/* Copyright (c) 2008, 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, Suite 500, Boston, MA 02110-1335 USA */

#include "my_global.h"
#include "my_thread.h"
#include "table_threads.h"
#include "sql_parse.h"
#include "pfs_instr_class.h"
#include "pfs_instr.h"

THR_LOCK table_threads::m_table_lock;

static const TABLE_FIELD_TYPE field_types[]=
{
  {
    { C_STRING_WITH_LEN("THREAD_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NAME") },
    { C_STRING_WITH_LEN("varchar(128)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("TYPE") },
    { C_STRING_WITH_LEN("varchar(10)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_USER") },
    { C_STRING_WITH_LEN("varchar(" USERNAME_CHAR_LENGTH_STR ")") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_HOST") },
    { C_STRING_WITH_LEN("varchar(60)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_DB") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_COMMAND") },
    { C_STRING_WITH_LEN("varchar(16)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_TIME") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_STATE") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PROCESSLIST_INFO") },
    { C_STRING_WITH_LEN("longtext") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("PARENT_THREAD_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ROLE") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("INSTRUMENTED") },
    { C_STRING_WITH_LEN("enum(\'YES\',\'NO\')") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("HISTORY") },
    { C_STRING_WITH_LEN("enum(\'YES\',\'NO\')") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("CONNECTION_TYPE") },
    { C_STRING_WITH_LEN("varchar(16)") },
    { NULL, 0 }
  },
  {
    { C_STRING_WITH_LEN("THREAD_OS_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
};

TABLE_FIELD_DEF
table_threads::m_field_def=
{ 17, field_types };

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

PFS_engine_table_share
table_threads::m_share=
{
  { C_STRING_WITH_LEN("threads") },
  &pfs_updatable_acl,
  table_threads::create,
  NULL, /* write_row */
  NULL, /* delete_all_rows */
  cursor_by_thread::get_row_count,
  sizeof(PFS_simple_index), /* ref length */
  &m_table_lock,
  &m_field_def,
  false, /* m_perpetual */
  false, /* m_optional */
  &m_share_state
};

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

table_threads::table_threads()
  : cursor_by_thread(& m_share),
  m_row_exists(false)
{}

void table_threads::make_row(PFS_thread *pfs)
{
  pfs_optimistic_state lock;
  pfs_optimistic_state session_lock;
  pfs_optimistic_state stmt_lock;
  PFS_stage_class *stage_class;
  PFS_thread_class *safe_class;

  m_row_exists= false;

  /* Protect this reader against thread termination */
  pfs->m_lock.begin_optimistic_lock(&lock);

  safe_class= sanitize_thread_class(pfs->m_class);
  if (unlikely(safe_class == NULL))
    return;

  m_row.m_thread_internal_id= pfs->m_thread_internal_id;
  m_row.m_parent_thread_internal_id= pfs->m_parent_thread_internal_id;
  m_row.m_processlist_id= pfs->m_processlist_id;
  m_row.m_thread_os_id= pfs->m_thread_os_id;
  m_row.m_name= safe_class->m_name;
  m_row.m_name_length= safe_class->m_name_length;

  /* Protect this reader against session attribute changes */
  pfs->m_session_lock.begin_optimistic_lock(&session_lock);

  m_row.m_username_length= pfs->m_username_length;
  if (unlikely(m_row.m_username_length > sizeof(m_row.m_username)))
    return;
  if (m_row.m_username_length != 0)
    memcpy(m_row.m_username, pfs->m_username, m_row.m_username_length);

  m_row.m_hostname_length= pfs->m_hostname_length;
  if (unlikely(m_row.m_hostname_length > sizeof(m_row.m_hostname)))
    return;
  if (m_row.m_hostname_length != 0)
    memcpy(m_row.m_hostname, pfs->m_hostname, m_row.m_hostname_length);

  if (! pfs->m_session_lock.end_optimistic_lock(& session_lock))
  {
    /*
      One of the columns:
      - PROCESSLIST_USER
      - PROCESSLIST_HOST
      is being updated.
      Do not discard the entire row.
      Do not loop waiting for a stable value.
      Just return NULL values.
    */
    m_row.m_username_length= 0;
    m_row.m_hostname_length= 0;
  }

  /* Protect this reader against statement attributes changes */
  pfs->m_stmt_lock.begin_optimistic_lock(&stmt_lock);

  m_row.m_dbname_length= pfs->m_dbname_length;
  if (unlikely(m_row.m_dbname_length > sizeof(m_row.m_dbname)))
    return;
  if (m_row.m_dbname_length != 0)
    memcpy(m_row.m_dbname, pfs->m_dbname, m_row.m_dbname_length);

  m_row.m_processlist_info_ptr= & pfs->m_processlist_info[0];
  m_row.m_processlist_info_length= pfs->m_processlist_info_length;

  if (! pfs->m_stmt_lock.end_optimistic_lock(& stmt_lock))
  {
    /*
      One of the columns:
      - PROCESSLIST_DB
      - PROCESSLIST_INFO
      is being updated.
      Do not discard the entire row.
      Do not loop waiting for a stable value.
      Just return NULL values.
    */
    m_row.m_dbname_length= 0;
    m_row.m_processlist_info_length= 0;
  }

  /* Dirty read, sanitize the command. */
  m_row.m_command= pfs->m_command;
  if ((m_row.m_command < 0) || (m_row.m_command > COM_END))
    m_row.m_command= COM_END;

  m_row.m_start_time= pfs->m_start_time;

  stage_class= find_stage_class(pfs->m_stage);
  if (stage_class != NULL)
  {
    m_row.m_processlist_state_ptr= stage_class->m_name + stage_class->m_prefix_length;
    m_row.m_processlist_state_length= stage_class->m_name_length - stage_class->m_prefix_length;
  }
  else
  {
    m_row.m_processlist_state_length= 0;
  }
  m_row.m_connection_type = pfs->m_connection_type;


  m_row.m_enabled= pfs->m_enabled;
  m_row.m_history= pfs->m_history;
  m_row.m_psi= pfs;

  if (pfs->m_lock.end_optimistic_lock(& lock))
    m_row_exists= true;
}

int table_threads::read_row_values(TABLE *table,
                                   unsigned char *buf,
                                   Field **fields,
                                   bool read_all)
{
  Field *f;
  const char *str= NULL;
  int len= 0;

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  assert(table->s->null_bytes == 2);
  buf[0]= 0;
  buf[1]= 0;

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* THREAD_ID */
        set_field_ulonglong(f, m_row.m_thread_internal_id);
        break;
      case 1: /* NAME */
        set_field_varchar_utf8(f, m_row.m_name, m_row.m_name_length);
        break;
      case 2: /* TYPE */
        if (m_row.m_processlist_id != 0)
          set_field_varchar_utf8(f, "FOREGROUND", 10);
        else
          set_field_varchar_utf8(f, "BACKGROUND", 10);
        break;
      case 3: /* PROCESSLIST_ID */
        if (m_row.m_processlist_id != 0)
          set_field_ulonglong(f, m_row.m_processlist_id);
        else
          f->set_null();
        break;
      case 4: /* PROCESSLIST_USER */
        if (m_row.m_username_length > 0)
          set_field_varchar_utf8(f, m_row.m_username,
                                 m_row.m_username_length);
        else
          f->set_null();
        break;
      case 5: /* PROCESSLIST_HOST */
        if (m_row.m_hostname_length > 0)
          set_field_varchar_utf8(f, m_row.m_hostname,
                                 m_row.m_hostname_length);
        else
          f->set_null();
        break;
      case 6: /* PROCESSLIST_DB */
        if (m_row.m_dbname_length > 0)
          set_field_varchar_utf8(f, m_row.m_dbname,
                                 m_row.m_dbname_length);
        else
          f->set_null();
        break;
      case 7: /* PROCESSLIST_COMMAND */
        if (m_row.m_processlist_id != 0)
          set_field_varchar_utf8(f, command_name[m_row.m_command].str,
                                 command_name[m_row.m_command].length);
        else
          f->set_null();
        break;
      case 8: /* PROCESSLIST_TIME */
        if (m_row.m_start_time)
        {
          time_t now= my_time(0);
          ulonglong elapsed= (now > m_row.m_start_time ? now - m_row.m_start_time : 0);
          set_field_ulonglong(f, elapsed);
        }
        else
          f->set_null();
        break;
      case 9: /* PROCESSLIST_STATE */
        /* This column's datatype is declared as varchar(64). Thread's state
           message cannot be more than 64 characters. Otherwise, we will end up
           in 'data truncated' warning/error (depends sql_mode setting) when
           server is updating this column for those threads. To prevent this
           kind of issue, an assert is added.
         */
        assert(m_row.m_processlist_state_length <= f->char_length());
        if (m_row.m_processlist_state_length > 0)
          set_field_varchar_utf8(f, m_row.m_processlist_state_ptr,
                                 m_row.m_processlist_state_length);
        else
          f->set_null();
        break;
      case 10: /* PROCESSLIST_INFO */
        if (m_row.m_processlist_info_length > 0)
          set_field_longtext_utf8(f, m_row.m_processlist_info_ptr,
                                  m_row.m_processlist_info_length);
        else
          f->set_null();
        break;
      case 11: /* PARENT_THREAD_ID */
        if (m_row.m_parent_thread_internal_id != 0)
          set_field_ulonglong(f, m_row.m_parent_thread_internal_id);
        else
          f->set_null();
        break;
      case 12: /* ROLE */
        f->set_null();
        break;
      case 13: /* INSTRUMENTED */
        set_field_enum(f, m_row.m_enabled ? ENUM_YES : ENUM_NO);
        break;
      case 14: /* HISTORY */
        set_field_enum(f, m_row.m_history ? ENUM_YES : ENUM_NO);
        break;
      case 15: /* CONNECTION_TYPE */
        get_vio_type_name(m_row.m_connection_type, & str, & len);
        if (len > 0)
          set_field_varchar_utf8(f, str, len);
        else
          f->set_null();
        break;
      case 16: /* THREAD_OS_ID */
        if (m_row.m_thread_os_id > 0)
          set_field_ulonglong(f, m_row.m_thread_os_id);
        else
          f->set_null();
        break;
      default:
        assert(false);
      }
    }
  }
  return 0;
}

int table_threads::update_row_values(TABLE *table,
                                     const unsigned char *old_buf,
                                     unsigned char *new_buf,
                                     Field **fields)
{
  Field *f;
  enum_yes_no value;

  for (; (f= *fields) ; fields++)
  {
    if (bitmap_is_set(table->write_set, f->field_index))
    {
      switch(f->field_index)
      {
      case 0: /* THREAD_ID */
      case 1: /* NAME */
      case 2: /* TYPE */
      case 3: /* PROCESSLIST_ID */
      case 4: /* PROCESSLIST_USER */
      case 5: /* PROCESSLIST_HOST */
      case 6: /* PROCESSLIST_DB */
      case 7: /* PROCESSLIST_COMMAND */
      case 8: /* PROCESSLIST_TIME */
      case 9: /* PROCESSLIST_STATE */
      case 10: /* PROCESSLIST_INFO */
      case 11: /* PARENT_THREAD_ID */
      case 12: /* ROLE */
        return HA_ERR_WRONG_COMMAND;
      case 13: /* INSTRUMENTED */
        value= (enum_yes_no) get_field_enum(f);
        m_row.m_psi->set_enabled((value == ENUM_YES) ? true : false);
        break;
      case 14: /* HISTORY */
        value= (enum_yes_no) get_field_enum(f);
        m_row.m_psi->set_history((value == ENUM_YES) ? true : false);
        break;
      case 15: /* CONNECTION_TYPE */
      case 16: /* THREAD_OS_ID */
        return HA_ERR_WRONG_COMMAND;
      default:
        assert(false);
      }
    }
  }
  return 0;
}