feat(nix-daemon): Implement more nix daemon operations.

In particular QueryPathFromHashPart, QueryValidPaths, QueryValidDerivers

Change-Id: Ie6ad83cec5ce9580044b85e201e4e23394f87075
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12762
Tested-by: BuildkiteCI
Reviewed-by: edef <edef@edef.eu>
Reviewed-by: flokli <flokli@flokli.de>

tvix/nix-compat/src/nix_daemon/mod.rs

@@ -2,7 +2,9 @@ pub mod worker_protocol;
 
 use std::io::Result;
 
-use types::UnkeyedValidPathInfo;
+use futures::future::try_join_all;
+use tracing::warn;
+use types::{QueryValidPaths, UnkeyedValidPathInfo};
 
 use crate::store_path::StorePath;
 
@@ -10,9 +12,200 @@ pub mod handler;
 pub mod types;
 
 /// Represents all possible operations over the nix-daemon protocol.
-pub trait NixDaemonIO {
+pub trait NixDaemonIO: Sync {
+    fn is_valid_path(
+        &self,
+        path: &StorePath<String>,
+    ) -> impl std::future::Future<Output = Result<bool>> + Send {
+        async move { Ok(self.query_path_info(path).await?.is_some()) }
+    }
+
     fn query_path_info(
         &self,
         path: &StorePath<String>,
     ) -> impl std::future::Future<Output = Result<Option<UnkeyedValidPathInfo>>> + Send;
+
+    fn query_path_from_hash_part(
+        &self,
+        hash: &[u8],
+    ) -> impl std::future::Future<Output = Result<Option<UnkeyedValidPathInfo>>> + Send;
+
+    fn query_valid_paths(
+        &self,
+        request: &QueryValidPaths,
+    ) -> impl std::future::Future<Output = Result<Vec<UnkeyedValidPathInfo>>> + Send {
+        async move {
+            if request.substitute {
+                warn!("tvix does not yet support substitution, ignoring the 'substitute' flag...");
+            }
+            // Using try_join_all here to avoid returning partial results to the client.
+            // The only reason query_path_info can fail is due to transient IO errors,
+            // so we return such errors to the client as opposed to only returning paths
+            // that succeeded.
+            let result =
+                try_join_all(request.paths.iter().map(|path| self.query_path_info(path))).await?;
+            let result: Vec<UnkeyedValidPathInfo> = result.into_iter().flatten().collect();
+            Ok(result)
+        }
+    }
+
+    fn query_valid_derivers(
+        &self,
+        path: &StorePath<String>,
+    ) -> impl std::future::Future<Output = Result<Vec<StorePath<String>>>> + Send {
+        async move {
+            let result = self.query_path_info(path).await?;
+            let result: Vec<_> = result.into_iter().filter_map(|info| info.deriver).collect();
+            Ok(result)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::{nix_daemon::types::QueryValidPaths, store_path::StorePath};
+
+    use super::{types::UnkeyedValidPathInfo, NixDaemonIO};
+
+    // Very simple mock
+    // Unable to use mockall as it does not support unboxed async traits.
+    pub struct MockNixDaemonIO {
+        query_path_info_result: Option<UnkeyedValidPathInfo>,
+    }
+
+    impl NixDaemonIO for MockNixDaemonIO {
+        async fn query_path_info(
+            &self,
+            _path: &StorePath<String>,
+        ) -> std::io::Result<Option<UnkeyedValidPathInfo>> {
+            Ok(self.query_path_info_result.clone())
+        }
+
+        async fn query_path_from_hash_part(
+            &self,
+            _hash: &[u8],
+        ) -> std::io::Result<Option<UnkeyedValidPathInfo>> {
+            Ok(None)
+        }
+    }
+
+    #[tokio::test]
+    async fn test_is_valid_path_returns_true() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: Some(UnkeyedValidPathInfo::default()),
+        };
+
+        let result = io
+            .is_valid_path(&path)
+            .await
+            .expect("expected to get a non-empty response");
+        assert!(result, "expected to get true");
+    }
+
+    #[tokio::test]
+    async fn test_is_valid_path_returns_false() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: None,
+        };
+
+        let result = io
+            .is_valid_path(&path)
+            .await
+            .expect("expected to get a non-empty response");
+        assert!(!result, "expected to get false");
+    }
+
+    #[tokio::test]
+    async fn test_query_valid_paths_returns_empty_response() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: None,
+        };
+
+        let result = io
+            .query_valid_paths(&QueryValidPaths {
+                paths: vec![path],
+                substitute: false,
+            })
+            .await
+            .expect("expected to get a non-empty response");
+        assert_eq!(result, vec![], "expected to get empty response");
+    }
+
+    #[tokio::test]
+    async fn test_query_valid_paths_returns_non_empty_response() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: Some(UnkeyedValidPathInfo::default()),
+        };
+
+        let result = io
+            .query_valid_paths(&QueryValidPaths {
+                paths: vec![path],
+                substitute: false,
+            })
+            .await
+            .expect("expected to get a non-empty response");
+        assert_eq!(
+            result,
+            vec![UnkeyedValidPathInfo::default()],
+            "expected to get non empty response"
+        );
+    }
+
+    #[tokio::test]
+    async fn test_query_valid_derivers_returns_empty_response() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: None,
+        };
+
+        let result = io
+            .query_valid_derivers(&path)
+            .await
+            .expect("expected to get a non-empty response");
+        assert_eq!(result, vec![], "expected to get empty response");
+    }
+
+    #[tokio::test]
+    async fn test_query_valid_derivers_returns_non_empty_response() {
+        let path =
+            StorePath::<String>::from_bytes("z6r3bn5l51679pwkvh9nalp6c317z34m-hello".as_bytes())
+                .unwrap();
+        let deriver = StorePath::<String>::from_bytes(
+            "z6r3bn5l51679pwkvh9nalp6c317z34m-hello.drv".as_bytes(),
+        )
+        .unwrap();
+        let io = MockNixDaemonIO {
+            query_path_info_result: Some(UnkeyedValidPathInfo {
+                deriver: Some(deriver.clone()),
+                nar_hash: "".to_owned(),
+                references: vec![],
+                registration_time: 0,
+                nar_size: 1,
+                ultimate: true,
+                signatures: vec![],
+                ca: None,
+            }),
+        };
+
+        let result = io
+            .query_valid_derivers(&path)
+            .await
+            .expect("expected to get a non-empty response");
+        assert_eq!(result, vec![deriver], "expected to get non empty response");
+    }
 }