Add failing test for bug 14404.
[lhc/web/wiklou.git] / includes / LinkBatch.php
1 <?php
2
3 /**
4 * Class representing a list of titles
5 * The execute() method checks them all for existence and adds them to a LinkCache object
6 *
7 * @ingroup Cache
8 */
9 class LinkBatch {
10 /**
11 * 2-d array, first index namespace, second index dbkey, value arbitrary
12 */
13 var $data = array();
14
15 /**
16 * For debugging which method is using this class.
17 */
18 protected $caller;
19
20 function __construct( $arr = array() ) {
21 foreach( $arr as $item ) {
22 $this->addObj( $item );
23 }
24 }
25
26 /**
27 * Use ->setCaller( __METHOD__ ) to indicate which code is using this
28 * class. Only used in debugging output.
29 * @since 1.17
30 */
31 public function setCaller( $caller ) {
32 $this->caller = $caller;
33 }
34
35 public function addObj( $title ) {
36 if ( is_object( $title ) ) {
37 $this->add( $title->getNamespace(), $title->getDBkey() );
38 } else {
39 wfDebug( "Warning: LinkBatch::addObj got invalid title object\n" );
40 }
41 }
42
43 public function add( $ns, $dbkey ) {
44 if ( $ns < 0 ) {
45 return;
46 }
47 if ( !array_key_exists( $ns, $this->data ) ) {
48 $this->data[$ns] = array();
49 }
50
51 $this->data[$ns][str_replace( ' ', '_', $dbkey )] = 1;
52 }
53
54 /**
55 * Set the link list to a given 2-d array
56 * First key is the namespace, second is the DB key, value arbitrary
57 */
58 public function setArray( $array ) {
59 $this->data = $array;
60 }
61
62 /**
63 * Returns true if no pages have been added, false otherwise.
64 */
65 public function isEmpty() {
66 return ($this->getSize() == 0);
67 }
68
69 /**
70 * Returns the size of the batch.
71 */
72 public function getSize() {
73 return count( $this->data );
74 }
75
76 /**
77 * Do the query and add the results to the LinkCache object
78 * Return an array mapping PDBK to ID
79 */
80 public function execute() {
81 $linkCache = LinkCache::singleton();
82 return $this->executeInto( $linkCache );
83 }
84
85 /**
86 * Do the query and add the results to a given LinkCache object
87 * Return an array mapping PDBK to ID
88 */
89 protected function executeInto( &$cache ) {
90 wfProfileIn( __METHOD__ );
91 $res = $this->doQuery();
92 $ids = $this->addResultToCache( $cache, $res );
93 wfProfileOut( __METHOD__ );
94 return $ids;
95 }
96
97 /**
98 * Add a ResultWrapper containing IDs and titles to a LinkCache object.
99 * As normal, titles will go into the static Title cache field.
100 * This function *also* stores extra fields of the title used for link
101 * parsing to avoid extra DB queries.
102 */
103 public function addResultToCache( $cache, $res ) {
104 if ( !$res ) {
105 return array();
106 }
107
108 // For each returned entry, add it to the list of good links, and remove it from $remaining
109
110 $ids = array();
111 $remaining = $this->data;
112 foreach ( $res as $row ) {
113 $title = Title::makeTitle( $row->page_namespace, $row->page_title );
114 $cache->addGoodLinkObj( $row->page_id, $title, $row->page_len, $row->page_is_redirect, $row->page_latest );
115 $ids[$title->getPrefixedDBkey()] = $row->page_id;
116 unset( $remaining[$row->page_namespace][$row->page_title] );
117 }
118
119 // The remaining links in $data are bad links, register them as such
120 foreach ( $remaining as $ns => $dbkeys ) {
121 foreach ( $dbkeys as $dbkey => $unused ) {
122 $title = Title::makeTitle( $ns, $dbkey );
123 $cache->addBadLinkObj( $title );
124 $ids[$title->getPrefixedDBkey()] = 0;
125 }
126 }
127 return $ids;
128 }
129
130 /**
131 * Perform the existence test query, return a ResultWrapper with page_id fields
132 */
133 public function doQuery() {
134 if ( $this->isEmpty() ) {
135 return false;
136 }
137 wfProfileIn( __METHOD__ );
138
139 // This is similar to LinkHolderArray::replaceInternal
140 $dbr = wfGetDB( DB_SLAVE );
141 $table = 'page';
142 $fields = array( 'page_id', 'page_namespace', 'page_title', 'page_len',
143 'page_is_redirect', 'page_latest' );
144 $conds = $this->constructSet( 'page', $dbr );
145
146 // Do query
147 $caller = __METHOD__;
148 if ( strval( $this->caller ) !== '' ) {
149 $caller .= " (for {$this->caller})";
150 }
151 $res = $dbr->select( $table, $fields, $conds, $caller );
152 wfProfileOut( __METHOD__ );
153 return $res;
154 }
155
156 /**
157 * Construct a WHERE clause which will match all the given titles.
158 *
159 * @param $prefix String: the appropriate table's field name prefix ('page', 'pl', etc)
160 * @param $db DatabaseBase object to use
161 * @return mixed string with SQL where clause fragment, or false if no items.
162 */
163 public function constructSet( $prefix, $db ) {
164 return $db->makeWhereFrom2d( $this->data, "{$prefix}_namespace", "{$prefix}_title" );
165 }
166 }