wiki.techinc.nl/includes/libs/rdbms/database/utils/GeneralizedSql.php
Timo Tijhof 6c5f64937c rdbms: Move Profiler @ingroup docs from file to class
The Profiler doc overview was missing these two classes,
it instead listed the class files as entries intead, which wasn't
very useful.

Bug: T232911
Change-Id: I6fe66fd16e7b5006e0af83d95b45a7ed25f060d7
2020-04-20 20:05:53 +01:00

96 lines
2.7 KiB
PHP

<?php
/**
* This program 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 2 of the License, or
* (at your option) any later version.
*
* 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 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 Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
namespace Wikimedia\Rdbms;
/**
* Lazy-loaded wrapper for simplification and scrubbing of SQL queries for profiling
*
* @since 1.34
* @ingroup Profiler
* @ingroup Database
*/
class GeneralizedSql {
/** @var string */
private $rawSql;
/** @var string */
private $trxId;
/** @var string */
private $prefix;
/** @var string|null */
private $genericSql;
/**
* @param string $rawSql
* @param string $trxId
* @param string $prefix
*/
public function __construct( $rawSql, $trxId, $prefix ) {
$this->rawSql = $rawSql;
$this->trxId = $trxId;
$this->prefix = $prefix;
}
/**
* Removes most variables from an SQL query and replaces them with X or N for numbers.
* It's only slightly flawed. Don't use for anything important.
*
* @param string $sql A SQL Query
*
* @return string
*/
private static function generalizeSQL( $sql ) {
# This does the same as the regexp below would do, but in such a way
# as to avoid crashing php on some large strings.
# $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
$sql = str_replace( "\\\\", '', $sql );
$sql = str_replace( "\\'", '', $sql );
$sql = str_replace( "\\\"", '', $sql );
$sql = preg_replace( "/'.*'/s", "'X'", $sql );
$sql = preg_replace( '/".*"/s', "'X'", $sql );
# All newlines, tabs, etc replaced by single space
$sql = preg_replace( '/\s+/', ' ', $sql );
# All numbers => N,
# except the ones surrounded by characters, e.g. l10n
$sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
$sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
return $sql;
}
/**
* @return string
*/
public function stringify() {
if ( $this->genericSql !== null ) {
return $this->genericSql;
}
$this->genericSql = $this->prefix .
substr( self::generalizeSQL( $this->rawSql ), 0, 255 ) .
( $this->trxId ? " [TRX#{$this->trxId}]" : "" );
return $this->genericSql;
}
}