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>

2 files changed, 7 insertions, 13 deletions

diff --git a/tvix/store/src/proto/grpc_blobservice_wrapper.rs b/tvix/store/src/proto/grpc_blobservice_wrapper.rs
index 3ec1d68872..066790daf3 100644
--- a/tvix/store/src/proto/grpc_blobservice_wrapper.rs
+++ b/tvix/store/src/proto/grpc_blobservice_wrapper.rs
@@ -1,7 +1,5 @@
 use crate::{
-    blobservice::{BlobService, BlobWriter},
-    proto::sync_read_into_async_read::SyncReadIntoAsyncRead,
-    B3Digest,
+    blobservice::BlobService, proto::sync_read_into_async_read::SyncReadIntoAsyncRead, B3Digest,
 };
 use std::{collections::VecDeque, io, pin::Pin};
 use tokio::task;
@@ -10,12 +8,12 @@ use tokio_util::io::ReaderStream;
 use tonic::{async_trait, Request, Response, Status, Streaming};
 use tracing::{instrument, warn};
 
-pub struct GRPCBlobServiceWrapper<BS: BlobService> {
-    blob_service: BS,
+pub struct GRPCBlobServiceWrapper {
+    blob_service: Box<dyn BlobService>,
 }
 
-impl<BS: BlobService> From<BS> for GRPCBlobServiceWrapper<BS> {
-    fn from(value: BS) -> Self {
+impl From<Box<dyn BlobService + 'static>> for GRPCBlobServiceWrapper {
+    fn from(value: Box<dyn BlobService>) -> Self {
         Self {
             blob_service: value,
         }
@@ -23,9 +21,7 @@ impl<BS: BlobService> From<BS> for GRPCBlobServiceWrapper<BS> {
 }
 
 #[async_trait]
-impl<BS: BlobService + Send + Sync + Clone + 'static> super::blob_service_server::BlobService
-    for GRPCBlobServiceWrapper<BS>
-{
+impl super::blob_service_server::BlobService for GRPCBlobServiceWrapper {
     // https://github.com/tokio-rs/tokio/issues/2723#issuecomment-1534723933
     type ReadStream =
         Pin<Box<dyn futures::Stream<Item = Result<super::BlobChunk, Status>> + Send + 'static>>;
diff --git a/tvix/store/src/proto/tests/grpc_blobservice.rs b/tvix/store/src/proto/tests/grpc_blobservice.rs
index 02e04e7d72..2f18ea4abb 100644
--- a/tvix/store/src/proto/tests/grpc_blobservice.rs
+++ b/tvix/store/src/proto/tests/grpc_blobservice.rs
@@ -1,12 +1,10 @@
-use crate::blobservice::BlobService;
 use crate::proto::blob_service_server::BlobService as GRPCBlobService;
 use crate::proto::{BlobChunk, GRPCBlobServiceWrapper, ReadBlobRequest, StatBlobRequest};
 use crate::tests::fixtures::{BLOB_A, BLOB_A_DIGEST};
 use crate::tests::utils::gen_blob_service;
 use tokio_stream::StreamExt;
 
-fn gen_grpc_blob_service(
-) -> GRPCBlobServiceWrapper<impl BlobService + Send + Sync + Clone + 'static> {
+fn gen_grpc_blob_service() -> GRPCBlobServiceWrapper {
     let blob_service = gen_blob_service();
     GRPCBlobServiceWrapper::from(blob_service)
 }