1 files changed, 12 insertions, 26 deletions
diff --git a/src/mongo/db/pipeline/pipeline.h b/src/mongo/db/pipeline/pipeline.h
index 04b5769792d..bcb7ee64521 100644
--- a/src/mongo/db/pipeline/pipeline.h
+++ b/src/mongo/db/pipeline/pipeline.h
@@ -39,8 +39,6 @@
 #include "mongo/db/pipeline/value.h"
 #include "mongo/db/query/explain_options.h"
 #include "mongo/db/query/query_knobs.h"
-#include "mongo/executor/task_executor.h"
-#include "mongo/s/query/async_results_merger_params_gen.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/util/intrusive_counter.h"
 #include "mongo/util/timer.h"
@@ -270,34 +268,13 @@ public:
     }
 
     /**
-     * Removes and returns the first stage of the pipeline. Returns nullptr if the pipeline is
-     * empty.
-     */
-    boost::intrusive_ptr<DocumentSource> popFront();
-
-    /**
-     * Removes and returns the last stage of the pipeline. Returns nullptr if the pipeline is empty.
-     */
-    boost::intrusive_ptr<DocumentSource> popBack();
-
-    /**
-     * Adds the given stage to the end of the pipeline.
-     */
-    void pushBack(boost::intrusive_ptr<DocumentSource>);
-
-    /**
-     * Removes and returns the first stage of the pipeline if its name is 'targetStageName'.
-     * Returns nullptr if there is no first stage with that name.
-     */
-    boost::intrusive_ptr<DocumentSource> popFrontWithName(StringData targetStageName);
-
-    /**
      * Removes and returns the first stage of the pipeline if its name is 'targetStageName' and the
      * given 'predicate' function, if present, returns 'true' when called with a pointer to the
      * stage. Returns nullptr if there is no first stage which meets these criteria.
      */
-    boost::intrusive_ptr<DocumentSource> popFrontWithNameAndCriteria(
-        StringData targetStageName, stdx::function<bool(const DocumentSource* const)> predicate);
+    boost::intrusive_ptr<DocumentSource> popFrontWithCriteria(
+        StringData targetStageName,
+        stdx::function<bool(const DocumentSource* const)> predicate = nullptr);
 
     /**
      * PipelineD is a "sister" class that has additional functionality for the Pipeline. It exists
@@ -309,6 +286,15 @@ public:
     friend class PipelineD;
 
 private:
+    class Optimizations {
+    public:
+        // This contains static functions that optimize pipelines in various ways.
+        // This is a class rather than a namespace so that it can be a friend of Pipeline.
+        // It is defined in pipeline_optimizations.h.
+        class Sharded;
+    };
+
+    friend class Optimizations::Sharded;
     friend class PipelineDeleter;
 
     /**