gnu-social/lib/search/search_engines.php

238 lines
7.9 KiB
PHP

<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social. If not, see <http://www.gnu.org/licenses/>.
defined('GNUSOCIAL') || die();
class SearchEngine
{
protected $target;
protected $table;
public function __construct($target, $table)
{
$this->target = $target;
$this->table = $table;
}
public function query($q)
{
}
public function limit($offset, $count, $rss = false)
{
return $this->target->limit($offset, $count);
}
public function set_sort_mode($mode)
{
switch ($mode) {
case 'chron':
return $this->target->orderBy('created DESC');
break;
case 'reverse_chron':
return $this->target->orderBy('created ASC');
break;
case 'nickname_desc':
if ($this->table != 'profile') {
throw new Exception(
'nickname_desc sort mode can only be use when searching profile.'
);
} else {
return $this->target->orderBy(sprintf('%1$s.nickname DESC', $this->table));
}
break;
case 'nickname_asc':
if ($this->table != 'profile') {
throw new Exception(
'nickname_desc sort mode can only be use when searching profile.'
);
} else {
return $this->target->orderBy(sprintf('%1$s.nickname ASC', $this->table));
}
break;
default:
return $this->target->orderBy('created DESC');
break;
}
}
}
class PostgreSQLSearch extends SearchEngine
{
public function query($q)
{
if ($this->table === 'profile') {
$cols = implode(" || ' ' || ", array_map(
function ($col) {
return sprintf(
'COALESCE(%s."%s", \'\')',
common_database_tablename($this->table),
$col
);
},
['nickname', 'fullname', 'location', 'bio', 'homepage']
));
$this->target->whereAdd(sprintf(
'to_tsvector(\'english\', %2$s) @@ websearch_to_tsquery(\'%1$s\')',
$this->target->escape($q, true),
$cols
));
return true;
} elseif ($this->table === 'notice') {
// Don't show direct messages.
$this->target->whereAdd('notice.scope <> ' . Notice::MESSAGE_SCOPE);
// Don't show imported notices
$this->target->whereAdd('notice.is_local <> ' . Notice::GATEWAY);
$this->target->whereAdd(sprintf(
'to_tsvector(\'english\', "content") @@ websearch_to_tsquery(\'%1$s\')',
$this->target->escape($q, true)
));
return true;
} else {
throw new ServerException('Unknown table: ' . $this->table);
}
}
}
class MySQLSearch extends SearchEngine
{
/*
* Creates a full-text MATCH IN BOOLEAN MODE from the query format
* analogous to PostgreSQL's websearch_to_tsquery.
* The resulting boolean search query should never raise syntax errors
* regardless of the kind of input this method receives.
*
* The syntax is as follows:
* - unquoted text: text not inside quote marks will be converted to
* individual quoted words with "+" operators each.
* - "quoted text": text inside quote marks will have the "+" operator
* prepended.
* - OR: causes the two adjoined words to lose the "+" operator.
* - "-": words prepended with the "-" operator will retain it unquoted.
*/
private function websearchToBoolean(string $input): string
{
$split = [];
preg_match_all('/(?:[^\s"]|["][^"]*["])+/', $input, $split);
$phrases = [];
$or_cond = false;
foreach ($split[0] as $phrase) {
if (strtoupper($phrase) === 'OR') {
$last = &$phrases[array_key_last($phrases)];
$last['op'] = '';
$or_cond = true;
continue;
}
if (substr($phrase, 0, 1) === '-') {
$phrases[] = ['op' => '-', 'text' => substr($phrase, 1)];
} elseif ($or_cond) {
$phrases[] = ['op' => '', 'text' => $phrase];
} else {
$phrases[] = ['op' => '+', 'text' => $phrase];
}
$or_cond = false;
}
return array_reduce(
$phrases,
function (string $carry, array $item): string {
// Strip all double quote marks and wrap with them around
$text = '"' . str_replace('"', '', $item['text']) . '"';
return $carry . ' ' . $item['op'] . $text;
},
''
);
}
public function query($q)
{
if ($this->table === 'profile') {
$tables = sprintf(
'%1$s.nickname, %1$s.fullname, %1$s.location, %1$s.bio, %1$s.homepage',
$this->table
);
} elseif ($this->table === 'notice') {
// Don't show direct messages.
$this->target->whereAdd('notice.scope <> ' . Notice::MESSAGE_SCOPE);
// Don't show imported notices
$this->target->whereAdd('notice.is_local <> ' . Notice::GATEWAY);
$tables = 'notice.content';
} else {
throw new ServerException('Unknown table: ' . $this->table);
}
$boolean_query = $this->websearchToBoolean($q);
$this->target->whereAdd(sprintf(
'MATCH (%1$s) AGAINST (\'%2$s\' IN BOOLEAN MODE)',
$tables,
$this->target->escape($boolean_query)
));
return true;
}
}
class SQLLikeSearch extends SearchEngine
{
public function query($q)
{
$q_escaped = $this->target->escape(mb_strtolower($q), true);
$cols = [];
if ($this->table === 'profile') {
$cols = ['nickname', 'fullname', 'location', 'bio', 'homepage'];
} elseif ($this->table === 'notice') {
// Don't show direct messages.
$this->target->whereAdd('notice.scope <> ' . Notice::MESSAGE_SCOPE);
// Don't show imported notices
$this->target->whereAdd('notice.is_local <> ' . Notice::GATEWAY);
$cols = ['content'];
} else {
throw new ServerException('Unknown table: ' . $this->table);
}
$conds = [];
foreach ($cols as $col) {
switch (common_config('db', 'type')) {
case 'pgsql':
// Faster than with the LOWER function
$cond = "{$this->table}.{$col} ILIKE";
break;
case 'mysql':
// Case-insensitive collation
$cond = "{$this->table}.{$col} LIKE";
break;
default:
$cond = "LOWER({$this->table}.{$col}) LIKE";
}
$conds[] = $cond . " '%" . $q_escaped . "%'";
}
$qry = '(' . implode(' OR ', $conds) . ')';
$this->target->whereAdd($qry);
return true;
}
}