From 3f80b41dc21bc7f7e2c8f78847cf762ada97b48d Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Sat, 5 Aug 2006 14:10:10 +0000
Subject: [PATCH] Added experimental history paging API, subject to change

---
 includes/Export.php        | 32 +++++++++++++++++++++++++++++---
 includes/SpecialExport.php | 34 +++++++++++++++++++++++++++++-----
 2 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/includes/Export.php b/includes/Export.php
index da92694e4d..19a6172f13 100644
--- a/includes/Export.php
+++ b/includes/Export.php
@@ -51,7 +51,11 @@ class WikiExporter {
 	 * main query is still running.
 	 *
 	 * @param Database $db
-	 * @param int $history one of MW_EXPORT_FULL or MW_EXPORT_CURRENT
+	 * @param mixed $history one of MW_EXPORT_FULL or MW_EXPORT_CURRENT, or an 
+	 *                       associative array:
+	 *                         offset: non-inclusive offset at which to start the query
+	 *                         limit: maximum number of rows to return
+	 *                         dir: "asc" or "desc" timestamp order
 	 * @param int $buffer one of MW_EXPORT_BUFFER or MW_EXPORT_STREAM
 	 */
 	function WikiExporter( &$db, $history = MW_EXPORT_CURRENT,
@@ -168,6 +172,9 @@ class WikiExporter {
 		$revision = $this->db->tableName( 'revision' );
 		$text     = $this->db->tableName( 'text' );
 		
+		$order = 'ORDER BY page_id';
+		$limit = '';
+		
 		if( $this->history == MW_EXPORT_FULL ) {
 			$join = 'page_id=rev_page';
 		} elseif( $this->history == MW_EXPORT_CURRENT ) {
@@ -175,6 +182,25 @@ class WikiExporter {
 				$this->do_list_authors ( $page , $revision , $cond );
 			}
 			$join = 'page_id=rev_page AND page_latest=rev_id';
+		} elseif ( is_array( $this->history ) ) {
+			$join = 'page_id=rev_page';
+			if ( $this->history['dir'] == 'asc' ) {
+				$op = '>';
+				$order .= ', rev_timestamp';
+			} else {
+				$op = '<';
+				$order .= ', rev_timestamp DESC';
+			}
+			if ( !empty( $this->history['offset'] ) ) {
+				$join .= " AND rev_timestamp $op " . $this->db->addQuotes( 
+					$this->db->timestamp( $this->history['offset'] ) );
+			}
+			if ( !empty( $this->history['limit'] ) ) {
+				$limitNum = intval( $this->history['limit'] );
+				if ( $limitNum > 0 ) {
+					$limit = "LIMIT $limitNum";
+				}
+			}
 		} else {
 			wfProfileOut( $fname );
 			return new WikiError( "$fname given invalid history dump type." );
@@ -198,14 +224,14 @@ class WikiExporter {
 					$page $pageindex,
 					$revision $revindex
 					WHERE $where $join
-					ORDER BY page_id";
+					$order $limit";
 		} else {
 			$sql = "SELECT $straight * FROM
 					$page $pageindex,
 					$revision $revindex,
 					$text
 					WHERE $where $join AND rev_text_id=old_id
-					ORDER BY page_id";
+					$order $limit";
 		}
 		$result = $this->db->query( $sql, $fname );
 		$wrapper = $this->db->resultObject( $result );
diff --git a/includes/SpecialExport.php b/includes/SpecialExport.php
index 73dcbcd588..525a2a03b6 100644
--- a/includes/SpecialExport.php
+++ b/includes/SpecialExport.php
@@ -31,18 +31,43 @@ require_once( 'Export.php' );
 function wfSpecialExport( $page = '' ) {
 	global $wgOut, $wgRequest, $wgExportAllowListContributors;
 	global $wgExportAllowHistory, $wgExportMaxHistory;
+	$maxLimit = 200;
 
 	$curonly = true;
+	$fullHistory = array(
+		'dir' => 'asc',
+		'offset' => false,
+		'limit' => $maxLimit,
+	);
 	if( $wgRequest->getVal( 'action' ) == 'submit') {
 		$page = $wgRequest->getText( 'pages' );
 		$curonly = $wgRequest->getCheck( 'curonly' );
-	}
-	if( $wgRequest->getCheck( 'history' ) ) {
-		$curonly = false;
+		$offset = wfTimestamp( TS_MW, $wgRequest->getVal( 'offset' ) );
+		$limit = $wgRequest->getInt( 'limit' );
+		$dir = $wgRequest->getVal( 'dir' );
+		$history = array(
+			'dir' => 'asc',
+			'offset' => false,
+			'limit' => $maxLimit,
+		);
+		$historyCheck = $wgRequest->getCheck( 'history' );
+		if ( $curonly ) {
+			$history = MW_EXPORT_CURRENT;
+		} elseif ( !$historyCheck ) {
+			if ( $limit > 0 && $limit < $maxLimit ) {
+				$history['limit'] = $limit;
+			}
+			if ( !is_null( $offset ) ) {
+				$history['offset'] = $offset;
+			}
+			if ( strtolower( $dir ) == 'desc' ) {
+				$history['dir'] = 'desc';
+			}
+		}
 	}
 	if( !$wgExportAllowHistory ) {
 		// Override
-		$curonly = true;
+		$history = MW_EXPORT_CURRENT;
 	}
 	
 	$list_authors = $wgRequest->getCheck( 'listauthors' );
@@ -63,7 +88,6 @@ function wfSpecialExport( $page = '' ) {
 		$pages = explode( "\n", $page );
 
 		$db =& wfGetDB( DB_SLAVE );
-		$history = $curonly ? MW_EXPORT_CURRENT : MW_EXPORT_FULL;
 		$exporter = new WikiExporter( $db, $history );
 		$exporter->list_authors = $list_authors ;
 		$exporter->openStream();
-- 
2.20.1