YugabyteDB (2.13.1.0-b60, 21121d69985fbf76aa6958d8f04a9bfa936293b5)

//  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.

#ifndef YB_ROCKSDB_DB_DB_ITER_H

#define YB_ROCKSDB_DB_DB_ITER_H

#pragma once

#include <stdint.h>

#include <string>

#include "yb/rocksdb/immutable_options.h"

#include "yb/rocksdb/iterator.h"

#include "yb/rocksdb/util/arena.h"

namespace rocksdb {

class Arena;

class DBIter;

class InternalIterator;

// Return a new iterator that converts internal keys (yielded by

// "*internal_iter") that were live at the specified "sequence" number

// into appropriate user keys.

extern Iterator* NewDBIterator(

    Env* env, const ImmutableCFOptions& options,

    const Comparator* user_key_comparator, InternalIterator* internal_iter,

    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,

    uint64_t version_number, const Slice* iterate_upper_bound = nullptr,

    bool prefix_same_as_start = false, bool pin_data = false);

// A wrapper iterator which wraps DB Iterator and the arena, with which the DB

// iterator is supposed be allocated. This class is used as an entry point of

// an iterator hierarchy whose memory can be allocated inline. In that way,

// accessing the iterator tree can be more cache friendly. It is also faster

// to allocate.

class ArenaWrappedDBIter : public Iterator {

 public:

  virtual ~ArenaWrappedDBIter();

  // Get the arena to be used to allocate memory for DBIter to be wrapped,

  // as well as child iterators in it.

  virtual Arena* GetArena() { return &arena_; }

  // Set the DB Iterator to be wrapped

  virtual void SetDBIter(DBIter* iter);

  // Set the internal iterator wrapped inside the DB Iterator. Usually it is

  // a merging iterator.

  virtual void SetIterUnderDBIter(InternalIterator* iter);

  virtual bool Valid() const override;

  virtual void SeekToFirst() override;

  virtual void SeekToLast() override;

  virtual void Seek(const Slice& target) override;

  virtual void Next() override;

  virtual void Prev() override;

  virtual Slice key() const override;

  virtual Slice value() const override;

  virtual Status status() const override;

  void RegisterCleanup(CleanupFunction function, void* arg1, void* arg2);

  virtual Status PinData();

  virtual Status ReleasePinnedData();

  virtual Status GetProperty(std::string prop_name, std::string* prop) override;

  void RevalidateAfterUpperBoundChange() override;

 private:

  DBIter* db_iter_;

  Arena arena_;

};

// Generate the arena wrapped iterator class.

extern ArenaWrappedDBIter* NewArenaWrappedDbIterator(

    Env* env, const ImmutableCFOptions& options,

    const Comparator* user_key_comparator, const SequenceNumber& sequence,

    uint64_t max_sequential_skip_in_iterations, uint64_t version_number,

    const Slice* iterate_upper_bound = nullptr,

    bool prefix_same_as_start = false, bool pin_data = false);

}  // namespace rocksdb

#endif // YB_ROCKSDB_DB_DB_ITER_H