polardbxengine/storage/perfschema/table_esmh_by_digest.cc

/* Copyright (c) 2016, 2019, 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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
  */

/**
  @file storage/perfschema/table_esmh_by_digest.cc
  Table EVENTS_STATEMENTS_HISTOGRAM_BY_DIGEST (implementation).
*/

#include "storage/perfschema/table_esmh_by_digest.h"

#include "my_thread.h"
#include "sql/field.h"
#include "sql/plugin_table.h"
#include "sql/table.h"
#include "storage/perfschema/pfs_column_types.h"
#include "storage/perfschema/pfs_column_values.h"
#include "storage/perfschema/pfs_digest.h"
#include "storage/perfschema/pfs_global.h"
#include "storage/perfschema/pfs_instr.h"
#include "storage/perfschema/pfs_instr_class.h"
#include "storage/perfschema/pfs_timer.h"
#include "storage/perfschema/pfs_visitor.h"

THR_LOCK table_esmh_by_digest::m_table_lock;

Plugin_table table_esmh_by_digest::m_table_def(
    /* Schema name */
    "performance_schema",
    /* Name */
    "events_statements_histogram_by_digest",
    /* Definition */
    "  SCHEMA_NAME VARCHAR(64),\n"
    "  DIGEST VARCHAR(64),\n"
    "  BUCKET_NUMBER INTEGER unsigned not null,\n"
    "  BUCKET_TIMER_LOW BIGINT unsigned not null,\n "
    "  BUCKET_TIMER_HIGH BIGINT unsigned not null,\n"
    "  COUNT_BUCKET BIGINT unsigned not null,\n"
    "  COUNT_BUCKET_AND_LOWER BIGINT unsigned not null,\n"
    "  BUCKET_QUANTILE DOUBLE(7,6) not null,\n"
    "  UNIQUE KEY (SCHEMA_NAME, DIGEST, BUCKET_NUMBER) USING HASH\n",
    /* Options */
    " ENGINE=PERFORMANCE_SCHEMA",
    /* Tablespace */
    nullptr);

PFS_engine_table_share table_esmh_by_digest::m_share = {
    &pfs_truncatable_acl,
    table_esmh_by_digest::create,
    NULL,
    table_esmh_by_digest::delete_all_rows,
    table_esmh_by_digest::get_row_count,
    sizeof(pos_t),
    &m_table_lock,
    &m_table_def,
    false,
    PFS_engine_table_proxy(),
    {0},
    false /* m_in_purgatory */
};

bool PFS_index_esmh_by_digest::match_digest(PFS_statements_digest_stat *pfs) {
  if (m_fields >= 1) {
    if (!m_key_1.match(pfs)) {
      return false;
    }
  }

  if (m_fields >= 2) {
    return m_key_2.match(pfs);
  }

  return true;
}

bool PFS_index_esmh_by_digest::match_bucket(ulong bucket_index) {
  if (m_fields >= 3) {
    return m_key_3.match(bucket_index);
  }

  return true;
}

PFS_engine_table *table_esmh_by_digest::create(PFS_engine_table_share *) {
  return new table_esmh_by_digest();
}

int table_esmh_by_digest::delete_all_rows() {
  reset_histogram_by_digest();
  return 0;
}

ha_rows table_esmh_by_digest::get_row_count(void) { return digest_max; }

table_esmh_by_digest::table_esmh_by_digest()
    : PFS_engine_table(&m_share, &m_pos),
      m_materialized_digest(NULL),
      m_pos(),
      m_next_pos() {}

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

int table_esmh_by_digest::rnd_next(void) {
  PFS_statements_digest_stat *digest_stat;

  if (statements_digest_stat_array == NULL) {
    return HA_ERR_END_OF_FILE;
  }

  for (m_pos.set_at(&m_next_pos); m_pos.has_more_digest();
       m_pos.next_digest()) {
    digest_stat = &statements_digest_stat_array[m_pos.m_index_1];
    if (digest_stat->m_lock.is_populated()) {
      if (digest_stat->m_first_seen != 0) {
        if (m_pos.m_index_2 < NUMBER_OF_BUCKETS) {
          make_row(digest_stat, m_pos.m_index_2);
          m_next_pos.set_after(&m_pos);
          return 0;
        }
      }
    }
  }

  return HA_ERR_END_OF_FILE;
}

int table_esmh_by_digest::rnd_pos(const void *pos) {
  PFS_statements_digest_stat *digest_stat;

  if (statements_digest_stat_array == NULL) {
    return HA_ERR_END_OF_FILE;
  }

  set_position(pos);
  digest_stat = &statements_digest_stat_array[m_pos.m_index_1];

  if (digest_stat->m_lock.is_populated()) {
    if (digest_stat->m_first_seen != 0) {
      return make_row(digest_stat, m_pos.m_index_2);
    }
  }

  return HA_ERR_RECORD_DELETED;
}

int table_esmh_by_digest::index_init(uint idx MY_ATTRIBUTE((unused)), bool) {
  PFS_index_esmh_by_digest *result = NULL;
  DBUG_ASSERT(idx == 0);
  result = PFS_NEW(PFS_index_esmh_by_digest);
  m_opened_index = result;
  m_index = result;
  return 0;
}

int table_esmh_by_digest::index_next(void) {
  PFS_statements_digest_stat *digest_stat;

  if (statements_digest_stat_array == NULL) {
    return HA_ERR_END_OF_FILE;
  }

  for (m_pos.set_at(&m_next_pos); m_pos.has_more_digest();
       m_pos.next_digest()) {
    digest_stat = &statements_digest_stat_array[m_pos.m_index_1];
    if (digest_stat->m_first_seen != 0) {
      if (!m_opened_index->match_digest(digest_stat)) {
        continue;
      }

      while (m_pos.has_more_buckets()) {
        if (m_opened_index->match_bucket(m_pos.m_index_2)) {
          if (!make_row(digest_stat, m_pos.m_index_2)) {
            m_next_pos.set_after(&m_pos);
            return 0;
          }
        }
        m_pos.next_bucket();
      }
    }
  }

  return HA_ERR_END_OF_FILE;
}

void table_esmh_by_digest::materialize(
    PFS_statements_digest_stat *digest_stat) {
  if (digest_stat != m_materialized_digest) {
    m_materialized_histogram.m_digest.make_row(digest_stat);

    PFS_histogram *histogram = &digest_stat->m_histogram;

    ulong index;
    ulonglong count = 0;
    ulonglong count_and_lower = 0;

    for (index = 0; index < NUMBER_OF_BUCKETS; index++) {
      count = histogram->read_bucket(index);
      count_and_lower += count;

      PFS_esmh_by_digest_bucket &b = m_materialized_histogram.m_buckets[index];

      b.m_count_bucket = count;
      b.m_count_bucket_and_lower = count_and_lower;
    }

    /* Cache this histogram. */
    m_materialized_digest = digest_stat;
  }
}

int table_esmh_by_digest::make_row(PFS_statements_digest_stat *digest_stat,
                                   ulong bucket_index) {
  DBUG_ASSERT(bucket_index < NUMBER_OF_BUCKETS);

  materialize(digest_stat);

  m_row.m_bucket_number = bucket_index;
  m_row.m_bucket_timer_low =
      g_histogram_pico_timers.m_bucket_timer[bucket_index];
  m_row.m_bucket_timer_high =
      g_histogram_pico_timers.m_bucket_timer[bucket_index + 1];

  m_row.m_count_bucket =
      m_materialized_histogram.m_buckets[bucket_index].m_count_bucket;
  m_row.m_count_bucket_and_lower =
      m_materialized_histogram.m_buckets[bucket_index].m_count_bucket_and_lower;

  ulonglong count_star =
      m_materialized_histogram.m_buckets[NUMBER_OF_BUCKETS - 1]
          .m_count_bucket_and_lower;

  if (count_star > 0) {
    double dividend = m_row.m_count_bucket_and_lower;
    double divisor = count_star;
    m_row.m_percentile = dividend / divisor; /* computed with double, not int */
  } else {
    m_row.m_percentile = 0.0;
  }

  return 0;
}

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

  /*
    Set the null bits. It indicates how many fields could be null
    in the table.
  */
  DBUG_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: /* SCHEMA_NAME */
        case 1: /* DIGEST */
          m_materialized_histogram.m_digest.set_field(f->field_index, f);
          break;
        case 2: /* BUCKET_NUMBER */
          set_field_ulong(f, m_row.m_bucket_number);
          break;
        case 3: /* BUCKET_TIMER_LOW */
          set_field_ulonglong(f, m_row.m_bucket_timer_low);
          break;
        case 4: /* BUCKET_TIMER_HIGH */
          set_field_ulonglong(f, m_row.m_bucket_timer_high);
          break;
        case 5: /* COUNT_BUCKET */
          set_field_ulonglong(f, m_row.m_count_bucket);
          break;
        case 6: /* COUNT_BUCKET_AND_LOWER */
          set_field_ulonglong(f, m_row.m_count_bucket_and_lower);
          break;
        case 7: /* BUCKET_QUANTILE */
          set_field_double(f, m_row.m_percentile);
          break;
        default:
          DBUG_ASSERT(false);
          break;
      }
    }
  }

  return 0;
}