1 files changed, 52 insertions, 0 deletions
diff --git a/tvix/store/src/nar/mod.rs b/tvix/store/src/nar/mod.rs
new file mode 100644
index 0000000000..164748a655
--- /dev/null
+++ b/tvix/store/src/nar/mod.rs
@@ -0,0 +1,52 @@
+use tonic::async_trait;
+use tvix_castore::B3Digest;
+
+mod import;
+mod renderer;
+pub use import::ingest_nar;
+pub use renderer::calculate_size_and_sha256;
+pub use renderer::write_nar;
+pub use renderer::SimpleRenderer;
+use tvix_castore::proto as castorepb;
+
+#[async_trait]
+pub trait NarCalculationService: Send + Sync {
+    /// Return the nar size and nar sha256 digest for a given root node.
+    /// This can be used to calculate NAR-based output paths.
+    async fn calculate_nar(
+        &self,
+        root_node: &castorepb::node::Node,
+    ) -> Result<(u64, [u8; 32]), tvix_castore::Error>;
+}
+
+#[async_trait]
+impl<A> NarCalculationService for A
+where
+    A: AsRef<dyn NarCalculationService> + Send + Sync,
+{
+    async fn calculate_nar(
+        &self,
+        root_node: &castorepb::node::Node,
+    ) -> Result<(u64, [u8; 32]), tvix_castore::Error> {
+        self.as_ref().calculate_nar(root_node).await
+    }
+}
+
+/// Errors that can encounter while rendering NARs.
+#[derive(Debug, thiserror::Error)]
+pub enum RenderError {
+    #[error("failure talking to a backing store client: {0}")]
+    StoreError(#[source] std::io::Error),
+
+    #[error("unable to find directory {}, referred from {:?}", .0, .1)]
+    DirectoryNotFound(B3Digest, bytes::Bytes),
+
+    #[error("unable to find blob {}, referred from {:?}", .0, .1)]
+    BlobNotFound(B3Digest, bytes::Bytes),
+
+    #[error("unexpected size in metadata for blob {}, referred from {:?} returned, expected {}, got {}", .0, .1, .2, .3)]
+    UnexpectedBlobMeta(B3Digest, bytes::Bytes, u32, u32),
+
+    #[error("failure using the NAR writer: {0}")]
+    NARWriterError(std::io::Error),
+}