polardbxengine/storage/perfschema/table_status_by_account.cc

/* Copyright (c) 2015, 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
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  permission to link the program and your derivative works with the
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  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_status_by_account.cc
  Table STATUS_BY_ACCOUNT (implementation).
*/

#include "storage/perfschema/table_status_by_account.h"

#include <stddef.h>
#include <new>

#include "my_dbug.h"
#include "my_thread.h"
#include "sql/current_thd.h"
#include "sql/field.h"
#include "sql/mysqld.h"
#include "sql/plugin_table.h"
#include "sql/sql_class.h"
#include "sql/table.h"
#include "storage/perfschema/pfs_account.h"
#include "storage/perfschema/pfs_column_types.h"
#include "storage/perfschema/pfs_column_values.h"
#include "storage/perfschema/pfs_global.h"
#include "storage/perfschema/pfs_instr_class.h"

THR_LOCK table_status_by_account::m_table_lock;

Plugin_table table_status_by_account::m_table_def(
    /* Schema name */
    "performance_schema",
    /* Name */
    "status_by_account",
    /* Definition */
    "  USER CHAR(32) collate utf8mb4_bin default null,\n"
    "  HOST CHAR(255) CHARACTER SET ASCII default null,\n"
    "  VARIABLE_NAME VARCHAR(64) not null,\n"
    "  VARIABLE_VALUE VARCHAR(1024),\n"
    "  UNIQUE KEY `ACCOUNT` (USER, HOST, VARIABLE_NAME) USING HASH\n",
    /* Options */
    " ENGINE=PERFORMANCE_SCHEMA",
    /* Tablespace */
    nullptr);

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

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

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

bool PFS_index_status_by_account::match(const Status_variable *pfs) {
  if (m_fields >= 3) {
    if (!m_key_3.match(pfs)) {
      return false;
    }
  }
  return true;
}

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

int table_status_by_account::delete_all_rows(void) {
  mysql_mutex_lock(&LOCK_status);
  reset_status_by_thread();
  reset_status_by_account();
  mysql_mutex_unlock(&LOCK_status);
  return 0;
}

ha_rows table_status_by_account::get_row_count(void) {
  mysql_mutex_lock(&LOCK_status);
  size_t status_var_count = all_status_vars.size();
  mysql_mutex_unlock(&LOCK_status);
  return (global_account_container.get_row_count() * status_var_count);
}

table_status_by_account::table_status_by_account()
    : PFS_engine_table(&m_share, &m_pos),
      m_status_cache(true),
      m_pos(),
      m_next_pos(),
      m_context(NULL) {}

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

int table_status_by_account::rnd_init(bool scan) {
  /* Build array of SHOW_VARs from the global status array. */
  m_status_cache.initialize_client_session();

  /* Record the version of the global status variable array, store in TLS. */
  ulonglong status_version = m_status_cache.get_status_array_version();

  m_context = (table_status_by_account_context *)current_thd->alloc(
      sizeof(table_status_by_account_context));
  new (m_context) table_status_by_account_context(status_version, !scan);
  return 0;
}

int table_status_by_account::rnd_next(void) {
  if (m_context && !m_context->versions_match()) {
    status_variable_warning();
    return HA_ERR_END_OF_FILE;
  }

  /*
    For each account, build a cache of status variables using totals from all
    threads associated with the account.
  */
  bool has_more_account = true;

  for (m_pos.set_at(&m_next_pos); has_more_account; m_pos.next_account()) {
    PFS_account *pfs_account =
        global_account_container.get(m_pos.m_index_1, &has_more_account);

    if (m_status_cache.materialize_account(pfs_account) == 0) {
      const Status_variable *stat_var = m_status_cache.get(m_pos.m_index_2);
      if (stat_var != NULL) {
        /* If make_row() fails, get the next account. */
        if (!make_row(pfs_account, stat_var)) {
          m_next_pos.set_after(&m_pos);
          return 0;
        }
      }
    }
  }
  return HA_ERR_END_OF_FILE;
}

int table_status_by_account::rnd_pos(const void *pos) {
  if (m_context && !m_context->versions_match()) {
    status_variable_warning();
    return HA_ERR_END_OF_FILE;
  }

  set_position(pos);
  DBUG_ASSERT(m_pos.m_index_1 < global_account_container.get_row_count());

  PFS_account *pfs_account = global_account_container.get(m_pos.m_index_1);

  if (m_status_cache.materialize_account(pfs_account) == 0) {
    const Status_variable *stat_var = m_status_cache.get(m_pos.m_index_2);
    if (stat_var != NULL) {
      return make_row(pfs_account, stat_var);
    }
  }
  return HA_ERR_RECORD_DELETED;
}

int table_status_by_account::index_init(uint idx MY_ATTRIBUTE((unused)), bool) {
  /* Build array of SHOW_VARs from the global status array prior to
   * materializing. */
  m_status_cache.initialize_client_session();

  /* Record the version of the global status variable, store in TLS. */
  ulonglong status_version = m_status_cache.get_status_array_version();
  m_context = (table_status_by_account_context *)current_thd->alloc(
      sizeof(table_status_by_account_context));
  new (m_context) table_status_by_account_context(status_version, false);

  PFS_index_status_by_account *result = NULL;
  DBUG_ASSERT(idx == 0);
  result = PFS_NEW(PFS_index_status_by_account);
  m_opened_index = result;
  m_index = result;
  return 0;
}

int table_status_by_account::index_next(void) {
  if (m_context && !m_context->versions_match()) {
    status_variable_warning();
    return HA_ERR_END_OF_FILE;
  }

  /*
    For each account, build a cache of status variables using totals from all
    threads associated with the account.
  */
  bool has_more_account = true;

  for (m_pos.set_at(&m_next_pos); has_more_account; m_pos.next_account()) {
    PFS_account *pfs_account =
        global_account_container.get(m_pos.m_index_1, &has_more_account);

    if (pfs_account != NULL) {
      if (m_opened_index->match(pfs_account)) {
        if (m_status_cache.materialize_account(pfs_account) == 0) {
          const Status_variable *stat_var;
          do {
            stat_var = m_status_cache.get(m_pos.m_index_2);
            if (stat_var != NULL) {
              if (m_opened_index->match(stat_var)) {
                if (!make_row(pfs_account, stat_var)) {
                  m_next_pos.set_after(&m_pos);
                  return 0;
                }
              }
              m_pos.m_index_2++;
            }
          } while (stat_var != NULL);
        }
      }
    }
  }
  return HA_ERR_END_OF_FILE;
}

int table_status_by_account::make_row(PFS_account *pfs_account,
                                      const Status_variable *status_var) {
  pfs_optimistic_state lock;
  pfs_account->m_lock.begin_optimistic_lock(&lock);

  if (m_row.m_account.make_row(pfs_account)) {
    return HA_ERR_RECORD_DELETED;
  }

  if (m_row.m_variable_name.make_row(status_var->m_name,
                                     status_var->m_name_length)) {
    return HA_ERR_RECORD_DELETED;
  }

  if (m_row.m_variable_value.make_row(status_var)) {
    return HA_ERR_RECORD_DELETED;
  }

  if (!pfs_account->m_lock.end_optimistic_lock(&lock)) {
    return HA_ERR_RECORD_DELETED;
  }

  return 0;
}

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

  /* Set the null bits */
  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: /* USER */
        case 1: /* HOST */
          m_row.m_account.set_field(f->field_index, f);
          break;
        case 2: /* VARIABLE_NAME */
          set_field_varchar_utf8(f, m_row.m_variable_name.m_str,
                                 m_row.m_variable_name.m_length);
          break;
        case 3: /* VARIABLE_VALUE */
          m_row.m_variable_value.set_field(f);
          break;
        default:
          DBUG_ASSERT(false);
      }
    }
  }

  return 0;
}