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.

//

#ifndef ROCKSDB_TABLE_INTERNAL_ITERATOR_H

#define ROCKSDB_TABLE_INTERNAL_ITERATOR_H

#pragma once

#include <string>

#include "yb/rocksdb/iterator.h"

#include "yb/rocksdb/status.h"

namespace rocksdb {

class InternalIterator : public Cleanable {

 public:

  InternalIterator() {}

  virtual ~InternalIterator() {}

  // An iterator is either positioned at a key/value pair, or

  // not valid.  This method returns true iff the iterator is valid.

  virtual bool Valid() const = 0;

  // Position at the first key in the source.  The iterator is Valid()

  // after this call iff the source is not empty.

  virtual void SeekToFirst() = 0;

  // Position at the last key in the source.  The iterator is

  // Valid() after this call iff the source is not empty.

  virtual void SeekToLast() = 0;

  // Position at the first key in the source that at or past target

  // The iterator is Valid() after this call iff the source contains

  // an entry that comes at or past target.

  // target is encoded representation of InternalKey.

  virtual void Seek(const Slice& target) = 0;

  // Moves to the next entry in the source.  After this call, Valid() is

  // true iff the iterator was not positioned at the last entry in the source.

  // REQUIRES: Valid()

  virtual void Next() = 0;

  // Moves to the previous entry in the source.  After this call, Valid() is

  // true iff the iterator was not positioned at the first entry in source.

  // REQUIRES: Valid()

  virtual void Prev() = 0;

  // Return the key for the current entry.  The underlying storage for

  // the returned slice is valid only until the next modification of

  // the iterator.

  // REQUIRES: Valid()

  virtual Slice key() const = 0;

  // Return the value for the current entry.  The underlying storage for

  // the returned slice is valid only until the next modification of

  // the iterator.

  // REQUIRES: !AtEnd() && !AtStart()

  virtual Slice value() const = 0;

  // If an error has occurred, return it.  Else return an ok status.

  // If non-blocking IO is requested and this operation cannot be

  // satisfied without doing some IO, then this returns STATUS(Incomplete, ).

  virtual Status status() const = 0;

  // Make sure that all current and future data blocks used by this iterator

  // will be pinned in memory and will not be released except when

  // ReleasePinnedData() is called or the iterator is deleted.

  virtual Status PinData() { return STATUS(NotSupported, ""); }

Unexecuted instantiation: rocksdb::InternalIterator::PinData()

Unexecuted instantiation: rocksdb::InternalIterator::PinData()

  // Release all blocks that were pinned because of PinData() and no future

  // blocks will be pinned.

  virtual Status ReleasePinnedData() { return STATUS(NotSupported, ""); }

Unexecuted instantiation: rocksdb::InternalIterator::ReleasePinnedData()

Unexecuted instantiation: rocksdb::InternalIterator::ReleasePinnedData()

  // If true, this means that the Slice returned by key() is valid as long

  // as the iterator is not deleted and ReleasePinnedData() is not called.

  //

  // IsKeyPinned() is guaranteed to always return true if

  //  - PinData() is called

  //  - DB tables were created with BlockBasedTableOptions::use_delta_encoding

  //    set to false.

  virtual bool IsKeyPinned() const { return false; }

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

    return STATUS(NotSupported, "");

  }

 private:

  // No copying allowed

  InternalIterator(const InternalIterator&) = delete;

  InternalIterator& operator=(const InternalIterator&) = delete;

};

// Return an empty iterator (yields nothing).

extern InternalIterator* NewEmptyInternalIterator();

// Return an empty iterator with the specified status.

extern InternalIterator* NewErrorInternalIterator(const Status& status);

}  // namespace rocksdb

#endif // ROCKSDB_TABLE_INTERNAL_ITERATOR_H