1 files changed, 131 insertions, 0 deletions
diff --git a/www/wiki/maintenance/populateParentId.php b/www/wiki/maintenance/populateParentId.php
new file mode 100644
index 00000000..2ef58b7c
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+++ b/www/wiki/maintenance/populateParentId.php
@@ -0,0 +1,131 @@
+<?php
+/**
+ * Makes the required database updates for rev_parent_id
+ * to be of any use. It can be used for some simple tracking
+ * and to find new page edits by users.
+ *
+ * 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 makes the required database updates for rev_parent_id
+ * to be of any use.
+ *
+ * @ingroup Maintenance
+ */
+class PopulateParentId extends LoggedUpdateMaintenance {
+	public function __construct() {
+		parent::__construct();
+		$this->addDescription( 'Populates rev_parent_id' );
+	}
+
+	protected function getUpdateKey() {
+		return 'populate rev_parent_id';
+	}
+
+	protected function updateSkippedMessage() {
+		return 'rev_parent_id column of revision table already populated.';
+	}
+
+	protected function doDBUpdates() {
+		$batchSize = $this->getBatchSize();
+		$db = $this->getDB( DB_MASTER );
+		if ( !$db->tableExists( 'revision' ) ) {
+			$this->error( "revision table does not exist" );
+
+			return false;
+		}
+		$this->output( "Populating rev_parent_id column\n" );
+		$start = $db->selectField( 'revision', 'MIN(rev_id)', '', __FUNCTION__ );
+		$end = $db->selectField( 'revision', 'MAX(rev_id)', '', __FUNCTION__ );
+		if ( is_null( $start ) || is_null( $end ) ) {
+			$this->output( "...revision table seems to be empty, nothing to do.\n" );
+
+			return true;
+		}
+		# Do remaining chunk
+		$blockStart = intval( $start );
+		$blockEnd = intval( $start ) + $batchSize - 1;
+		$count = 0;
+		$changed = 0;
+		while ( $blockStart <= $end ) {
+			$this->output( "...doing rev_id from $blockStart to $blockEnd\n" );
+			$cond = "rev_id BETWEEN $blockStart AND $blockEnd";
+			$res = $db->select( 'revision',
+				[ 'rev_id', 'rev_page', 'rev_timestamp', 'rev_parent_id' ],
+				[ $cond, 'rev_parent_id' => null ], __METHOD__ );
+			# Go through and update rev_parent_id from these rows.
+			# Assume that the previous revision of the title was
+			# the original previous revision of the title when the
+			# edit was made...
+			foreach ( $res as $row ) {
+				# First, check rows with the same timestamp other than this one
+				# with a smaller rev ID. The highest ID "wins". This avoids loops
+				# as timestamp can only decrease and never loops with IDs (from parent to parent)
+				$previousID = $db->selectField( 'revision', 'rev_id',
+					[ 'rev_page' => $row->rev_page, 'rev_timestamp' => $row->rev_timestamp,
+						"rev_id < " . intval( $row->rev_id ) ],
+					__METHOD__,
+					[ 'ORDER BY' => 'rev_id DESC' ] );
+				# If there are none, check the highest ID with a lower timestamp
+				if ( !$previousID ) {
+					# Get the highest older timestamp
+					$lastTimestamp = $db->selectField(
+						'revision',
+						'rev_timestamp',
+						[
+							'rev_page' => $row->rev_page,
+							"rev_timestamp < " . $db->addQuotes( $row->rev_timestamp )
+						],
+						__METHOD__,
+						[ 'ORDER BY' => 'rev_timestamp DESC' ]
+					);
+					# If there is one, let the highest rev ID win
+					if ( $lastTimestamp ) {
+						$previousID = $db->selectField( 'revision', 'rev_id',
+							[ 'rev_page' => $row->rev_page, 'rev_timestamp' => $lastTimestamp ],
+							__METHOD__,
+							[ 'ORDER BY' => 'rev_id DESC' ] );
+					}
+				}
+				$previousID = intval( $previousID );
+				if ( $previousID != $row->rev_parent_id ) {
+					$changed++;
+				}
+				# Update the row...
+				$db->update( 'revision',
+					[ 'rev_parent_id' => $previousID ],
+					[ 'rev_id' => $row->rev_id ],
+					__METHOD__ );
+				$count++;
+			}
+			$blockStart += $batchSize;
+			$blockEnd += $batchSize;
+			wfWaitForSlaves();
+		}
+		$this->output( "rev_parent_id population complete ... {$count} rows [{$changed} changed]\n" );
+
+		return true;
+	}
+}
+
+$maintClass = PopulateParentId::class;
+require_once RUN_MAINTENANCE_IF_MAIN;