Pass getTreeEntryForRootId to ObjectStore

Summary: This will add the same getTreeEntryForRootId to ObjectStore

Reviewed By: chadaustin

Differential Revision: D29920475

fbshipit-source-id: 15bfc6a2ba70cce2095dfcf1f434fd7087605e04

eden/fs/store/ObjectStore.cpp

@@ -138,6 +138,21 @@ Future<shared_ptr<const Tree>> ObjectStore::getRootTree(
       });
 }
 
+folly::Future<std::shared_ptr<TreeEntry>> ObjectStore::getTreeEntryForRootId(
+    const RootId& rootId,
+    facebook::eden::TreeEntryType treeEntryType,
+    facebook::eden::PathComponentPiece pathComponentPiece,
+    ObjectFetchContext& context) const {
+  XLOG(DBG3) << "getTreeEntryForRootId(" << rootId << ")";
+
+  // TODO: We can cache the treeEntry to the localStore like Tree or
+  // blob
+  return backingStore_
+      ->getTreeEntryForRootId(
+          rootId, treeEntryType, pathComponentPiece, context)
+      .via(executor_);
+}
+
 Future<shared_ptr<const Tree>> ObjectStore::getTree(
     const Hash& id,
     ObjectFetchContext& fetchContext) const {

eden/fs/store/ObjectStore.h

@@ -131,6 +131,19 @@ class ObjectStore : public IObjectStore,
       const RootId& rootId,
       ObjectFetchContext& context) const override;
 
+  /**
+   * Get a TreeEntry by ID
+   *
+   * This returns a Future object that will produce the TreeEntry when it is
+   * ready. It may result in a std::domain_error if the specified tree ID does
+   * not exist, or possibly other exceptions on error.
+   */
+  folly::Future<std::shared_ptr<TreeEntry>> getTreeEntryForRootId(
+      const RootId& rootId,
+      facebook::eden::TreeEntryType treeEntryType,
+      facebook::eden::PathComponentPiece pathComponentPiece,
+      ObjectFetchContext& context) const;
+
   /**
    * Get a Tree by ID.
    *