Check concurrent batches conflict, add extra impl

Author: erickt

tuf/src/repository.rs

@@ -189,6 +189,29 @@ where
     }
 }
 
+impl<T, D> RepositoryStorage<D> for &T
+where
+    T: RepositoryStorage<D>,
+    D: DataInterchange + Sync,
+{
+    fn store_metadata<'a>(
+        &'a self,
+        meta_path: &MetadataPath,
+        version: MetadataVersion,
+        metadata: &'a mut (dyn AsyncRead + Send + Unpin),
+    ) -> BoxFuture<'a, Result<()>> {
+        (**self).store_metadata(meta_path, version, metadata)
+    }
+
+    fn store_target<'a>(
+        &'a self,
+        target_path: &TargetPath,
+        target: &'a mut (dyn AsyncRead + Send + Unpin),
+    ) -> BoxFuture<'a, Result<()>> {
+        (**self).store_target(target_path, target)
+    }
+}
+
 impl<T, D> RepositoryStorage<D> for &mut T
 where
     T: RepositoryStorage<D>,
@@ -317,6 +340,28 @@ where
     }
 }
 
+impl<D> RepositoryStorage<D> for &dyn RepositoryStorage<D>
+where
+    D: DataInterchange + Sync,
+{
+    fn store_metadata<'a>(
+        &'a self,
+        meta_path: &MetadataPath,
+        version: MetadataVersion,
+        metadata: &'a mut (dyn AsyncRead + Send + Unpin),
+    ) -> BoxFuture<'a, Result<()>> {
+        (**self).store_metadata(meta_path, version, metadata)
+    }
+
+    fn store_target<'a>(
+        &'a self,
+        target_path: &TargetPath,
+        target: &'a mut (dyn AsyncRead + Send + Unpin),
+    ) -> BoxFuture<'a, Result<()>> {
+        (**self).store_target(target_path, target)
+    }
+}
+
 impl<D> RepositoryStorage<D> for &mut dyn RepositoryStorage<D>
 where
     D: DataInterchange + Sync,

tuf/src/repository/ephemeral.rs

@@ -524,6 +524,29 @@ mod test {
                 .unwrap();
 
             assert_matches!(batch.commit().await, Err(CommitError::Conflict));
+
+            // multiple batches should conflict.
+            let batch1 = repo.batch_update();
+            let batch2 = repo.batch_update();
+
+            batch1
+                .store_target(
+                    &TargetPath::new("target4").unwrap(),
+                    &mut "target4".as_bytes(),
+                )
+                .await
+                .unwrap();
+
+            batch2
+                .store_target(
+                    &TargetPath::new("target5").unwrap(),
+                    &mut "target5".as_bytes(),
+                )
+                .await
+                .unwrap();
+
+            assert_matches!(batch1.commit().await, Ok(()));
+            assert_matches!(batch2.commit().await, Err(CommitError::Conflict));
         })
     }
 }

tuf/src/repository/file_system.rs

@@ -765,6 +765,29 @@ mod test {
                 .unwrap();
 
             assert_matches!(batch.commit().await, Err(CommitError::Conflict));
+
+            // multiple batches should conflict.
+            let batch1 = repo.batch_update();
+            let batch2 = repo.batch_update();
+
+            batch1
+                .store_target(
+                    &TargetPath::new("target4").unwrap(),
+                    &mut "target4".as_bytes(),
+                )
+                .await
+                .unwrap();
+
+            batch2
+                .store_target(
+                    &TargetPath::new("target5").unwrap(),
+                    &mut "target5".as_bytes(),
+                )
+                .await
+                .unwrap();
+
+            assert_matches!(batch1.commit().await, Ok(()));
+            assert_matches!(batch2.commit().await, Err(CommitError::Conflict));
         })
     }
 }