Your IP : 192.168.165.1
<?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/>.
/**
* Simple moodle database engine.
*
* @package search_simpledb
* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace search_simpledb;
defined('MOODLE_INTERNAL') || die();
/**
* Simple moodle database engine.
*
* @package search_simpledb
* @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class engine extends \core_search\engine {
/**
* Total number of available results.
*
* @var null|int
*/
protected $totalresults = null;
/**
* Prepares a SQL query, applies filters and executes it returning its results.
*
* @throws \core_search\engine_exception
* @param stdClass $filters Containing query and filters.
* @param array $usercontexts Contexts where the user has access. True if the user can access all contexts.
* @param int $limit The maximum number of results to return.
* @return \core_search\document[] Results or false if no results
*/
public function execute_query($filters, $usercontexts, $limit = 0) {
global $DB, $USER;
$serverstatus = $this->is_server_ready();
if ($serverstatus !== true) {
throw new \core_search\engine_exception('engineserverstatus', 'search');
}
if (empty($limit)) {
$limit = \core_search\manager::MAX_RESULTS;
}
$params = array();
// To store all conditions we will add to where.
$ands = array();
// Get results only available for the current user.
$ands[] = '(owneruserid = ? OR owneruserid = ?)';
$params = array_merge($params, array(\core_search\manager::NO_OWNER_ID, $USER->id));
// Restrict it to the context where the user can access, we want this one cached.
// If the user can access all contexts $usercontexts value is just true, we don't need to filter
// in that case.
if ($usercontexts && is_array($usercontexts)) {
// Join all area contexts into a single array and implode.
$allcontexts = array();
foreach ($usercontexts as $areaid => $areacontexts) {
if (!empty($filters->areaids) && !in_array($areaid, $filters->areaids)) {
// Skip unused areas.
continue;
}
foreach ($areacontexts as $contextid) {
// Ensure they are unique.
$allcontexts[$contextid] = $contextid;
}
}
if (empty($allcontexts)) {
// This means there are no valid contexts for them, so they get no results.
return array();
}
list($contextsql, $contextparams) = $DB->get_in_or_equal($allcontexts);
$ands[] = 'contextid ' . $contextsql;
$params = array_merge($params, $contextparams);
}
// Course id filter.
if (!empty($filters->courseids)) {
list($conditionsql, $conditionparams) = $DB->get_in_or_equal($filters->courseids);
$ands[] = 'courseid ' . $conditionsql;
$params = array_merge($params, $conditionparams);
}
// Area id filter.
if (!empty($filters->areaids)) {
list($conditionsql, $conditionparams) = $DB->get_in_or_equal($filters->areaids);
$ands[] = 'areaid ' . $conditionsql;
$params = array_merge($params, $conditionparams);
}
if (!empty($filters->title)) {
$ands[] = $DB->sql_like('title', '?', false, false);
$params[] = $filters->title;
}
if (!empty($filters->timestart)) {
$ands[] = 'modified >= ?';
$params[] = $filters->timestart;
}
if (!empty($filters->timeend)) {
$ands[] = 'modified <= ?';
$params[] = $filters->timeend;
}
// And finally the main query after applying all AND filters.
if (!empty($filters->q)) {
switch ($DB->get_dbfamily()) {
case 'postgres':
$ands[] = "(" .
"to_tsvector('simple', title) @@ plainto_tsquery('simple', ?) OR ".
"to_tsvector('simple', content) @@ plainto_tsquery('simple', ?) OR ".
"to_tsvector('simple', description1) @@ plainto_tsquery('simple', ?) OR ".
"to_tsvector('simple', description2) @@ plainto_tsquery('simple', ?)".
")";
$params[] = $filters->q;
$params[] = $filters->q;
$params[] = $filters->q;
$params[] = $filters->q;
break;
case 'mysql':
if ($DB->is_fulltext_search_supported()) {
$ands[] = "MATCH (title, content, description1, description2) AGAINST (?)";
$params[] = $filters->q;
// Sorry for the hack, but it does not seem that we will have a solution for
// this soon (https://bugs.mysql.com/bug.php?id=78485).
if ($filters->q === '*') {
return array();
}
} else {
// Clumsy version for mysql versions with no fulltext support.
list($queryand, $queryparams) = $this->get_simple_query($filters->q);
$ands[] = $queryand;
$params = array_merge($params, $queryparams);
}
break;
case 'mssql':
if ($DB->is_fulltext_search_supported()) {
$ands[] = "CONTAINS ((title, content, description1, description2), ?)";
// Special treatment for double quotes:
// - Puntuation is ignored so we can get rid of them.
// - Phrases should be enclosed in double quotation marks.
$params[] = '"' . str_replace('"', '', $filters->q) . '"';
} else {
// Clumsy version for mysql versions with no fulltext support.
list($queryand, $queryparams) = $this->get_simple_query($filters->q);
$ands[] = $queryand;
$params = array_merge($params, $queryparams);
}
break;
default:
list($queryand, $queryparams) = $this->get_simple_query($filters->q);
$ands[] = $queryand;
$params = array_merge($params, $queryparams);
break;
}
}
// It is limited to $limit, no need to use recordsets.
$documents = $DB->get_records_select('search_simpledb_index', implode(' AND ', $ands), $params, '', '*', 0, $limit);
// Hopefully database cached results as this applies the same filters than above.
$this->totalresults = $DB->count_records_select('search_simpledb_index', implode(' AND ', $ands), $params);
$numgranted = 0;
// Iterate through the results checking its availability and whether they are available for the user or not.
$docs = array();
foreach ($documents as $docdata) {
if ($docdata->owneruserid != \core_search\manager::NO_OWNER_ID && $docdata->owneruserid != $USER->id) {
// If owneruserid is set, no other user should be able to access this record.
continue;
}
if (!$searcharea = $this->get_search_area($docdata->areaid)) {
$this->totalresults--;
continue;
}
// Switch id back to the document id.
$docdata->id = $docdata->docid;
unset($docdata->docid);
$access = $searcharea->check_access($docdata->itemid);
switch ($access) {
case \core_search\manager::ACCESS_DELETED:
$this->delete_by_id($docdata->id);
$this->totalresults--;
break;
case \core_search\manager::ACCESS_DENIED:
$this->totalresults--;
break;
case \core_search\manager::ACCESS_GRANTED:
$numgranted++;
$docs[] = $this->to_document($searcharea, (array)$docdata);
break;
}
// This should never happen.
if ($numgranted >= $limit) {
$docs = array_slice($docs, 0, $limit, true);
break;
}
}
return $docs;
}
/**
* Adds a document to the search engine.
*
* This does not commit to the search engine.
*
* @param \core_search\document $document
* @param bool $fileindexing True if file indexing is to be used
* @return bool False if the file was skipped or failed, true on success
*/
public function add_document($document, $fileindexing = false) {
global $DB;
$doc = (object)$document->export_for_engine();
// Moodle's ids using DML are always autoincremented.
$doc->docid = $doc->id;
unset($doc->id);
$id = $DB->get_field('search_simpledb_index', 'id', array('docid' => $doc->docid));
try {
if ($id) {
$doc->id = $id;
$DB->update_record('search_simpledb_index', $doc);
} else {
$DB->insert_record('search_simpledb_index', $doc);
}
} catch (\dml_exception $ex) {
debugging('dml error while trying to insert document with id ' . $doc->docid . ': ' . $ex->getMessage(),
DEBUG_DEVELOPER);
return false;
}
return true;
}
/**
* Deletes the specified document.
*
* @param string $id The document id to delete
* @return void
*/
public function delete_by_id($id) {
global $DB;
$DB->delete_records('search_simpledb_index', array('docid' => $id));
}
/**
* Delete all area's documents.
*
* @param string $areaid
* @return void
*/
public function delete($areaid = null) {
global $DB;
if ($areaid) {
$DB->delete_records('search_simpledb_index', array('areaid' => $areaid));
} else {
$DB->delete_records('search_simpledb_index');
}
}
/**
* Checks that the required table was installed.
*
* @return true|string Returns true if all good or an error string.
*/
public function is_server_ready() {
global $DB;
if (!$DB->get_manager()->table_exists('search_simpledb_index')) {
return 'search_simpledb_index table does not exist';
}
return true;
}
/**
* It is always installed.
*
* @return true
*/
public function is_installed() {
return true;
}
/**
* Returns the total results.
*
* Including skipped results.
*
* @return int
*/
public function get_query_total_count() {
if (!is_null($this->totalresults)) {
// This is a just in case as we count total results in execute_query.
return \core_search\manager::MAX_RESULTS;
}
return $this->totalresults;
}
/**
* Returns the default query for db engines.
*
* @param string $q The query string
* @return array SQL string and params list
*/
protected function get_simple_query($q) {
global $DB;
$sql = '(' .
$DB->sql_like('title', '?', false, false) . ' OR ' .
$DB->sql_like('content', '?', false, false) . ' OR ' .
$DB->sql_like('description1', '?', false, false) . ' OR ' .
$DB->sql_like('description2', '?', false, false) .
')';
$params = array(
'%' . $q . '%',
'%' . $q . '%',
'%' . $q . '%',
'%' . $q . '%'
);
return array($sql, $params);
}
/**
* Simpledb supports deleting the index for a context.
*
* @param int $oldcontextid Context that has been deleted
* @return bool True to indicate that any data was actually deleted
* @throws \core_search\engine_exception
*/
public function delete_index_for_context(int $oldcontextid) {
global $DB;
try {
$DB->delete_records('search_simpledb_index', ['contextid' => $oldcontextid]);
} catch (\dml_exception $e) {
throw new \core_search\engine_exception('dbupdatefailed');
}
return true;
}
/**
* Simpledb supports deleting the index for a course.
*
* @param int $oldcourseid
* @return bool True to indicate that any data was actually deleted
* @throws \core_search\engine_exception
*/
public function delete_index_for_course(int $oldcourseid) {
global $DB;
try {
$DB->delete_records('search_simpledb_index', ['courseid' => $oldcourseid]);
} catch (\dml_exception $e) {
throw new \core_search\engine_exception('dbupdatefailed');
}
return true;
}
}