wikimedia / mediawiki

maintenance/storage/moveToExternal.php

<?php

For compatibility and reusability of your code, PSR1 recommends that a file should introduce either new symbols (like classes, functions, etc.) or have side-effects (like outputting something, or including other files), but not both at the same time. The first symbol is defined on line 24 and the first side effect is on line 27.

/**
 * Move revision's text to external storage
 *
 * 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 ExternalStorage
 */

define( 'REPORTING_INTERVAL', 1 );

if ( !defined( 'MEDIAWIKI' ) ) {
	$optionsWithArgs = [ 'e', 's' ];
	require_once __DIR__ . '/../commandLine.inc';
	require_once 'resolveStubs.php';

	$fname = 'moveToExternal';

	if ( !isset( $args[0] ) ) {
		print "Usage: php moveToExternal.php [-s <startid>] [-e <endid>] <cluster>\n";
		exit;
	}

	$cluster = $args[0];
	$dbw = wfGetDB( DB_MASTER );

	if ( isset( $options['e'] ) ) {
		$maxID = $options['e'];
	} else {
		$maxID = $dbw->selectField( 'text', 'MAX(old_id)', false, $fname );
	}
	$minID = isset( $options['s'] ) ? $options['s'] : 1;

	moveToExternal( $cluster, $maxID, $minID );
}

function moveToExternal( $cluster, $maxID, $minID = 1 ) {
	$fname = 'moveToExternal';
	$dbw = wfGetDB( DB_MASTER );
	$dbr = wfGetDB( DB_REPLICA );

	$count = $maxID - $minID + 1;
	$blockSize = 1000;
	$numBlocks = ceil( $count / $blockSize );
	print "Moving text rows from $minID to $maxID to external storage\n";
	$ext = new ExternalStoreDB;
	$numMoved = 0;

	for ( $block = 0; $block < $numBlocks; $block++ ) {
		$blockStart = $block * $blockSize + $minID;
		$blockEnd = $blockStart + $blockSize - 1;

		if ( !( $block % REPORTING_INTERVAL ) ) {
			print "oldid=$blockStart, moved=$numMoved\n";
			wfWaitForSlaves();

The function wfWaitForSlaves() has been deprecated with message: since 1.27 Use LBFactory::waitForReplication

		}

		$res = $dbr->select( 'text', [ 'old_id', 'old_flags', 'old_text' ],
			[
				"old_id BETWEEN $blockStart AND $blockEnd",
				'old_flags NOT ' . $dbr->buildLike( $dbr->anyString(), 'external', $dbr->anyString() ),
			], $fname );
		foreach ( $res as $row ) {
			# Resolve stubs
			$text = $row->old_text;
			$id = $row->old_id;
			if ( $row->old_flags === '' ) {
				$flags = 'external';
			} else {
				$flags = "{$row->old_flags},external";
			}

			if ( strpos( $flags, 'object' ) !== false ) {
				$obj = unserialize( $text );
				$className = strtolower( get_class( $obj ) );
				if ( $className == 'historyblobstub' ) {
					# resolveStub( $id, $row->old_text, $row->old_flags );
					# $numStubs++;
					continue;
				} elseif ( $className == 'historyblobcurstub' ) {
					$text = gzdeflate( $obj->getText() );
					$flags = 'utf-8,gzip,external';
				} elseif ( $className == 'concatenatedgziphistoryblob' ) {

This elseif statement is empty, and could be removed.

					// Do nothing
				} else {
					print "Warning: unrecognised object class \"$className\"\n";
					continue;
				}
			} else {
				$className = false;
			}

			if ( strlen( $text ) < 100 && $className === false ) {
				// Don't move tiny revisions
				continue;
			}

			# print "Storing "  . strlen( $text ) . " bytes to $url\n";
			# print "old_id=$id\n";

			$url = $ext->store( $cluster, $text );
			if ( !$url ) {
				print "Error writing to external storage\n";
				exit;

The function moveToExternal() contains an exit expression.

			}
			$dbw->update( 'text',
				[ 'old_flags' => $flags, 'old_text' => $url ],
				[ 'old_id' => $id ], $fname );
			$numMoved++;
		}
	}
}