SERVER-22541 Manage aggregation cursors on global cursor manager.

Moves registration of aggregation cursors to the global cursor manager.
This simplifies the logic for acquiring locks and resolving view
namespaces within the getMore and killCursors commands.

1 files changed, 32 insertions, 45 deletions

diff --git a/src/mongo/db/clientcursor.h b/src/mongo/db/clientcursor.h
index 44ae4600ac6..91e7a0d325c 100644
--- a/src/mongo/db/clientcursor.h
+++ b/src/mongo/db/clientcursor.h
@@ -28,6 +28,7 @@
 
 #pragma once
 
+#include "mongo/client/dbclientinterface.h"
 #include "mongo/db/cursor_id.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/query/plan_executor.h"
@@ -42,30 +43,30 @@ class CursorManager;
 class RecoveryUnit;
 
 /**
- * Parameters used for constructing a ClientCursor. ClientCursors cannot be constructed in
- * isolation, but rather must be constructed and managed using a CursorManager. See cursor_manager.h
- * for more details.
+ * Parameters used for constructing a ClientCursor. Makes an owned copy of 'originatingCommandObj'
+ * to be used across getMores.
+ *
+ * ClientCursors cannot be constructed in isolation, but rather must be
+ * constructed and managed using a CursorManager. See cursor_manager.h for more details.
  */
 struct ClientCursorParams {
-    ClientCursorParams(PlanExecutor* exec,
-                       std::string ns,
+    ClientCursorParams(std::unique_ptr<PlanExecutor> planExecutor,
+                       NamespaceString nss,
                        bool isReadCommitted,
-                       int qopts = 0,
-                       const BSONObj query = BSONObj(),
-                       bool isAggCursor = false)
-        : exec(exec),
-          ns(std::move(ns)),
+                       BSONObj originatingCommandObj)
+        : exec(std::move(planExecutor)),
+          nss(std::move(nss)),
           isReadCommitted(isReadCommitted),
-          qopts(qopts),
-          query(query),
-          isAggCursor(isAggCursor) {}
+          queryOptions(exec->getCanonicalQuery()
+                           ? exec->getCanonicalQuery()->getQueryRequest().getOptions()
+                           : 0),
+          originatingCommandObj(originatingCommandObj.getOwned()) {}
 
-    PlanExecutor* exec = nullptr;
-    const std::string ns;
+    std::unique_ptr<PlanExecutor> exec;
+    const NamespaceString nss;
     bool isReadCommitted = false;
-    int qopts = 0;
-    const BSONObj query = BSONObj();
-    bool isAggCursor = false;
+    int queryOptions = 0;
+    BSONObj originatingCommandObj;
 };
 
 /**
@@ -92,18 +93,14 @@ public:
         return _cursorid;
     }
 
-    std::string ns() const {
-        return _ns;
+    const NamespaceString& nss() const {
+        return _nss;
     }
 
     bool isReadCommitted() const {
         return _isReadCommitted;
     }
 
-    bool isAggCursor() const {
-        return _isAggCursor;
-    }
-
     PlanExecutor* getExecutor() const {
         return _exec.get();
     }
@@ -112,8 +109,8 @@ public:
         return _queryOptions;
     }
 
-    const BSONObj& getQuery() const {
-        return _query;
+    const BSONObj& getOriginatingCommandObj() const {
+        return _originatingCommand;
     }
 
     /**
@@ -223,7 +220,7 @@ private:
      * Constructs a ClientCursor. Since cursors must come into being registered and pinned, this is
      * private. See cursor_manager.h for more details.
      */
-    ClientCursor(const ClientCursorParams& params, CursorManager* cursorManager, CursorId cursorId);
+    ClientCursor(ClientCursorParams&& params, CursorManager* cursorManager, CursorId cursorId);
 
     /**
      * Constructs a special ClientCursor used to track sharding state for the given collection.
@@ -246,11 +243,15 @@ private:
      */
     void kill();
 
+    bool isNoTimeout() const {
+        return (_queryOptions & QueryOption_NoCursorTimeout);
+    }
+
     // The ID of the ClientCursor. A value of 0 is used to mean that no cursor id has been assigned.
     CursorId _cursorid = 0;
 
     // The namespace we're operating on.
-    std::string _ns;
+    const NamespaceString _nss;
 
     const bool _isReadCommitted = false;
 
@@ -265,21 +266,11 @@ private:
     // Tracks the number of results returned by this cursor so far.
     long long _pos = 0;
 
-    // If this cursor was created by a find operation, '_query' holds the query predicate for
-    // the find. If this cursor was created by a command (e.g. the aggregate command), then
-    // '_query' holds the command specification received from the client.
-    BSONObj _query;
+    // Holds an owned copy of the command specification received from the client.
+    const BSONObj _originatingCommand;
 
     // See the QueryOptions enum in dbclientinterface.h.
-    int _queryOptions = 0;
-
-    // Is this ClientCursor backed by an aggregation pipeline?
-    //
-    // Agg executors differ from others in that they manage their own locking internally and
-    // should not be killed or destroyed when the underlying collection is deleted.
-    //
-    // Note: This should *not* be set for the internal cursor used as input to an aggregation.
-    const bool _isAggCursor = false;
+    const int _queryOptions = 0;
 
     // While a cursor is being used by a client, it is marked as "pinned". See ClientCursorPin
     // below.
@@ -287,10 +278,6 @@ private:
     // Cursors always come into existence in a pinned state.
     bool _isPinned = true;
 
-    // Is the "no timeout" flag set on this cursor?  If false, this cursor may be automatically
-    // deleted after an interval of inactivity.
-    bool _isNoTimeout = false;
-
     // The replication position only used in master-slave.
     Timestamp _slaveReadTill;