err(PoolError::ConnectionError)
85    }
86
87    async fn check(&self, mut conn: Self::Connection) -> Result<Self::Connection, Self::Error> {
88        conn.ping(&self.manager_config.recycling_method)
89            .await
90            .map_err(PoolError::QueryError)?;
91        Ok(conn)
92    }
93}
diesel_async/pooled_connection/mobc.rs

diesel_async/pooled_connection/
mobc.rs
