polardbxengine/storage/ndb/plugin/ndb_sql_metadata_table.cc

/*
   Copyright (c) 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
*/

#include "storage/ndb/plugin/ndb_sql_metadata_table.h"

#include <sstream>

#include "storage/ndb/plugin/ndb_thd_ndb.h"

Ndb_sql_metadata_table::Ndb_sql_metadata_table(Thd_ndb *thd_ndb)
    : Ndb_util_table(thd_ndb, "mysql", "ndb_sql_metadata", true, false) {}

bool Ndb_sql_metadata_table::define_table_ndb(NdbDictionary::Table &new_table,
                                              unsigned) const {
  static const char *COL_TYPE = "type";
  static const char *COL_NAME = "name";
  static const char *COL_SEQUENCE = "seq";
  static const char *COL_NOTE = "note";
  static const char *COL_TEXT = "sql_ddl_text";

  // Allow later online add column
  new_table.setForceVarPart(true);

  // Allow table to be read+write also in single user mode
  new_table.setSingleUserMode(NdbDictionary::Table::SingleUserModeReadWrite);

  {
    // `type` smallint(6) NOT NULL
    NdbDictionary::Column col_type(COL_TYPE);
    col_type.setType(NdbDictionary::Column::Smallint);
    col_type.setNullable(false);
    col_type.setPrimaryKey(true);
    if (!define_table_add_column(new_table, col_type)) return false;
  }

  {
    // `name` varbinary(400) NOT NULL
    NdbDictionary::Column col_name(COL_NAME);
    col_name.setType(NdbDictionary::Column::Longvarbinary);
    col_name.setLength(400);
    col_name.setNullable(false);
    col_name.setPrimaryKey(true);
    if (!define_table_add_column(new_table, col_name)) return false;
  }

  {
    // `seq` smallint(6) unsigned NOT NULL
    NdbDictionary::Column col_seq(COL_SEQUENCE);
    col_seq.setType(NdbDictionary::Column::Smallunsigned);
    col_seq.setNullable(false);
    col_seq.setPrimaryKey(true);
    if (!define_table_add_column(new_table, col_seq)) return false;
  }

  {
    // `note` int unsigned
    NdbDictionary::Column col_note(COL_NOTE);
    col_note.setType(NdbDictionary::Column::Unsigned);
    col_note.setNullable(true);
    if (!define_table_add_column(new_table, col_note)) return false;
  }

  {
    // `sql_ddl_text` varbinary(12000) DEFAULT NULL
    NdbDictionary::Column col_text(COL_TEXT);
    col_text.setType(NdbDictionary::Column::Longvarbinary);
    col_text.setLength(12000);
    if (!define_table_add_column(new_table, col_text)) return false;
  }

  return true;
}

bool Ndb_sql_metadata_table::define_indexes(const NdbDictionary::Table &table,
                                            unsigned) const {
  return create_primary_ordered_index(table);
}

bool Ndb_sql_metadata_table::check_schema() const { return true; }

bool Ndb_sql_metadata_table::need_upgrade() const { return false; }

std::string Ndb_sql_metadata_table::define_table_dd() const {
  std::stringstream ss;
  ss << "CREATE TABLE " << db_name() << "." << table_name() << "(\n";
  ss << "type smallint not null,"
        "name varbinary(400) NOT NULL,"
        "seq smallint unsigned not null,"
        "note int unsigned,"
        "sql_ddl_text varbinary(12000),"
        "PRIMARY KEY (type,name,seq)"
     << ") ENGINE=ndbcluster";
  return ss.str();
}

Ndb_sql_metadata_table::~Ndb_sql_metadata_table() {}

// Ndb_sql_metadata_api

/*  Map the table.
    Determine record sizes for a key record, a partial row record,
    and a full row record. Create NdbRecords for the hash primary key,
    ordered index, partial row, and full row.
    After setup_records() is called, the API's getters and setters become
    usable.
    Returns true on success.
*/
void Ndb_sql_metadata_api::setup(NdbDictionary::Dictionary *dict,
                                 const NdbDictionary::Table *table) {
  m_record_layout.addColumn(table->getColumn("type"));
  m_record_layout.addColumn(table->getColumn("name"));
  m_record_layout.addColumn(table->getColumn("seq"));
  m_key_record_size = m_record_layout.record_size;

  m_record_layout.addColumn(table->getColumn("note"));
  m_note_record_size = m_record_layout.record_size;

  m_record_layout.addColumn(table->getColumn("sql_ddl_text"));
  m_full_record_size = m_record_layout.record_size;

  m_row_rec = dict->createRecord(table, m_record_layout.record_specs,
                                 5,  // ALL FIVE COLUMNS
                                 sizeof(m_record_layout.record_specs[0]));
  m_note_rec = dict->createRecord(table, m_record_layout.record_specs,
                                  4,  // FIRST FOUR COLUMNS
                                  sizeof(m_record_layout.record_specs[0]));
  m_hash_key_rec = dict->createRecord(table, m_record_layout.record_specs,
                                      3,  // FIRST THREE COLUMNS
                                      sizeof(m_record_layout.record_specs[0]));

  const NdbDictionary::Index *primary = dict->getIndexGlobal("PRIMARY", *table);
  /* There is a test case where primary == nullptr because NDB has been
     configured with __at_restart_skip_indexes, and presumably there are also
     real-world data corruption situations where the table is available but
     the index is not. Do not handle those conditions here. They are detected
     later, when isInitialized() returns false.
  */
  if (primary) {
    m_ordered_index_rec =
        dict->createRecord(primary, table, m_record_layout.record_specs,
                           3,  // FIRST THREE COLUMNS
                           sizeof(m_record_layout.record_specs[0]));
    dict->removeIndexGlobal(*primary, false);
  }
}

void Ndb_sql_metadata_api::clear(NdbDictionary::Dictionary *dict) {
  if (m_full_record_size) {
    dict->releaseRecord(m_row_rec);
    m_row_rec = nullptr;
    dict->releaseRecord(m_note_rec);
    m_note_rec = nullptr;
    dict->releaseRecord(m_hash_key_rec);
    m_hash_key_rec = nullptr;
    m_key_record_size = 0;
    m_note_record_size = 0;
    m_full_record_size = 0;
  }

  if (m_ordered_index_rec) {
    dict->releaseRecord(m_ordered_index_rec);
    m_ordered_index_rec = nullptr;
  }

  m_record_layout.clear();
}