table_data_locks.h

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/* Copyright (c) 2016, 2022, Oracle and/or its affiliates.
 
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
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  as designated in a particular file or component or in included license
  documentation.  The authors of MySQL hereby grant you an additional
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  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License, version 2.0, for more details.
 
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef TABLE_DATA_LOCK_H
#define TABLE_DATA_LOCK_H
 
/**
  @file storage/perfschema/table_data_locks.h
  Table DATA_LOCKS (declarations).
*/
 
#include <sys/types.h>
 
#include "my_base.h"
#include "storage/perfschema/pfs.h"
#include "storage/perfschema/pfs_data_lock.h"
#include "storage/perfschema/pfs_engine_table.h"
 
class Field;
class PSI_engine_data_lock_iterator;
class Plugin_table;
struct TABLE;
struct THR_LOCK;
 
/**
  @addtogroup Performance_schema_tables
  @{
*/
 
/**
  Position of a cursor on
  PERFORMANCE_SCHEMA.DATA_LOCKS.
  Index 1 on engine (0 based)
  Index 2 on engine index (0 based)
*/
struct scan_pos_data_lock {
  scan_pos_data_lock() {
    m_index_1 = 0;
    m_index_2 = 0;
  }
 
  inline void reset(void) {
    m_index_1 = 0;
    m_index_2 = 0;
  }
 
  void set_at(const scan_pos_data_lock *other) {
    m_index_1 = other->m_index_1;
    m_index_2 = other->m_index_2;
  }
 
  void set_after(const scan_pos_data_lock *other) {
    m_index_1 = other->m_index_1;
    m_index_2 = other->m_index_2 + 1;
  }
 
  inline bool has_more_engine() {
    return (m_index_1 < COUNT_DATA_LOCK_ENGINES);
  }
 
  inline void next_engine() {
    m_index_1++;
    m_index_2 = 0;
  }
 
  unsigned int m_index_1;
  unsigned int m_index_2;
};
 
/** Table PERFORMANCE_SCHEMA.DATA_LOCKS. */
class table_data_locks : public PFS_engine_table {
  typedef scan_pos_data_lock scan_pos_t;
  typedef pk_pos_data_lock pk_pos_t;
 
 public:
  /** Table share. */
  static PFS_engine_table_share m_share;
  static PFS_engine_table *create(PFS_engine_table_share *);
  static ha_rows get_row_count();
 
  int rnd_next() override;
  int rnd_pos(const void *pos) override;
  void reset_position(void) override;
 
  int index_init(uint idx, bool sorted) override;
  int index_next() override;
 
 private:
  int read_row_values(TABLE *table, unsigned char *buf, Field **fields,
                      bool read_all) override;
 
  table_data_locks();
 
  void destroy_iterators();
 
 public:
  ~table_data_locks() override;
 
 private:
  /** Table share lock. */
  static THR_LOCK m_table_lock;
  /** Table definition. */
  static Plugin_table m_table_def;
 
  /** Current row. */
  row_data_lock *m_row;
  /** Current scan position. */
  scan_pos_t m_pos;
  /** Next scan position. */
  scan_pos_t m_next_pos;
  /** Current pk position. */
  pk_pos_t m_pk_pos;
 
  PFS_data_lock_container m_container;
  PSI_engine_data_lock_iterator *m_iterator[COUNT_DATA_LOCK_ENGINES];
 
  PFS_index_data_locks *m_opened_index;
};
 
/** @} */
#endif