diff --git a/store/mockstore/mocktikv/copr_handler.go b/store/mockstore/mocktikv/copr_handler.go
new file mode 100644
index 0000000000..ea9b16acd8
--- /dev/null
+++ b/store/mockstore/mocktikv/copr_handler.go
@@ -0,0 +1,65 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mocktikv
+
+import (
+	"context"
+
+	"github.com/pingcap/errors"
+	"github.com/pingcap/kvproto/pkg/coprocessor"
+	"github.com/pingcap/tidb/kv"
+	"github.com/pingcap/tipb/go-tipb"
+)
+
+type coprHandler struct {
+	*Session
+}
+
+func (h coprHandler) handleBatchCopRequest(ctx context.Context, req *coprocessor.BatchRequest) (*mockBatchCopDataClient, error) {
+	client := &mockBatchCopDataClient{}
+	for _, ri := range req.Regions {
+		cop := coprocessor.Request{
+			Tp:      kv.ReqTypeDAG,
+			Data:    req.Data,
+			StartTs: req.StartTs,
+			Ranges:  ri.Ranges,
+		}
+		_, exec, dagReq, err := h.buildDAGExecutor(&cop)
+		if err != nil {
+			return nil, errors.Trace(err)
+		}
+		chunk, err := drainRowsFromExecutor(ctx, exec, dagReq)
+		if err != nil {
+			return nil, errors.Trace(err)
+		}
+		client.chunks = append(client.chunks, chunk)
+	}
+	return client, nil
+}
+
+func drainRowsFromExecutor(ctx context.Context, e executor, req *tipb.DAGRequest) (tipb.Chunk, error) {
+	var chunk tipb.Chunk
+	for {
+		row, err := e.Next(ctx)
+		if err != nil {
+			return chunk, errors.Trace(err)
+		}
+		if row == nil {
+			return chunk, nil
+		}
+		for _, offset := range req.OutputOffsets {
+			chunk.RowsData = append(chunk.RowsData, row[offset]...)
+		}
+	}
+}
diff --git a/store/mockstore/mocktikv/rpc.go b/store/mockstore/mocktikv/rpc.go
index 30ea0a969c..4ba4da6e60 100644
--- a/store/mockstore/mocktikv/rpc.go
+++ b/store/mockstore/mocktikv/rpc.go
@@ -33,7 +33,6 @@ import (
 	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/store/tikv/tikvrpc"
-	"github.com/pingcap/tipb/go-tipb"
 )
 
 // For gofail injection.
@@ -553,48 +552,6 @@ func (h kvHandler) handleSplitRegion(req *kvrpcpb.SplitRegionRequest) *kvrpcpb.S
 	return resp
 }
 
-func drainRowsFromExecutor(ctx context.Context, e executor, req *tipb.DAGRequest) (tipb.Chunk, error) {
-	var chunk tipb.Chunk
-	for {
-		row, err := e.Next(ctx)
-		if err != nil {
-			return chunk, errors.Trace(err)
-		}
-		if row == nil {
-			return chunk, nil
-		}
-		for _, offset := range req.OutputOffsets {
-			chunk.RowsData = append(chunk.RowsData, row[offset]...)
-		}
-	}
-}
-
-type coprHandler struct {
-	*Session
-}
-
-func (h coprHandler) handleBatchCopRequest(ctx context.Context, req *coprocessor.BatchRequest) (*mockBatchCopDataClient, error) {
-	client := &mockBatchCopDataClient{}
-	for _, ri := range req.Regions {
-		cop := coprocessor.Request{
-			Tp:      kv.ReqTypeDAG,
-			Data:    req.Data,
-			StartTs: req.StartTs,
-			Ranges:  ri.Ranges,
-		}
-		_, exec, dagReq, err := h.buildDAGExecutor(&cop)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		chunk, err := drainRowsFromExecutor(ctx, exec, dagReq)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		client.chunks = append(client.chunks, chunk)
-	}
-	return client, nil
-}
-
 // Client is a client that sends RPC.
 // This is same with tikv.Client, define again for avoid circle import.
 type Client interface {