YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.

//  This source code is licensed under the BSD-style license found in the

//  LICENSE file in the root directory of this source tree. An additional grant

//  of patent rights can be found in the PATENTS file in the same directory.

//

// The following only applies to changes made to this file as part of YugaByte development.

//

// Portions Copyright (c) YugaByte, 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, 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.

//

// Copyright (c) 2011 The LevelDB Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file. See the AUTHORS file for names of contributors.

#pragma once

#include "yb/rocksdb/iterator.h"

#include "yb/rocksdb/table/internal_iterator.h"

namespace rocksdb {

struct ReadOptions;

class InternalKeyComparator;

class Arena;

struct TwoLevelIteratorState {

  explicit TwoLevelIteratorState(bool _check_prefix_may_match)

      : check_prefix_may_match(_check_prefix_may_match) {}

  virtual ~TwoLevelIteratorState() {}

  virtual InternalIterator* NewSecondaryIterator(const Slice& handle) = 0;

  virtual bool PrefixMayMatch(const Slice& internal_key) = 0;

  // If call PrefixMayMatch()

  bool check_prefix_may_match;

};

// Return a new two level iterator.  A two-level iterator contains an

// index iterator whose values point to a sequence of blocks where

// each block is itself a sequence of key,value pairs.  The returned

// two-level iterator yields the concatenation of all key/value pairs

// in the sequence of blocks.  Takes ownership of "index_iter" and

// will delete it when no longer needed.

//

// Uses a supplied function to convert an index_iter value into

// an iterator over the contents of the corresponding block.

// arena: If not null, the arena is used to allocate the Iterator.

//        When destroying the iterator, the destructor will destroy

//        all the states but those allocated in arena.

// need_free_iter_and_state: free `state` and `first_level_iter` if

//                           true. Otherwise, just call destructor.

extern InternalIterator* NewTwoLevelIterator(

    TwoLevelIteratorState* state, InternalIterator* first_level_iter, Arena* arena = nullptr,

    bool need_free_iter_and_state = true);

}  // namespace rocksdb