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Diffstat (limited to 'includes/search/SearchPostgres.php')
| -rw-r--r-- | includes/search/SearchPostgres.php | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/includes/search/SearchPostgres.php b/includes/search/SearchPostgres.php new file mode 100644 index 00000000..0006fa82 --- /dev/null +++ b/includes/search/SearchPostgres.php @@ -0,0 +1,246 @@ +<?php +# Copyright (C) 2006-2007 Greg Sabino Mullane <greg@turnstep.com> +# http://www.mediawiki.org/ +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program; if not, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +# http://www.gnu.org/copyleft/gpl.html + +/** + * @file + * @ingroup Search + */ + +/** + * Search engine hook base class for Postgres + * @ingroup Search + */ +class SearchPostgres extends SearchEngine { + + function __construct( $db ) { + $this->db = $db; + } + + /** + * Perform a full text search query via tsearch2 and return a result set. + * Currently searches a page's current title (page.page_title) and + * latest revision article text (pagecontent.old_text) + * + * @param $term String: raw search term + * @return PostgresSearchResultSet + */ + 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 ); + } + + + /* + * Transform the user's search string into a better form for tsearch2 + * Returns an SQL fragment consisting of quoted text to search for. + */ + 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') { + $searchstring .= ' & '; + } + else if (strtolower($terms[2]) === 'or' or $terms[2] === '|') { + $searchstring .= ' | '; + } + else if (strtolower($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; + + } + + /** + * Construct the full SQL query to do the search. + * @param $filteredTerm String + * @param $fulltext String + */ + function searchQuery( $term, $fulltext, $colname ) { + global $wgDBversion; + + if ( !isset( $wgDBversion ) ) { + $this->db->getServerVersion(); + $wgDBversion = $this->db->numeric_version; + } + $prefix = $wgDBversion < 8.3 ? "'default'," : ''; + + # 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 + $SQL = "SELECT to_tsquery($prefix $searchstring)"; + $res = $this->db->doQuery($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"); + } + $top = pg_fetch_result($res,0,0); + + 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]; + } + } + + $rankscore = $wgDBversion > 8.2 ? 5 : 1; + $rank = $wgDBversion < 8.3 ? 'rank' : 'ts_rank'; + $query = "SELECT page_id, page_namespace, page_title, ". + "$rank($fulltext, to_tsquery($prefix $searchstring), $rankscore) 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 $fulltext @@ to_tsquery($prefix $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)"; + $this->db->doQuery($SQL); + return true; + } + + function updateTitle( $id, $title ) { + return true; + } + +} ## end of the SearchPostgres class + +/** + * @ingroup Search + */ +class PostgresSearchResult extends SearchResult { + function __construct( $row ) { + parent::__construct($row); + $this->score = $row->score; + } + function getScore() { + return $this->score; + } +} + +/** + * @ingroup Search + */ +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 ); + } + } +} |