// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 KUDU_FS_BLOCK_ID_H
#define KUDU_FS_BLOCK_ID_H

#include <cinttypes>
#include <cstddef>
#include <cstdint>
#include <iosfwd>
#include <string>
#include <unordered_set>
#include <vector>

#include "kudu/gutil/stringprintf.h"

namespace kudu {

class BlockIdPB;

class BlockId {
 public:
  BlockId()
    : id_(kInvalidId) {
  }

  explicit BlockId(uint64_t id) {
    SetId(id);
  }

  void SetId(uint64_t id) {
    id_ = id;
  }

  bool IsNull() const { return id_ == kInvalidId; }

  std::string ToString() const {
    return StringPrintf("%016" PRIu64, id_);
  }

  bool operator==(const BlockId& other) const {
    return id_ == other.id_;
  }

  bool operator!=(const BlockId& other) const {
    return id_ != other.id_;
  }

  bool operator<(const BlockId& other) const {
    return id_ < other.id_;
  }

  // Returns the raw ID. Use with care; in most cases the BlockId should be
  // treated as a completely opaque value.
  uint64_t id() const { return id_; }

  // Join the given block IDs with ','. Useful for debug printouts.
  static std::string JoinStrings(const std::vector<BlockId>& blocks);

  void CopyToPB(BlockIdPB* pb) const;

  static BlockId FromPB(const BlockIdPB& pb);

 private:
  static const uint64_t kInvalidId;

  uint64_t id_;
};

std::ostream& operator<<(std::ostream& o, const BlockId& block_id);

struct BlockIdHash {
  size_t operator()(const BlockId& block_id) const {
    return block_id.id();
  }
};

struct BlockIdCompare {
  bool operator()(const BlockId& first, const BlockId& second) const {
    return first < second;
  }
};

struct BlockIdEqual {
  bool operator()(const BlockId& first, const BlockId& second) const {
    return first == second;
  }
};

typedef std::unordered_set<BlockId, BlockIdHash, BlockIdEqual> BlockIdSet;
typedef std::vector<BlockId> BlockIdContainer;
} // namespace kudu
#endif /* KUDU_FS_BLOCK_ID_H */