Remove load array indexes from LoadBalancer errors

[mediawiki.git] / maintenance / updateCollation.php

<?php
/**
 * Find all rows in the categorylinks table whose collation is out-of-date
 * (cl_collation != $wgCategoryCollation) and repopulate cl_sortkey
 * using the page title and cl_sortkey_prefix.
 *
 * 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 Maintenance
 * @author Aryeh Gregor (Simetrical)
 */

require_once __DIR__ . '/Maintenance.php';

use Wikimedia\Rdbms\IDatabase;

/**
 * Maintenance script that will find all rows in the categorylinks table
 * whose collation is out-of-date.
 *
 * @ingroup Maintenance
 */
class UpdateCollation extends Maintenance {
        const BATCH_SIZE = 100; // Number of rows to process in one batch
        const SYNC_INTERVAL = 5; // Wait for replica DBs after this many batches

        public $sizeHistogram = [];

        public function __construct() {
                parent::__construct();

                global $wgCategoryCollation;
                $this->addDescription( <<<TEXT
This script will find all rows in the categorylinks table whose collation is
out-of-date (cl_collation != '$wgCategoryCollation') and repopulate cl_sortkey
using the page title and cl_sortkey_prefix.  If all collations are
up-to-date, it will do nothing.
TEXT
                );

                $this->addOption( 'force', 'Run on all rows, even if the collation is ' .
                        'supposed to be up-to-date.', false, false, 'f' );
                $this->addOption( 'previous-collation', 'Set the previous value of ' .
                        '$wgCategoryCollation here to speed up this script, especially if your ' .
                        'categorylinks table is large. This will only update rows with that ' .
                        'collation, though, so it may miss out-of-date rows with a different, ' .
                        'even older collation.', false, true );
                $this->addOption( 'target-collation', 'Set this to the new collation type to ' .
                        'use instead of $wgCategoryCollation. Usually you should not use this, ' .
                        'you should just update $wgCategoryCollation in LocalSettings.php.',
                        false, true );
                $this->addOption( 'dry-run', 'Don\'t actually change the collations, just ' .
                        'compile statistics.' );
                $this->addOption( 'verbose-stats', 'Show more statistics.' );
        }

        public function execute() {
                global $wgCategoryCollation;

                $dbw = $this->getDB( DB_MASTER );
                $dbr = $this->getDB( DB_REPLICA );
                $force = $this->getOption( 'force' );
                $dryRun = $this->getOption( 'dry-run' );
                $verboseStats = $this->getOption( 'verbose-stats' );
                if ( $this->hasOption( 'target-collation' ) ) {
                        $collationName = $this->getOption( 'target-collation' );
                        $collation = Collation::factory( $collationName );
                } else {
                        $collationName = $wgCategoryCollation;
                        $collation = Collation::singleton();
                }

                // Collation sanity check: in some cases the constructor will work,
                // but this will raise an exception, breaking all category pages
                $collation->getFirstLetter( 'MediaWiki' );

                // Locally at least, (my local is a rather old version of mysql)
                // mysql seems to filesort if there is both an equality
                // (but not for an inequality) condition on cl_collation in the
                // WHERE and it is also the first item in the ORDER BY.
                if ( $this->hasOption( 'previous-collation' ) ) {
                        $orderBy = 'cl_to, cl_type, cl_from';
                } else {
                        $orderBy = 'cl_collation, cl_to, cl_type, cl_from';
                }
                $options = [
                        'LIMIT' => self::BATCH_SIZE,
                        'ORDER BY' => $orderBy,
                        'STRAIGHT_JOIN' // per T58041
                ];

                if ( $force ) {
                        $collationConds = [];
                } else {
                        if ( $this->hasOption( 'previous-collation' ) ) {
                                $collationConds['cl_collation'] = $this->getOption( 'previous-collation' );
                        } else {
                                $collationConds = [ 0 =>
                                        'cl_collation != ' . $dbw->addQuotes( $collationName )
                                ];
                        }

                        $count = $dbr->estimateRowCount(
                                'categorylinks',
                                '*',
                                $collationConds,
                                __METHOD__
                        );
                        // Improve estimate if feasible
                        if ( $count < 1000000 ) {
                                $count = $dbr->selectField(
                                        'categorylinks',
                                        'COUNT(*)',
                                        $collationConds,
                                        __METHOD__
                                );
                        }
                        if ( $count == 0 ) {
                                $this->output( "Collations up-to-date.\n" );

                                return;
                        }
                        if ( $dryRun ) {
                                $this->output( "$count rows would be updated.\n" );
                        } else {
                                $this->output( "Fixing collation for $count rows.\n" );
                        }
                        wfWaitForSlaves();
                }
                $count = 0;
                $batchCount = 0;
                $batchConds = [];
                do {
                        $this->output( "Selecting next " . self::BATCH_SIZE . " rows..." );

                        // cl_type must be selected as a number for proper paging because
                        // enums suck.
                        if ( $dbw->getType() === 'mysql' ) {
                                $clType = 'cl_type+0 AS "cl_type_numeric"';
                        } else {
                                $clType = 'cl_type';
                        }
                        $res = $dbw->select(
                                [ 'categorylinks', 'page' ],
                                [ 'cl_from', 'cl_to', 'cl_sortkey_prefix', 'cl_collation',
                                        'cl_sortkey', $clType,
                                        'page_namespace', 'page_title'
                                ],
                                array_merge( $collationConds, $batchConds, [ 'cl_from = page_id' ] ),
                                __METHOD__,
                                $options
                        );
                        $this->output( " processing..." );

                        if ( !$dryRun ) {
                                $this->beginTransaction( $dbw, __METHOD__ );
                        }
                        foreach ( $res as $row ) {
                                $title = Title::newFromRow( $row );
                                if ( !$row->cl_collation ) {
                                        # This is an old-style row, so the sortkey needs to be
                                        # converted.
                                        if ( $row->cl_sortkey == $title->getText()
                                                || $row->cl_sortkey == $title->getPrefixedText()
                                        ) {
                                                $prefix = '';
                                        } else {
                                                # Custom sortkey, use it as a prefix
                                                $prefix = $row->cl_sortkey;
                                        }
                                } else {
                                        $prefix = $row->cl_sortkey_prefix;
                                }
                                # cl_type will be wrong for lots of pages if cl_collation is 0,
                                # so let's update it while we're here.
                                if ( $title->getNamespace() == NS_CATEGORY ) {
                                        $type = 'subcat';
                                } elseif ( $title->getNamespace() == NS_FILE ) {
                                        $type = 'file';
                                } else {
                                        $type = 'page';
                                }
                                $newSortKey = $collation->getSortKey(
                                        $title->getCategorySortkey( $prefix ) );
                                if ( $verboseStats ) {
                                        $this->updateSortKeySizeHistogram( $newSortKey );
                                }

                                if ( !$dryRun ) {
                                        $dbw->update(
                                                'categorylinks',
                                                [
                                                        'cl_sortkey' => $newSortKey,
                                                        'cl_sortkey_prefix' => $prefix,
                                                        'cl_collation' => $collationName,
                                                        'cl_type' => $type,
                                                        'cl_timestamp = cl_timestamp',
                                                ],
                                                [ 'cl_from' => $row->cl_from, 'cl_to' => $row->cl_to ],
                                                __METHOD__
                                        );
                                }
                                if ( $row ) {
                                        $batchConds = [ $this->getBatchCondition( $row, $dbw ) ];
                                }
                        }
                        if ( !$dryRun ) {
                                $this->commitTransaction( $dbw, __METHOD__ );
                        }

                        $count += $res->numRows();
                        $this->output( "$count done.\n" );

                        if ( !$dryRun && ++$batchCount % self::SYNC_INTERVAL == 0 ) {
                                $this->output( "Waiting for replica DBs ... " );
                                wfWaitForSlaves();
                                $this->output( "done\n" );
                        }
                } while ( $res->numRows() == self::BATCH_SIZE );

                $this->output( "$count rows processed\n" );

                if ( $verboseStats ) {
                        $this->output( "\n" );
                        $this->showSortKeySizeHistogram();
                }
        }

        /**
         * Return an SQL expression selecting rows which sort above the given row,
         * assuming an ordering of cl_collation, cl_to, cl_type, cl_from
         * @param stdClass $row
         * @param IDatabase $dbw
         * @return string
         */
        function getBatchCondition( $row, $dbw ) {
                if ( $this->hasOption( 'previous-collation' ) ) {
                        $fields = [ 'cl_to', 'cl_type', 'cl_from' ];
                } else {
                        $fields = [ 'cl_collation', 'cl_to', 'cl_type', 'cl_from' ];
                }
                $first = true;
                $cond = false;
                $prefix = false;
                foreach ( $fields as $field ) {
                        if ( $dbw->getType() === 'mysql' && $field === 'cl_type' ) {
                                // Range conditions with enums are weird in mysql
                                // This must be a numeric literal, or it won't work.
                                $encValue = intval( $row->cl_type_numeric );
                        } else {
                                $encValue = $dbw->addQuotes( $row->$field );
                        }
                        $inequality = "$field > $encValue";
                        $equality = "$field = $encValue";
                        if ( $first ) {
                                $cond = $inequality;
                                $prefix = $equality;
                                $first = false;
                        } else {
                                $cond .= " OR ($prefix AND $inequality)";
                                $prefix .= " AND $equality";
                        }
                }

                return $cond;
        }

        function updateSortKeySizeHistogram( $key ) {
                $length = strlen( $key );
                if ( !isset( $this->sizeHistogram[$length] ) ) {
                        $this->sizeHistogram[$length] = 0;
                }
                $this->sizeHistogram[$length]++;
        }

        function showSortKeySizeHistogram() {
                $maxLength = max( array_keys( $this->sizeHistogram ) );
                if ( $maxLength == 0 ) {
                        return;
                }
                $numBins = 20;
                $coarseHistogram = array_fill( 0, $numBins, 0 );
                $coarseBoundaries = [];
                $boundary = 0;
                for ( $i = 0; $i < $numBins - 1; $i++ ) {
                        $boundary += $maxLength / $numBins;
                        $coarseBoundaries[$i] = round( $boundary );
                }
                $coarseBoundaries[$numBins - 1] = $maxLength + 1;
                $raw = '';
                for ( $i = 0; $i <= $maxLength; $i++ ) {
                        if ( $raw !== '' ) {
                                $raw .= ', ';
                        }
                        if ( !isset( $this->sizeHistogram[$i] ) ) {
                                $val = 0;
                        } else {
                                $val = $this->sizeHistogram[$i];
                        }
                        for ( $coarseIndex = 0; $coarseIndex < $numBins - 1; $coarseIndex++ ) {
                                if ( $coarseBoundaries[$coarseIndex] > $i ) {
                                        $coarseHistogram[$coarseIndex] += $val;
                                        break;
                                }
                        }
                        if ( $coarseIndex == $numBins - 1 ) {
                                $coarseHistogram[$coarseIndex] += $val;
                        }
                        $raw .= $val;
                }

                $this->output( "Sort key size histogram\nRaw data: $raw\n\n" );

                $maxBinVal = max( $coarseHistogram );
                $scale = 60 / $maxBinVal;
                $prevBoundary = 0;
                for ( $coarseIndex = 0; $coarseIndex < $numBins; $coarseIndex++ ) {
                        if ( !isset( $coarseHistogram[$coarseIndex] ) ) {
                                $val = 0;
                        } else {
                                $val = $coarseHistogram[$coarseIndex];
                        }
                        $boundary = $coarseBoundaries[$coarseIndex];
                        $this->output( sprintf( "%-10s %-10d |%s\n",
                                $prevBoundary . '-' . ( $boundary - 1 ) . ': ',
                                $val,
                                str_repeat( '*', $scale * $val ) ) );
                        $prevBoundary = $boundary;
                }
        }
}

$maintClass = "UpdateCollation";
require_once RUN_MAINTENANCE_IF_MAIN;