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>

1 files changed, 25 insertions, 42 deletions

diff --git a/tvix/glue/src/tvix_store_io.rs b/tvix/glue/src/tvix_store_io.rs
index 54e3550fc940..c92a9c57e0c7 100644
--- a/tvix/glue/src/tvix_store_io.rs
+++ b/tvix/glue/src/tvix_store_io.rs
@@ -15,15 +15,12 @@ use tokio_util::io::SyncIoBridge;
 use tracing::{error, instrument, warn, Level, Span};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
 use tvix_build::buildservice::BuildService;
-use tvix_castore::proto::node::Node;
 use tvix_eval::{EvalIO, FileType, StdIO};
 use tvix_store::nar::NarCalculationService;
 
 use tvix_castore::{
     blobservice::BlobService,
-    directoryservice::{self, DirectoryService},
-    proto::NamedNode,
-    B3Digest,
+    directoryservice::{self, DirectoryService, NamedNode, Node},
 };
 use tvix_store::{pathinfoservice::PathInfoService, proto::PathInfo};
 
@@ -122,7 +119,12 @@ impl TvixStoreIO {
             .await?
         {
             // if we have a PathInfo, we know there will be a root_node (due to validation)
-            Some(path_info) => path_info.node.expect("no node").node.expect("no node"),
+            Some(path_info) => path_info
+                .node
+                .as_ref()
+                .expect("no node")
+                .try_into()
+                .expect("invalid node"),
             // If there's no PathInfo found, this normally means we have to
             // trigger the build (and insert into PathInfoService, after
             // reference scanning).
@@ -284,19 +286,17 @@ impl TvixStoreIO {
 
                         // For each output, insert a PathInfo.
                         for output in &build_result.outputs {
-                            let root_node = output.node.as_ref().expect("invalid root node");
+                            let root_node = output.try_into().expect("invalid root node");
 
                             // calculate the nar representation
                             let (nar_size, nar_sha256) = self
                                 .nar_calculation_service
-                                .calculate_nar(root_node)
+                                .calculate_nar(&root_node)
                                 .await?;
 
                             // assemble the PathInfo to persist
                             let path_info = PathInfo {
-                                node: Some(tvix_castore::proto::Node {
-                                    node: Some(root_node.clone()),
-                                }),
+                                node: Some((&root_node).into()),
                                 references: vec![], // TODO: refscan
                                 narinfo: Some(tvix_store::proto::NarInfo {
                                     nar_size,
@@ -332,13 +332,11 @@ impl TvixStoreIO {
                         build_result
                             .outputs
                             .into_iter()
+                            .map(|output_node| Node::try_from(&output_node).expect("invalid node"))
                             .find(|output_node| {
-                                output_node.node.as_ref().expect("invalid node").get_name()
-                                    == store_path.to_string().as_bytes()
+                                output_node.get_name() == store_path.to_string().as_bytes()
                             })
                             .expect("build didn't produce the store path")
-                            .node
-                            .expect("invalid node")
                     }
                 }
             }
@@ -460,20 +458,12 @@ impl EvalIO for TvixStoreIO {
                         ))
                     }
                     Node::File(file_node) => {
-                        let digest: B3Digest =
-                            file_node.digest.clone().try_into().map_err(|_e| {
-                                error!(
-                                    file_node = ?file_node,
-                                    "invalid digest"
-                                );
-                                io::Error::new(
-                                    io::ErrorKind::InvalidData,
-                                    format!("invalid digest length in file node: {:?}", file_node),
-                                )
-                            })?;
-
                         self.tokio_handle.block_on(async {
-                            let resp = self.blob_service.as_ref().open_read(&digest).await?;
+                            let resp = self
+                                .blob_service
+                                .as_ref()
+                                .open_read(file_node.digest())
+                                .await?;
                             match resp {
                                 Some(blob_reader) => {
                                     // The VM Response needs a sync [std::io::Reader].
@@ -482,12 +472,12 @@ impl EvalIO for TvixStoreIO {
                                 }
                                 None => {
                                     error!(
-                                        blob.digest = %digest,
+                                        blob.digest = %file_node.digest(),
                                         "blob not found",
                                     );
                                     Err(io::Error::new(
                                         io::ErrorKind::NotFound,
-                                        format!("blob {} not found", &digest),
+                                        format!("blob {} not found", &file_node.digest()),
                                     ))
                                 }
                             }
@@ -543,16 +533,7 @@ impl EvalIO for TvixStoreIO {
                 match node {
                     Node::Directory(directory_node) => {
                         // fetch the Directory itself.
-                        let digest: B3Digest =
-                            directory_node.digest.clone().try_into().map_err(|_e| {
-                                io::Error::new(
-                                    io::ErrorKind::InvalidData,
-                                    format!(
-                                        "invalid digest length in directory node: {:?}",
-                                        directory_node
-                                    ),
-                                )
-                            })?;
+                        let digest = directory_node.digest().clone();
 
                         if let Some(directory) = self.tokio_handle.block_on(async {
                             self.directory_service.as_ref().get(&digest).await
@@ -560,9 +541,11 @@ impl EvalIO for TvixStoreIO {
                             let mut children: Vec<(bytes::Bytes, FileType)> = Vec::new();
                             for node in directory.nodes() {
                                 children.push(match node {
-                                    Node::Directory(e) => (e.name, FileType::Directory),
-                                    Node::File(e) => (e.name, FileType::Regular),
-                                    Node::Symlink(e) => (e.name, FileType::Symlink),
+                                    Node::Directory(e) => {
+                                        (e.get_name().clone(), FileType::Directory)
+                                    }
+                                    Node::File(e) => (e.get_name().clone(), FileType::Regular),
+                                    Node::Symlink(e) => (e.get_name().clone(), FileType::Symlink),
                                 })
                             }
                             Ok(children)