1 files changed, 219 insertions, 0 deletions
diff --git a/www/wiki/maintenance/populateRevisionSha1.php b/www/wiki/maintenance/populateRevisionSha1.php
new file mode 100644
index 00000000..9662044a
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+++ b/www/wiki/maintenance/populateRevisionSha1.php
@@ -0,0 +1,219 @@
+<?php
+/**
+ * Fills the rev_sha1 and ar_sha1 columns of revision
+ * and archive tables for revisions created before MW 1.19.
+ *
+ * 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 fills the rev_sha1 and ar_sha1 columns of revision
+ * and archive tables for revisions created before MW 1.19.
+ *
+ * @ingroup Maintenance
+ */
+class PopulateRevisionSha1 extends LoggedUpdateMaintenance {
+	public function __construct() {
+		parent::__construct();
+		$this->addDescription( 'Populates the rev_sha1 and ar_sha1 fields' );
+		$this->setBatchSize( 200 );
+	}
+
+	protected function getUpdateKey() {
+		return 'populate rev_sha1';
+	}
+
+	protected function doDBUpdates() {
+		$db = $this->getDB( DB_MASTER );
+
+		if ( !$db->tableExists( 'revision' ) ) {
+			$this->fatalError( "revision table does not exist" );
+		} elseif ( !$db->tableExists( 'archive' ) ) {
+			$this->fatalError( "archive table does not exist" );
+		} elseif ( !$db->fieldExists( 'revision', 'rev_sha1', __METHOD__ ) ) {
+			$this->output( "rev_sha1 column does not exist\n\n", true );
+
+			return false;
+		}
+
+		$this->output( "Populating rev_sha1 column\n" );
+		$rc = $this->doSha1Updates( 'revision', 'rev_id', Revision::getQueryInfo(), 'rev' );
+
+		$this->output( "Populating ar_sha1 column\n" );
+		$ac = $this->doSha1Updates( 'archive', 'ar_rev_id', Revision::getArchiveQueryInfo(), 'ar' );
+		$this->output( "Populating ar_sha1 column legacy rows\n" );
+		$ac += $this->doSha1LegacyUpdates();
+
+		$this->output( "rev_sha1 and ar_sha1 population complete "
+			. "[$rc revision rows, $ac archive rows].\n" );
+
+		return true;
+	}
+
+	/**
+	 * @param string $table
+	 * @param string $idCol
+	 * @param array $queryInfo
+	 * @param string $prefix
+	 * @return int Rows changed
+	 */
+	protected function doSha1Updates( $table, $idCol, $queryInfo, $prefix ) {
+		$db = $this->getDB( DB_MASTER );
+		$batchSize = $this->getBatchSize();
+		$start = $db->selectField( $table, "MIN($idCol)", '', __METHOD__ );
+		$end = $db->selectField( $table, "MAX($idCol)", '', __METHOD__ );
+		if ( !$start || !$end ) {
+			$this->output( "...$table table seems to be empty.\n" );
+
+			return 0;
+		}
+
+		$count = 0;
+		# Do remaining chunk
+		$end += $batchSize - 1;
+		$blockStart = $start;
+		$blockEnd = $start + $batchSize - 1;
+		while ( $blockEnd <= $end ) {
+			$this->output( "...doing $idCol from $blockStart to $blockEnd\n" );
+			$cond = "$idCol BETWEEN " . (int)$blockStart . " AND " . (int)$blockEnd .
+				" AND $idCol IS NOT NULL AND {$prefix}_sha1 = ''";
+			$res = $db->select(
+				$queryInfo['tables'], $queryInfo['fields'], $cond, __METHOD__, [], $queryInfo['joins']
+			);
+
+			$this->beginTransaction( $db, __METHOD__ );
+			foreach ( $res as $row ) {
+				if ( $this->upgradeRow( $row, $table, $idCol, $prefix ) ) {
+					$count++;
+				}
+			}
+			$this->commitTransaction( $db, __METHOD__ );
+
+			$blockStart += $batchSize;
+			$blockEnd += $batchSize;
+		}
+
+		return $count;
+	}
+
+	/**
+	 * @return int
+	 */
+	protected function doSha1LegacyUpdates() {
+		$count = 0;
+		$db = $this->getDB( DB_MASTER );
+		$arQuery = Revision::getArchiveQueryInfo();
+		$res = $db->select( $arQuery['tables'], $arQuery['fields'],
+			[ 'ar_rev_id IS NULL', 'ar_sha1' => '' ], __METHOD__, [], $arQuery['joins'] );
+
+		$updateSize = 0;
+		$this->beginTransaction( $db, __METHOD__ );
+		foreach ( $res as $row ) {
+			if ( $this->upgradeLegacyArchiveRow( $row ) ) {
+				++$count;
+			}
+			if ( ++$updateSize >= 100 ) {
+				$updateSize = 0;
+				$this->commitTransaction( $db, __METHOD__ );
+				$this->output( "Commited row with ar_timestamp={$row->ar_timestamp}\n" );
+				$this->beginTransaction( $db, __METHOD__ );
+			}
+		}
+		$this->commitTransaction( $db, __METHOD__ );
+
+		return $count;
+	}
+
+	/**
+	 * @param stdClass $row
+	 * @param string $table
+	 * @param string $idCol
+	 * @param string $prefix
+	 * @return bool
+	 */
+	protected function upgradeRow( $row, $table, $idCol, $prefix ) {
+		$db = $this->getDB( DB_MASTER );
+		try {
+			$rev = ( $table === 'archive' )
+				? Revision::newFromArchiveRow( $row )
+				: new Revision( $row );
+			$text = $rev->getSerializedData();
+		} catch ( Exception $e ) {
+			$this->output( "Data of revision with {$idCol}={$row->$idCol} unavailable!\n" );
+
+			return false; // T24624?
+		}
+		if ( !is_string( $text ) ) {
+			# This should not happen, but sometimes does (T22757)
+			$this->output( "Data of revision with {$idCol}={$row->$idCol} unavailable!\n" );
+
+			return false;
+		} else {
+			$db->update( $table,
+				[ "{$prefix}_sha1" => Revision::base36Sha1( $text ) ],
+				[ $idCol => $row->$idCol ],
+				__METHOD__
+			);
+
+			return true;
+		}
+	}
+
+	/**
+	 * @param stdClass $row
+	 * @return bool
+	 */
+	protected function upgradeLegacyArchiveRow( $row ) {
+		$db = $this->getDB( DB_MASTER );
+		try {
+			$rev = Revision::newFromArchiveRow( $row );
+		} catch ( Exception $e ) {
+			$this->output( "Text of revision with timestamp {$row->ar_timestamp} unavailable!\n" );
+
+			return false; // T24624?
+		}
+		$text = $rev->getSerializedData();
+		if ( !is_string( $text ) ) {
+			# This should not happen, but sometimes does (T22757)
+			$this->output( "Data of revision with timestamp {$row->ar_timestamp} unavailable!\n" );
+
+			return false;
+		} else {
+			# Archive table as no PK, but (NS,title,time) should be near unique.
+			# Any duplicates on those should also have duplicated text anyway.
+			$db->update( 'archive',
+				[ 'ar_sha1' => Revision::base36Sha1( $text ) ],
+				[
+					'ar_namespace' => $row->ar_namespace,
+					'ar_title' => $row->ar_title,
+					'ar_timestamp' => $row->ar_timestamp,
+					'ar_len' => $row->ar_len // extra sanity
+				],
+				__METHOD__
+			);
+
+			return true;
+		}
+	}
+}
+
+$maintClass = PopulateRevisionSha1::class;
+require_once RUN_MAINTENANCE_IF_MAIN;