diff options
Diffstat (limited to 'CheckUser/src/CompareService.php')
| -rw-r--r-- | CheckUser/src/CompareService.php | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/CheckUser/src/CompareService.php b/CheckUser/src/CompareService.php new file mode 100644 index 00000000..f1ab687e --- /dev/null +++ b/CheckUser/src/CompareService.php @@ -0,0 +1,220 @@ +<?php + +namespace MediaWiki\CheckUser; + +use Wikimedia\Rdbms\ILoadBalancer; +use Wikimedia\Rdbms\Subquery; + +class CompareService extends ChangeService { + /** @var int */ + private $limit; + + /** + * @param ILoadBalancer $loadBalancer + * @param UserManager $userManager + * @param int $limit Maximum number of rows to access (T245499) + */ + public function __construct( + ILoadBalancer $loadBalancer, + UserManager $userManager, + $limit = 100000 + ) { + parent::__construct( $loadBalancer, $userManager ); + $this->limit = $limit; + } + + /** + * Get edits made from an ip + * + * @param string $ipHex + * @param string|null $excludeUser + * @return int + */ + public function getTotalEditsFromIp( + string $ipHex, + string $excludeUser = null + ) : int { + $db = $this->loadBalancer->getConnectionRef( DB_REPLICA ); + $conds = [ + 'cuc_ip_hex' => $ipHex, + 'cuc_type' => [ RC_EDIT, RC_NEW ], + ]; + + if ( $excludeUser ) { + $conds[] = 'cuc_user_text != ' . $db->addQuotes( $excludeUser ); + } + + return $db->selectRowCount( 'cu_changes', '*', $conds, __METHOD__ ); + } + + /** + * Get the compare query info + * + * @param string[] $targets + * @param string[] $excludeTargets + * @param string $start + * @return array + */ + public function getQueryInfo( array $targets, array $excludeTargets, string $start ): array { + $db = $this->loadBalancer->getConnectionRef( DB_REPLICA ); + + if ( $targets === [] ) { + throw new \LogicException( 'Cannot get query info when $targets is empty.' ); + } + $limit = (int)( $this->limit / count( $targets ) ); + + $sqlText = []; + foreach ( $targets as $target ) { + $info = $this->getQueryInfoForSingleTarget( $target, $excludeTargets, $start, $limit ); + if ( $info !== null ) { + if ( !$db->unionSupportsOrderAndLimit() ) { + unset( $info['options']['ORDER BY'], $info['options']['LIMIT'] ); + } + + $sqlText[] = $db->selectSQLText( + $info['tables'], + $info['fields'], + $info['conds'], + __METHOD__, + $info['options'] + ); + } + } + + $derivedTable = $db->unionQueries( $sqlText, $db::UNION_DISTINCT ); + + return [ + 'tables' => [ 'a' => new Subquery( $derivedTable ) ], + 'fields' => [ + 'cuc_user' => 'a.cuc_user', + 'cuc_user_text' => 'a.cuc_user_text', + 'cuc_ip' => 'a.cuc_ip', + 'cuc_ip_hex' => 'a.cuc_ip_hex', + 'cuc_agent' => 'a.cuc_agent', + 'first_edit' => 'MIN(a.cuc_timestamp)', + 'last_edit' => 'MAX(a.cuc_timestamp)', + 'total_edits' => 'count(*)', + ], + 'options' => [ + 'GROUP BY' => [ + 'cuc_user_text', + 'cuc_ip_hex', + 'cuc_agent', + ], + ], + ]; + } + + /** + * Get the query info for a single target. + * + * For the main investigation, this becomes a subquery that contributes to a derived + * table, used by getQueryInfo. + * + * For a limit check, this query is used to check whether the number of results for + * the target exceed the limit-per-target in getQueryInfo. + * + * @param string $target + * @param string[] $excludeTargets + * @param string $start + * @param int $limitPerTarget + * @param bool $limitCheck + * @return array|null Return null for invalid target + */ + public function getQueryInfoForSingleTarget( + string $target, + array $excludeTargets, + string $start, + int $limitPerTarget, + $limitCheck = false + ) : ?array { + if ( $limitCheck ) { + $orderBy = null; + $offset = $limitPerTarget; + $limit = 1; + } else { + $orderBy = 'cuc_timestamp DESC'; + $offset = null; + $limit = $limitPerTarget; + } + + $conds = $this->buildTargetConds( $target ); + if ( $conds === [] ) { + return null; + } + + $conds = array_merge( + $conds, + $this->buildExcludeTargetsConds( $excludeTargets ), + $this->buildStartConds( $start ) + ); + + $conds['cuc_type'] = [ RC_EDIT, RC_NEW ]; + + return [ + 'tables' => 'cu_changes', + 'fields' => [ + 'cuc_id', + 'cuc_user', + 'cuc_user_text', + 'cuc_ip', + 'cuc_ip_hex', + 'cuc_agent', + 'cuc_timestamp', + ], + 'conds' => $conds, + 'options' => [ + 'ORDER BY' => $orderBy, + 'LIMIT' => $limit, + 'OFFSET' => $offset, + ], + ]; + } + + /** + * Check if we have incomplete data for any of the targets. + * + * @param string[] $targets + * @param string[] $excludeTargets + * @param string $start + * @return string[] + */ + public function getTargetsOverLimit( + array $targets, + array $excludeTargets, + string $start + ) : array { + if ( $targets === [] ) { + return $targets; + } + + $db = $this->loadBalancer->getConnectionRef( DB_REPLICA ); + + // If the database does not support order and limit on a UNION + // then none of the targets can be over the limit. + if ( !$db->unionSupportsOrderAndLimit() ) { + return []; + } + + $targetsOverLimit = []; + $offset = (int)( $this->limit / count( $targets ) ); + + foreach ( $targets as $target ) { + $info = $this->getQueryInfoForSingleTarget( $target, $excludeTargets, $start, $offset, true ); + if ( $info !== null ) { + $limitCheck = $db->select( + $info['tables'], + $info['fields'], + $info['conds'], + __METHOD__, + $info['options'] + ); + if ( $limitCheck->numRows() > 0 ) { + $targetsOverLimit[] = $target; + } + } + } + + return $targetsOverLimit; + } +} |