lib/dml/oci_native_moodle_temptables.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * OCI specific temptables store. Needed because temporary tables
  19  * in Oracle are global (to all sessions), so we need to rename them
  20  * on the fly in order to get local (different for each session) table names.
  21  * Also used to be able to retrieve temp table names included in the get_tables()
  22  * method of the DB.
  23  *
  24  * @package    core_dml
  25  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  26  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  27  */
  28
  29 defined('MOODLE_INTERNAL') || die();
  30
  31 require_once(__DIR__.'/moodle_temptables.php');
  32
  33 class oci_native_moodle_temptables extends moodle_temptables {
  34
  35     /** @var int To store unique_session_id. Needed for temp tables unique naming (upto 24cc) */
  36     protected $unique_session_id; //
  37     /** @var int To get incrementally different temptable names on each add_temptable() request */
  38     protected $counter;
  39
  40     /**
  41      * Creates new moodle_temptables instance
  42      * @param object moodle_database instance
  43      */
  44     public function __construct($mdb, $unique_session_id) {
  45         $this->unique_session_id = $unique_session_id;
  46         $this->counter = 1;
  47         parent::__construct($mdb);
  48     }
  49
  50     /**
  51      * Add one temptable to the store.
  52      *
  53      * Overridden because OCI only support global temptables, so we need to change completely the name, based
  54      * in unique session identifier, to get local-like temp tables support
  55      * tables before the prefix.
  56      *
  57      * Given one moodle temptable name (without prefix), add it to the store, with the
  58      * key being the original moodle name and the value being the real db temptable name
  59      * already prefixed
  60      *
  61      * Override and use this *only* if the database requires modification in the table name.
  62      *
  63      * @param string $tablename name without prefix of the table created as temptable
  64      */
  65     public function add_temptable($tablename) {
  66         // TODO: throw exception if exists: if ($this->is_temptable...
  67         $this->temptables[$tablename] = $this->prefix . $this->unique_session_id . $this->counter;
  68         $this->counter++;
  69     }
  70 }