ceph/src/rocksdb/utilities/compaction_filters/layered_compaction_filter_base.h

   1 // Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
   2 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   3 // Use of this source code is governed by a BSD-style license that can be
   4 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   5
   6 #pragma once
   7 #include <memory>
   8
   9 #include "rocksdb/compaction_filter.h"
  10
  11 namespace ROCKSDB_NAMESPACE {
  12
  13 // Abstract base class for building layered compaction filter on top of
  14 // user compaction filter.
  15 // See BlobIndexCompactionFilter or TtlCompactionFilter for a basic usage.
  16 class LayeredCompactionFilterBase : public CompactionFilter {
  17  public:
  18   LayeredCompactionFilterBase(
  19       const CompactionFilter* _user_comp_filter,
  20       std::unique_ptr<const CompactionFilter> _user_comp_filter_from_factory)
  21       : user_comp_filter_(_user_comp_filter),
  22         user_comp_filter_from_factory_(
  23             std::move(_user_comp_filter_from_factory)) {
  24     if (!user_comp_filter_) {
  25       user_comp_filter_ = user_comp_filter_from_factory_.get();
  26     }
  27   }
  28
  29   // Return a pointer to user compaction filter
  30   const CompactionFilter* user_comp_filter() const { return user_comp_filter_; }
  31
  32   const Customizable* Inner() const override { return user_comp_filter_; }
  33
  34  protected:
  35   const CompactionFilter* user_comp_filter_;
  36
  37  private:
  38   std::unique_ptr<const CompactionFilter> user_comp_filter_from_factory_;
  39 };
  40
  41 }  //  namespace ROCKSDB_NAMESPACE