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mediawiki_ynh/sources/mediawiki/maintenance/syncFileBackend.php

299 lines
10 KiB
PHP

<?php
/**
* Sync one file backend to another based on the journal of later.
*
* 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
*/
require_once __DIR__ . '/Maintenance.php';
/**
* Maintenance script that syncs one file backend to another based on
* the journal of later.
*
* @ingroup Maintenance
*/
class SyncFileBackend extends Maintenance {
public function __construct() {
parent::__construct();
$this->mDescription = "Sync one file backend with another using the journal";
$this->addOption( 'src', 'Name of backend to sync from', true, true );
$this->addOption( 'dst', 'Name of destination backend to sync', false, true );
$this->addOption( 'start', 'Starting journal ID', false, true );
$this->addOption( 'end', 'Ending journal ID', false, true );
$this->addOption( 'posdir', 'Directory to read/record journal positions', false, true );
$this->addOption( 'posdump', 'Just dump current journal position into the position dir.' );
$this->addOption( 'postime', 'For position dumps, get the ID at this time', false, true );
$this->addOption( 'backoff', 'Stop at entries younger than this age (sec).', false, true );
$this->addOption( 'verbose', 'Verbose mode', false, false, 'v' );
$this->setBatchSize( 50 );
}
public function execute() {
$src = FileBackendGroup::singleton()->get( $this->getOption( 'src' ) );
$posDir = $this->getOption( 'posdir' );
$posFile = $posDir ? $posDir . '/' . wfWikiID() : false;
if ( $this->hasOption( 'posdump' ) ) {
// Just dump the current position into the specified position dir
if ( !$this->hasOption( 'posdir' ) ) {
$this->error( "Param posdir required!", 1 );
}
if ( $this->hasOption( 'postime' ) ) {
$id = (int)$src->getJournal()->getPositionAtTime( $this->getOption( 'postime' ) );
$this->output( "Requested journal position is $id.\n" );
} else {
$id = (int)$src->getJournal()->getCurrentPosition();
$this->output( "Current journal position is $id.\n" );
}
if ( file_put_contents( $posFile, $id, LOCK_EX ) !== false ) {
$this->output( "Saved journal position file.\n" );
} else {
$this->output( "Could not save journal position file.\n" );
}
if ( $this->isQuiet() ) {
print $id; // give a single machine-readable number
}
return;
}
if ( !$this->hasOption( 'dst' ) ) {
$this->error( "Param dst required!", 1 );
}
$dst = FileBackendGroup::singleton()->get( $this->getOption( 'dst' ) );
$start = $this->getOption( 'start', 0 );
if ( !$start && $posFile && is_dir( $posDir ) ) {
$start = is_file( $posFile )
? (int)trim( file_get_contents( $posFile ) )
: 0;
++$start; // we already did this ID, start with the next one
$startFromPosFile = true;
} else {
$startFromPosFile = false;
}
if ( $this->hasOption( 'backoff' ) ) {
$time = time() - $this->getOption( 'backoff', 0 );
$end = (int)$src->getJournal()->getPositionAtTime( $time );
} else {
$end = $this->getOption( 'end', INF );
}
$this->output( "Synchronizing backend '{$dst->getName()}' to '{$src->getName()}'...\n" );
$this->output( "Starting journal position is $start.\n" );
if ( is_finite( $end ) ) {
$this->output( "Ending journal position is $end.\n" );
}
// Periodically update the position file
$callback = function( $pos ) use ( $startFromPosFile, $posFile, $start ) {
if ( $startFromPosFile && $pos >= $start ) { // successfully advanced
file_put_contents( $posFile, $pos, LOCK_EX );
}
};
// Actually sync the dest backend with the reference backend
$lastOKPos = $this->syncBackends( $src, $dst, $start, $end, $callback );
// Update the sync position file
if ( $startFromPosFile && $lastOKPos >= $start ) { // successfully advanced
if ( file_put_contents( $posFile, $lastOKPos, LOCK_EX ) !== false ) {
$this->output( "Updated journal position file.\n" );
} else {
$this->output( "Could not update journal position file.\n" );
}
}
if ( $lastOKPos === false ) {
if ( !$start ) {
$this->output( "No journal entries found.\n" );
} else {
$this->output( "No new journal entries found.\n" );
}
} else {
$this->output( "Stopped synchronization at journal position $lastOKPos.\n" );
}
if ( $this->isQuiet() ) {
print $lastOKPos; // give a single machine-readable number
}
}
/**
* Sync $dst backend to $src backend based on the $src logs given after $start.
* Returns the journal entry ID this advanced to and handled (inclusive).
*
* @param $src FileBackend
* @param $dst FileBackend
* @param $start integer Starting journal position
* @param $end integer Starting journal position
* @param $callback Closure Callback to update any position file
* @return integer|false Journal entry ID or false if there are none
*/
protected function syncBackends(
FileBackend $src, FileBackend $dst, $start, $end, Closure $callback
) {
$lastOKPos = 0; // failed
$first = true; // first batch
if ( $start > $end ) { // sanity
$this->error( "Error: given starting ID greater than ending ID.", 1 );
}
do {
$limit = min( $this->mBatchSize, $end - $start + 1 ); // don't go pass ending ID
$this->output( "Doing id $start to " . ( $start + $limit - 1 ) . "...\n" );
$entries = $src->getJournal()->getChangeEntries( $start, $limit, $next );
$start = $next; // start where we left off next time
if ( $first && !count( $entries ) ) {
return false; // nothing to do
}
$first = false;
$lastPosInBatch = 0;
$pathsInBatch = array(); // changed paths
foreach ( $entries as $entry ) {
if ( $entry['op'] !== 'null' ) { // null ops are just for reference
$pathsInBatch[$entry['path']] = 1; // remove duplicates
}
$lastPosInBatch = $entry['id'];
}
$status = $this->syncFileBatch( array_keys( $pathsInBatch ), $src, $dst );
if ( $status->isOK() ) {
$lastOKPos = max( $lastOKPos, $lastPosInBatch );
$callback( $lastOKPos ); // update position file
} else {
$this->error( print_r( $status->getErrorsArray(), true ) );
break; // no gaps; everything up to $lastPos must be OK
}
if ( !$start ) {
$this->output( "End of journal entries.\n" );
}
} while ( $start && $start <= $end );
return $lastOKPos;
}
/**
* Sync particular files of backend $src to the corresponding $dst backend files
*
* @param $paths Array
* @param $src FileBackend
* @param $dst FileBackend
* @return Status
*/
protected function syncFileBatch( array $paths, FileBackend $src, FileBackend $dst ) {
$status = Status::newGood();
if ( !count( $paths ) ) {
return $status; // nothing to do
}
// Source: convert internal backend names (FileBackendMultiWrite) to the public one
$sPaths = $this->replaceNamePaths( $paths, $src );
// Destination: get corresponding path name
$dPaths = $this->replaceNamePaths( $paths, $dst );
// Lock the live backend paths from modification
$sLock = $src->getScopedFileLocks( $sPaths, LockManager::LOCK_UW, $status );
$eLock = $dst->getScopedFileLocks( $dPaths, LockManager::LOCK_EX, $status );
if ( !$status->isOK() ) {
return $status;
}
$ops = array();
$fsFiles = array();
foreach ( $sPaths as $i => $sPath ) {
$dPath = $dPaths[$i]; // destination
$sExists = $src->fileExists( array( 'src' => $sPath, 'latest' => 1 ) );
if ( $sExists === true ) { // exists in source
if ( $this->filesAreSame( $src, $dst, $sPath, $dPath ) ) {
continue; // avoid local copies for non-FS backends
}
// Note: getLocalReference() is fast for FS backends
$fsFile = $src->getLocalReference( array( 'src' => $sPath, 'latest' => 1 ) );
if ( !$fsFile ) {
$this->error( "Unable to sync '$dPath': could not get local copy." );
$status->fatal( 'backend-fail-internal', $src->getName() );
return $status;
}
$fsFiles[] = $fsFile; // keep TempFSFile objects alive as needed
// Note: prepare() is usually fast for key/value backends
$status->merge( $dst->prepare( array(
'dir' => dirname( $dPath ), 'bypassReadOnly' => 1 ) ) );
if ( !$status->isOK() ) {
return $status;
}
$ops[] = array( 'op' => 'store',
'src' => $fsFile->getPath(), 'dst' => $dPath, 'overwrite' => 1 );
} elseif ( $sExists === false ) { // does not exist in source
$ops[] = array( 'op' => 'delete', 'src' => $dPath, 'ignoreMissingSource' => 1 );
} else { // error
$this->error( "Unable to sync '$dPath': could not stat file." );
$status->fatal( 'backend-fail-internal', $src->getName() );
return $status;
}
}
$t_start = microtime( true );
$status = $dst->doQuickOperations( $ops, array( 'bypassReadOnly' => 1 ) );
if ( !$status->isOK() ) {
sleep( 10 ); // wait and retry copy again
$status = $dst->doQuickOperations( $ops, array( 'bypassReadOnly' => 1 ) );
}
$ellapsed_ms = floor( ( microtime( true ) - $t_start ) * 1000 );
if ( $status->isOK() && $this->getOption( 'verbose' ) ) {
$this->output( "Synchronized these file(s) [{$ellapsed_ms}ms]:\n" .
implode( "\n", $dPaths ) . "\n" );
}
return $status;
}
/**
* Substitute the backend name of storage paths with that of a given one
*
* @param $paths Array|string List of paths or single string path
* @return Array|string
*/
protected function replaceNamePaths( $paths, FileBackend $backend ) {
return preg_replace(
'!^mwstore://([^/]+)!',
StringUtils::escapeRegexReplacement( "mwstore://" . $backend->getName() ),
$paths // string or array
);
}
protected function filesAreSame( FileBackend $src, FileBackend $dst, $sPath, $dPath ) {
return (
( $src->getFileSize( array( 'src' => $sPath ) )
=== $dst->getFileSize( array( 'src' => $dPath ) ) // short-circuit
) && ( $src->getFileSha1Base36( array( 'src' => $sPath ) )
=== $dst->getFileSha1Base36( array( 'src' => $dPath ) )
)
);
}
}
$maintClass = "SyncFileBackend";
require_once RUN_MAINTENANCE_IF_MAIN;