refactor(tvix/src/nar): drop NARCalculationService r/6270

There's only one way to calculate NAR files, by walking through them.

Things like caching such replies should be done closer to where we use
these, composing NARCalculationService doesn't actually give us much.

Instead, expose two functions, `nar::calculate_size_and_sha256` and
`nar::writer_nar`, the latter writing NAR to a writer, the former using
write_nar to only keeping the NAR size and digest.

Change-Id: Ie5d2cfea35470fdbb5cbf9da1136b0cdf0250266
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8723
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>

2 files changed, 30 insertions, 16 deletions

diff --git a/tvix/store/src/proto/grpc_pathinfoservice_wrapper.rs b/tvix/store/src/proto/grpc_pathinfoservice_wrapper.rs
index e82557b3a06c..c070b883fa16 100644
--- a/tvix/store/src/proto/grpc_pathinfoservice_wrapper.rs
+++ b/tvix/store/src/proto/grpc_pathinfoservice_wrapper.rs
@@ -1,19 +1,27 @@
-use crate::nar::RenderError;
+use crate::blobservice::BlobService;
+use crate::directoryservice::DirectoryService;
+use crate::nar::{calculate_size_and_sha256, RenderError};
+use crate::pathinfoservice::PathInfoService;
 use crate::proto;
-use crate::{nar::NARCalculationService, pathinfoservice::PathInfoService};
 use tonic::{async_trait, Request, Response, Result, Status};
 use tracing::{instrument, warn};
 
-pub struct GRPCPathInfoServiceWrapper<PS: PathInfoService, NS: NARCalculationService> {
+pub struct GRPCPathInfoServiceWrapper<PS: PathInfoService, DS: DirectoryService> {
     path_info_service: PS,
-    nar_calculation_service: NS,
+    blob_service: Box<dyn BlobService>,
+    directory_service: DS,
 }
 
-impl<PS: PathInfoService, NS: NARCalculationService> GRPCPathInfoServiceWrapper<PS, NS> {
-    pub fn new(path_info_service: PS, nar_calculation_service: NS) -> Self {
+impl<PS: PathInfoService, DS: DirectoryService> GRPCPathInfoServiceWrapper<PS, DS> {
+    pub fn new(
+        path_info_service: PS,
+        blob_service: Box<dyn BlobService>,
+        directory_service: DS,
+    ) -> Self {
         Self {
             path_info_service,
-            nar_calculation_service,
+            blob_service,
+            directory_service,
         }
     }
 }
@@ -21,8 +29,8 @@ impl<PS: PathInfoService, NS: NARCalculationService> GRPCPathInfoServiceWrapper<
 #[async_trait]
 impl<
         PS: PathInfoService + Send + Sync + 'static,
-        NS: NARCalculationService + Send + Sync + 'static,
-    > proto::path_info_service_server::PathInfoService for GRPCPathInfoServiceWrapper<PS, NS>
+        DS: DirectoryService + Send + Sync + Clone + 'static,
+    > proto::path_info_service_server::PathInfoService for GRPCPathInfoServiceWrapper<PS, DS>
 {
     #[instrument(skip(self))]
     async fn get(
@@ -69,13 +77,19 @@ impl<
     ) -> Result<Response<proto::CalculateNarResponse>> {
         match request.into_inner().node {
             None => Err(Status::invalid_argument("no root node sent")),
-            Some(root_node) => match self.nar_calculation_service.calculate_nar(&root_node) {
-                Ok((nar_size, nar_sha256)) => Ok(Response::new(proto::CalculateNarResponse {
+            Some(root_node) => {
+                let (nar_size, nar_sha256) = calculate_size_and_sha256(
+                    &root_node,
+                    &self.blob_service,
+                    self.directory_service.clone(),
+                )
+                .expect("error during nar calculation"); // TODO: handle error
+
+                Ok(Response::new(proto::CalculateNarResponse {
                     nar_size,
                     nar_sha256: nar_sha256.to_vec(),
-                })),
-                Err(e) => Err(e.into()),
-            },
+                }))
+            }
         }
     }
 }
diff --git a/tvix/store/src/proto/tests/grpc_pathinfoservice.rs b/tvix/store/src/proto/tests/grpc_pathinfoservice.rs
index 11cab2c264cc..dbcdc5ced056 100644
--- a/tvix/store/src/proto/tests/grpc_pathinfoservice.rs
+++ b/tvix/store/src/proto/tests/grpc_pathinfoservice.rs
@@ -1,4 +1,3 @@
-use crate::nar::NonCachingNARCalculationService;
 use crate::proto::get_path_info_request::ByWhat::ByOutputHash;
 use crate::proto::node::Node::Symlink;
 use crate::proto::path_info_service_server::PathInfoService as GRPCPathInfoService;
@@ -17,7 +16,8 @@ use tonic::Request;
 fn gen_grpc_service() -> impl GRPCPathInfoService {
     GRPCPathInfoServiceWrapper::new(
         gen_pathinfo_service(),
-        NonCachingNARCalculationService::new(gen_blob_service(), gen_directory_service()),
+        gen_blob_service(),
+        gen_directory_service(),
     )
 }