refactor(tvix): remove usage of async-recursion r/8082

Rust 1.77 supports async recursion as long as there is some form of
indirection (ie. `Box::pin`). This removes the need to use the
async-recursion crate.

Change-Id: Ic9613ab7f32016f0103032a861edff92e2fb8b41
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11596
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI

3 files changed, 17 insertions, 13 deletions

diff --git a/tvix/store/Cargo.toml b/tvix/store/Cargo.toml
index 7034a95f3808..f82cdef30077 100644
--- a/tvix/store/Cargo.toml
+++ b/tvix/store/Cargo.toml
@@ -40,7 +40,6 @@ tracing-subscriber = { version = "0.3.16", features = ["env-filter", "json"] }
 tvix-castore = { path = "../castore" }
 url = "2.4.0"
 walkdir = "2.4.0"
-async-recursion = "1.0.5"
 reqwest = { version = "0.11.22", features = ["rustls-tls-native-roots", "stream"], default-features = false }
 
 [dependencies.tonic-reflection]
diff --git a/tvix/store/src/nar/import.rs b/tvix/store/src/nar/import.rs
index bfb65629e6b6..cc62c1a4e902 100644
--- a/tvix/store/src/nar/import.rs
+++ b/tvix/store/src/nar/import.rs
@@ -1,4 +1,3 @@
-use async_recursion::async_recursion;
 use nix_compat::nar::reader::r#async as nar_reader;
 use tokio::{io::AsyncBufRead, sync::mpsc, try_join};
 use tvix_castore::{
@@ -54,10 +53,9 @@ where
     Ok(node.rename("".into()))
 }
 
-#[async_recursion]
-async fn produce_nar_inner<'a: 'async_recursion, 'r: 'async_recursion, BS>(
+async fn produce_nar_inner<BS>(
     blob_service: BS,
-    node: nar_reader::Node<'a, 'r>,
+    node: nar_reader::Node<'_, '_>,
     path: PathBuf,
     tx: mpsc::Sender<Result<IngestionEntry, Error>>,
 ) -> Result<IngestionEntry, Error>
@@ -93,8 +91,13 @@ where
                 path.try_push(&entry.name)
                     .expect("Tvix bug: failed to join name");
 
-                let entry =
-                    produce_nar_inner(blob_service.clone(), entry.node, path, tx.clone()).await?;
+                let entry = Box::pin(produce_nar_inner(
+                    blob_service.clone(),
+                    entry.node,
+                    path,
+                    tx.clone(),
+                ))
+                .await?;
 
                 tx.send(Ok(entry)).await.map_err(|e| {
                     Error::IO(std::io::Error::new(std::io::ErrorKind::BrokenPipe, e))
diff --git a/tvix/store/src/nar/renderer.rs b/tvix/store/src/nar/renderer.rs
index 0816b8e973c7..3b39f700bd38 100644
--- a/tvix/store/src/nar/renderer.rs
+++ b/tvix/store/src/nar/renderer.rs
@@ -1,7 +1,6 @@
 use crate::utils::AsyncIoBridge;
 
 use super::RenderError;
-use async_recursion::async_recursion;
 use count_write::CountWrite;
 use nix_compat::nar::writer::r#async as nar_writer;
 use sha2::{Digest, Sha256};
@@ -72,9 +71,8 @@ where
 
 /// Process an intermediate node in the structure.
 /// This consumes the node.
-#[async_recursion]
 async fn walk_node<BS, DS>(
-    nar_node: nar_writer::Node<'async_recursion, '_>,
+    nar_node: nar_writer::Node<'_, '_>,
     proto_node: &castorepb::node::Node,
     blob_service: BS,
     directory_service: DS,
@@ -164,9 +162,13 @@ where
                             .await
                             .map_err(RenderError::NARWriterError)?;
 
-                        (blob_service, directory_service) =
-                            walk_node(child_node, &proto_node, blob_service, directory_service)
-                                .await?;
+                        (blob_service, directory_service) = Box::pin(walk_node(
+                            child_node,
+                            &proto_node,
+                            blob_service,
+                            directory_service,
+                        ))
+                        .await?;
                     }
 
                     // close the directory