SERVER-35860 Maintain multikey metadata keys for allPaths indexes

1 files changed, 12 insertions, 9 deletions

diff --git a/src/mongo/db/exec/projection_exec_agg.h b/src/mongo/db/exec/projection_exec_agg.h
index f796a250d37..6989478b812 100644
--- a/src/mongo/db/exec/projection_exec_agg.h
+++ b/src/mongo/db/exec/projection_exec_agg.h
@@ -62,21 +62,24 @@ public:
 
     ~ProjectionExecAgg();
 
+    BSONObj applyProjection(BSONObj inputDoc) const;
+
+    stdx::unordered_set<std::string> applyProjectionToFields(
+        const stdx::unordered_set<std::string>& fields) const;
+
+    /**
+     * Returns the exhaustive set of all paths that will be preserved by this projection, or an
+     * empty set if the exhaustive set cannot be determined. An inclusion will always produce an
+     * exhaustive set; an exclusion will always produce an empty set.
+     */
+    std::set<std::string> getExhaustivePaths() const;
+
     ProjectionType getType() const;
 
     BSONObj getProjectionSpec() const {
         return _projSpec;
     }
 
-    const BSONObj& getSpec() const {
-        return _projSpec;
-    }
-
-    BSONObj applyProjection(BSONObj inputDoc) const;
-
-    stdx::unordered_set<std::string> applyProjectionToFields(
-        const stdx::unordered_set<std::string>& fields) const;
-
 private:
     /**
      * ProjectionExecAgg::ProjectionExecutor wraps all agg-specific calls, and is forward-declared