wikimedia /
mediawiki
Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php |
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| 34 | class ApiQueryContributors extends ApiQueryBase { |
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| 35 | /** We don't want to process too many pages at once (it hits cold |
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| 36 | * database pages too heavily), so only do the first MAX_PAGES input pages |
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| 37 | * in each API call (leaving the rest for continuation). |
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| 38 | */ |
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| 39 | const MAX_PAGES = 100; |
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| 40 | |||
| 41 | public function __construct( ApiQuery $query, $moduleName ) { |
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| 46 | |||
| 47 | public function execute() { |
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| 48 | $db = $this->getDB(); |
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| 49 | $params = $this->extractRequestParams(); |
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| 50 | $this->requireMaxOneParameter( $params, 'group', 'excludegroup', 'rights', 'excluderights' ); |
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| 51 | |||
| 52 | // Only operate on existing pages |
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| 53 | $pages = array_keys( $this->getPageSet()->getGoodTitles() ); |
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| 54 | |||
| 55 | // Filter out already-processed pages |
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| 56 | if ( $params['continue'] !== null ) { |
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| 57 | $cont = explode( '|', $params['continue'] ); |
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| 58 | $this->dieContinueUsageIf( count( $cont ) != 2 ); |
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| 59 | $cont_page = (int)$cont[0]; |
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| 60 | $pages = array_filter( $pages, function ( $v ) use ( $cont_page ) { |
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| 61 | return $v >= $cont_page; |
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| 62 | } ); |
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| 63 | } |
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| 64 | if ( !count( $pages ) ) { |
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| 65 | // Nothing to do |
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| 66 | return; |
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| 67 | } |
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| 68 | |||
| 69 | // Apply MAX_PAGES, leaving any over the limit for a continue. |
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| 70 | sort( $pages ); |
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| 71 | $continuePages = null; |
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| 72 | if ( count( $pages ) > self::MAX_PAGES ) { |
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| 73 | $continuePages = $pages[self::MAX_PAGES] . '|0'; |
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| 74 | $pages = array_slice( $pages, 0, self::MAX_PAGES ); |
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| 75 | } |
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| 76 | |||
| 77 | $result = $this->getResult(); |
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| 78 | |||
| 79 | // First, count anons |
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| 80 | $this->addTables( 'revision' ); |
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| 81 | $this->addFields( [ |
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| 82 | 'page' => 'rev_page', |
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| 83 | 'anons' => 'COUNT(DISTINCT rev_user_text)', |
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| 84 | ] ); |
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| 85 | $this->addWhereFld( 'rev_page', $pages ); |
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| 86 | $this->addWhere( 'rev_user = 0' ); |
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| 87 | $this->addWhere( $db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0' ); |
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| 88 | $this->addOption( 'GROUP BY', 'rev_page' ); |
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| 89 | $res = $this->select( __METHOD__ ); |
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| 90 | foreach ( $res as $row ) { |
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| 91 | $fit = $result->addValue( [ 'query', 'pages', $row->page ], |
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| 92 | 'anoncontributors', (int)$row->anons |
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| 93 | ); |
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| 94 | if ( !$fit ) { |
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| 95 | // This not fitting isn't reasonable, so it probably means that |
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| 96 | // some other module used up all the space. Just set a dummy |
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| 97 | // continue and hope it works next time. |
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| 98 | $this->setContinueEnumParameter( 'continue', |
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| 99 | $params['continue'] !== null ? $params['continue'] : '0|0' |
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| 100 | ); |
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| 101 | |||
| 102 | return; |
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| 103 | } |
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| 104 | } |
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| 105 | |||
| 106 | // Next, add logged-in users |
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| 107 | $this->resetQueryParams(); |
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| 108 | $this->addTables( 'revision' ); |
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| 109 | $this->addFields( [ |
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| 110 | 'page' => 'rev_page', |
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| 111 | 'user' => 'rev_user', |
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| 112 | 'username' => 'MAX(rev_user_text)', // Non-MySQL databases don't like partial group-by |
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| 113 | ] ); |
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| 114 | $this->addWhereFld( 'rev_page', $pages ); |
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| 115 | $this->addWhere( 'rev_user != 0' ); |
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| 116 | $this->addWhere( $db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0' ); |
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| 117 | $this->addOption( 'GROUP BY', 'rev_page, rev_user' ); |
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| 118 | $this->addOption( 'LIMIT', $params['limit'] + 1 ); |
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| 119 | |||
| 120 | // Force a sort order to ensure that properties are grouped by page |
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| 121 | // But only if pp_page is not constant in the WHERE clause. |
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| 122 | if ( count( $pages ) > 1 ) { |
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| 123 | $this->addOption( 'ORDER BY', 'rev_page, rev_user' ); |
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| 124 | } else { |
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| 125 | $this->addOption( 'ORDER BY', 'rev_user' ); |
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| 126 | } |
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| 127 | |||
| 128 | $limitGroups = []; |
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| 129 | if ( $params['group'] ) { |
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| 130 | $excludeGroups = false; |
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| 131 | $limitGroups = $params['group']; |
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| 132 | } elseif ( $params['excludegroup'] ) { |
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| 133 | $excludeGroups = true; |
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| 134 | $limitGroups = $params['excludegroup']; |
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| 135 | } elseif ( $params['rights'] ) { |
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| 136 | $excludeGroups = false; |
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| 137 | foreach ( $params['rights'] as $r ) { |
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| 138 | $limitGroups = array_merge( $limitGroups, User::getGroupsWithPermission( $r ) ); |
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| 139 | } |
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| 140 | |||
| 141 | // If no group has the rights requested, no need to query |
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| 142 | if ( !$limitGroups ) { |
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| 143 | if ( $continuePages !== null ) { |
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| 144 | // But we still need to continue for the next page's worth |
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| 145 | // of anoncontributors |
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| 146 | $this->setContinueEnumParameter( 'continue', $continuePages ); |
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| 147 | } |
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| 148 | |||
| 149 | return; |
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| 150 | } |
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| 151 | } elseif ( $params['excluderights'] ) { |
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| 152 | $excludeGroups = true; |
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| 153 | foreach ( $params['excluderights'] as $r ) { |
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| 154 | $limitGroups = array_merge( $limitGroups, User::getGroupsWithPermission( $r ) ); |
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| 155 | } |
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| 156 | } |
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| 157 | |||
| 158 | if ( $limitGroups ) { |
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| 159 | $limitGroups = array_unique( $limitGroups ); |
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| 160 | $this->addTables( 'user_groups' ); |
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| 161 | $this->addJoinConds( [ 'user_groups' => [ |
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| 162 | $excludeGroups ? 'LEFT OUTER JOIN' : 'INNER JOIN', |
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| 163 | [ 'ug_user=rev_user', 'ug_group' => $limitGroups ] |
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| 164 | ] ] ); |
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| 165 | $this->addWhereIf( 'ug_user IS NULL', $excludeGroups ); |
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| 166 | } |
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| 167 | |||
| 168 | if ( $params['continue'] !== null ) { |
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| 169 | $cont = explode( '|', $params['continue'] ); |
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| 170 | $this->dieContinueUsageIf( count( $cont ) != 2 ); |
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| 171 | $cont_page = (int)$cont[0]; |
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| 172 | $cont_user = (int)$cont[1]; |
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| 173 | $this->addWhere( |
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| 174 | "rev_page > $cont_page OR " . |
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| 175 | "(rev_page = $cont_page AND " . |
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| 176 | "rev_user >= $cont_user)" |
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| 177 | ); |
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| 178 | } |
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| 179 | |||
| 180 | $res = $this->select( __METHOD__ ); |
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| 181 | $count = 0; |
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| 182 | foreach ( $res as $row ) { |
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| 183 | View Code Duplication | if ( ++$count > $params['limit'] ) { |
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| 184 | // We've reached the one extra which shows that |
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| 185 | // there are additional pages to be had. Stop here... |
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| 186 | $this->setContinueEnumParameter( 'continue', $row->page . '|' . $row->user ); |
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| 187 | |||
| 188 | return; |
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| 189 | } |
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| 190 | |||
| 191 | $fit = $this->addPageSubItem( $row->page, |
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| 192 | [ 'userid' => (int)$row->user, 'name' => $row->username ], |
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| 193 | 'user' |
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| 194 | ); |
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| 195 | if ( !$fit ) { |
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| 196 | $this->setContinueEnumParameter( 'continue', $row->page . '|' . $row->user ); |
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| 197 | |||
| 198 | return; |
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| 199 | } |
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| 200 | } |
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| 201 | |||
| 202 | if ( $continuePages !== null ) { |
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| 203 | $this->setContinueEnumParameter( 'continue', $continuePages ); |
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| 204 | } |
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| 205 | } |
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| 206 | |||
| 207 | public function getCacheMode( $params ) { |
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| 210 | |||
| 211 | public function getAllowedParams() { |
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| 244 | |||
| 245 | protected function getExamplesMessages() { |
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| 251 | |||
| 252 | public function getHelpUrls() { |
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| 255 | } |
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| 256 |
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: