1 files changed, 47 insertions, 16 deletions

diff --git a/src/mongo/db/pipeline/process_interface/mongo_process_interface.h b/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
index 19477adf8c9..5ee0e401924 100644
--- a/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
+++ b/src/mongo/db/pipeline/process_interface/mongo_process_interface.h
@@ -78,7 +78,7 @@ class MongoProcessInterface {
 public:
     /**
      * Storage for a batch of BSON Objects to be updated in the write namespace. For each element
-     * in the batch we store a tuple of the folliwng elements:
+     * in the batch we store a tuple of the following elements:
      *   1. BSONObj - specifies the query that identifies a document in the to collection to be
      *      updated.
      *   2. write_ops::UpdateModification - either the new document we want to upsert or insert into
@@ -106,6 +106,30 @@ public:
     enum class CurrentOpBacktraceMode { kIncludeBacktrace, kExcludeBacktrace };
 
     /**
+     * Interface which estimates the size of a given write operation.
+     */
+    class WriteSizeEstimator {
+    public:
+        virtual ~WriteSizeEstimator() = default;
+
+        /**
+         * Set of functions which estimate the entire size of a write command except for the array
+         * of write statements themselves.
+         */
+        virtual int estimateInsertHeaderSize(
+            const write_ops::InsertCommandRequest& insertReq) const = 0;
+        virtual int estimateUpdateHeaderSize(
+            const write_ops::UpdateCommandRequest& updateReq) const = 0;
+
+        /**
+         * Set of functions which estimate the size of a single write statement.
+         */
+        virtual int estimateInsertSizeBytes(const BSONObj& insert) const = 0;
+        virtual int estimateUpdateSizeBytes(const BatchObject& batchObject,
+                                            UpsertType type) const = 0;
+    };
+
+    /**
      * Factory function to create MongoProcessInterface of the right type. The implementation will
      * be installed by a lib higher up in the link graph depending on the application type.
      */
@@ -127,6 +151,12 @@ public:
     virtual ~MongoProcessInterface(){};
 
     /**
+     * Returns an instance of a 'WriteSizeEstimator' interface.
+     */
+    virtual std::unique_ptr<WriteSizeEstimator> getWriteSizeEstimator(
+        OperationContext* opCtx, const NamespaceString& ns) const = 0;
+
+    /**
      * Creates a new TransactionHistoryIterator object. Only applicable in processes which support
      * locally traversing the oplog.
      */
@@ -149,29 +179,30 @@ public:
     virtual void updateClientOperationTime(OperationContext* opCtx) const = 0;
 
     /**
-     * Inserts 'objs' into 'ns' and returns an error Status if the insert fails. If 'targetEpoch' is
-     * set, throws ErrorCodes::StaleEpoch if the targeted collection does not have the same epoch or
-     * the epoch changes during the course of the insert.
+     * Executes 'insertCommand' against 'ns' and returns an error Status if the insert fails. If
+     * 'targetEpoch' is set, throws ErrorCodes::StaleEpoch if the targeted collection does not have
+     * the same epoch or the epoch changes during the course of the insert.
      */
     virtual Status insert(const boost::intrusive_ptr<ExpressionContext>& expCtx,
                           const NamespaceString& ns,
-                          std::vector<BSONObj>&& objs,
+                          std::unique_ptr<write_ops::InsertCommandRequest> insertCommand,
                           const WriteConcernOptions& wc,
                           boost::optional<OID> targetEpoch) = 0;
 
     /**
-     * Updates the documents matching 'queries' with the objects 'updates'. Returns an error Status
-     * if any of the updates fail, otherwise returns an 'UpdateResult' objects with the details of
-     * the update operation.  If 'targetEpoch' is set, throws ErrorCodes::StaleEpoch if the targeted
-     * collection does not have the same epoch, or if the epoch changes during the update.
+     * Executes the updates described by 'updateCommand'. Returns an error Status if any of the
+     * updates fail, otherwise returns an 'UpdateResult' objects with the details of the update
+     * operation.  If 'targetEpoch' is set, throws ErrorCodes::StaleEpoch if the targeted collection
+     * does not have the same epoch, or if the epoch changes during the update.
      */
-    virtual StatusWith<UpdateResult> update(const boost::intrusive_ptr<ExpressionContext>& expCtx,
-                                            const NamespaceString& ns,
-                                            BatchedObjects&& batch,
-                                            const WriteConcernOptions& wc,
-                                            UpsertType upsert,
-                                            bool multi,
-                                            boost::optional<OID> targetEpoch) = 0;
+    virtual StatusWith<UpdateResult> update(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx,
+        const NamespaceString& ns,
+        std::unique_ptr<write_ops::UpdateCommandRequest> updateCommand,
+        const WriteConcernOptions& wc,
+        UpsertType upsert,
+        bool multi,
+        boost::optional<OID> targetEpoch) = 0;
 
     /**
      * Returns index usage statistics for each index on collection 'ns' along with additional