radicle: add ReadRepository::contains

It can be useful to be able to check if a repository contains a given
commit. Add a `contains` method to the `ReadRepository` trait to
handle this.

Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett

radicle/src/storage.rs

@@ -433,6 +433,9 @@ pub trait ReadRepository: Sized + ValidateRepository {
     /// Perform a revision walk of a commit history starting from the given head.
     fn revwalk(&self, head: Oid) -> Result<git2::Revwalk, git2::Error>;
 
+    /// Check if the underlying ODB contains the given `oid`.
+    fn contains(&self, oid: Oid) -> Result<bool, git2::Error>;
+
     /// Check whether the given commit is an ancestor of another commit.
     fn is_ancestor_of(&self, ancestor: Oid, head: Oid) -> Result<bool, git::ext::Error>;
 

radicle/src/storage/git.rs

@@ -565,6 +565,10 @@ impl ReadRepository for Repository {
         Ok(revwalk)
     }
 
+    fn contains(&self, oid: Oid) -> Result<bool, raw::Error> {
+        self.backend.odb().map(|odb| odb.exists(oid.into()))
+    }
+
     fn is_ancestor_of(&self, ancestor: Oid, head: Oid) -> Result<bool, git::Error> {
         self.backend
             .graph_descendant_of(head.into(), ancestor.into())

radicle/src/storage/git/cob.rs

@@ -278,6 +278,10 @@ impl<'a, R: storage::ReadRepository> ReadRepository for DraftStore<'a, R> {
         self.repo.revwalk(head)
     }
 
+    fn contains(&self, oid: Oid) -> Result<bool, raw::Error> {
+        self.repo.contains(oid)
+    }
+
     fn is_ancestor_of(&self, ancestor: Oid, head: Oid) -> Result<bool, git_ext::Error> {
         self.repo.is_ancestor_of(ancestor, head)
     }

radicle/src/test/storage.rs

@@ -188,6 +188,13 @@ impl ReadRepository for MockRepository {
         todo!()
     }
 
+    fn contains(&self, oid: Oid) -> Result<bool, git2::Error> {
+        Ok(self
+            .remotes
+            .values()
+            .any(|sigrefs| sigrefs.at == oid || sigrefs.refs.values().any(|oid_| *oid_ == oid)))
+    }
+
     fn is_ancestor_of(&self, _ancestor: Oid, _head: Oid) -> Result<bool, git_ext::Error> {
         Ok(true)
     }