sess0sess.h

Go to the documentation of this file.

/*****************************************************************************
 
Copyright (c) 2013, 2025, 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 designed to work 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 either included with
the program or referenced in the documentation.
 
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 include/sess0sess.h
 InnoDB session state tracker.
 Multi file, shared, system tablespace implementation.
 
 Created 2014-04-30 by Krunal Bauskar
 *******************************************************/
 
#ifndef sess0sess_h
#define sess0sess_h
 
#include <sql_thd_internal_api.h>
#include "dict0mem.h"
#include "log0meb.h"
#include "srv0tmp.h"
#include "trx0trx.h"
#include "univ.i"
#include "ut0new.h"
 
#include <map>
 
class dict_intrinsic_table_t {
 public:
  /** Constructor
  @param[in,out]        handler         table handler. */
  dict_intrinsic_table_t(dict_table_t *handler) : m_handler(handler) {
    /* Do nothing. */
  }
 
  /** Destructor */
  ~dict_intrinsic_table_t() { m_handler = nullptr; }
 
 public:
  /* Table Handler holding other metadata information commonly needed
  for any table. */
  dict_table_t *m_handler;
};
 
/** InnoDB private data that is cached in THD */
typedef std::map<
    std::string, dict_intrinsic_table_t *, std::less<std::string>,
    ut::allocator<std::pair<const std::string, dict_intrinsic_table_t *>>>
    table_cache_t;
 
class innodb_session_t {
 public:
  /** Constructor */
  innodb_session_t()
      : m_trx(), m_open_tables(), m_usr_temp_tblsp(), m_intrinsic_temp_tblsp() {
    /* Do nothing. */
  }
 
  /** Destructor */
  ~innodb_session_t() {
    m_trx = nullptr;
 
    for (table_cache_t::iterator it = m_open_tables.begin();
         it != m_open_tables.end(); ++it) {
      delete (it->second);
    }
 
    meb::redo_log_archive_session_end(this);
 
    if (m_usr_temp_tblsp != nullptr) {
      ibt::free_tmp(m_usr_temp_tblsp);
    }
 
    if (m_intrinsic_temp_tblsp != nullptr) {
      ibt::free_tmp(m_intrinsic_temp_tblsp);
    }
  }
 
  /** Cache table handler.
  @param[in]    table_name      name of the table
  @param[in,out]        table           table handler to register */
  void register_table_handler(const char *table_name, dict_table_t *table) {
    ut_ad(lookup_table_handler(table_name) == nullptr);
    m_open_tables.insert(table_cache_t::value_type(
        table_name, new dict_intrinsic_table_t(table)));
  }
 
  /** Lookup for table handler given table_name.
  @param[in]    table_name      name of the table to lookup */
  dict_table_t *lookup_table_handler(const char *table_name) {
    table_cache_t::iterator it = m_open_tables.find(table_name);
    return ((it == m_open_tables.end()) ? nullptr : it->second->m_handler);
  }
 
  /** Remove table handler entry.
  @param[in]    table_name      name of the table to remove */
  void unregister_table_handler(const char *table_name) {
    table_cache_t::iterator it = m_open_tables.find(table_name);
    if (it == m_open_tables.end()) {
      return;
    }
 
    delete (it->second);
    m_open_tables.erase(table_name);
  }
 
  /** Count of register table handler.
  @return number of register table handlers */
  uint count_register_table_handler() const {
    return (static_cast<uint>(m_open_tables.size()));
  }
 
  ibt::Tablespace *get_usr_temp_tblsp() {
    if (m_usr_temp_tblsp == nullptr) {
      my_thread_id id = thd_thread_id(m_trx->mysql_thd);
      m_usr_temp_tblsp = ibt::tbsp_pool->get(id, ibt::TBSP_USER);
    }
 
    return (m_usr_temp_tblsp);
  }
 
  ibt::Tablespace *get_instrinsic_temp_tblsp() {
    if (m_intrinsic_temp_tblsp == nullptr) {
      my_thread_id id = thd_thread_id(m_trx->mysql_thd);
      m_intrinsic_temp_tblsp = ibt::tbsp_pool->get(id, ibt::TBSP_INTRINSIC);
    }
 
    return (m_intrinsic_temp_tblsp);
  }
 
 public:
  /** transaction handler. */
  trx_t *m_trx;
 
  /** Handler of tables that are created or open but not added
  to InnoDB dictionary as they are session specific.
  Currently, limited to intrinsic temporary tables only. */
  table_cache_t m_open_tables;
 
 private:
  /** Current session's user temp tablespace */
  ibt::Tablespace *m_usr_temp_tblsp;
 
  /** Current session's optimizer temp tablespace */
  ibt::Tablespace *m_intrinsic_temp_tblsp;
};
 
#endif /* sess0sess_h */