feat(tvix/store): eliminate generics in BlobStore r/6269

To construct various stores at runtime, we need to eliminate associated
types from the BlobService trait, and return Box<dyn …> instead of
specific types.

This also means we can't consume self in the close() method, so
everything we write to is put in an Option<>, and during the first close
we take from there.

Change-Id: Ia523b6ab2f2a5276f51cb5d17e81a5925bce69b6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8647
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

1 files changed, 4 insertions, 5 deletions

diff --git a/tvix/store/src/nar/renderer.rs b/tvix/store/src/nar/renderer.rs
index c10f2ddf52fa..a9a6d989e1b8 100644
--- a/tvix/store/src/nar/renderer.rs
+++ b/tvix/store/src/nar/renderer.rs
@@ -11,14 +11,13 @@ use tracing::warn;
 
 /// A NAR renderer, using a blob_service, chunk_service and directory_service
 /// to render a NAR to a writer.
-#[derive(Clone)]
-pub struct NARRenderer<BS: BlobService, DS: DirectoryService> {
-    blob_service: BS,
+pub struct NARRenderer<DS: DirectoryService> {
+    blob_service: Box<dyn BlobService>,
     directory_service: DS,
 }
 
-impl<BS: BlobService, DS: DirectoryService> NARRenderer<BS, DS> {
-    pub fn new(blob_service: BS, directory_service: DS) -> Self {
+impl<DS: DirectoryService> NARRenderer<DS> {
+    pub fn new(blob_service: Box<dyn BlobService>, directory_service: DS) -> Self {
         Self {
             blob_service,
             directory_service,