wiki.techinc.nl/includes/SearchEngine.php

642 lines
17 KiB
PHP

<?php
/**
* Contain site class
* See search.doc
* @package MediaWiki
*/
/**
*
*/
define( 'MW_SEARCH_OK', true );
define( 'MW_SEARCH_BAD_QUERY', false );
/**
* @todo document
* @package MediaWiki
*/
class SearchEngine {
/* private */ var $rawText, $filteredText, $searchTerms;
/* private */ var $titleCond, $textCond;
var $doSearchRedirects = true;
var $addToQuery = array();
var $namespacesToSearch = array();
var $alternateTitle;
var $allTitles = false;
function SearchEngine( $text ) {
$this->rawText = trim( $text );
# We display the query, so let's strip it for safety
#
global $wgDBmysql4;
$lc = SearchEngine::legalSearchChars() . '()';
if( $wgDBmysql4 ) {
$lc .= "\"~<>*+-";
}
$this->filteredText = trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
$this->searchTerms = array();
$this->strictMatching = true; # Google-style, add '+' on all terms
$this->db =& wfGetDB( DB_SLAVE );
}
/**
* Return a partial WHERE clause to limit the search to the given namespaces
*/
function queryNamespaces() {
$namespaces = implode( ',', $this->namespacesToSearch );
if ($namespaces == '') {
$namespaces = '0';
}
return "AND cur_namespace IN (" . $namespaces . ')';
}
/**
* Return a partial WHERE clause to include or exclude redirects from results
*/
function searchRedirects() {
if ( $this->doSearchRedirects ) {
return '';
} else {
return 'AND cur_is_redirect=0 ';
}
}
/**
* @access private
*/ function initNamespaceCheckbox( $i ) {
global $wgUser, $wgNamespacesToBeSearchedDefault;
if ($wgUser->getID()) {
// User is logged in so we retrieve his default namespaces
return $wgUser->getOption( 'searchNs'.$i );
} else {
// User is not logged in so we give him the global default namespaces
return !empty($wgNamespacesToBeSearchedDefault[ $i ]);
}
}
/**
* Display the "power search" footer. Does not actually perform the search,
* that is done by showResults()
*/
function powersearch() {
global $wgUser, $wgOut, $wgLang, $wgTitle, $wgRequest;
$sk =& $wgUser->getSkin();
$search = $this->rawText;
$searchx = $wgRequest->getVal( 'searchx' );
$listredirs = $wgRequest->getVal( 'redirs' );
$ret = wfMsg('powersearchtext'); # Text to be returned
$tempText = ''; # Temporary text, for substitution into $ret
if( isset( $_REQUEST['searchx'] ) ) {
$this->addToQuery['searchx'] = '1';
}
# Do namespace checkboxes
$namespaces = $wgLang->getNamespaces();
foreach ( $namespaces as $i => $namespace ) {
# Skip virtual namespaces
if ( $i < 0 ) {
continue;
}
$formVar = 'ns'.$i;
# Initialise checkboxValues, either from defaults or from
# a previous invocation
if ( !isset( $searchx ) ) {
$checkboxValue = $this->initNamespaceCheckbox( $i );
} else {
$checkboxValue = $wgRequest->getVal( $formVar );
}
$checked = '';
if ( $checkboxValue == 1 ) {
$checked = ' checked="checked"';
$this->addToQuery['ns'.$i] = 1;
array_push( $this->namespacesToSearch, $i );
}
$name = str_replace( '_', ' ', $namespaces[$i] );
if ( '' == $name ) {
$name = wfMsg( 'blanknamespace' );
}
if ( $tempText !== '' ) {
$tempText .= ' ';
}
$tempText .= "<input type='checkbox' value=\"1\" name=\"" .
"ns{$i}\"{$checked} />{$name}\n";
}
$ret = str_replace ( '$1', $tempText, $ret );
# List redirects checkbox
$checked = '';
if ( $listredirs == 1 ) {
$this->addToQuery['redirs'] = 1;
$checked = ' checked="checked"';
}
$tempText = "<input type='checkbox' value='1' name=\"redirs\"{$checked} />\n";
$ret = str_replace( '$2', $tempText, $ret );
# Search field
$tempText = "<input type='text' name=\"search\" value=\"" .
htmlspecialchars( $search ) ."\" width=\"80\" />\n";
$ret = str_replace( "$3", $tempText, $ret );
# Searchx button
$tempText = '<input type="submit" name="searchx" value="' .
wfMsg('powersearch') . "\" />\n";
$ret = str_replace( '$9', $tempText, $ret );
$action = $sk->escapeSearchLink();
$ret = "<br /><br />\n<form id=\"powersearch\" method=\"get\" " .
"action=\"$action\">\n{$ret}\n</form>\n";
if ( isset ( $searchx ) ) {
if ( ! $listredirs ) {
$this->doSearchRedirects = false;
}
}
return $ret;
}
function setupPage() {
global $wgOut;
$wgOut->setPageTitle( wfMsg( 'searchresults' ) );
$wgOut->setSubtitle( wfMsg( 'searchquery', htmlspecialchars( $this->rawText ) ) );
$wgOut->setArticleRelated( false );
$wgOut->setRobotpolicy( 'noindex,nofollow' );
}
/**
* Perform the search and construct the results page
*/
function showResults() {
global $wgUser, $wgTitle, $wgOut, $wgLang;
global $wgDisableTextSearch, $wgInputEncoding;
$fname = 'SearchEngine::showResults';
$search = $this->rawText;
$powersearch = $this->powersearch(); /* Need side-effects here? */
$this->setupPage();
$sk = $wgUser->getSkin();
$wgOut->addWikiText( wfMsg( 'searchresulttext' ) );
if ( !$this->parseQuery() ) {
$wgOut->addWikiText(
'==' . wfMsg( 'badquery' ) . "==\n" .
wfMsg( 'badquerytext' ) );
return;
}
list( $limit, $offset ) = wfCheckLimits( 20, 'searchlimit' );
if ( $wgDisableTextSearch ) {
$wgOut->addHTML( wfMsg( 'searchdisabled' ) );
$wgOut->addHTML( wfMsg( 'googlesearch',
htmlspecialchars( $this->rawText ),
htmlspecialchars( $wgInputEncoding ) ) );
return;
}
$titleMatches = $this->getMatches( $this->titleCond, $limit, $offset );
$textMatches = $this->getMatches( $this->textCond, $limit, $offset );
$sk = $wgUser->getSkin();
$num = count( $titleMatches ) + count( $textMatches );
if ( $num >= $limit ) {
$top = wfShowingResults( $offset, $limit );
} else {
$top = wfShowingResultsNum( $offset, $limit, $num );
}
$wgOut->addHTML( "<p>{$top}</p>\n" );
# For powersearch
$a2l = '';
$akk = array_keys( $this->addToQuery );
foreach ( $akk AS $ak ) {
$a2l .= "&{$ak}={$this->addToQuery[$ak]}" ;
}
$prevnext = wfViewPrevNext( $offset, $limit, '',
'search=' . wfUrlencode( $this->filteredText ) . $a2l );
$wgOut->addHTML( "<br />{$prevnext}\n" );
$foundsome = $this->showMatches( $titleMatches, $offset, 'notitlematches', 'titlematches' )
|| $this->showMatches( $textMatches, $offset, 'notextmatches', 'textmatches' );
if ( !$foundsome ) {
$wgOut->addWikiText( wfMsg( 'nonefound' ) );
}
$wgOut->addHTML( "<p>{$prevnext}</p>\n" );
$wgOut->addHTML( $powersearch );
}
function legalSearchChars() {
$lc = "A-Za-z_'0-9\\x80-\\xFF\\-";
return $lc;
}
function parseQuery() {
global $wgDBmysql4;
if( $wgDBmysql4 ) {
# Use cleaner boolean search if available
return $this->parseQuery4();
} else {
# Fall back to ugly hack with multiple search clauses
return $this->parseQuery3();
}
}
function parseQuery3() {
global $wgDBminWordLen, $wgLang;
# on non mysql4 database: get list of words we don't want to search for
require_once( 'FulltextStoplist.php' );
$lc = SearchEngine::legalSearchChars() . '()';
$q = preg_replace( "/([()])/", " \\1 ", $this->filteredText );
$q = preg_replace( "/\\s+/", " ", $q );
$w = explode( ' ', trim( $q ) );
$last = $cond = '';
foreach ( $w as $word ) {
$word = $wgLang->stripForSearch( $word );
if ( 'and' == $word || 'or' == $word || 'not' == $word
|| '(' == $word || ')' == $word ) {
$cond .= ' ' . strtoupper( $word );
$last = '';
} else if ( strlen( $word ) < $wgDBminWordLen ) {
continue;
} else if ( FulltextStoplist::inList( $word ) ) {
continue;
} else {
if ( '' != $last ) { $cond .= ' AND'; }
$cond .= " (MATCH (##field##) AGAINST ('" .
$this->db->strencode( $word ). "'))";
$last = $word;
array_push( $this->searchTerms, "\\b" . $word . "\\b" );
}
}
if ( 0 == count( $this->searchTerms ) ) {
return MW_SEARCH_BAD_QUERY;
}
$this->titleCond = '(' . str_replace( '##field##',
'si_title', $cond ) . ' )';
$this->textCond = '(' . str_replace( '##field##',
'si_text', $cond ) . ' AND (cur_is_redirect=0) )';
return MW_SEARCH_OK;
}
function parseQuery4() {
global $wgLang;
$lc = SearchEngine::legalSearchChars();
$searchon = '';
$this->searchTerms = array();
# FIXME: This doesn't handle parenthetical expressions.
if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
$this->filteredText, $m, PREG_SET_ORDER ) ) {
foreach( $m as $terms ) {
if( $searchon !== '' ) $searchon .= ' ';
if( $this->strictMatching && ($terms[1] == '') ) {
$terms[1] = '+';
}
$searchon .= $terms[1] . $wgLang->stripForSearch( $terms[2] );
if( !empty( $terms[3] ) ) {
$regexp = preg_quote( $terms[3] );
if( $terms[4] ) $regexp .= "[0-9A-Za-z_]+";
} else {
$regexp = preg_quote( str_replace( '"', '', $terms[2] ) );
}
$this->searchTerms[] = $regexp;
}
wfDebug( "Would search with '$searchon'\n" );
wfDebug( "Match with /\b" . implode( '\b|\b', $this->searchTerms ) . "\b/\n" );
} else {
wfDebug( "Can't understand search query '{$this->filteredText}'\n" );
}
$searchon = $this->db->strencode( $searchon );
$this->titleCond = " MATCH(si_title) AGAINST('$searchon' IN BOOLEAN MODE)";
$this->textCond = " (MATCH(si_text) AGAINST('$searchon' IN BOOLEAN MODE) AND cur_is_redirect=0)";
return MW_SEARCH_OK;
}
function &getMatches( $cond, $limit, $offset = 0 ) {
$searchindex = $this->db->tableName( 'searchindex' );
$cur = $this->db->tableName( 'cur' );
$searchnamespaces = $this->queryNamespaces();
$redircond = $this->searchRedirects();
$sql = "SELECT cur_id,cur_namespace,cur_title," .
"cur_text FROM $cur,$searchindex " .
"WHERE cur_id=si_page AND {$cond} " .
"{$searchnamespaces} {$redircond} " .
$this->db->limitResult( $limit, $offset );
$res = $this->db->query( $sql, 'SearchEngine::getMatches' );
$matches = array();
while ( $row = $this->db->fetchObject( $res ) ) {
$matches[] = $row;
}
$this->db->freeResult( $res );
return $matches;
}
function showMatches( &$matches, $offset, $msgEmpty, $msgFound ) {
global $wgOut;
if ( 0 == count( $matches ) ) {
$wgOut->addHTML( "<h2>" . wfMsg( $msgEmpty ) .
"</h2>\n" );
return false;
} else {
$off = $offset + 1;
$wgOut->addHTML( "<h2>" . wfMsg( $msgFound ) .
"</h2>\n<ol start='{$off}'>" );
foreach( $matches as $row ) {
$this->showHit( $row );
}
$wgOut->addHTML( "</ol>\n" );
return true;
}
}
function showHit( $row ) {
global $wgUser, $wgOut, $wgLang;
$t = Title::makeName( $row->cur_namespace, $row->cur_title );
if( is_null( $t ) ) {
$wgOut->addHTML( "<!-- Broken link in search result -->\n" );
return;
}
$sk = $wgUser->getSkin();
$contextlines = $wgUser->getOption( 'contextlines' );
if ( '' == $contextlines ) { $contextlines = 5; }
$contextchars = $wgUser->getOption( 'contextchars' );
if ( '' == $contextchars ) { $contextchars = 50; }
$link = $sk->makeKnownLink( $t, '' );
$size = wfMsg( 'nbytes', strlen( $row->cur_text ) );
$wgOut->addHTML( "<li>{$link} ({$size})" );
$lines = explode( "\n", $row->cur_text );
$pat1 = "/(.*)(" . implode( "|", $this->searchTerms ) . ")(.*)/i";
$lineno = 0;
foreach ( $lines as $line ) {
if ( 0 == $contextlines ) {
break;
}
--$contextlines;
++$lineno;
if ( ! preg_match( $pat1, $line, $m ) ) {
continue;
}
$pre = $wgLang->truncate( $m[1], -$contextchars, '...' );
if ( count( $m ) < 3 ) {
$post = '';
} else {
$post = $wgLang->truncate( $m[3], $contextchars, '...' );
}
$found = $m[2];
$line = htmlspecialchars( $pre . $found . $post );
$pat2 = '/(' . implode( '|', $this->searchTerms ) . ")/i";
$line = preg_replace( $pat2,
"<span class='searchmatch'>\\1</span>", $line );
$wgOut->addHTML( "<br /><small>{$lineno}: {$line}</small>\n" );
}
$wgOut->addHTML( "</li>\n" );
}
function getNearMatch() {
# Exact match? No need to look further.
$title = Title::newFromText( $this->rawText );
if ( $title->getNamespace() == NS_SPECIAL || 0 != $title->getArticleID() ) {
return $title;
}
# Now try all lower case (i.e. first letter capitalized)
#
$title = Title::newFromText( strtolower( $this->rawText ) );
if ( 0 != $title->getArticleID() ) {
return $title;
}
# Now try capitalized string
#
$title = Title::newFromText( ucwords( strtolower( $this->rawText ) ) );
if ( 0 != $title->getArticleID() ) {
return $title;
}
# Now try all upper case
#
$title = Title::newFromText( strtoupper( $this->rawText ) );
if ( 0 != $title->getArticleID() ) {
return $title;
}
# Entering an IP address goes to the contributions page
if ( preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/', $this->rawText ) ) {
$title = Title::makeTitle( NS_SPECIAL, "Contributions/" . $this->rawText );
return $title;
}
return NULL;
}
function goResult() {
global $wgOut, $wgGoToEdit;
global $wgDisableTextSearch;
$fname = 'SearchEngine::goResult';
# Try to go to page as entered.
#
$t = Title::newFromText( $this->rawText );
# If the string cannot be used to create a title
if( is_null( $t ) ){
$this->showResults();
return;
}
# If there's an exact or very near match, jump right there.
$t = $this->getNearMatch();
if( !is_null( $t ) ) {
$wgOut->redirect( $t->getFullURL() );
return;
}
# No match, generate an edit URL
$t = Title::newFromText( $this->rawText );
# If the feature is enabled, go straight to the edit page
if ( $wgGoToEdit ) {
$wgOut->redirect( $t->getFullURL( 'action=edit' ) );
return;
}
if( $t ) {
$editurl = $t->escapeLocalURL( 'action=edit' );
} else {
$editurl = ''; # ??
}
$wgOut->addHTML( '<p>' . wfMsg('nogomatch', $editurl ) . "</p>\n" );
# Try a fuzzy title search
$anyhit = false;
global $wgDisableFuzzySearch;
if(! $wgDisableFuzzySearch ){
foreach( array(NS_MAIN, NS_PROJECT, NS_USER, NS_IMAGE, NS_MEDIAWIKI) as $namespace){
$anyhit |= SearchEngine::doFuzzyTitleSearch( $this->rawText, $namespace );
}
}
if( ! $anyhit ){
return $this->showResults();
}
}
/**
* @static
*/
function doFuzzyTitleSearch( $search, $namespace ){
global $wgLang, $wgOut;
$this->setupPage();
$sstr = ucfirst($search);
$sstr = str_replace(' ', '_', $sstr);
$fuzzymatches = SearchEngine::fuzzyTitles( $sstr, $namespace );
$fuzzymatches = array_slice($fuzzymatches, 0, 10);
$slen = strlen( $search );
$wikitext = '';
foreach($fuzzymatches as $res){
$t = str_replace('_', ' ', $res[1]);
$tfull = $wgLang->getNsText( $namespace ) . ":$t|$t";
if( $namespace == NS_MAIN )
$tfull = "$t";
$distance = $res[0];
$closeness = (strlen( $search ) - $distance) / strlen( $search );
$percent = intval( $closeness * 100 ) . '%';
$stars = str_repeat('*', ceil(5 * $closeness) );
$wikitext .= "* [[$tfull]] $percent ($stars)\n";
}
if( $wikitext ){
if( $namespace != NS_MAIN )
$wikitext = '=== ' . $wgLang->getNsText( $namespace ) . " ===\n" . $wikitext;
$wgOut->addWikiText( $wikitext );
return true;
}
return false;
}
/**
* @static
*/
function fuzzyTitles( $sstr, $namespace = NS_MAIN ){
$span = 0.10; // weed on title length before doing levenshtein.
$tolerance = 0.35; // allowed percentage of erronous characters
$slen = strlen($sstr);
$tolerance_count = ceil($tolerance * $slen);
$spanabs = ceil($slen * (1 + $span)) - $slen;
# print "Word: $sstr, len = $slen, range = [$min, $max], tolerance_count = $tolerance_count<BR>\n";
$result = array();
$cnt = 0;
for( $i=0; $i <= $spanabs; $i++ ){
$titles = SearchEngine::getTitlesByLength( $slen + $i, $namespace );
if( $i != 0) {
$titles = array_merge($titles, SearchEngine::getTitlesByLength( $slen - $i, $namespace ) );
}
foreach($titles as $t){
$d = levenshtein($sstr, $t);
if($d < $tolerance_count)
$result[] = array($d, $t);
$cnt++;
}
}
usort($result, 'SearchEngine_pcmp');
return $result;
}
/**
* static
*/
function getTitlesByLength($aLength, $aNamespace = 0){
global $wgMemc, $wgDBname;
$fname = 'SearchEngin::getTitlesByLength';
// to avoid multiple costly SELECTs in case of no memcached
if( $this->allTitles ){
if( isset( $this->allTitles[$aLength][$aNamespace] ) ){
return $this->allTitles[$aLength][$aNamespace];
} else {
return array();
}
}
$mkey = "$wgDBname:titlesbylength:$aLength:$aNamespace";
$mkeyts = "$wgDBname:titlesbylength:createtime";
$ts = $wgMemc->get( $mkeyts );
$result = $wgMemc->get( $mkey );
if( time() - $ts < 3600 ){
// note: in case of insufficient memcached space, we return
// an empty list instead of starting to hit the DB.
return is_array( $result ) ? $result : array();
}
$wgMemc->set( $mkeyts, time() );
$res = $this->db->select( 'cur', array( 'cur_title', 'cur_namespace' ), false, $fname );
$titles = array(); // length, ns, [titles]
while( $obj = $this->db->fetchObject( $res ) ){
$title = $obj->cur_title;
$ns = $obj->cur_namespace;
$len = strlen( $title );
$titles[$len][$ns][] = $title;
}
foreach($titles as $length => $length_arr){
foreach($length_arr as $ns => $title_arr){
$mkey = "$wgDBname:titlesbylength:$length:$ns";
$wgMemc->set( $mkey, $title_arr, 3600 * 24 );
}
}
$this->allTitles = $titles;
if( isset( $titles[$aLength][$aNamespace] ) )
return $titles[$aLength][$aNamespace];
else
return array();
}
}
/**
* @access private
* @static
*/
function SearchEngine_pcmp($a, $b){ return $a[0] - $b[0]; }
?>