frame for interity check on object store (#287)

Author: Byron

git-odb/src/store_impls/dynamic/mod.rs

@@ -55,6 +55,9 @@ pub(crate) mod handle;
 ///
 pub mod load_index;
 
+///
+pub mod verify;
+
 mod load_one;
 
 mod metrics;

git-odb/src/store_impls/dynamic/verify.rs

@@ -0,0 +1,48 @@
+use crate::pack;
+use git_features::progress::Progress;
+use std::sync::atomic::AtomicBool;
+
+#[allow(missing_docs, unused)]
+
+///
+pub mod integrity {
+    use crate::pack;
+
+    /// Returned by [`Store::verify_integrity()`][crate::Store::verify_integrity()].
+    #[derive(Debug, thiserror::Error)]
+    #[allow(missing_docs)]
+    pub enum Error {
+        #[error(transparent)]
+        MultiIndex(#[from] pack::index::traverse::Error<pack::multi_index::verify::integrity::Error>),
+        #[error(transparent)]
+        Index(#[from] pack::index::traverse::Error<pack::index::verify::integrity::Error>),
+    }
+
+    /// Returned by [`Store::verify_integrity()`][crate::Store::verify_integrity()].
+    pub struct Outcome<P> {
+        /// Pack traversal statistics for each pack whose objects were checked.
+        pub pack_traverse_statistics: Vec<pack::index::traverse::Statistics>,
+        /// The provided progress instance.
+        pub progress: P,
+    }
+}
+
+impl super::Store {
+    /// Check the integrity of all objects as per the given `options`.
+    ///
+    /// Note that this will not not force loading all indices or packs permanently, as we will only use the momentarily loaded disk state.
+    /// This does, however, include all alternates.
+    pub fn verify_integrity<C, P, F>(
+        &self,
+        _progress: P,
+        _should_interrupt: &AtomicBool,
+        _options: pack::index::verify::integrity::Options<F>,
+    ) -> Result<integrity::Outcome<P>, pack::index::traverse::Error<integrity::Error>>
+    where
+        P: Progress,
+        C: pack::cache::DecodeEntry,
+        F: Fn() -> C + Send + Clone,
+    {
+        todo!()
+    }
+}

git-odb/tests/odb/store/dynamic.rs

@@ -567,3 +567,41 @@ fn auto_refresh_with_and_without_id_stability() -> crate::Result {
     );
     Ok(())
 }
+
+mod verify {
+    use crate::store::dynamic::db;
+    use git_features::progress;
+    use std::sync::atomic::AtomicBool;
+
+    #[test]
+    #[ignore]
+    fn verify_integrity() {
+        let handle = db();
+        let outcome = handle
+            .store_ref()
+            .verify_integrity(progress::Discard, &AtomicBool::new(false), Default::default())
+            .unwrap();
+        assert_eq!(
+            outcome.pack_traverse_statistics.len(),
+            3,
+            "there are only three packs to check"
+        );
+
+        assert_eq!(
+            handle.store_ref().metrics(),
+            git_odb::store::Metrics {
+                num_handles: 1,
+                num_refreshes: 1,
+                open_reachable_indices: 0,
+                known_reachable_indices: 3,
+                open_reachable_packs: 0,
+                known_packs: 3,
+                unused_slots: 29,
+                loose_dbs: 1,
+                unreachable_indices: 0,
+                unreachable_packs: 0
+            },
+            "verification only discovers files on disk but won't cause them to be opened permanently"
+        );
+    }
+}