3 * Job to update link tables for pages
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25 * Job to update link tables for pages
27 * This job comes in a few variants:
28 * - a) Recursive jobs to update links for backlink pages for a given title
29 * - b) Jobs to update links for a set of titles (the job title is ignored)
30 * - c) Jobs to update links for a single title (the job title)
34 class RefreshLinksJob
extends Job
{
37 function __construct( $title, $params = '', $id = 0 ) {
38 parent
::__construct( 'refreshLinks', $title, $params, $id );
39 $this->params
['version'] = self
::VERSION
;
40 // Base backlink update jobs and per-title update jobs can be de-duplicated.
41 // If template A changes twice before any jobs run, a clean queue will have:
43 // The second job is ignored by the queue on insertion.
44 // Suppose, many pages use template A, and that template itself uses template B.
45 // An edit to both will first create two base jobs. A clean FIFO queue will have:
47 // When these jobs run, the queue will have per-title and remnant partition jobs:
48 // (titleX,titleY,titleZ,...,A remnant,titleM,titleN,titleO,...,B remnant)
49 // Some these jobs will be the same, and will automatically be ignored by
50 // the queue upon insertion. Some title jobs will run before the duplicate is
51 // inserted, so the work will still be done twice in those cases. More titles
52 // can be de-duplicated as the remnant jobs continue to be broken down. This
53 // works best when $wgUpdateRowsPerJob, and either the pages have few backlinks
54 // and/or the backlink sets for pages A and B are almost identical.
55 $this->removeDuplicates
= !isset( $params['range'] )
56 && ( !isset( $params['pages'] ) ||
count( $params['pages'] ) == 1 );
60 global $wgUpdateRowsPerJob;
62 if ( is_null( $this->title
) ) {
63 $this->setLastError( "Invalid page title" );
67 // Job to update all (or a range of) backlink pages for a page
68 if ( isset( $this->params
['recursive'] ) ) {
69 // Carry over information for de-duplication
70 $extraParams = $this->getRootJobParams();
71 // Avoid slave lag when fetching templates.
72 // When the outermost job is run, we know that the caller that enqueued it must have
73 // committed the relevant changes to the DB by now. At that point, record the master
74 // position and pass it along as the job recursively breaks into smaller range jobs.
75 // Hopefully, when leaf jobs are popped, the slaves will have reached that position.
76 if ( isset( $this->params
['masterPos'] ) ) {
77 $extraParams['masterPos'] = $this->params
['masterPos'];
78 } elseif ( wfGetLB()->getServerCount() > 1 ) {
79 $extraParams['masterPos'] = wfGetLB()->getMasterPos();
81 $extraParams['masterPos'] = false;
83 // Convert this into no more than $wgUpdateRowsPerJob RefreshLinks per-title
84 // jobs and possibly a recursive RefreshLinks job for the rest of the backlinks
85 $jobs = BacklinkJobUtils
::partitionBacklinkJob(
89 array( 'params' => $extraParams )
91 JobQueueGroup
::singleton()->push( $jobs );
92 // Job to update link tables for for a set of titles
93 } elseif ( isset( $this->params
['pages'] ) ) {
94 foreach ( $this->params
['pages'] as $pageId => $nsAndKey ) {
95 list( $ns, $dbKey ) = $nsAndKey;
96 $this->runForTitle( Title
::makeTitleSafe( $ns, $dbKey ) );
98 // Job to update link tables for a given title
100 $this->runForTitle( $this->mTitle
);
106 protected function runForTitle( Title
$title = null ) {
107 $linkCache = LinkCache
::singleton();
110 if ( is_null( $title ) ) {
111 $this->setLastError( "refreshLinks: Invalid title" );
115 // Wait for the DB of the current/next slave DB handle to catch up to the master.
116 // This way, we get the correct page_latest for templates or files that just changed
117 // milliseconds ago, having triggered this job to begin with.
118 if ( isset( $this->params
['masterPos'] ) && $this->params
['masterPos'] !== false ) {
119 wfGetLB()->waitFor( $this->params
['masterPos'] );
122 $parserOutput = false;
123 // If page_touched changed after this root job (with a good slave lag skew factor),
124 // then it is likely that any views of the pages already resulted in re-parses which
125 // are now in cache. This can be reused to avoid expensive parsing in some cases.
126 if ( isset( $this->params
['rootJobTimestamp'] ) ) {
127 $page = WikiPage
::factory( $title );
128 $skewedTimestamp = wfTimestamp( TS_UNIX
, $this->params
['rootJobTimestamp'] ) +
5;
129 if ( $page->getTouched() > wfTimestamp( TS_MW
, $skewedTimestamp ) ) {
130 $parserOptions = $page->makeParserOptions( 'canonical' );
131 $parserOutput = ParserCache
::singleton()->getDirty( $page, $parserOptions );
132 if ( $parserOutput->getCacheTime() <= $skewedTimestamp ) {
133 $parserOutput = false; // too stale
137 // Fetch the current revision and parse it if necessary...
138 if ( $parserOutput == false ) {
139 $revision = Revision
::newFromTitle( $title, false, Revision
::READ_NORMAL
);
141 $this->setLastError( "refreshLinks: Article not found {$title->getPrefixedDBkey()}" );
142 return false; // XXX: what if it was just deleted?
145 $content = $revision->getContent( Revision
::RAW
);
147 // If there is no content, pretend the content is empty
148 $content = $revision->getContentHandler()->makeEmptyContent();
151 // Revision ID must be passed to the parser output to get revision variables correct
152 $parserOutput = $content->getParserOutput( $title, $revision->getId(), null, false );
155 $updates = $content->getSecondaryDataUpdates( $title, null, false, $parserOutput );
156 DataUpdate
::runUpdates( $updates );
158 InfoAction
::invalidateCache( $title );
163 public function getDeduplicationInfo() {
164 $info = parent
::getDeduplicationInfo();
165 if ( is_array( $info['params'] ) ) {
166 // Don't let highly unique "masterPos" values ruin duplicate detection
167 unset( $info['params']['masterPos'] );
168 // For per-pages jobs, the job title is that of the template that changed
169 // (or similar), so remove that since it ruins duplicate detection
170 if ( isset( $info['pages'] ) ) {
171 unset( $info['namespace'] );
172 unset( $info['title'] );