Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle 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 for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * @package    moodlecore

 * @subpackage backup-dbops

 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

/**

 * Non instantiable helper class providing DB support to the backup_structure stuff

 *

 * This class contains various static methods available for all the DB operations

 * performed by the backup_structure stuff (mainly @backup_nested_element class)

 *

 * TODO: Finish phpdocs

 */

abstract class backup_structure_dbops extends backup_dbops {

    public static function get_iterator($element, $params, $processor) {

        global $DB;

        // Check we are going to get_iterator for one backup_nested_element

        if (! $element instanceof backup_nested_element) {

            throw new base_element_struct_exception('backup_nested_element_expected');

        }

        // If var_array, table and sql are null, and element has no final elements it is one nested element without source

        // Just return one 1 element iterator without information

        if ($element->get_source_array() === null && $element->get_source_table() === null &&

            $element->get_source_sql() === null && count($element->get_final_elements()) == 0) {

            return new backup_array_iterator(array(0 => null));

        } else if ($element->get_source_array() !== null) { // It's one array, return array_iterator

            return new backup_array_iterator($element->get_source_array());

        } else if ($element->get_source_table() !== null) { // It's one table, return recordset iterator

            return $DB->get_recordset($element->get_source_table(), self::convert_params_to_values($params, $processor), $element->get_source_table_sortby());

        } else if ($element->get_source_sql() !== null) { // It's one sql, return recordset iterator

            return $DB->get_recordset_sql($element->get_source_sql(), self::convert_params_to_values($params, $processor));

        } else { // No sources, supress completely, using null iterator

            return new backup_null_iterator();

        }

    }

    public static function convert_params_to_values($params, $processor) {

        $newparams = array();

        foreach ($params as $key => $param) {

            $newvalue = null;

            // If we have a base element, get its current value, exception if not set

            if ($param instanceof base_atom) {

                if ($param->is_set()) {

                    $newvalue = $param->get_value();

                } else {

                    throw new base_element_struct_exception('valueofparamelementnotset', $param->get_name());

                }

            } else if (is_int($param) && $param < 0) { // Possibly one processor variable, let's process it

                // See @backup class for all the VAR_XXX variables available.

                // Note1: backup::VAR_PARENTID is handled by nested elements themselves

                // Note2: trying to use one non-existing var will throw exception

                $newvalue = $processor->get_var($param);

            // Else we have one raw param value, use it

            } else {

                $newvalue = $param;

            }

            $newparams[$key] = $newvalue;

        }

        return $newparams;

    }

    public static function insert_backup_ids_record($backupid, $itemname, $itemid) {

        global $DB;

        // We need to do some magic with scales (that are stored in negative way)

        if ($itemname == 'scale') {

            $itemid = -($itemid);

        }

        // Now, we skip any annotation with negatives/zero/nulls, ids table only stores true id (always > 0)

        if ($itemid <= 0 || is_null($itemid)) {

            return;

        }

        // TODO: Analyze if some static (and limited) cache by the 3 params could save us a bunch of record_exists() calls

        // Note: Sure it will!

        if (!$DB->record_exists('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname, 'itemid' => $itemid))) {

            $DB->insert_record('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname, 'itemid' => $itemid));

        }

    }

    /**

     * Adds backup id database record for all files in the given file area.

     *

     * @param string $backupid Backup ID

     * @param int $contextid Context id

     * @param string $component Component

     * @param string $filearea File area

     * @param int $itemid Item id

     * @param \core\progress\base $progress

     */

    public static function annotate_files($backupid, $contextid, $component, $filearea, $itemid,

            \core\progress\base $progress = null) {

        global $DB;

        $sql = 'SELECT id

                  FROM {files}

                 WHERE contextid = ?

                   AND component = ?';

        $params = array($contextid, $component);

        if (!is_null($filearea)) { // Add filearea to query and params if necessary

            $sql .= ' AND filearea = ?';

            $params[] = $filearea;

        }

        if (!is_null($itemid)) { // Add itemid to query and params if necessary

            $sql .= ' AND itemid = ?';

            $params[] = $itemid;

        }

        if ($progress) {

            $progress->start_progress('');

        }

        $rs = $DB->get_recordset_sql($sql, $params);

        foreach ($rs as $record) {

            if ($progress) {

                $progress->progress();

            }

            self::insert_backup_ids_record($backupid, 'file', $record->id);

        }

        if ($progress) {

            $progress->end_progress();

        }

        $rs->close();

    }

    /**

     * Moves all the existing 'item' annotations to their final 'itemfinal' ones

     * for a given backup.

     *

     * @param string $backupid Backup ID

     * @param string $itemname Item name

     * @param \core\progress\base $progress Progress tracker

     */

    public static function move_annotations_to_final($backupid, $itemname, \core\progress\base $progress) {

        global $DB;

        $progress->start_progress('move_annotations_to_final');

        $rs = $DB->get_recordset('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));

        $progress->progress();

        foreach($rs as $annotation) {

            // If corresponding 'itemfinal' annotation does not exist, update 'item' to 'itemfinal'

            if (! $DB->record_exists('backup_ids_temp', array('backupid' => $backupid,

                                                              'itemname' => $itemname . 'final',

                                                              'itemid' => $annotation->itemid))) {

                $DB->set_field('backup_ids_temp', 'itemname', $itemname . 'final', array('id' => $annotation->id));

            }

            $progress->progress();

        }

        $rs->close();

        // All the remaining $itemname annotations can be safely deleted

        $DB->delete_records('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));

        $progress->end_progress();

    }

    /**

     * Returns true/false if there are annotations for a given item

     */

    public static function annotations_exist($backupid, $itemname) {

        global $DB;

        return (bool)$DB->count_records('backup_ids_temp', array('backupid' => $backupid, 'itemname' => $itemname));

    }

}