SERVER-29128 Fix performance regression on awaitData with lastKnownCommittedOpTime

Revert "Revert "SERVER-29128 Make $changeNotification stage return a tailable, awaitData cursor that continuously gives out oplog entries""

This reverts commit d29e92cffcb4db3cdd77b1e53d5d005db6cc309d.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/mongo/db/clientcursor.h b/src/mongo/db/clientcursor.h
index 32fb018a8e1..f75d41e3089 100644
--- a/src/mongo/db/clientcursor.h
+++ b/src/mongo/db/clientcursor.h
@@ -71,6 +71,20 @@ struct ClientCursorParams {
         }
     }
 
+    void setTailable(bool tailable) {
+        if (tailable)
+            queryOptions |= QueryOption_CursorTailable;
+        else
+            queryOptions &= ~QueryOption_CursorTailable;
+    }
+
+    void setAwaitData(bool awaitData) {
+        if (awaitData)
+            queryOptions |= QueryOption_AwaitData;
+        else
+            queryOptions &= ~QueryOption_AwaitData;
+    }
+
     std::unique_ptr<PlanExecutor, PlanExecutor::Deleter> exec;
     const NamespaceString nss;
     std::vector<UserName> authenticatedUsers;
@@ -127,10 +141,23 @@ public:
         return _exec.get();
     }
 
+    /**
+     * Returns the query options bitmask.  If you'd like to know if the cursor is tailable or
+     * awaitData, prefer using the specific methods isTailable() and isAwaitData() over using this
+     * method.
+     */
     int queryOptions() const {
         return _queryOptions;
     }
 
+    bool isTailable() const {
+        return _queryOptions & QueryOption_CursorTailable;
+    }
+
+    bool isAwaitData() const {
+        return _queryOptions & QueryOption_AwaitData;
+    }
+
     const BSONObj& getOriginatingCommandObj() const {
         return _originatingCommand;
     }