set

写单行数据

  1.     ///
  2.     /// \brief set
  3.     ///     store the k-v to the cluster.
  4.     ///     key is composed of hashkey and sortkey.
  5.     /// \param hashkey
  6.     /// used to decide which partition to put this k-v
  7.     /// \param sortkey
  8.     /// all the k-v under hashkey will be sorted by sortkey.
  9.     /// \param value
  10.     /// the value we want to store.
  11.     /// \param timeout_milliseconds
  12.     /// if wait longer than this value, will return time out error
  13.     /// \param ttl_seconds
  14.     /// time to live of this value, if expired, will return not found; 0 means no ttl
  15.     /// \return
  16.     /// int, the error indicates whether or not the operation is succeeded.
  17.     /// this error can be converted to a string using get_error_string()
  18.     ///
  19.     virtual int set(const std::string &hashkey,
  20.                     const std::string &sortkey,
  21.                     const std::string &value,
  22.                     int timeout_milliseconds = 5000,
  23.                     int ttl_seconds = 0,
  24.                     internal_info *info = NULL) = 0;

注：

  • internal_info 结构如下，主要是记录在写入成功之后，该条数据的一些信息，在使用之前需要判断info是否为空
  1.     struct internal_info
  2.     {
  3.         int32_t app_id;
  4.         int32_t partition_index;
  5.         int64_t decree;
  6.         std::string server;
  7.         internal_info() : app_id(-1), partition_index(-1), decree(-1) {}
  8.      }
  • 返回值：int值来表示是否成功，通过get_error_string() 函数来判断返回值的意义（下面的所有同步接口的返回值，都可以通过该函数判断返回值意义）
  1.     ///
  2.     /// \brief get_error_string
  3.     /// get error string
  4.     /// all the function above return an int value that indicates an error can be converted into a
  5.     /// string for human reading.
  6.     /// \param error_code
  7.     /// all the error code are defined in "error_def.h"
  8.     /// \return
  9.     ///
  10.     virtual const char *get_error_string(int error_code) const = 0;