Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/rocksdb/utilities/merge_operators/sortlist.h b/src/rocksdb/utilities/merge_operators/sortlist.h
new file mode 100644
index 000000000..eaa4e76fb
--- /dev/null
+++ b/src/rocksdb/utilities/merge_operators/sortlist.h
@@ -0,0 +1,42 @@
+//  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).
+
+// A MergeOperator for RocksDB that implements Merge Sort.
+// It is built using the MergeOperator interface. The operator works by taking
+// an input which contains one or more merge operands where each operand is a
+// list of sorted ints and merges them to form a large sorted list.
+#pragma once
+
+#include "rocksdb/merge_operator.h"
+#include "rocksdb/slice.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class SortList : public MergeOperator {
+ public:
+  bool FullMergeV2(const MergeOperationInput& merge_in,
+                   MergeOperationOutput* merge_out) const override;
+
+  bool PartialMerge(const Slice& /*key*/, const Slice& left_operand,
+                    const Slice& right_operand, std::string* new_value,
+                    Logger* /*logger*/) const override;
+
+  bool PartialMergeMulti(const Slice& key,
+                         const std::deque<Slice>& operand_list,
+                         std::string* new_value, Logger* logger) const override;
+
+  static const char* kClassName() { return "MergeSortOperator"; }
+  static const char* kNickName() { return "sortlist"; }
+
+  const char* Name() const override { return kClassName(); }
+  const char* NickName() const override { return kNickName(); }
+
+  void MakeVector(std::vector<int>& operand, Slice slice) const;
+
+ private:
+  std::vector<int> Merge(std::vector<int>& left, std::vector<int>& right) const;
+};
+
+}  // namespace ROCKSDB_NAMESPACE