diff --git a/common/cow_operation_convert.cc b/common/cow_operation_convert.cc
new file mode 100644
index 0000000..a4eaba3
--- /dev/null
+++ b/common/cow_operation_convert.cc
@@ -0,0 +1,30 @@
+//
+// Copyright (C) 2020 The Android Open Source Project
+//
+// 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "update_engine/common/cow_operation_convert.h"
+
+#include "update_engine/payload_generator/extent_ranges.h"
+
+namespace chromeos_update_engine {
+std::vector<CowOperation> ConvertToCowOperations(
+    const ::google::protobuf::RepeatedPtrField<
+        ::chromeos_update_engine::InstallOperation>& operations,
+    const ::google::protobuf::RepeatedPtrField<CowMergeOperation>&
+        merge_operations) {
+  // TODO(zhangkelvin) Implement this.
+  return {};
+}
+}  // namespace chromeos_update_engine
diff --git a/common/cow_operation_convert.h b/common/cow_operation_convert.h
new file mode 100644
index 0000000..bca10ac
--- /dev/null
+++ b/common/cow_operation_convert.h
@@ -0,0 +1,55 @@
+//
+// Copyright (C) 2020 The Android Open Source Project
+//
+// 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+#ifndef __COW_OPERATION_CONVERT_H
+#define __COW_OPERATION_CONVERT_H
+
+#include <vector>
+
+#include <libsnapshot/cow_format.h>
+
+#include "update_engine/update_metadata.pb.h"
+
+namespace chromeos_update_engine {
+struct CowOperation {
+  enum Type {
+    CowCopy = android::snapshot::kCowCopyOp,
+    CowReplace = android::snapshot::kCowReplaceOp,
+  };
+  Type op;
+  uint64_t src_block;
+  uint64_t dst_block;
+};
+
+// Convert SOURCE_COPY operations in `operations` list to a list of
+// CowOperations according to the merge sequence. This function only converts
+// SOURCE_COPY, other operations are ignored. If there's a merge conflict in
+// SOURCE_COPY operations, some blocks may be converted to COW_REPLACE instead
+// of COW_COPY.
+
+// The list returned does not necessarily preserve the order of
+// SOURCE_COPY in `operations`. The only guarantee about ordering in the
+// returned list is that if operations are applied in such order, there would be
+// no merge conflicts.
+
+// This funnction is intended to be used by delta_performer to perform
+// SOURCE_COPY operations on Virtual AB Compression devices.
+std::vector<CowOperation> ConvertToCowOperations(
+    const ::google::protobuf::RepeatedPtrField<
+        ::chromeos_update_engine::InstallOperation>& operations,
+    const ::google::protobuf::RepeatedPtrField<CowMergeOperation>&
+        merge_operations);
+}  // namespace chromeos_update_engine
+#endif