1 files changed, 52 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/merge_operators.h b/src/rocksdb/utilities/merge_operators.h
new file mode 100644
index 00000000..4c720b82
--- /dev/null
+++ b/src/rocksdb/utilities/merge_operators.h
@@ -0,0 +1,52 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+#pragma once
+#include "rocksdb/merge_operator.h"
+
+#include <stdio.h>
+
+#include <memory>
+#include <string>
+
+namespace rocksdb {
+
+class MergeOperators {
+ public:
+  static std::shared_ptr<MergeOperator> CreatePutOperator();
+  static std::shared_ptr<MergeOperator> CreateDeprecatedPutOperator();
+  static std::shared_ptr<MergeOperator> CreateUInt64AddOperator();
+  static std::shared_ptr<MergeOperator> CreateStringAppendOperator();
+  static std::shared_ptr<MergeOperator> CreateStringAppendOperator(char delim_char);
+  static std::shared_ptr<MergeOperator> CreateStringAppendTESTOperator();
+  static std::shared_ptr<MergeOperator> CreateMaxOperator();
+  static std::shared_ptr<MergeOperator> CreateBytesXOROperator();
+
+  // Will return a different merge operator depending on the string.
+  // TODO: Hook the "name" up to the actual Name() of the MergeOperators?
+  static std::shared_ptr<MergeOperator> CreateFromStringId(
+      const std::string& name) {
+    if (name == "put") {
+      return CreatePutOperator();
+    } else if (name == "put_v1") {
+      return CreateDeprecatedPutOperator();
+    } else if ( name == "uint64add") {
+      return CreateUInt64AddOperator();
+    } else if (name == "stringappend") {
+      return CreateStringAppendOperator();
+    } else if (name == "stringappendtest") {
+      return CreateStringAppendTESTOperator();
+    } else if (name == "max") {
+      return CreateMaxOperator();
+    } else if (name == "bytesxor") {
+      return CreateBytesXOROperator();
+    } else {
+      // Empty or unknown, just return nullptr
+      return nullptr;
+    }
+  }
+};
+
+}  // namespace rocksdb