table_base.h

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/* Copyright (c) 2022, 2026, Oracle and/or its affiliates.
 
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#ifndef TABLE_BASE_INCLUDED
#define TABLE_BASE_INCLUDED
 
/* Common header for all Health Monitor tables. */
 
#include "component_table.h"
#include "health_monitor_constants.h"
 
namespace hm {
 
struct table_base_pos {
  table_base_pos() : m_index{0} {}
  void reset() { m_index = 0; }
  void set_at(const table_base_pos *other) { m_index = other->m_index; }
  void set_after(const table_base_pos *other) { m_index = other->m_index + 1; }
  // Record id, zero-based
  unsigned int m_index;
};
 
class table_base {
 public:
  typedef table_base_pos pos_t;
 
  table_base() = default;
  virtual ~table_base() = default;
 
  table_base(const table_base &) = default;
  table_base &operator=(const table_base &) = default;
  table_base(table_base &&) = default;
  table_base &operator=(table_base &&) = default;
 
  virtual int rnd_init(bool /*scan*/) { return 0; }
  virtual int rnd_next() = 0;
  virtual int rnd_pos() = 0;
  virtual void reset_position() { m_pos.reset(); }
  virtual int read_column_value(PSI_field *field, unsigned int index) = 0;
  virtual void close_table() {}
 
  /* C interface */
  static int rnd_init(PSI_table_handle *handle, bool /*scan*/);
  static int rnd_next(PSI_table_handle *handle);
  static int rnd_pos(PSI_table_handle *handle);
  static void reset_position(PSI_table_handle *handle);
  static int read_column_value(PSI_table_handle *handle, PSI_field *field,
                               unsigned int index);
  static void close_table(PSI_table_handle *handle);
 
  pos_t m_pos;
  pos_t m_next_pos;
};
 
}  // namespace hm
 
#endif  // TABLE_BASE_INCLUDED