1use std::{2 ffi::OsString,3 sync::{Arc, OnceLock},4};56use r2d2::Pool;78use crate::{Error, NixSession, Result, session::NixSessionInner};910pub struct NixSessionPool(Pool<NixSessionPoolInner>);11impl NixSessionPool {12 pub async fn new(13 flake: OsString,14 nix_args: Vec<OsString>,15 nix_system: String,16 fail_fast: bool,17 ) -> Result<Self> {18 let inner = tokio::task::block_in_place(|| {19 r2d2::Builder::<NixSessionPoolInner>::new()20 .min_idle(Some(0))21 .build(NixSessionPoolInner {22 flake,23 nix_args,24 nix_system,25 fail_fast,26 })27 })?;28 Ok(Self(inner))29 }30 pub async fn get(&self) -> Result<NixSession> {31 let v = tokio::task::block_in_place(|| self.0.get())?;32 Ok(NixSession(Arc::new(tokio::sync::Mutex::new(v))))33 }34}3536pub(crate) struct NixSessionPoolInner {37 flake: OsString,38 nix_args: Vec<OsString>,39 fail_fast: bool,40 pub(crate) nix_system: String,41}4243impl r2d2::ManageConnection for NixSessionPoolInner {44 type Connection = NixSessionInner;45 type Error = Error;46 fn connect(&self) -> std::result::Result<Self::Connection, Self::Error> {47 let _v = TOKIO_RUNTIME48 .get()49 .expect("missed tokio runtime init!")50 .enter();51 futures::executor::block_on(NixSessionInner::new(52 self.flake.as_os_str(),53 self.nix_args.iter().map(OsString::as_os_str),54 self.nix_system.clone(),55 self.fail_fast,56 ))57 }5859 fn is_valid(&self, conn: &mut Self::Connection) -> std::result::Result<(), Self::Error> {60 let _v = TOKIO_RUNTIME61 .get()62 .expect("missed tokio runtime init!")63 .enter();64 let res = futures::executor::block_on(conn.execute_expression_number("2 + 2"))?;65 if res != 4 {66 67 return Err(Error::SessionInit("misbehaving session"));68 };69 Ok(())70 }7172 fn has_broken(&self, _conn: &mut Self::Connection) -> bool {73 false74 }75}76pub static TOKIO_RUNTIME: OnceLock<tokio::runtime::Handle> = OnceLock::new();