5d95792cf93cf4fae44808082fb4a6abbdc8def8
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 * These jobs have (recursive:true,table:<table>) set.
30 * - b) Jobs to update links for a set of pages (the job title is ignored).
31 * These jobs have (pages:(<page ID>:(<namespace>,<title>),...) set.
32 * - c) Jobs to update links for a single page (the job title)
33 * These jobs need no extra fields set.
37 class RefreshLinksJob
extends Job
{
38 const PARSE_THRESHOLD_SEC
= 1.0;
40 function __construct( $title, $params = '' ) {
41 parent
::__construct( 'refreshLinks', $title, $params );
42 // Base backlink update jobs and per-title update jobs can be de-duplicated.
43 // If template A changes twice before any jobs run, a clean queue will have:
45 // The second job is ignored by the queue on insertion.
46 // Suppose, many pages use template A, and that template itself uses template B.
47 // An edit to both will first create two base jobs. A clean FIFO queue will have:
49 // When these jobs run, the queue will have per-title and remnant partition jobs:
50 // (titleX,titleY,titleZ,...,A remnant,titleM,titleN,titleO,...,B remnant)
51 // Some these jobs will be the same, and will automatically be ignored by
52 // the queue upon insertion. Some title jobs will run before the duplicate is
53 // inserted, so the work will still be done twice in those cases. More titles
54 // can be de-duplicated as the remnant jobs continue to be broken down. This
55 // works best when $wgUpdateRowsPerJob, and either the pages have few backlinks
56 // and/or the backlink sets for pages A and B are almost identical.
57 $this->removeDuplicates
= !isset( $params['range'] )
58 && ( !isset( $params['pages'] ) ||
count( $params['pages'] ) == 1 );
62 global $wgUpdateRowsPerJob;
64 // Job to update all (or a range of) backlink pages for a page
65 if ( !empty( $this->params
['recursive'] ) ) {
66 // Carry over information for de-duplication
67 $extraParams = $this->getRootJobParams();
68 // Avoid slave lag when fetching templates.
69 // When the outermost job is run, we know that the caller that enqueued it must have
70 // committed the relevant changes to the DB by now. At that point, record the master
71 // position and pass it along as the job recursively breaks into smaller range jobs.
72 // Hopefully, when leaf jobs are popped, the slaves will have reached that position.
73 if ( isset( $this->params
['masterPos'] ) ) {
74 $extraParams['masterPos'] = $this->params
['masterPos'];
75 } elseif ( wfGetLB()->getServerCount() > 1 ) {
76 $extraParams['masterPos'] = wfGetLB()->getMasterPos();
78 $extraParams['masterPos'] = false;
80 // Convert this into no more than $wgUpdateRowsPerJob RefreshLinks per-title
81 // jobs and possibly a recursive RefreshLinks job for the rest of the backlinks
82 $jobs = BacklinkJobUtils
::partitionBacklinkJob(
86 array( 'params' => $extraParams )
88 JobQueueGroup
::singleton()->push( $jobs );
89 // Job to update link tables for a set of titles
90 } elseif ( isset( $this->params
['pages'] ) ) {
91 foreach ( $this->params
['pages'] as $pageId => $nsAndKey ) {
92 list( $ns, $dbKey ) = $nsAndKey;
93 $this->runForTitle( Title
::makeTitleSafe( $ns, $dbKey ) );
95 // Job to update link tables for a given title
97 $this->runForTitle( $this->title
);
103 protected function runForTitle( Title
$title = null ) {
104 $linkCache = LinkCache
::singleton();
107 if ( is_null( $title ) ) {
108 $this->setLastError( "refreshLinks: Invalid title" );
112 // Wait for the DB of the current/next slave DB handle to catch up to the master.
113 // This way, we get the correct page_latest for templates or files that just changed
114 // milliseconds ago, having triggered this job to begin with.
115 if ( isset( $this->params
['masterPos'] ) && $this->params
['masterPos'] !== false ) {
116 wfGetLB()->waitFor( $this->params
['masterPos'] );
119 $page = WikiPage
::factory( $title );
121 // Fetch the current revision...
122 $revision = Revision
::newFromTitle( $title, false, Revision
::READ_NORMAL
);
124 $this->setLastError( "refreshLinks: Article not found {$title->getPrefixedDBkey()}" );
125 return false; // XXX: what if it was just deleted?
127 $content = $revision->getContent( Revision
::RAW
);
129 // If there is no content, pretend the content is empty
130 $content = $revision->getContentHandler()->makeEmptyContent();
133 $parserOutput = false;
134 $parserOptions = $page->makeParserOptions( 'canonical' );
135 // If page_touched changed after this root job (with a good slave lag skew factor),
136 // then it is likely that any views of the pages already resulted in re-parses which
137 // are now in cache. This can be reused to avoid expensive parsing in some cases.
138 if ( isset( $this->params
['rootJobTimestamp'] ) ) {
139 $skewedTimestamp = wfTimestamp( TS_UNIX
, $this->params
['rootJobTimestamp'] ) +
5;
140 if ( $page->getLinksTimestamp() > wfTimestamp( TS_MW
, $skewedTimestamp ) ) {
141 // Something already updated the backlinks since this job was made
144 if ( $page->getTouched() > wfTimestamp( TS_MW
, $skewedTimestamp ) ) {
145 $parserOutput = ParserCache
::singleton()->getDirty( $page, $parserOptions );
146 if ( $parserOutput && $parserOutput->getCacheTime() <= $skewedTimestamp ) {
147 $parserOutput = false; // too stale
151 // Fetch the current revision and parse it if necessary...
152 if ( $parserOutput == false ) {
153 $start = microtime( true );
154 // Revision ID must be passed to the parser output to get revision variables correct
155 $parserOutput = $content->getParserOutput(
156 $title, $revision->getId(), $parserOptions, false );
157 $ellapsed = microtime( true ) - $start;
158 // If it took a long time to render, then save this back to the cache to avoid
159 // wasted CPU by other apaches or job runners. We don't want to always save to
160 // cache as this can cause high cache I/O and LRU churn when a template changes.
161 if ( $ellapsed >= self
::PARSE_THRESHOLD_SEC
162 && $page->isParserCacheUsed( $parserOptions, $revision->getId() )
163 && $parserOutput->isCacheable()
165 $ctime = wfTimestamp( TS_MW
, (int)$start ); // cache time
166 ParserCache
::singleton()->save(
167 $parserOutput, $page, $parserOptions, $ctime, $revision->getId()
172 $updates = $content->getSecondaryDataUpdates( $title, null, false, $parserOutput );
173 DataUpdate
::runUpdates( $updates );
175 InfoAction
::invalidateCache( $title );
180 public function getDeduplicationInfo() {
181 $info = parent
::getDeduplicationInfo();
182 if ( is_array( $info['params'] ) ) {
183 // Don't let highly unique "masterPos" values ruin duplicate detection
184 unset( $info['params']['masterPos'] );
185 // For per-pages jobs, the job title is that of the template that changed
186 // (or similar), so remove that since it ruins duplicate detection
187 if ( isset( $info['pages'] ) ) {
188 unset( $info['namespace'] );
189 unset( $info['title'] );
196 public function workItemCount() {
197 return isset( $this->params
['pages'] ) ?
count( $this->params
['pages'] ) : 1;