refactor(tvix/nix-compat): make NixHash an enum with fixed-len bytes r/6807

Less Vec<u8> passed around.

Change-Id: Ie153a6bfaa084d7490ffa38634efdf5f3c31a768
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9722
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

1 files changed, 11 insertions, 13 deletions

diff --git a/tvix/nix-compat/src/derivation/write.rs b/tvix/nix-compat/src/derivation/write.rs
index 9a62344248..5e1aefa16f 100644
--- a/tvix/nix-compat/src/derivation/write.rs
+++ b/tvix/nix-compat/src/derivation/write.rs
@@ -79,22 +79,20 @@ pub fn write_outputs(
 
         let mut elements: Vec<&str> = vec![output_name, &output.path];
 
-        let (e2, e3) = match &output.hash_with_mode {
-            Some(hash) => match hash {
-                crate::nixhash::NixHashWithMode::Flat(h) => (
-                    h.algo.to_string(),
-                    data_encoding::HEXLOWER.encode(&h.digest),
-                ),
-                crate::nixhash::NixHashWithMode::Recursive(h) => (
-                    format!("r:{}", h.algo),
-                    data_encoding::HEXLOWER.encode(&h.digest),
-                ),
-            },
+        let (mode_and_algo, digest) = match &output.hash_with_mode {
+            Some(crate::nixhash::NixHashWithMode::Flat(h)) => (
+                h.algo().to_string(),
+                data_encoding::HEXLOWER.encode(h.digest_as_bytes()),
+            ),
+            Some(crate::nixhash::NixHashWithMode::Recursive(h)) => (
+                format!("r:{}", h.algo()),
+                data_encoding::HEXLOWER.encode(h.digest_as_bytes()),
+            ),
             None => ("".to_string(), "".to_string()),
         };
 
-        elements.push(&e2);
-        elements.push(&e3);
+        elements.push(&mode_and_algo);
+        elements.push(&digest);
 
         write_array_elements(writer, &elements)?;