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_TABLE_BLOCK_BUILDER_H

#define YB_ROCKSDB_TABLE_BLOCK_BUILDER_H

#include <stdint.h>

#include <vector>

#include "yb/rocksdb/types.h"

#include "yb/util/slice.h"

namespace rocksdb {

class BlockBuilder {

 public:

  BlockBuilder(const BlockBuilder&) = delete;

  void operator=(const BlockBuilder&) = delete;

  explicit BlockBuilder(int block_restart_interval,

                        KeyValueEncodingFormat key_value_encoding_format,

                        bool use_delta_encoding = true);

  // Reset the contents as if the BlockBuilder was just constructed.

  void Reset();

  // REQUIRES: Finish() has not been called since the last call to Reset().

  // REQUIRES: key is larger than any previously added key

  void Add(const Slice& key, const Slice& value);

  // Finish building the block and return a slice that refers to the

  // block contents.  The returned slice will remain valid for the

  // lifetime of this builder or until Reset() is called.

  Slice Finish();

  // Returns an estimate of the current (uncompressed) size of the block

  // we are building.

  size_t CurrentSizeEstimate() const;

  // Returns an estimated block size after appending key and value.

  size_t EstimateSizeAfterKV(const Slice& key, const Slice& value) const;

  size_t NumKeys() const;

  // Return true iff no entries have been added since the last Reset()

  bool empty() const {

    return buffer_.empty();

  }

 private:

  const int block_restart_interval_;

  const bool use_delta_encoding_;

  const KeyValueEncodingFormat key_value_encoding_format_;

  std::string           buffer_;    // Destination buffer

  std::vector<uint32_t> restarts_;  // Restart points

  int                   counter_;   // Number of entries emitted since restart

  bool                  finished_;  // Has Finish() been called?

  std::string           last_key_;

};

}  // namespace rocksdb

#endif // YB_ROCKSDB_TABLE_BLOCK_BUILDER_H