refactor(tvix/store): use strictly typed PathInfo struct r/8787

This switches the PathInfoService trait from using the proto-derived
PathInfo struct to a more restrictive struct, and updates all
implementations to use it.

It removes a lot of the previous conversion and checks, as invalid
states became nonrepresentable, and validations are expressed on the
type level.

PathInfoService implementations consuming protobuf need to convert and
do the verification internally, and can only return the strongly typed
variant.

The nix_compat::narinfo::NarInfo conversions for the proto PathInfo
are removed, we only keep a version showing a NarInfo representation for
the strong struct.

Converting back to a PathInfo requires the root node now, but is
otherwise trivial, so left to the users.

Co-Authored-By: Florian Klink <flokli@flokli.de>
Change-Id: I6fdfdb44063efebb44a8f0097b6b81a828717e03
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12588
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

1 files changed, 12 insertions, 11 deletions

diff --git a/tvix/store/src/pathinfoservice/combinators.rs b/tvix/store/src/pathinfoservice/combinators.rs
index bb5595f72b10..1f413cf310a2 100644
--- a/tvix/store/src/pathinfoservice/combinators.rs
+++ b/tvix/store/src/pathinfoservice/combinators.rs
@@ -1,6 +1,5 @@
 use std::sync::Arc;
 
-use crate::proto::PathInfo;
 use futures::stream::BoxStream;
 use nix_compat::nixbase32;
 use tonic::async_trait;
@@ -8,7 +7,7 @@ use tracing::{debug, instrument};
 use tvix_castore::composition::{CompositionContext, ServiceBuilder};
 use tvix_castore::Error;
 
-use super::PathInfoService;
+use super::{PathInfo, PathInfoService};
 
 /// Asks near first, if not found, asks far.
 /// If found in there, returns it, and *inserts* it into
@@ -105,11 +104,9 @@ mod test {
 
     use crate::{
         pathinfoservice::{LruPathInfoService, MemoryPathInfoService, PathInfoService},
-        tests::fixtures::PATH_INFO_WITH_NARINFO,
+        tests::fixtures::PATH_INFO,
     };
 
-    const PATH_INFO_DIGEST: [u8; 20] = [0; 20];
-
     /// Helper function setting up an instance of a "far" and "near"
     /// PathInfoService.
     async fn create_pathinfoservice() -> super::Cache<LruPathInfoService, MemoryPathInfoService> {
@@ -129,21 +126,25 @@ mod test {
         let svc = create_pathinfoservice().await;
 
         // query the PathInfo, things should not be there.
-        assert!(svc.get(PATH_INFO_DIGEST).await.unwrap().is_none());
+        assert!(svc
+            .get(*PATH_INFO.store_path.digest())
+            .await
+            .unwrap()
+            .is_none());
 
         // insert it into the far one.
-        svc.far.put(PATH_INFO_WITH_NARINFO.clone()).await.unwrap();
+        svc.far.put(PATH_INFO.clone()).await.unwrap();
 
         // now try getting it again, it should succeed.
         assert_eq!(
-            Some(PATH_INFO_WITH_NARINFO.clone()),
-            svc.get(PATH_INFO_DIGEST).await.unwrap()
+            Some(PATH_INFO.clone()),
+            svc.get(*PATH_INFO.store_path.digest()).await.unwrap()
         );
 
         // peek near, it should now be there.
         assert_eq!(
-            Some(PATH_INFO_WITH_NARINFO.clone()),
-            svc.near.get(PATH_INFO_DIGEST).await.unwrap()
+            Some(PATH_INFO.clone()),
+            svc.near.get(*PATH_INFO.store_path.digest()).await.unwrap()
         );
     }
 }