--- /dev/null
+<?php
+
+$optionsWithArgs = RecompressTracked::getOptionsWithArgs();
+require( dirname( __FILE__ ) .'/../commandLine.inc' );
+
+if ( count( $args ) < 1 ) {
+ echo "Usage: php recompressTracked.php <cluster> [... <cluster>...]\n";
+ echo "Moves blobs indexed by trackBlobs.php to a specified list of destination
+clusters, and recompresses them in the process. Restartable.\n";
+ exit( 1 );
+}
+
+$job = RecompressTracked::newFromCommandLine( $args, $options );
+$job->execute();
+
+class RecompressTracked {
+ var $destClusters;
+ var $batchSize = 1000;
+ var $reportingInterval = 10;
+ var $numProcs = 8;
+ var $slavePipes, $slaveProcs, $prevSlaveId;
+ var $blobClass = 'DiffHistoryBlob';
+ var $copyOnly = false;
+ var $isChild = false;
+ var $slaveId = false;
+ var $store;
+
+ static $optionsWithArgs = array( 'procs', 'class' );
+ static $cmdLineOptionMap = array(
+ 'procs' => 'numProcs',
+ 'class' => 'blobClass',
+ 'copy-only' => 'copyOnly',
+ 'child' => 'isChild',
+ 'slave-id' => 'slaveId',
+ );
+
+ static function getOptionsWithArgs() {
+ return self::$optionsWithArgs;
+ }
+
+ static function newFromCommandLine( $args, $options ) {
+ $jobOptions = array( 'destClusters' => $args );
+ foreach ( self::$cmdLineOptionMap as $cmdOption => $classOption ) {
+ if ( isset( $options[$cmdOption] ) ) {
+ $jobOptions[$classOption] = $options[$cmdOption];
+ }
+ }
+ return new self( $jobOptions );
+ }
+
+ function __construct( $options ) {
+ foreach ( $options as $name => $value ) {
+ $this->$name = $value;
+ }
+ $this->store = new ExternalStoreDB;
+ }
+
+ function debug( $msg ) {
+ if ( $this->slaveId !== false ) {
+ $msg = "{$this->slaveId}: $msg";
+ }
+ $msg .= "\n";
+ wfDebug( $msg );
+ }
+
+ /**
+ * Wait until the selected slave has caught up to the master.
+ * This allows us to use the slave for things that were committed in a
+ * previous part of this batch process.
+ */
+ function syncDBs() {
+ $dbw = wfGetDB( DB_MASTER );
+ $dbr = wfGetDB( DB_SLAVE );
+ $pos = $dbw->getMasterPos();
+ $dbr->masterPosWait( $pos, 100000 );
+ }
+
+ /**
+ * Execute parent or child depending on the isChild option
+ */
+ function execute() {
+ if ( $this->isChild ) {
+ $this->executeChild();
+ } else {
+ $this->executeParent();
+ }
+ }
+
+ /**
+ * Execute the parent process
+ */
+ function executeParent() {
+ if ( !$this->checkTrackingTable() ) {
+ return;
+ }
+
+ $this->syncDBs();
+ $this->startSlaveProcs();
+ $this->doAllPages();
+ $this->doAllOrphans();
+ $this->killSlaveProcs();
+ }
+
+ /**
+ * Make sure the tracking table exists and isn't empty
+ */
+ function checkTrackingTable() {
+ $dbr = wfGetDB( DB_SLAVE );
+ if ( !$dbr->tableExists( 'blob_tracking' ) ) {
+ echo "Error: blob_tracking table does not exist\n";
+ return false;
+ }
+ $row = $dbr->selectRow( 'blob_tracking', '*', false, __METHOD__ );
+ if ( !$row ) {
+ echo "Warning: blob_tracking table contains no rows, skipping this wiki.\n";
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Start the worker processes.
+ * These processes will listen on stdin for commands.
+ * This necessary because text recompression is slow: loading, compressing and
+ * writing are all slow.
+ */
+ function startSlaveProcs() {
+ $cmd = 'php ' . wfEscapeShellArg( __FILE__ );
+ foreach ( self::$cmdLineOptionMap as $cmdOption => $classOption ) {
+ if ( in_array( $cmdOption, self::$optionsWithArgs ) ) {
+ $cmd .= " --$cmdOption " . wfEscapeShellArg( $this->$classOption );
+ } elseif ( $this->$classOption ) {
+ $cmd .= " --$cmdOption";
+ }
+ }
+ $cmd .= ' --child' .
+ ' --wiki ' . wfEscapeShellArg( wfWikiID() ) .
+ ' ' . call_user_func_array( 'wfEscapeShellArg', $this->destClusters );
+
+ $this->slavePipes = $this->slaveProcs = array();
+ for ( $i = 0; $i < $this->numProcs; $i++ ) {
+ $pipes = false;
+ $spec = array(
+ array( 'pipe', 'r' ),
+ array( 'file', '/dev/stdout', 'w' ),
+ array( 'file', '/dev/stderr', 'w' )
+ );
+ wfSuppressWarnings();
+ $proc = proc_open( $cmd, $spec, $pipes );
+ wfRestoreWarnings();
+ if ( !$proc ) {
+ echo "Error opening slave process\n";
+ exit( 1 );
+ }
+ $this->slaveProcs[$i] = $proc;
+ $this->slavePipes[$i] = $pipes[0];
+ }
+ $this->prevSlaveId = -1;
+ }
+
+ /**
+ * Gracefully terminate the child processes
+ */
+ function killSlaveProcs() {
+ for ( $i = 0; $i < $this->numProcs; $i++ ) {
+ $this->dispatchToSlave( $i, 'quit' );
+ }
+ for ( $i = 0; $i < $this->numProcs; $i++ ) {
+ proc_close( $this->slaveProcs[$i] );
+ }
+ }
+
+ /**
+ * Dispatch a command to the next available slave.
+ * This may block until a slave finishes its work and becomes available.
+ */
+ function dispatch( /*...*/ ) {
+ $args = func_get_args();
+ $pipes = $this->slavePipes;
+ $numPipes = stream_select( $x=array(), $pipes, $y=array(), 3600 );
+ if ( !$numPipes ) {
+ echo "Error waiting to write to slaves. Aborting\n";
+ exit( 1 );
+ }
+ for ( $i = 0; $i < $this->numProcs; $i++ ) {
+ $slaveId = ( $i + $this->prevSlaveId + 1 ) % $this->numProcs;
+ if ( isset( $pipes[$slaveId] ) ) {
+ $this->prevSlaveId = $slaveId;
+ $this->dispatchToSlave( $slaveId, $args );
+ return;
+ }
+ }
+ echo "Unreachable\n";
+ exit( 1 );
+ }
+
+ /**
+ * Dispatch a command to a specified slave
+ */
+ function dispatchToSlave( $slaveId, $args ) {
+ $args = (array)$args;
+ $cmd = implode( ' ', $args );
+ fwrite( $this->slavePipes[$slaveId], "$cmd\n" );
+ }
+
+ /**
+ * Move all tracked pages to the new clusters
+ */
+ function doAllPages() {
+ $dbr = wfGetDB( DB_SLAVE );
+ $startId = 0;
+ $endId = $dbr->selectField( 'blob_tracking', 'MAX(bt_page)',
+ # A condition is required so that this query uses the index
+ array( 'bt_moved' => 0 ),
+ __METHOD__ );
+ echo "Moving pages...\n";
+ while ( true ) {
+ $res = $dbr->select( 'blob_tracking',
+ array( 'bt_page' ),
+ array(
+ 'bt_moved' => 0,
+ 'bt_page > ' . $dbr->addQuotes( $startId )
+ ),
+ __METHOD__,
+ array(
+ 'DISTINCT',
+ 'ORDER BY' => 'bt_page',
+ 'LIMIT' => $this->batchSize,
+ )
+ );
+ if ( !$res->numRows() ) {
+ break;
+ }
+ foreach ( $res as $row ) {
+ $this->dispatch( 'doPage', $row->bt_page );
+ }
+ $startId = $row->bt_page;
+ $this->report( $startId, $endId );
+ }
+ echo "Done moving pages.\n";
+ }
+
+ /**
+ * Display a progress report
+ */
+ function report( $start, $end ) {
+ $this->numBatches++;
+ if ( $this->numBatches >= $this->reportingInterval ) {
+ $this->numBatches = 0;
+ echo "$start / $end\n";
+ wfWaitForSlaves( 5 );
+ }
+ }
+
+ /**
+ * Move all orphan text to the new clusters
+ */
+ function doAllOrphans() {
+ $dbr = wfGetDB( DB_SLAVE );
+ $startId = 0;
+ $endId = $dbr->selectField( 'blob_tracking', 'MAX(bt_text_id)',
+ array( 'bt_moved' => 0, 'bt_page' => 0 ),
+ __METHOD__ );
+ if ( !$endId ) {
+ return;
+ }
+ echo "Moving orphans...\n";
+
+ while ( true ) {
+ $res = $dbr->select( 'blob_tracking',
+ array( 'bt_text_id' ),
+ array(
+ 'bt_moved' => 0,
+ 'bt_page' => 0,
+ 'bt_text_id > ' . $dbr->addQuotes( $startId )
+ ),
+ __METHOD__,
+ array(
+ 'DISTINCT',
+ 'ORDER BY' => 'bt_text_id',
+ 'LIMIT' => $this->batchSize
+ )
+ );
+ if ( !$res->numRows() ) {
+ break;
+ }
+ $args = array( 'doOrphanList' );
+ foreach ( $res as $row ) {
+ $args[] = $row->bt_text_id;
+ }
+ call_user_func_array( array( $this, 'dispatch' ), $args );
+ $startId = $row->bt_text_id;
+ $this->report( $startId, $endId );
+ }
+ echo "Done moving orphans.\n";
+ }
+
+ /**
+ * Main entry point for worker processes
+ */
+ function executeChild() {
+ $this->syncDBs();
+
+ while ( !feof( STDIN ) ) {
+ $line = rtrim( fgets( STDIN ) );
+ if ( $line == '' ) {
+ continue;
+ }
+ $args = explode( ' ', $line );
+ $cmd = array_shift( $args );
+ switch ( $cmd ) {
+ case 'doPage':
+ $this->doPage( intval( $args[0] ) );
+ break;
+ case 'doOrphanList':
+ $this->doOrphanList( array_map( 'intval', $args ) );
+ break;
+ case 'quit':
+ return;
+ }
+ }
+ }
+
+ /**
+ * Move tracked text in a given page
+ */
+ function doPage( $pageId ) {
+ $dbr = wfGetDB( DB_SLAVE );
+
+ // Finish any incomplete transactions
+ if ( !$this->copyOnly ) {
+ $this->finishIncompleteMoves();
+ }
+
+ $startId = 0;
+ $trx = new CgzCopyTransaction( $this );
+
+ while ( true ) {
+ $res = $dbr->select(
+ array( 'blob_tracking', 'text' ),
+ '*',
+ array(
+ 'bt_page' => $pageId,
+ 'bt_text_id > ' . $dbr->addQuotes( $startId ),
+ 'bt_moved' => 0,
+ 'bt_new_url' => '',
+ 'bt_text_id=old_id',
+ ),
+ __METHOD__,
+ array(
+ 'ORDER BY' => 'bt_text_id',
+ 'LIMIT' => $this->batchSize
+ )
+ );
+ if ( !$res->numRows() ) {
+ break;
+ }
+
+ $lastTextId = 0;
+ foreach ( $res as $row ) {
+ if ( $lastTextId == $row->bt_text_id ) {
+ // Duplicate (null edit)
+ continue;
+ }
+ $lastTextId = $row->bt_text_id;
+ // Load the text
+ $text = Revision::getRevisionText( $row );
+ if ( $text === false ) {
+ echo "Error loading {$row->bt_rev_id}/{$row->bt_text_id}\n";
+ continue;
+ }
+
+ // Queue it
+ if ( !$trx->addItem( $text, $row->bt_text_id ) ) {
+ $trx->commit();
+ $trx = new CgzCopyTransaction( $this );
+ }
+ }
+ $startId = $row->bt_text_id;
+ }
+ $trx->commit();
+ }
+
+ /**
+ * Atomic move operation.
+ *
+ * Write the new URL to the text table and set the bt_moved flag.
+ *
+ * This is done in a single transaction to provide restartable behaviour
+ * without data loss.
+ *
+ * The transaction is kept short to reduce locking.
+ */
+ function moveTextRow( $textId, $url ) {
+ $dbw = wfGetDB( DB_MASTER );
+ $dbw->begin();
+ $dbw->update( 'text',
+ array( // set
+ 'old_text' => $url,
+ 'old_flags' => 'external,utf8',
+ ),
+ array( // where
+ 'old_id' => $textId
+ ),
+ __METHOD__
+ );
+ $dbw->update( 'blob_tracking',
+ array( 'bt_moved' => 1 ),
+ array( 'bt_text_id' => $textId ),
+ __METHOD__
+ );
+ $dbw->commit();
+ }
+
+ /**
+ * Moves are done in two phases: bt_new_url and then bt_moved.
+ * - bt_new_url indicates that the text has been copied to the new cluster.
+ * - bt_moved indicates that the text table has been updated.
+ *
+ * This function completes any moves that only have done bt_new_url. This
+ * can happen when the script is interrupted, or when --copy-only is used.
+ */
+ function finishIncompleteMoves() {
+ $dbr = wfGetDB( DB_SLAVE );
+
+ $startId = 0;
+ while ( true ) {
+ $res = $dbr->select( 'blob_tracking',
+ '*',
+ array(
+ 'bt_text_id > ' . $dbr->addQuotes( $startId ),
+ 'bt_moved' => 0,
+ "bt_new_url <> ''",
+ ),
+ __METHOD__,
+ array(
+ 'ORDER BY' => 'bt_text_id',
+ 'LIMIT' => $this->batchSize,
+ )
+ );
+ if ( !$res->numRows() ) {
+ break;
+ }
+ foreach ( $res as $row ) {
+ $this->moveTextRow( $row->bt_text_id, $row->bt_new_url );
+ }
+ $startId = $row->bt_text_id;
+ }
+ }
+
+ /**
+ * Returns the name of the next target cluster
+ */
+ function getTargetCluster() {
+ $cluster = next( $this->destClusters );
+ if ( $cluster === false ) {
+ $cluster = reset( $this->destClusters );
+ }
+ return $cluster;
+ }
+
+ /**
+ * Gets a DB master connection for the given external cluster name
+ */
+ function getExtDB( $cluster ) {
+ $lb = wfGetLBFactory()->getExternalLB( $cluster );
+ return $lb->getConnection( DB_MASTER );
+ }
+
+ /**
+ * Move an orphan text_id to the new cluster
+ */
+ function doOrphanList( $textIds ) {
+ $trx = new CgzCopyTransaction( $this );
+ foreach ( $textIds as $textId ) {
+ $row = wfGetDB( DB_SLAVE )->selectRow( 'text', array( 'old_text', 'old_flags' ),
+ array( 'old_id' => $textId ), __METHOD__ );
+ $text = Revision::getRevisionText( $row );
+ if ( $text === false ) {
+ echo "Error: cannot load revision text for $textId\n";
+ continue;
+ }
+
+ if ( !$trx->addItem( $text, $textId ) ) {
+ $trx->commit();
+ $trx = new CgzCopyTransaction( $this );
+ }
+ }
+ }
+}
+
+/**
+ * Class to represent a recompression operation for a single CGZ blob
+ */
+class CgzCopyTransaction {
+ var $blobClass;
+ var $cgz;
+ var $referrers;
+
+ /**
+ * Create a transaction from a RecompressTracked object
+ */
+ function __construct( $parent ) {
+ $this->blobClass = $parent->blobClass;
+ $this->cgz = false;
+ $this->texts = array();
+ }
+
+ /**
+ * Add text.
+ * Returns false if it's ready to commit.
+ */
+ function addItem( $text, $textId ) {
+ if ( !$this->cgz ) {
+ $class = $this->blobClass;
+ $this->cgz = new $class;
+ }
+ $hash = $this->cgz->addItem( $text );
+ $this->referrers[$textId] = $hash;
+ $this->texts[$textId] = $text;
+ return $this->cgz->isHappy();
+ }
+
+ /**
+ * Recompress text after some aberrant modification
+ */
+ function recompress() {
+ $class = $this->blobClass;
+ $this->cgz = new $class;
+ $this->referrers = array();
+ foreach ( $this->texts as $textId => $text ) {
+ $hash = $this->cgz->addItem( $text );
+ $this->referrers[$textId] = $hash;
+ }
+ }
+
+ /**
+ * Commit the blob.
+ * Does nothing if no text items have been added.
+ * May skip the move if --copy-only is set.
+ */
+ function commit() {
+ $originalCount = count( $this->texts );
+ if ( !$originalCount ) {
+ return;
+ }
+
+ // Check to see if the target text_ids have been moved already.
+ //
+ // We originally read from the slave, so this can happen when a single
+ // text_id is shared between multiple pages. It's rare, but possible
+ // if a delete/move/undelete cycle splits up a null edit.
+ //
+ // We do a locking read to prevent closer-run race conditions.
+ $dbw = wfGetDB( DB_MASTER );
+ $dbw->begin();
+ $dirty = false;
+ foreach ( $this->referrers as $textId => $hash ) {
+ $moved = $dbw->selectField( 'blob_tracking', 'bt_moved',
+ array( 'bt_text_id' => $textId ),
+ __METHOD__,
+ array( 'FOR UPDATE' )
+ );
+ if ( !$moved ) {
+ # This row has already been moved, remove it
+ unset( $this->texts[$textId] );
+ $dirty = true;
+ }
+ }
+
+ // Recompress the blob if necessary
+ if ( $dirty ) {
+ if ( !count( $this->texts ) ) {
+ // All have been moved already
+ if ( $originalCount > 1 ) {
+ // This is suspcious, make noise
+ echo "Warning: concurrent operation detected, are there two conflicting\n" .
+ "processes running, doing the same job?\n";
+ }
+ return;
+ }
+ $this->recompress();
+ }
+
+ // Insert the data into the destination cluster
+ $targetCluster = $this->parent->getTargetCluster();
+ $store = $this->parent->store;
+ $targetDB = $store->getMaster( $targetCluster );
+ $targetDB->clearFlag( DBO_TRX ); // we manage the transactions
+ $targetDB->begin();
+ $baseUrl = $this->parent->store->store( $targetCluster, serialize( $this->cgz ) );
+
+ // Write the new URLs to the blob_tracking table
+ foreach ( $this->referrers as $textId => $hash ) {
+ $url = $baseUrl . '/' . $hash;
+ $dbw->update( 'blob_tracking',
+ array( 'bt_new_url' => $url ),
+ array(
+ 'bt_text_id' => $textId,
+ 'bt_moved' => 0, # Check for concurrent conflicting update
+ ),
+ __METHOD__
+ );
+ }
+
+ $targetDB->commit();
+ // Critical section here: interruption at this point causes blob duplication
+ // Reversing the order of the commits would cause data loss instead
+ $dbw->commit();
+
+ // Write the new URLs to the text table and set the moved flag
+ if ( !$this->parent->copyOnly ) {
+ foreach ( $this->referrers as $textId => $hash ) {
+ $url = $baseUrl . '/' . $hash;
+ $this->parent->moveTextRow( $textId, $url );
+ }
+ }
+ }
+
+ function signalHandler() {
+ $this->signalled = true;
+ }
+}
+
dépôts / lhc / web / wiklou.git / commitdiff