1 files changed, 67 insertions, 0 deletions
diff --git a/tvix/nix-daemon/src/lib.rs b/tvix/nix-daemon/src/lib.rs
new file mode 100644
index 000000000000..e508d0750c9b
--- /dev/null
+++ b/tvix/nix-daemon/src/lib.rs
@@ -0,0 +1,67 @@
+use std::{
+    io::{Error, Result},
+    sync::Arc,
+};
+
+use nix_compat::{
+    nix_daemon::{types::UnkeyedValidPathInfo, NixDaemonIO},
+    nixbase32,
+    store_path::StorePath,
+};
+use tvix_store::{path_info::PathInfo, pathinfoservice::PathInfoService};
+
+#[allow(dead_code)]
+pub struct TvixDaemon {
+    path_info_service: Arc<dyn PathInfoService>,
+}
+
+impl TvixDaemon {
+    pub fn new(path_info_service: Arc<dyn PathInfoService>) -> Self {
+        Self { path_info_service }
+    }
+}
+
+/// Implements [NixDaemonIO] backed by tvix services.
+impl NixDaemonIO for TvixDaemon {
+    async fn query_path_info(
+        &self,
+        path: &StorePath<String>,
+    ) -> Result<Option<UnkeyedValidPathInfo>> {
+        match self.path_info_service.get(*path.digest()).await? {
+            Some(path_info) => {
+                if path_info.store_path.name() == path.name() {
+                    Ok(Some(into_unkeyed_path_info(path_info)))
+                } else {
+                    Ok(None)
+                }
+            }
+            None => Ok(None),
+        }
+    }
+
+    async fn query_path_from_hash_part(&self, hash: &[u8]) -> Result<Option<UnkeyedValidPathInfo>> {
+        let digest = hash
+            .try_into()
+            .map_err(|_| Error::other("invalid digest length"))?;
+        match self.path_info_service.get(digest).await? {
+            Some(path_info) => Ok(Some(into_unkeyed_path_info(path_info))),
+            None => Ok(None),
+        }
+    }
+}
+
+// PathInfo lives in the tvix-store crate, but does not depend on nix-compat's wire feature,
+// while UnkeyedValidPathInfo is only available if that feature is enabled. To avoid complexity
+// we manually convert as opposed to creating a From<PathInfo>.
+fn into_unkeyed_path_info(info: PathInfo) -> UnkeyedValidPathInfo {
+    UnkeyedValidPathInfo {
+        deriver: info.deriver,
+        nar_hash: nixbase32::encode(&info.nar_sha256),
+        references: info.references,
+        registration_time: 0,
+        nar_size: info.nar_size,
+        ultimate: false,
+        signatures: info.signatures,
+        ca: info.ca,
+    }
+}