refactor(tvix/castore): use Directory struct separate from proto one r/8484

This uses our own data type to deal with Directories in the castore model.

It makes some undesired states unrepresentable, removing the need for conversions and checking in various places:

 - In the protobuf, blake3 digests could have a wrong length, as proto doesn't know fixed-size fields. We now use `B3Digest`, which makes cloning cheaper, and removes the need to do size-checking everywhere.
 - In the protobuf, we had three different lists for `files`, `symlinks` and `directories`. This was mostly a protobuf size optimization, but made interacting with them a bit awkward. This has now been replaced with a list of enums, and convenience iterators to get various nodes, and add new ones.

Change-Id: I7b92691bb06d77ff3f58a5ccea94a22c16f84f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12057
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>

4 files changed, 23 insertions, 19 deletions

diff --git a/tvix/store/src/pathinfoservice/fs/mod.rs b/tvix/store/src/pathinfoservice/fs/mod.rs
index aa64b1c01f16..664cb8bbd54e 100644
--- a/tvix/store/src/pathinfoservice/fs/mod.rs
+++ b/tvix/store/src/pathinfoservice/fs/mod.rs
@@ -1,10 +1,10 @@
 use futures::stream::BoxStream;
 use futures::StreamExt;
 use tonic::async_trait;
+use tvix_castore::directoryservice::Node;
 use tvix_castore::fs::{RootNodes, TvixStoreFs};
-use tvix_castore::proto as castorepb;
-use tvix_castore::Error;
 use tvix_castore::{blobservice::BlobService, directoryservice::DirectoryService};
+use tvix_castore::{Error, ValidateNodeError};
 
 use super::PathInfoService;
 
@@ -48,7 +48,7 @@ impl<T> RootNodes for RootNodesWrapper<T>
 where
     T: AsRef<dyn PathInfoService> + Send + Sync,
 {
-    async fn get_by_basename(&self, name: &[u8]) -> Result<Option<castorepb::node::Node>, Error> {
+    async fn get_by_basename(&self, name: &[u8]) -> Result<Option<Node>, Error> {
         let Ok(store_path) = nix_compat::store_path::StorePath::from_bytes(name) else {
             return Ok(None);
         };
@@ -61,20 +61,23 @@ where
             .map(|path_info| {
                 path_info
                     .node
+                    .as_ref()
                     .expect("missing root node")
-                    .node
-                    .expect("empty node")
-            }))
+                    .try_into()
+                    .map_err(|e: ValidateNodeError| Error::StorageError(e.to_string()))
+            })
+            .transpose()?)
     }
 
-    fn list(&self) -> BoxStream<Result<castorepb::node::Node, Error>> {
+    fn list(&self) -> BoxStream<Result<Node, Error>> {
         Box::pin(self.0.as_ref().list().map(|result| {
-            result.map(|path_info| {
+            result.and_then(|path_info| {
                 path_info
                     .node
+                    .as_ref()
                     .expect("missing root node")
-                    .node
-                    .expect("empty node")
+                    .try_into()
+                    .map_err(|e: ValidateNodeError| Error::StorageError(e.to_string()))
             })
         }))
     }
diff --git a/tvix/store/src/pathinfoservice/grpc.rs b/tvix/store/src/pathinfoservice/grpc.rs
index 2ac0e43303cb..1ba1279ec626 100644
--- a/tvix/store/src/pathinfoservice/grpc.rs
+++ b/tvix/store/src/pathinfoservice/grpc.rs
@@ -11,7 +11,8 @@ use tonic::{async_trait, Code};
 use tracing::{instrument, Span};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
 use tvix_castore::composition::{CompositionContext, ServiceBuilder};
-use tvix_castore::{proto as castorepb, Error};
+use tvix_castore::directoryservice::Node;
+use tvix_castore::Error;
 
 /// Connects to a (remote) tvix-store PathInfoService over gRPC.
 #[derive(Clone)]
@@ -123,10 +124,7 @@ where
     T::Future: Send,
 {
     #[instrument(level = "trace", skip_all, fields(root_node = ?root_node, indicatif.pb_show=1))]
-    async fn calculate_nar(
-        &self,
-        root_node: &castorepb::node::Node,
-    ) -> Result<(u64, [u8; 32]), Error> {
+    async fn calculate_nar(&self, root_node: &Node) -> Result<(u64, [u8; 32]), Error> {
         let span = Span::current();
         span.pb_set_message("Waiting for NAR calculation");
         span.pb_start();
@@ -134,8 +132,8 @@ where
         let path_info = self
             .grpc_client
             .clone()
-            .calculate_nar(castorepb::Node {
-                node: Some(root_node.clone()),
+            .calculate_nar(tvix_castore::proto::Node {
+                node: Some(root_node.into()),
             })
             .await
             .map_err(|e| Error::StorageError(e.to_string()))?
diff --git a/tvix/store/src/pathinfoservice/lru.rs b/tvix/store/src/pathinfoservice/lru.rs
index 39c592bc96fb..5d808cd988aa 100644
--- a/tvix/store/src/pathinfoservice/lru.rs
+++ b/tvix/store/src/pathinfoservice/lru.rs
@@ -109,7 +109,10 @@ mod test {
             let root_node = p.node.as_mut().unwrap();
             if let castorepb::Node { node: Some(node) } = root_node {
                 let n = node.to_owned();
-                *node = n.rename("11111111111111111111111111111111-dummy2".into());
+                *node = (&tvix_castore::directoryservice::Node::try_from(&n)
+                    .unwrap()
+                    .rename("11111111111111111111111111111111-dummy2".into()))
+                    .into();
             } else {
                 unreachable!()
             }
diff --git a/tvix/store/src/pathinfoservice/nix_http.rs b/tvix/store/src/pathinfoservice/nix_http.rs
index a2756033172f..c10b97857ea1 100644
--- a/tvix/store/src/pathinfoservice/nix_http.rs
+++ b/tvix/store/src/pathinfoservice/nix_http.rs
@@ -230,7 +230,7 @@ where
         Ok(Some(PathInfo {
             node: Some(castorepb::Node {
                 // set the name of the root node to the digest-name of the store path.
-                node: Some(root_node.rename(narinfo.store_path.to_string().to_owned().into())),
+                node: Some((&root_node.rename(narinfo.store_path.to_string().into())).into()),
             }),
             references: pathinfo.references,
             narinfo: pathinfo.narinfo,