refactor(tvix/src/nar): drop NARCalculationService r/6270

There's only one way to calculate NAR files, by walking through them.

Things like caching such replies should be done closer to where we use
these, composing NARCalculationService doesn't actually give us much.

Instead, expose two functions, `nar::calculate_size_and_sha256` and
`nar::writer_nar`, the latter writing NAR to a writer, the former using
write_nar to only keeping the NAR size and digest.

Change-Id: Ie5d2cfea35470fdbb5cbf9da1136b0cdf0250266
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8723
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>

1 files changed, 0 insertions, 34 deletions

diff --git a/tvix/store/src/nar/non_caching_calculation_service.rs b/tvix/store/src/nar/non_caching_calculation_service.rs
deleted file mode 100644
index b743f264b0ff..000000000000
--- a/tvix/store/src/nar/non_caching_calculation_service.rs
+++ /dev/null
@@ -1,34 +0,0 @@
-use count_write::CountWrite;
-use sha2::{Digest, Sha256};
-
-use crate::blobservice::BlobService;
-use crate::directoryservice::DirectoryService;
-use crate::proto;
-
-use super::renderer::NARRenderer;
-use super::{NARCalculationService, RenderError};
-
-/// A NAR calculation service which simply renders the whole NAR whenever
-/// we ask for the calculation.
-pub struct NonCachingNARCalculationService<DS: DirectoryService> {
-    nar_renderer: NARRenderer<DS>,
-}
-
-impl<DS: DirectoryService> NonCachingNARCalculationService<DS> {
-    pub fn new(blob_service: Box<dyn BlobService>, directory_service: DS) -> Self {
-        Self {
-            nar_renderer: NARRenderer::new(blob_service, directory_service),
-        }
-    }
-}
-
-impl<DS: DirectoryService> NARCalculationService for NonCachingNARCalculationService<DS> {
-    fn calculate_nar(&self, root_node: &proto::node::Node) -> Result<(u64, [u8; 32]), RenderError> {
-        let h = Sha256::new();
-        let mut cw = CountWrite::from(h);
-
-        self.nar_renderer.write_nar(&mut cw, root_node)?;
-
-        Ok((cw.count(), cw.into_inner().finalize().into()))
-    }
-}