SERVER-29908 Move OpObserver and MigrationSourceManager logic out of CollectionShardingState.

Makes MigrationSourceManager a decoration on CollectionShardingState,
not a member and moves the op observer behavior from
CollectionShardingState to free functions in shard_server_op_observer.h/cpp.

1 files changed, 2 insertions, 61 deletions

diff --git a/src/mongo/db/s/collection_sharding_state.h b/src/mongo/db/s/collection_sharding_state.h
index 6aa2463dc9d..2df1699c450 100644
--- a/src/mongo/db/s/collection_sharding_state.h
+++ b/src/mongo/db/s/collection_sharding_state.h
@@ -36,10 +36,10 @@
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/s/metadata_manager.h"
 #include "mongo/db/s/sharding_migration_critical_section.h"
+#include "mongo/util/decorable.h"
 
 namespace mongo {
 
-class MigrationSourceManager;
 class OperationContext;
 
 /**
@@ -50,7 +50,7 @@ class OperationContext;
  * Synchronization rules: In order to look-up this object in the instance's sharding map, one must
  * have some lock on the respective collection.
  */
-class CollectionShardingState {
+class CollectionShardingState : public Decorable<CollectionShardingState> {
     MONGO_DISALLOW_COPYING(CollectionShardingState);
 
 public:
@@ -60,22 +60,6 @@ public:
      * Instantiates a new per-collection sharding state as unsharded.
      */
     CollectionShardingState(ServiceContext* sc, NamespaceString nss);
-    ~CollectionShardingState();
-
-    /**
-     * Details of documents being removed from a sharded collection.
-     */
-    struct DeleteState {
-        // Contains the fields of the document that are in the collection's shard key, and "_id".
-        BSONObj documentKey;
-
-        // True if the document being deleted belongs to a chunk which, while still in the shard,
-        // is being migrated out. (Not to be confused with "fromMigrate", which tags operations
-        // that are steps in performing the migration.)
-        bool isMigrating;
-    };
-
-    DeleteState makeDeleteState(OperationContext* opCtx, BSONObj const& doc);
 
     /**
      * Obtains the sharding state for the specified collection. If it does not exist, it will be
@@ -168,24 +152,6 @@ public:
     }
 
     /**
-     * Attaches a migration source manager to this collection's sharding state. Must be called with
-     * collection X lock. May not be called if there is a migration source manager already
-     * installed. Must be followed by a call to clearMigrationSourceManager.
-     */
-    void setMigrationSourceManager(OperationContext* opCtx, MigrationSourceManager* sourceMgr);
-
-    auto getMigrationSourceManager() const {
-        return _sourceMgr;
-    }
-
-    /**
-     * Removes a migration source manager from this collection's sharding state. Must be called with
-     * collection X lock. May not be called if there isn't a migration source manager installed
-     * already through a previous call to setMigrationSourceManager.
-     */
-    void clearMigrationSourceManager(OperationContext* opCtx);
-
-    /**
      * Checks whether the shard version in the context is compatible with the shard version of the
      * collection locally and if not throws StaleConfigException populated with the expected and
      * actual versions.
@@ -226,24 +192,6 @@ public:
      */
     boost::optional<ChunkRange> getNextOrphanRange(BSONObj const& startingFrom);
 
-    /**
-     * Replication oplog OpObserver hooks. Informs the sharding system of changes that may be
-     * relevant to ongoing operations.
-     *
-     * The global exclusive lock is expected to be held by the caller of any of these functions.
-     */
-    void onInsertOp(OperationContext* opCtx,
-                    const BSONObj& insertedDoc,
-                    const repl::OpTime& opTime);
-    void onUpdateOp(OperationContext* opCtx,
-                    const BSONObj& updatedDoc,
-                    const repl::OpTime& opTime,
-                    const repl::OpTime& prePostImageOpTime);
-    void onDeleteOp(OperationContext* opCtx,
-                    const DeleteState& deleteState,
-                    const repl::OpTime& opTime,
-                    const repl::OpTime& preImageOpTime);
-
 private:
     /**
      * Checks whether the shard version of the operation matches that of the collection.
@@ -271,13 +219,6 @@ private:
 
     ShardingMigrationCriticalSection _critSec;
 
-    // If this collection is serving as a source shard for chunk migration, this value will be
-    // non-null. To write this value there needs to be X-lock on the collection in order to
-    // synchronize with other callers, which read it.
-    //
-    // NOTE: The value is not owned by this class.
-    MigrationSourceManager* _sourceMgr{nullptr};
-
     // for access to _metadataManager
     friend auto CollectionRangeDeleter::cleanUpNextRange(OperationContext*,
                                                          NamespaceString const&,