+<?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
+ * @ingroup Profiler
+ */
+
+namespace Wikimedia\Rdbms;
+
+/**
+ * Lazy-loaded wrapper for simplification and scrubbing of SQL queries for profiling
+ *
+ * @since 1.34
+ */
+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;
+ }
+}