mariadb/storage/perfschema/table_table_handles.cc

/* Copyright (c) 2012, 2023, 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
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  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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  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 Street, Suite 500, Boston, MA 02110-1335 USA */

/**
  @file storage/perfschema/table_table_handles.cc
  Table TABLE_TABLE_HANDLES (implementation).
*/

#include "my_global.h"
#include "my_thread.h"
#include "pfs_instr_class.h"
#include "pfs_column_types.h"
#include "pfs_column_values.h"
#include "table_table_handles.h"
#include "pfs_global.h"
#include "pfs_stat.h"
#include "pfs_buffer_container.h"
#include "field.h"

THR_LOCK table_table_handles::m_table_lock;

PFS_engine_table_share_state
table_table_handles::m_share_state = {
  false /* m_checked */
};

PFS_engine_table_share
table_table_handles::m_share=
{
  { C_STRING_WITH_LEN("table_handles") },
  &pfs_readonly_acl,
  table_table_handles::create,
  NULL, /* write_row */
  NULL, /* delete_all_rows */
  table_table_handles::get_row_count,
  sizeof(PFS_simple_index),
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE table_handles("
  "OBJECT_TYPE VARCHAR(64) not null comment 'The table opened by a table handle.',"
  "OBJECT_SCHEMA VARCHAR(64) not null comment 'The schema that contains the object.',"
  "OBJECT_NAME VARCHAR(64) not null comment 'The name of the instrumented object.',"
  "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'The table handle address in memory.',"
  "OWNER_THREAD_ID BIGINT unsigned comment 'The thread owning the table handle.',"
  "OWNER_EVENT_ID BIGINT unsigned comment 'The event which caused the table handle to be opened.',"
  "INTERNAL_LOCK VARCHAR(64) comment 'The table lock used at the SQL level.',"
  "EXTERNAL_LOCK VARCHAR(64) comment 'The table lock used at the storage engine level.')") },
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

PFS_engine_table*
table_table_handles::create(void)
{
  return new table_table_handles();
}

ha_rows
table_table_handles::get_row_count(void)
{
  return global_table_container.get_row_count();
}

table_table_handles::table_table_handles()
  : PFS_engine_table(&m_share, &m_pos),
    m_row_exists(false), m_pos(0), m_next_pos(0)
{}

void table_table_handles::reset_position(void)
{
  m_pos.m_index= 0;
  m_next_pos.m_index= 0;
}

int table_table_handles::rnd_init(bool scan)
{
  return 0;
}

int table_table_handles::rnd_next(void)
{
  PFS_table *pfs;

  m_pos.set_at(&m_next_pos);
  PFS_table_iterator it= global_table_container.iterate(m_pos.m_index);
  pfs= it.scan_next(& m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    m_next_pos.set_after(&m_pos);
    return 0;
  }

  return HA_ERR_END_OF_FILE;
}

int
table_table_handles::rnd_pos(const void *pos)
{
  PFS_table *pfs;

  set_position(pos);

  pfs= global_table_container.get(m_pos.m_index);
  if (pfs != NULL)
  {
    make_row(pfs);
    return 0;
  }

  return HA_ERR_RECORD_DELETED;
}

void table_table_handles::make_row(PFS_table *table)
{
  pfs_optimistic_state lock;
  PFS_table_share *share;
  PFS_thread *thread;

  m_row_exists= false;

  table->m_lock.begin_optimistic_lock(&lock);

  share= sanitize_table_share(table->m_share);
  if (share == NULL)
    return;

  if (m_row.m_object.make_row(share))
    return;

  m_row.m_identity= table->m_identity;

  thread= sanitize_thread(table->m_thread_owner);
  if (thread != NULL)
  {
    m_row.m_owner_thread_id= thread->m_thread_internal_id;
    m_row.m_owner_event_id= table->m_owner_event_id;
  }
  else
  {
    m_row.m_owner_thread_id= 0;
    m_row.m_owner_event_id= 0;
  }

  m_row.m_internal_lock= table->m_internal_lock;
  m_row.m_external_lock= table->m_external_lock;

  if (! table->m_lock.end_optimistic_lock(&lock))
    return;

  m_row_exists= true;
}

int table_table_handles::read_row_values(TABLE *table,
                                         unsigned char *buf,
                                         Field **fields,
                                         bool read_all)
{
  Field *f;

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  assert(table->s->null_bytes == 1);
  buf[0]= 0;

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* OBJECT_TYPE */
      case 1: /* SCHEMA_NAME */
      case 2: /* OBJECT_NAME */
        m_row.m_object.set_field(f->field_index, f);
        break;
      case 3: /* OBJECT_INSTANCE_BEGIN */
        set_field_ulonglong(f, (intptr) m_row.m_identity);
        break;
      case 4: /* OWNER_THREAD_ID */
        set_field_ulonglong(f, m_row.m_owner_thread_id);
        break;
      case 5: /* OWNER_EVENT_ID */
        set_field_ulonglong(f, m_row.m_owner_event_id);
        break;
      case 6: /* INTERNAL_LOCK */
        set_field_lock_type(f, m_row.m_internal_lock);
        break;
      case 7: /* EXTERNAL_LOCK */
        set_field_lock_type(f, m_row.m_external_lock);
        break;
      default:
        assert(false);
      }
    }
  }

  return 0;
}