1use std::{2 ffi::OsString,3 sync::{Arc, OnceLock},4};56use r2d2::Pool;78use crate::{session::NixSessionInner, Error, NixSession, Result};910pub struct NixSessionPool(Pool<NixSessionPoolInner>);11impl NixSessionPool {12 pub async fn new(flake: OsString, nix_args: Vec<OsString>, nix_system: String) -> Result<Self> {13 let inner = tokio::task::block_in_place(|| {14 r2d2::Builder::<NixSessionPoolInner>::new()15 .min_idle(Some(0))16 .build(NixSessionPoolInner {17 flake,18 nix_args,19 nix_system,20 })21 })?;22 Ok(Self(inner))23 }24 pub async fn get(&self) -> Result<NixSession> {25 let v = tokio::task::block_in_place(|| self.0.get())?;26 Ok(NixSession(Arc::new(tokio::sync::Mutex::new(v))))27 }28}2930pub(crate) struct NixSessionPoolInner {31 flake: OsString,32 nix_args: Vec<OsString>,33 pub(crate) nix_system: String,34}3536impl r2d2::ManageConnection for NixSessionPoolInner {37 type Connection = NixSessionInner;38 type Error = Error;39 fn connect(&self) -> std::result::Result<Self::Connection, Self::Error> {40 let _v = TOKIO_RUNTIME41 .get()42 .expect("missed tokio runtime init!")43 .enter();44 Ok(futures::executor::block_on(NixSessionInner::new(45 self.flake.as_os_str(),46 self.nix_args.iter().map(OsString::as_os_str),47 self.nix_system.clone(),48 ))?)49 }5051 fn is_valid(&self, conn: &mut Self::Connection) -> std::result::Result<(), Self::Error> {52 let _v = TOKIO_RUNTIME53 .get()54 .expect("missed tokio runtime init!")55 .enter();56 let res = futures::executor::block_on(conn.execute_expression_number("2 + 2"))?;57 if res != 4 {58 59 return Err(Error::SessionInit("misbehaving session"));60 };61 Ok(())62 }6364 fn has_broken(&self, _conn: &mut Self::Connection) -> bool {65 false66 }67}68pub static TOKIO_RUNTIME: OnceLock<tokio::runtime::Handle> = OnceLock::new();