Plume/plume-models/src/db_conn.rs
Kitaiti Makoto 4df2c3e6f6 Clippy
2023-01-03 02:53:12 +09:00

76 lines
2.4 KiB
Rust

use crate::Connection;
use diesel::r2d2::{
ConnectionManager, CustomizeConnection, Error as ConnError, Pool, PooledConnection,
};
#[cfg(feature = "sqlite")]
use diesel::{dsl::sql_query, ConnectionError, RunQueryDsl};
use rocket::{
http::Status,
request::{self, FromRequest},
Outcome, Request, State,
};
use std::ops::Deref;
pub type DbPool = Pool<ConnectionManager<Connection>>;
// From rocket documentation
// Connection request guard type: a wrapper around an r2d2 pooled connection.
pub struct DbConn(pub PooledConnection<ConnectionManager<Connection>>);
/// Attempts to retrieve a single connection from the managed database pool. If
/// no pool is currently managed, fails with an `InternalServerError` status. If
/// no connections are available, fails with a `ServiceUnavailable` status.
impl<'a, 'r> FromRequest<'a, 'r> for DbConn {
type Error = ();
fn from_request(request: &'a Request<'r>) -> request::Outcome<Self, Self::Error> {
let pool = request.guard::<State<'_, DbPool>>()?;
match pool.get() {
Ok(conn) => Outcome::Success(DbConn(conn)),
Err(_) => Outcome::Failure((Status::ServiceUnavailable, ())),
}
}
}
// For the convenience of using an &DbConn as an &Connection.
impl Deref for DbConn {
type Target = Connection;
fn deref(&self) -> &Self::Target {
&self.0
}
}
// Execute a pragma for every new sqlite connection
#[derive(Debug)]
pub struct PragmaForeignKey;
impl CustomizeConnection<Connection, ConnError> for PragmaForeignKey {
#[cfg(feature = "sqlite")] // will default to an empty function for postgres
fn on_acquire(&self, conn: &mut Connection) -> Result<(), ConnError> {
sql_query("PRAGMA foreign_keys = on;")
.execute(conn)
.map(|_| ())
.map_err(|_| {
ConnError::ConnectionError(ConnectionError::BadConnection(String::from(
"PRAGMA foreign_keys = on failed",
)))
})
}
}
#[cfg(test)]
pub(crate) mod tests {
use super::*;
use diesel::Connection as _;
#[derive(Debug)]
pub struct TestConnectionCustomizer;
impl CustomizeConnection<Connection, ConnError> for TestConnectionCustomizer {
fn on_acquire(&self, conn: &mut Connection) -> Result<(), ConnError> {
PragmaForeignKey.on_acquire(conn)?;
conn.begin_test_transaction().unwrap();
Ok(())
}
}
}