#pragma
#include <iostream>
#include "leveldb/db.h"
#include <vector>
#include <mutex>
namespace leveldb {
class LEVELDB_EXPORT MyLevelDB : leveldb::DB {
 public:
  MyLevelDB(Options& options, std::string db_name) 
  : _op(options), _db_name(db_name) {
	//打开数据库
    Status status = DB::Open(options, db_name + "_main", &_fields_db);
    if (!status.ok()) {
      std::cerr << "Open main database failure: " << status.ToString() << std::endl;
      abort();
    }
  }
  //序列化为字符串
  void SerializeValue(const FieldArray& fields, std::string& resString);
  // 反序列化为字段数组
  void ParseValue(const std::string& value_str, FieldArray& resFieldArray);
  //字段存储
  Status PutWithFields(const WriteOptions& options, const std::string& key,const FieldArray& fields);
  //字段查找
  Status FindKeysByField(const ReadOptions& options, const Field field,std::vector<std::string>* keys);
  //创建索引
  Status CreateIndexOnField(const std::string& field_name);
  //删除索引
  Status DeleteIndex(std::string& field_name);
  void QueryByIndex(const ReadOptions& options, Field& field,
                    std::vector<std::string>& keys);
 public:
   Status Put(const WriteOptions& options, const Slice& key,
             const Slice& value) override;

  Status Delete(const WriteOptions& options, const Slice& key) override;

  Status Write(const WriteOptions& options, WriteBatch* updates) override;

  Status Get(const ReadOptions& options, const Slice& key,
             std::string* value) override;

  Iterator* NewIterator(const ReadOptions& options) override;

  const Snapshot* GetSnapshot() override;

  void ReleaseSnapshot(const Snapshot* snapshot) override;

  bool GetProperty(const Slice& property, std::string* value) override;

  void GetApproximateSizes(const Range* range, int n, uint64_t* sizes) override;

  void CompactRange(const Slice* begin, const Slice* end) override;
 private:
  Options _op;
  std::string _db_name;
  DB* _fields_db;
  std::vector<std::string> index_list_;
  std::mutex mutex_;
  std::vector<DB*> index_db;
};
}