SearchPostgres.php

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<?php
class SearchPostgres extends SearchEngine {

        protected $db;
        function __construct( $db ) {
                parent::__construct( $db );
        }

        function searchTitle( $term ) {
                $q = $this->searchQuery( $term , 'titlevector', 'page_title' );
                $olderror = error_reporting(E_ERROR);
                $resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
                error_reporting($olderror);
                if (!$resultSet) {
                        // Needed for "Query requires full scan, GIN doesn't support it"
                        return new SearchResultTooMany();
                }
                return new PostgresSearchResultSet( $resultSet, $this->searchTerms );
        }

        function searchText( $term ) {
                $q = $this->searchQuery( $term, 'textvector', 'old_text' );
                $olderror = error_reporting(E_ERROR);
                $resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
                error_reporting($olderror);
                if (!$resultSet) {
                        return new SearchResultTooMany();
                }
                return new PostgresSearchResultSet( $resultSet, $this->searchTerms );
        }

        function parseQuery( $term ) {

                wfDebug( "parseQuery received: $term \n" );

                ## No backslashes allowed
                $term = preg_replace('/\\\/', '', $term);

                ## Collapse parens into nearby words:
                $term = preg_replace('/\s*\(\s*/', ' (', $term);
                $term = preg_replace('/\s*\)\s*/', ') ', $term);

                ## Treat colons as word separators:
                $term = preg_replace('/:/', ' ', $term);

                $searchstring = '';
                $m = array();
                if( preg_match_all('/([-!]?)(\S+)\s*/', $term, $m, PREG_SET_ORDER ) ) {
                        foreach( $m as $terms ) {
                                if (strlen($terms[1])) {
                                        $searchstring .= ' & !';
                                }
                                if (strtolower($terms[2]) === 'and') {
                                        $searchstring .= ' & ';
                                }
                                elseif (strtolower($terms[2]) === 'or' or $terms[2] === '|') {
                                        $searchstring .= ' | ';
                                }
                                elseif (strtolower($terms[2]) === 'not') {
                                        $searchstring .= ' & !';
                                }
                                else {
                                        $searchstring .= " & $terms[2]";
                                }
                        }
                }

                ## Strip out leading junk
                $searchstring = preg_replace('/^[\s\&\|]+/', '', $searchstring);

                ## Remove any doubled-up operators
                $searchstring = preg_replace('/([\!\&\|]) +(?:[\&\|] +)+/', "$1 ", $searchstring);

                ## Remove any non-spaced operators (e.g. "Zounds!")
                $searchstring = preg_replace('/([^ ])[\!\&\|]/', "$1", $searchstring);

                ## Remove any trailing whitespace or operators
                $searchstring = preg_replace('/[\s\!\&\|]+$/', '', $searchstring);

                ## Remove unnecessary quotes around everything
                $searchstring = preg_replace('/^[\'"](.*)[\'"]$/', "$1", $searchstring);

                ## Quote the whole thing
                $searchstring = $this->db->addQuotes($searchstring);

                wfDebug( "parseQuery returned: $searchstring \n" );

                return $searchstring;

        }

        function searchQuery( $term, $fulltext, $colname ) {
                # Get the SQL fragment for the given term
                $searchstring = $this->parseQuery( $term );

                ## We need a separate query here so gin does not complain about empty searches
                $SQL = "SELECT to_tsquery($searchstring)";
                $res = $this->db->query($SQL);
                if (!$res) {
                        ## TODO: Better output (example to catch: one 'two)
                        die ("Sorry, that was not a valid search string. Please go back and try again");
                }
                $top = $res->fetchRow();
                $top = $top[0];

                if ($top === "") { ## e.g. if only stopwords are used XXX return something better
                        $query = "SELECT page_id, page_namespace, page_title, 0 AS score ".
                                "FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
                                "AND r.rev_text_id = c.old_id AND 1=0";
                }
                else {
                        $m = array();
                        if( preg_match_all("/'([^']+)'/", $top, $m, PREG_SET_ORDER ) ) {
                                foreach( $m as $terms ) {
                                        $this->searchTerms[$terms[1]] = $terms[1];
                                }
                        }

                        $query = "SELECT page_id, page_namespace, page_title, ".
                        "ts_rank($fulltext, to_tsquery($searchstring), 5) AS score ".
                        "FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
                        "AND r.rev_text_id = c.old_id AND $fulltext @@ to_tsquery($searchstring)";
                }

                ## Redirects
                if (! $this->showRedirects)
                        $query .= ' AND page_is_redirect = 0';

                ## Namespaces - defaults to 0
                if( !is_null($this->namespaces) ){ // null -> search all
                        if ( count($this->namespaces) < 1)
                                $query .= ' AND page_namespace = 0';
                        else {
                                $namespaces = $this->db->makeList( $this->namespaces );
                                $query .= " AND page_namespace IN ($namespaces)";
                        }
                }

                $query .= " ORDER BY score DESC, page_id DESC";

                $query .= $this->db->limitResult( '', $this->limit, $this->offset );

                wfDebug( "searchQuery returned: $query \n" );

                return $query;
        }

        ## Most of the work of these two functions are done automatically via triggers

        function update( $pageid, $title, $text ) {
                ## We don't want to index older revisions
                $SQL = "UPDATE pagecontent SET textvector = NULL WHERE old_id IN ".
                                "(SELECT rev_text_id FROM revision WHERE rev_page = " . intval( $pageid ) .
                                " ORDER BY rev_text_id DESC OFFSET 1)";
                $this->db->query($SQL);
                return true;
        }

        function updateTitle( $id, $title ) {
                return true;
        }

} ## end of the SearchPostgres class

class PostgresSearchResult extends SearchResult {
        function __construct( $row ) {
                parent::__construct($row);
                $this->score = $row->score;
        }
        function getScore() {
                return $this->score;
        }
}

class PostgresSearchResultSet extends SqlSearchResultSet {
        function __construct( $resultSet, $terms ) {
                parent::__construct( $resultSet, $terms );
        }

        function next() {
                $row = $this->mResultSet->fetchObject();
                if( $row === false ) {
                        return false;
                } else {
                        return new PostgresSearchResult( $row );
                }
        }
}