/* Copyright (c) 2011, 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.

  This program is also distributed with certain software (including
  but not limited to OpenSSL) that is licensed under separate terms,
  as designated in a particular file or component or in included license
  documentation.  The authors of MySQL hereby grant you an additional
  permission to link the program and your derivative works with the
  separately licensed software that they have included with MySQL.

  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,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */

#include "my_global.h"
#include "my_thread.h"
#include "table_hosts.h"
#include "pfs_instr_class.h"
#include "pfs_instr.h"
#include "pfs_account.h"
#include "pfs_host.h"
#include "pfs_visitor.h"
#include "pfs_memory.h"
#include "pfs_status.h"
#include "field.h"

THR_LOCK table_hosts::m_table_lock;

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

PFS_engine_table_share
table_hosts::m_share=
{
  { C_STRING_WITH_LEN("hosts") },
  &pfs_truncatable_acl,
  table_hosts::create,
  NULL, /* write_row */
  table_hosts::delete_all_rows,
  cursor_by_host::get_row_count,
  sizeof(PFS_simple_index), /* ref length */
  &m_table_lock,
  { C_STRING_WITH_LEN("CREATE TABLE hosts("
                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host name used by the client to connect, NULL for internal threads or user sessions that failed to authenticate.',"
                      "CURRENT_CONNECTIONS bigint not null comment 'Current number of the host''s connections.',"
                      "TOTAL_CONNECTIONS bigint not null comment 'Total number of the host''s connections')") },
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

PFS_engine_table* table_hosts::create()
{
  return new table_hosts();
}

int
table_hosts::delete_all_rows(void)
{
  reset_events_waits_by_thread();
  reset_events_waits_by_account();
  reset_events_waits_by_host();
  reset_events_stages_by_thread();
  reset_events_stages_by_account();
  reset_events_stages_by_host();
  reset_events_statements_by_thread();
  reset_events_statements_by_account();
  reset_events_statements_by_host();
  reset_events_transactions_by_thread();
  reset_events_transactions_by_account();
  reset_events_transactions_by_host();
  reset_memory_by_thread();
  reset_memory_by_account();
  reset_memory_by_host();
  reset_status_by_thread();
  reset_status_by_account();
  reset_status_by_host();
  purge_all_account();
  purge_all_host();
  return 0;
}

table_hosts::table_hosts()
  : cursor_by_host(& m_share),
  m_row_exists(false)
{}

void table_hosts::make_row(PFS_host *pfs)
{
  pfs_optimistic_state lock;

  m_row_exists= false;
  pfs->m_lock.begin_optimistic_lock(&lock);

  if (m_row.m_host.make_row(pfs))
    return;

  PFS_connection_stat_visitor visitor;
  PFS_connection_iterator::visit_host(pfs,
                                      true,  /* accounts */
                                      true,  /* threads */
                                      false, /* THDs */
                                      & visitor);

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

  m_row.m_connection_stat.set(& visitor.m_stat);
  m_row_exists= true;
}

int table_hosts::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: /* HOST */
        m_row.m_host.set_field(f);
        break;
      case 1: /* CURRENT_CONNECTIONS */
      case 2: /* TOTAL_CONNECTIONS */
        m_row.m_connection_stat.set_field(f->field_index - 1, f);
        break;
      default:
        assert(false);
      }
    }
  }
  return 0;
}