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, 22 insertions, 16 deletions

diff --git a/tvix/glue/src/fetchers/mod.rs b/tvix/glue/src/fetchers/mod.rs
index eb035a5a905c..9cab1adc04a3 100644
--- a/tvix/glue/src/fetchers/mod.rs
+++ b/tvix/glue/src/fetchers/mod.rs
@@ -12,8 +12,8 @@ use tracing::{instrument, warn, Span};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
 use tvix_castore::{
     blobservice::BlobService,
-    directoryservice::DirectoryService,
-    proto::{node::Node, FileNode},
+    directoryservice::{DirectoryService, FileNode, Node},
+    ValidateNodeError,
 };
 use tvix_store::{nar::NarCalculationService, pathinfoservice::PathInfoService, proto::PathInfo};
 use url::Url;
@@ -331,12 +331,10 @@ where
 
                 // Construct and return the FileNode describing the downloaded contents.
                 Ok((
-                    Node::File(FileNode {
-                        name: vec![].into(),
-                        digest: blob_writer.close().await?.into(),
-                        size: blob_size,
-                        executable: false,
-                    }),
+                    Node::File(
+                        FileNode::new(vec![].into(), blob_writer.close().await?, blob_size, false)
+                            .map_err(|e| FetcherError::Io(std::io::Error::other(e.to_string())))?,
+                    ),
                     CAHash::Flat(actual_hash),
                     blob_size,
                 ))
@@ -531,12 +529,13 @@ where
 
                 // Construct and return the FileNode describing the downloaded contents,
                 // make it executable.
-                let root_node = Node::File(FileNode {
-                    name: vec![].into(),
-                    digest: blob_digest.into(),
-                    size: file_size,
-                    executable: true,
-                });
+                let root_node = Node::File(
+                    FileNode::new(vec![].into(), blob_digest, file_size, true).map_err(
+                        |e: ValidateNodeError| {
+                            FetcherError::Io(std::io::Error::other(e.to_string()))
+                        },
+                    )?,
+                );
 
                 Ok((root_node, CAHash::Nar(actual_hash), file_size))
             }
@@ -580,7 +579,7 @@ where
 
         // Construct the PathInfo and persist it.
         let path_info = PathInfo {
-            node: Some(tvix_castore::proto::Node { node: Some(node) }),
+            node: Some((&node).into()),
             references: vec![],
             narinfo: Some(tvix_store::proto::NarInfo {
                 nar_size,
@@ -598,7 +597,14 @@ where
             .await
             .map_err(|e| FetcherError::Io(e.into()))?;
 
-        Ok((store_path, path_info.node.unwrap().node.unwrap()))
+        Ok((
+            store_path,
+            (&path_info.node.unwrap().node.unwrap())
+                .try_into()
+                .map_err(|e: ValidateNodeError| {
+                    FetcherError::Io(std::io::Error::other(e.to_string()))
+                })?,
+        ))
     }
 }