/* Copyright (c) 2010, 2018, Oracle and/or its affiliates. All rights reserved.

  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 */

/**
  @file storage/perfschema/table_events_statements.cc
  Table EVENTS_STATEMENTS_xxx (implementation).
*/

#include "my_global.h"
#include "my_thread.h"
#include "table_events_statements.h"
#include "pfs_instr_class.h"
#include "pfs_instr.h"
#include "pfs_events_statements.h"
#include "pfs_timer.h"
#include "sp_head.h" /* TYPE_ENUM_FUNCTION, ... */
#include "table_helper.h"
#include "my_md5.h"
#include "pfs_buffer_container.h"

THR_LOCK table_events_statements_current::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("EVENT_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("END_EVENT_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("EVENT_NAME") },
    { C_STRING_WITH_LEN("varchar(128)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SOURCE") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("TIMER_START") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("TIMER_END") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("TIMER_WAIT") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("LOCK_TIME") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SQL_TEXT") },
    { C_STRING_WITH_LEN("longtext") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("DIGEST") },
    { C_STRING_WITH_LEN("varchar(32)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("DIGEST_TEXT") },
    { C_STRING_WITH_LEN("longtext") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("CURRENT_SCHEMA") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("OBJECT_TYPE") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("OBJECT_SCHEMA") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("OBJECT_NAME") },
    { C_STRING_WITH_LEN("varchar(64)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("OBJECT_INSTANCE_BEGIN") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("MYSQL_ERRNO") },
    { C_STRING_WITH_LEN("int(11)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("RETURNED_SQLSTATE") },
    { C_STRING_WITH_LEN("varchar(5)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("MESSAGE_TEXT") },
    { C_STRING_WITH_LEN("varchar(128)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ERRORS") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("WARNINGS") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ROWS_AFFECTED") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ROWS_SENT") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ROWS_EXAMINED") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("CREATED_TMP_DISK_TABLES") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("CREATED_TMP_TABLES") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SELECT_FULL_JOIN") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SELECT_FULL_RANGE_JOIN") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SELECT_RANGE") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SELECT_RANGE_CHECK") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SELECT_SCAN") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SORT_MERGE_PASSES") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SORT_RANGE") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SORT_ROWS") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("SORT_SCAN") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NO_INDEX_USED") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NO_GOOD_INDEX_USED") },
    { C_STRING_WITH_LEN("bigint") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NESTING_EVENT_ID") },
    { C_STRING_WITH_LEN("bigint(20)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NESTING_EVENT_TYPE") },
    { C_STRING_WITH_LEN("enum(\'TRANSACTION\',\'STATEMENT\',\'STAGE\',\'WAIT\'") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("NESTING_EVENT_LEVEL") },
    { C_STRING_WITH_LEN("int(11)") },
    { NULL, 0}
  }
};

TABLE_FIELD_DEF
table_events_statements_current::m_field_def=
{41 , field_types };

PFS_engine_table_share
table_events_statements_current::m_share=
{
  { C_STRING_WITH_LEN("events_statements_current") },
  &pfs_truncatable_acl,
  table_events_statements_current::create,
  NULL, /* write_row */
  table_events_statements_current::delete_all_rows,
  table_events_statements_current::get_row_count,
  sizeof(pos_events_statements_current), /* ref length */
  &m_table_lock,
  &m_field_def,
  false, /* checked */
  false  /* perpetual */
};

THR_LOCK table_events_statements_history::m_table_lock;

PFS_engine_table_share
table_events_statements_history::m_share=
{
  { C_STRING_WITH_LEN("events_statements_history") },
  &pfs_truncatable_acl,
  table_events_statements_history::create,
  NULL, /* write_row */
  table_events_statements_history::delete_all_rows,
  table_events_statements_history::get_row_count,
  sizeof(pos_events_statements_history), /* ref length */
  &m_table_lock,
  &table_events_statements_current::m_field_def,
  false, /* checked */
  false  /* perpetual */
};

THR_LOCK table_events_statements_history_long::m_table_lock;

PFS_engine_table_share
table_events_statements_history_long::m_share=
{
  { C_STRING_WITH_LEN("events_statements_history_long") },
  &pfs_truncatable_acl,
  table_events_statements_history_long::create,
  NULL, /* write_row */
  table_events_statements_history_long::delete_all_rows,
  table_events_statements_history_long::get_row_count,
  sizeof(PFS_simple_index), /* ref length */
  &m_table_lock,
  &table_events_statements_current::m_field_def,
  false, /* checked */
  false  /* perpetual */
};

table_events_statements_common::table_events_statements_common
(const PFS_engine_table_share *share, void *pos)
  : PFS_engine_table(share, pos),
  m_row_exists(false)
{}

/**
  Build a row.
  @param statement                      the statement the cursor is reading
*/
void table_events_statements_common::make_row_part_1(PFS_events_statements *statement,
                                                     sql_digest_storage *digest)
{
  ulonglong timer_end;

  m_row_exists= false;

  PFS_statement_class *unsafe= (PFS_statement_class*) statement->m_class;
  PFS_statement_class *klass= sanitize_statement_class(unsafe);
  if (unlikely(klass == NULL))
    return;

  m_row.m_thread_internal_id= statement->m_thread_internal_id;
  m_row.m_event_id= statement->m_event_id;
  m_row.m_end_event_id= statement->m_end_event_id;
  m_row.m_nesting_event_id= statement->m_nesting_event_id;
  m_row.m_nesting_event_type= statement->m_nesting_event_type;
  m_row.m_nesting_event_level= statement->m_nesting_event_level;

  if (m_row.m_end_event_id == 0)
  {
    timer_end= get_timer_raw_value(statement_timer);
  }
  else
  {
    timer_end= statement->m_timer_end;
  }

  m_normalizer->to_pico(statement->m_timer_start, timer_end,
                      & m_row.m_timer_start, & m_row.m_timer_end, & m_row.m_timer_wait);
  m_row.m_lock_time= statement->m_lock_time * MICROSEC_TO_PICOSEC;

  m_row.m_name= klass->m_name;
  m_row.m_name_length= klass->m_name_length;

  CHARSET_INFO *cs= get_charset(statement->m_sqltext_cs_number, MYF(0));
  size_t valid_length= statement->m_sqltext_length;

  if (cs != NULL)
  {
    if (cs->mbmaxlen > 1)
    {
      int well_formed_error;
      valid_length= cs->cset->well_formed_len(cs,
                                              statement->m_sqltext,
                                              statement->m_sqltext + valid_length,
                                              valid_length,
                                              &well_formed_error);
    }
  }

  m_row.m_sqltext.set_charset(cs);
  m_row.m_sqltext.length(0);
  m_row.m_sqltext.append(statement->m_sqltext, (uint32)valid_length, cs);

  /* Indicate that sqltext is truncated or not well-formed. */
  if (statement->m_sqltext_truncated || valid_length < statement->m_sqltext_length)
  {
    size_t chars= m_row.m_sqltext.numchars();
    if (chars > 3)
    {
      chars-= 3;
      size_t bytes_offset= m_row.m_sqltext.charpos(chars, 0);
      m_row.m_sqltext.length(bytes_offset);
      m_row.m_sqltext.append("...", 3);
    }
  }

  m_row.m_current_schema_name_length= statement->m_current_schema_name_length;
  if (m_row.m_current_schema_name_length > 0)
    memcpy(m_row.m_current_schema_name, statement->m_current_schema_name, m_row.m_current_schema_name_length);

  m_row.m_object_type= statement->m_sp_type;

  m_row.m_schema_name_length= statement->m_schema_name_length;
  if (m_row.m_schema_name_length > 0)
    memcpy(m_row.m_schema_name, statement->m_schema_name, m_row.m_schema_name_length);

  m_row.m_object_name_length= statement->m_object_name_length;
  if (m_row.m_object_name_length > 0)
    memcpy(m_row.m_object_name, statement->m_object_name, m_row.m_object_name_length);

  /* Disable source file and line to avoid stale __FILE__ pointers. */
  m_row.m_source_length= 0;

  memcpy(m_row.m_message_text, statement->m_message_text, sizeof(m_row.m_message_text));
  m_row.m_sql_errno= statement->m_sql_errno;
  memcpy(m_row.m_sqlstate, statement->m_sqlstate, SQLSTATE_LENGTH);
  m_row.m_error_count= statement->m_error_count;
  m_row.m_warning_count= statement->m_warning_count;
  m_row.m_rows_affected= statement->m_rows_affected;

  m_row.m_rows_sent= statement->m_rows_sent;
  m_row.m_rows_examined= statement->m_rows_examined;
  m_row.m_created_tmp_disk_tables= statement->m_created_tmp_disk_tables;
  m_row.m_created_tmp_tables= statement->m_created_tmp_tables;
  m_row.m_select_full_join= statement->m_select_full_join;
  m_row.m_select_full_range_join= statement->m_select_full_range_join;
  m_row.m_select_range= statement->m_select_range;
  m_row.m_select_range_check= statement->m_select_range_check;
  m_row.m_select_scan= statement->m_select_scan;
  m_row.m_sort_merge_passes= statement->m_sort_merge_passes;
  m_row.m_sort_range= statement->m_sort_range;
  m_row.m_sort_rows= statement->m_sort_rows;
  m_row.m_sort_scan= statement->m_sort_scan;
  m_row.m_no_index_used= statement->m_no_index_used;
  m_row.m_no_good_index_used= statement->m_no_good_index_used;

  /*
    Making a copy of digest storage.
  */
  digest->copy(& statement->m_digest_storage);

  m_row_exists= true;
  return;
}

void table_events_statements_common::make_row_part_2(const sql_digest_storage *digest)
{
  /*
    Filling up statement digest information.
  */
  size_t safe_byte_count= digest->m_byte_count;
  if (safe_byte_count > 0 &&
      safe_byte_count <= pfs_max_digest_length)
  {
    /* Generate the DIGEST string from the MD5 digest  */
    MD5_HASH_TO_STRING(digest->m_md5,
                       m_row.m_digest.m_digest);
    m_row.m_digest.m_digest_length= MD5_HASH_TO_STRING_LENGTH;

    /* Generate the DIGEST_TEXT string from the token array */
    compute_digest_text(digest, &m_row.m_digest.m_digest_text);

    if (m_row.m_digest.m_digest_text.length() == 0)
      m_row.m_digest.m_digest_length= 0;
  }
  else
  {
    m_row.m_digest.m_digest_length= 0;
    m_row.m_digest.m_digest_text.length(0);
  }

  return;
}

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

  if (unlikely(! m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  DBUG_ASSERT(table->s->null_bytes == 3);
  buf[0]= 0;
  buf[1]= 0;
  buf[2]= 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: /* EVENT_ID */
        set_field_ulonglong(f, m_row.m_event_id);
        break;
      case 2: /* END_EVENT_ID */
        if (m_row.m_end_event_id > 0)
          set_field_ulonglong(f, m_row.m_end_event_id - 1);
        else
          f->set_null();
        break;
      case 3: /* EVENT_NAME */
        set_field_varchar_utf8(f, m_row.m_name, m_row.m_name_length);
        break;
      case 4: /* SOURCE */
        set_field_varchar_utf8(f, m_row.m_source, m_row.m_source_length);
        break;
      case 5: /* TIMER_START */
        if (m_row.m_timer_start != 0)
          set_field_ulonglong(f, m_row.m_timer_start);
        else
          f->set_null();
        break;
      case 6: /* TIMER_END */
        if (m_row.m_timer_end != 0)
          set_field_ulonglong(f, m_row.m_timer_end);
        else
          f->set_null();
        break;
      case 7: /* TIMER_WAIT */
        if (m_row.m_timer_wait != 0)
          set_field_ulonglong(f, m_row.m_timer_wait);
        else
          f->set_null();
        break;
      case 8: /* LOCK_TIME */
        if (m_row.m_lock_time != 0)
          set_field_ulonglong(f, m_row.m_lock_time);
        else
          f->set_null();
        break;
      case 9: /* SQL_TEXT */
        if (m_row.m_sqltext.length())
          set_field_longtext_utf8(f, m_row.m_sqltext.ptr(), m_row.m_sqltext.length());
        else
          f->set_null();
        break;
      case 10: /* DIGEST */
        if (m_row.m_digest.m_digest_length > 0)
          set_field_varchar_utf8(f, m_row.m_digest.m_digest,
                                 m_row.m_digest.m_digest_length);
        else
          f->set_null();
        break;
      case 11: /* DIGEST_TEXT */
        if (m_row.m_digest.m_digest_text.length() > 0)
           set_field_longtext_utf8(f, m_row.m_digest.m_digest_text.ptr(),
                                   m_row.m_digest.m_digest_text.length());
        else
          f->set_null();
        break;
      case 12: /* CURRENT_SCHEMA */
        if (m_row.m_current_schema_name_length)
          set_field_varchar_utf8(f, m_row.m_current_schema_name,
                                 m_row.m_current_schema_name_length);
        else
          f->set_null();
        break;
     case 13: /* OBJECT_TYPE */
        if (m_row.m_object_name_length > 0)
          set_field_object_type(f, m_row.m_object_type);
        else
          f->set_null();
        break;
      case 14: /* OBJECT_SCHEMA */
        if (m_row.m_schema_name_length)
          set_field_varchar_utf8(f, m_row.m_schema_name,
                                 m_row.m_schema_name_length);
        else
          f->set_null();
        break;
      case 15: /* OBJECT_NAME */
        if (m_row.m_object_name_length)
          set_field_varchar_utf8(f, m_row.m_object_name,
                                 m_row.m_object_name_length);
        else
          f->set_null();
        break;
      case 16: /* OBJECT_INSTANCE_BEGIN */
        f->set_null();
        break;
      case 17: /* MYSQL_ERRNO */
        set_field_ulong(f, m_row.m_sql_errno);
        break;
      case 18: /* RETURNED_SQLSTATE */
        if (m_row.m_sqlstate[0] != 0)
          set_field_varchar_utf8(f, m_row.m_sqlstate, SQLSTATE_LENGTH);
        else
          f->set_null();
        break;
      case 19: /* MESSAGE_TEXT */
        len= strlen(m_row.m_message_text);
        if (len)
          set_field_varchar_utf8(f, m_row.m_message_text, len);
        else
          f->set_null();
        break;
      case 20: /* ERRORS */
        set_field_ulonglong(f, m_row.m_error_count);
        break;
      case 21: /* WARNINGS */
        set_field_ulonglong(f, m_row.m_warning_count);
        break;
      case 22: /* ROWS_AFFECTED */
        set_field_ulonglong(f, m_row.m_rows_affected);
        break;
      case 23: /* ROWS_SENT */
        set_field_ulonglong(f, m_row.m_rows_sent);
        break;
      case 24: /* ROWS_EXAMINED */
        set_field_ulonglong(f, m_row.m_rows_examined);
        break;
      case 25: /* CREATED_TMP_DISK_TABLES */
        set_field_ulonglong(f, m_row.m_created_tmp_disk_tables);
        break;
      case 26: /* CREATED_TMP_TABLES */
        set_field_ulonglong(f, m_row.m_created_tmp_tables);
        break;
      case 27: /* SELECT_FULL_JOIN */
        set_field_ulonglong(f, m_row.m_select_full_join);
        break;
      case 28: /* SELECT_FULL_RANGE_JOIN */
        set_field_ulonglong(f, m_row.m_select_full_range_join);
        break;
      case 29: /* SELECT_RANGE */
        set_field_ulonglong(f, m_row.m_select_range);
        break;
      case 30: /* SELECT_RANGE_CHECK */
        set_field_ulonglong(f, m_row.m_select_range_check);
        break;
      case 31: /* SELECT_SCAN */
        set_field_ulonglong(f, m_row.m_select_scan);
        break;
      case 32: /* SORT_MERGE_PASSES */
        set_field_ulonglong(f, m_row.m_sort_merge_passes);
        break;
      case 33: /* SORT_RANGE */
        set_field_ulonglong(f, m_row.m_sort_range);
        break;
      case 34: /* SORT_ROWS */
        set_field_ulonglong(f, m_row.m_sort_rows);
        break;
      case 35: /* SORT_SCAN */
        set_field_ulonglong(f, m_row.m_sort_scan);
        break;
      case 36: /* NO_INDEX_USED */
        set_field_ulonglong(f, m_row.m_no_index_used);
        break;
      case 37: /* NO_GOOD_INDEX_USED */
        set_field_ulonglong(f, m_row.m_no_good_index_used);
        break;
      case 38: /* NESTING_EVENT_ID */
        if (m_row.m_nesting_event_id != 0)
          set_field_ulonglong(f, m_row.m_nesting_event_id);
        else
          f->set_null();
        break;
      case 39: /* NESTING_EVENT_TYPE */
        if (m_row.m_nesting_event_id != 0)
          set_field_enum(f, m_row.m_nesting_event_type);
        else
          f->set_null();
        break;
      case 40: /* NESTING_EVENT_LEVEL */
          set_field_ulong(f, m_row.m_nesting_event_level);
        break;
      default:
        DBUG_ASSERT(false);
      }
    }
  }
  return 0;
}

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

table_events_statements_current::table_events_statements_current()
  : table_events_statements_common(&m_share, &m_pos),
  m_pos(), m_next_pos()
{}

void table_events_statements_current::reset_position(void)
{
  m_pos.reset();
  m_next_pos.reset();
}

int table_events_statements_current::rnd_init(bool scan)
{
  m_normalizer= time_normalizer::get(statement_timer);
  return 0;
}

int table_events_statements_current::rnd_next(void)
{
  PFS_thread *pfs_thread;
  PFS_events_statements *statement;
  bool has_more_thread= true;

  for (m_pos.set_at(&m_next_pos);
       has_more_thread;
       m_pos.next_thread())
  {
    pfs_thread= global_thread_container.get(m_pos.m_index_1, & has_more_thread);
    if (pfs_thread != NULL)
    {
      uint safe_events_statements_count= pfs_thread->m_events_statements_count;

      if (safe_events_statements_count == 0)
      {
        /* Display the last top level statement, when completed */
        if (m_pos.m_index_2 >= 1)
          continue;
      }
      else
      {
        /* Display all pending statements, when in progress */
        if (m_pos.m_index_2 >= safe_events_statements_count)
          continue;
      }

      statement= &pfs_thread->m_statement_stack[m_pos.m_index_2];

      make_row(pfs_thread, statement);
      m_next_pos.set_after(&m_pos);
      return 0;
    }
  }

  return HA_ERR_END_OF_FILE;
}

int table_events_statements_current::rnd_pos(const void *pos)
{
  PFS_thread *pfs_thread;
  PFS_events_statements *statement;

  set_position(pos);

  pfs_thread= global_thread_container.get(m_pos.m_index_1);
  if (pfs_thread != NULL)
  {
    uint safe_events_statements_count= pfs_thread->m_events_statements_count;

    if (safe_events_statements_count == 0)
    {
      /* Display the last top level statement, when completed */
      if (m_pos.m_index_2 >= 1)
        return HA_ERR_RECORD_DELETED;
    }
    else
    {
      /* Display all pending statements, when in progress */
      if (m_pos.m_index_2 >= safe_events_statements_count)
        return HA_ERR_RECORD_DELETED;
    }

    DBUG_ASSERT(m_pos.m_index_2 < statement_stack_max);

    statement= &pfs_thread->m_statement_stack[m_pos.m_index_2];

    if (statement->m_class != NULL)
    {
      make_row(pfs_thread, statement);
      return 0;
    }
  }

  return HA_ERR_RECORD_DELETED;
}

void table_events_statements_current::make_row(PFS_thread *pfs_thread,
                                               PFS_events_statements *statement)
{
  sql_digest_storage digest;
  pfs_optimistic_state lock;
  pfs_optimistic_state stmt_lock;

  digest.reset(m_token_array, MAX_DIGEST_STORAGE_SIZE);
  /* Protect this reader against thread termination. */
  pfs_thread->m_lock.begin_optimistic_lock(&lock);
  /* Protect this reader against writing on statement information. */
  pfs_thread->m_stmt_lock.begin_optimistic_lock(&stmt_lock);

  table_events_statements_common::make_row_part_1(statement, &digest);

  if (!pfs_thread->m_stmt_lock.end_optimistic_lock(&stmt_lock) ||
      !pfs_thread->m_lock.end_optimistic_lock(&lock))
  {
    m_row_exists= false;
    return;
  }
  table_events_statements_common::make_row_part_2(&digest);
  return;
}

int table_events_statements_current::delete_all_rows(void)
{
  reset_events_statements_current();
  return 0;
}

ha_rows
table_events_statements_current::get_row_count(void)
{
  return global_thread_container.get_row_count() * statement_stack_max;
}

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

table_events_statements_history::table_events_statements_history()
  : table_events_statements_common(&m_share, &m_pos),
  m_pos(), m_next_pos()
{}

void table_events_statements_history::reset_position(void)
{
  m_pos.reset();
  m_next_pos.reset();
}

int table_events_statements_history::rnd_init(bool scan)
{
  m_normalizer= time_normalizer::get(statement_timer);
  return 0;
}

int table_events_statements_history::rnd_next(void)
{
  PFS_thread *pfs_thread;
  PFS_events_statements *statement;
  bool has_more_thread= true;

  if (events_statements_history_per_thread == 0)
    return HA_ERR_END_OF_FILE;

  for (m_pos.set_at(&m_next_pos);
       has_more_thread;
       m_pos.next_thread())
  {
    pfs_thread= global_thread_container.get(m_pos.m_index_1, & has_more_thread);
    if (pfs_thread != NULL)
    {
      if (m_pos.m_index_2 >= events_statements_history_per_thread)
      {
        /* This thread does not have more (full) history */
        continue;
      }

      if ( ! pfs_thread->m_statements_history_full &&
          (m_pos.m_index_2 >= pfs_thread->m_statements_history_index))
      {
        /* This thread does not have more (not full) history */
        continue;
      }

      statement= &pfs_thread->m_statements_history[m_pos.m_index_2];

      if (statement->m_class != NULL)
      {
        make_row(pfs_thread, statement);
        /* Next iteration, look for the next history in this thread */
        m_next_pos.set_after(&m_pos);
        return 0;
      }
    }
  }

  return HA_ERR_END_OF_FILE;
}

int table_events_statements_history::rnd_pos(const void *pos)
{
  PFS_thread *pfs_thread;
  PFS_events_statements *statement;

  DBUG_ASSERT(events_statements_history_per_thread != 0);
  set_position(pos);

  pfs_thread= global_thread_container.get(m_pos.m_index_1);
  if (pfs_thread != NULL)
  {
    DBUG_ASSERT(m_pos.m_index_2 < events_statements_history_per_thread);

    if ( ! pfs_thread->m_statements_history_full &&
        (m_pos.m_index_2 >= pfs_thread->m_statements_history_index))
      return HA_ERR_RECORD_DELETED;

    statement= &pfs_thread->m_statements_history[m_pos.m_index_2];
    if (statement->m_class != NULL)
    {
      make_row(pfs_thread, statement);
      return 0;
    }
  }

  return HA_ERR_RECORD_DELETED;
}

void table_events_statements_history::make_row(PFS_thread *pfs_thread,
                                               PFS_events_statements *statement)
{
  sql_digest_storage digest;
  pfs_optimistic_state lock;

  digest.reset(m_token_array, MAX_DIGEST_STORAGE_SIZE);
  /* Protect this reader against thread termination. */
  pfs_thread->m_lock.begin_optimistic_lock(&lock);

  table_events_statements_common::make_row_part_1(statement, &digest);

  if (!pfs_thread->m_lock.end_optimistic_lock(&lock))
  {
    m_row_exists= false;
    return;
  }
  table_events_statements_common::make_row_part_2(&digest);
  return;
}


int table_events_statements_history::delete_all_rows(void)
{
  reset_events_statements_history();
  return 0;
}

ha_rows
table_events_statements_history::get_row_count(void)
{
  return events_statements_history_per_thread * global_thread_container.get_row_count();
}

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

table_events_statements_history_long::table_events_statements_history_long()
  : table_events_statements_common(&m_share, &m_pos),
  m_pos(0), m_next_pos(0)
{}

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

int table_events_statements_history_long::rnd_init(bool scan)
{
  m_normalizer= time_normalizer::get(statement_timer);
  return 0;
}

int table_events_statements_history_long::rnd_next(void)
{
  PFS_events_statements *statement;
  uint limit;

  if (events_statements_history_long_size == 0)
    return HA_ERR_END_OF_FILE;

  if (events_statements_history_long_full)
    limit= events_statements_history_long_size;
  else
    limit= events_statements_history_long_index.m_u32 % events_statements_history_long_size;

  for (m_pos.set_at(&m_next_pos); m_pos.m_index < limit; m_pos.next())
  {
    statement= &events_statements_history_long_array[m_pos.m_index];

    if (statement->m_class != NULL)
    {
      make_row(statement);
      /* Next iteration, look for the next entry */
      m_next_pos.set_after(&m_pos);
      return 0;
    }
  }

  return HA_ERR_END_OF_FILE;
}

int table_events_statements_history_long::rnd_pos(const void *pos)
{
  PFS_events_statements *statement;
  uint limit;

  if (events_statements_history_long_size == 0)
    return HA_ERR_RECORD_DELETED;

  set_position(pos);

  if (events_statements_history_long_full)
    limit= events_statements_history_long_size;
  else
    limit= events_statements_history_long_index.m_u32 % events_statements_history_long_size;

  if (m_pos.m_index >= limit)
    return HA_ERR_RECORD_DELETED;

  statement= &events_statements_history_long_array[m_pos.m_index];

  if (statement->m_class == NULL)
    return HA_ERR_RECORD_DELETED;

  make_row(statement);
  return 0;
}

void table_events_statements_history_long::make_row(PFS_events_statements *statement)
{
  sql_digest_storage digest;

  digest.reset(m_token_array, MAX_DIGEST_STORAGE_SIZE);
  table_events_statements_common::make_row_part_1(statement, &digest);

  table_events_statements_common::make_row_part_2(&digest);
  return;
}

int table_events_statements_history_long::delete_all_rows(void)
{
  reset_events_statements_history_long();
  return 0;
}

ha_rows
table_events_statements_history_long::get_row_count(void)
{
  return events_statements_history_long_size;
}

