wiki.techinc.nl/includes/SearchEngine.php
2004-04-24 07:48:07 +00:00

596 lines
17 KiB
PHP

<?php
# See search.doc
class SearchEngine {
/* private */ var $mUsertext, $mSearchterms;
/* private */ var $mTitlecond, $mTextcond;
var $doSearchRedirects = true;
var $addtoquery = array();
var $namespacesToSearch = array();
var $alternateTitle;
var $all_titles = false;
function SearchEngine( $text )
{
# We display the query, so let's strip it for safety
#
global $wgDBmysql4;
$lc = SearchEngine::legalSearchChars() . "()";
if( $wgDBmysql4 ) $lc .= "\"~<>*+-";
$this->mUsertext = trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
$this->mSearchterms = array();
$this->mStrictMatching = true; # Google-style, add '+' on all terms
}
function queryNamespaces()
{
$namespaces = implode( ",", $this->namespacesToSearch );
if ($namespaces == "") {
$namespaces = "0";
}
return "AND cur_namespace IN (" . $namespaces . ")";
}
function searchRedirects()
{
if ( $this->doSearchRedirects ) {
return "";
} else {
return "AND cur_is_redirect=0 ";
}
}
/* 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 = $wgRequest->getText( 'search' );
$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" ) );
$q = wfMsg( "searchquery", htmlspecialchars( $this->mUsertext ) );
$wgOut->setSubtitle( $q );
$wgOut->setArticleRelated( false );
$wgOut->setRobotpolicy( "noindex,nofollow" );
}
# Perform the search and construct the results page
function showResults()
{
global $wgUser, $wgTitle, $wgOut, $wgLang, $wgRequest;
global $wgDisableTextSearch, $wgInputEncoding;
$fname = "SearchEngine::showResults";
$search = $wgRequest->getText( 'search' );
$powersearch = $this->powersearch(); /* Need side-effects here? */
$this->setupPage();
$sk = $wgUser->getSkin();
$header = wfMsg( "searchresulttext", $sk->makeKnownLink(
wfMsg( "searchhelppage" ), wfMsg( "searchingwikipedia" ) ) );
$wgOut->addHTML( $header );
$this->parseQuery();
if ( "" == $this->mTitlecond || "" == $this->mTextcond ) {
$wgOut->addHTML( "<h2>" . wfMsg( "badquery" ) . "</h2>\n" .
"<p>" . wfMsg( "badquerytext" ) . "</p>\n" );
return;
}
list( $limit, $offset ) = wfCheckLimits( 20, "searchlimit" );
$searchnamespaces = $this->queryNamespaces();
$redircond = $this->searchRedirects();
if ( $wgDisableTextSearch ) {
$wgOut->addHTML( wfMsg( "searchdisabled" ) );
$wgOut->addHTML( wfMsg( "googlesearch", htmlspecialchars( $search ), $GLOBALS['wgInputEncoding'] ) );
} else {
$sql = "SELECT cur_id,cur_namespace,cur_title," .
"cur_text FROM cur,searchindex " .
"WHERE cur_id=si_page AND {$this->mTitlecond} " .
"{$searchnamespaces} {$redircond}" .
"LIMIT {$offset}, {$limit}";
$res1 = wfQuery( $sql, DB_READ, $fname );
$num = wfNumRows($res1);
$sk = $wgUser->getSkin();
$text = "";
$this->parseQuery();
if ( "" == $this->mTitlecond || "" == $this->mTextcond ) {
$wgOut->addHTML( "<h2>" . wfMsg( "badquery" ) . "</h2>\n" .
"<p>" . wfMsg( "badquerytext" ) . "</p>\n" );
return;
}
list( $limit, $offset ) = wfCheckLimits( 20, "searchlimit" );
$searchnamespaces = $this->queryNamespaces();
$redircond = $this->searchRedirects();
$sql = "SELECT cur_id,cur_namespace,cur_title," .
"cur_text FROM cur,searchindex " .
"WHERE cur_id=si_page AND {$this->mTitlecond} " .
"{$searchnamespaces} {$redircond}" .
"LIMIT {$offset}, {$limit}";
$res1 = wfQuery( $sql, DB_READ, $fname );
$num = wfNumRows($res1);
$sql = "SELECT cur_id,cur_namespace,cur_title," .
"cur_text FROM cur,searchindex " .
"WHERE cur_id=si_page AND {$this->mTextcond} " .
"{$searchnamespaces} {$redircond} " .
"LIMIT {$offset}, {$limit}";
$res2 = wfQuery( $sql, DB_READ, $fname );
$num = $num + wfNumRows($res2);
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]}" ;
}
$sl = wfViewPrevNext( $offset, $limit, "",
"search=" . wfUrlencode( $this->mUsertext ) . $a2l );
$wgOut->addHTML( "<br />{$sl}\n" );
$foundsome = false;
if ( 0 == wfNumRows( $res1 ) ) {
$wgOut->addHTML( "<h2>" . wfMsg( "notitlematches" ) .
"</h2>\n" );
} else {
$foundsome = true;
$off = $offset + 1;
$wgOut->addHTML( "<h2>" . wfMsg( "titlematches" ) .
"</h2>\n<ol start='{$off}'>" );
while ( $row = wfFetchObject( $res1 ) ) {
$this->showHit( $row );
}
wfFreeResult( $res1 );
$wgOut->addHTML( "</ol>\n" );
}
if ( 0 == wfNumRows( $res2 ) ) {
$wgOut->addHTML( "<h2>" . wfMsg( "notextmatches" ) .
"</h2>\n" );
} else {
$foundsome = true;
$off = $offset + 1;
$wgOut->addHTML( "<h2>" . wfMsg( "textmatches" ) . "</h2>\n" .
"<ol start='{$off}'>" );
while ( $row = wfFetchObject( $res2 ) ) {
$this->showHit( $row );
}
wfFreeResult( $res2 );
$wgOut->addHTML( "</ol>\n" );
}
if ( ! $foundsome ) {
$wgOut->addHTML( "<p>" . wfMsg( "nonefound" ) . "</p>\n" );
}
$wgOut->addHTML( "<p>{$sl}</p>\n" );
$wgOut->addHTML( $powersearch );
}
}
function legalSearchChars()
{
$lc = "A-Za-z_'0-9\\x80-\\xFF\\-";
return $lc;
}
function parseQuery()
{
global $wgDBminWordLen, $wgLang, $wgDBmysql4;
if( $wgDBmysql4 ) {
# Use cleaner boolean search if available
return $this->parseQuery4();
}
$lc = SearchEngine::legalSearchChars() . "()";
$q = preg_replace( "/([()])/", " \\1 ", $this->mUsertext );
$q = preg_replace( "/\\s+/", " ", $q );
$w = explode( " ", strtolower( 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 ('" .
wfStrencode( $word ). "'))";
$last = $word;
array_push( $this->mSearchterms, "\\b" . $word . "\\b" );
}
}
if ( 0 == count( $this->mSearchterms ) ) { return; }
$this->mTitlecond = "(" . str_replace( "##field##",
"si_title", $cond ) . " )";
$this->mTextcond = "(" . str_replace( "##field##",
"si_text", $cond ) . " AND (cur_is_redirect=0) )";
}
function parseQuery4()
{
global $wgLang;
$lc = SearchEngine::legalSearchChars();
$searchon = "";
$this->mSearchterms = array();
# FIXME: This doesn't handle parenthetical expressions.
if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
$this->mUsertext, $m, PREG_SET_ORDER ) ) {
foreach( $m as $terms ) {
if( $searchon !== "" ) $searchon .= " ";
if( $this->mStrictMatching && ($terms[1] == "") ) {
$terms[1] = "+";
}
$searchon .= $terms[1] . $wgLang->stripForSearch( $terms[2] );
if( $terms[3] ) {
$regexp = preg_quote( $terms[3] );
if( $terms[4] ) $regexp .= "[0-9A-Za-z_]+";
} else {
$regexp = preg_quote( str_replace( '"', '', $terms[2] ) );
}
$this->mSearchterms[] = $regexp;
}
wfDebug( "Would search with '$searchon'\n" );
wfDebug( "Match with /\b" . implode( '\b|\b', $this->mSearchterms ) . "\b/\n" );
} else {
wfDebug( "Can't understand search query '$this->mUsertext'\n" );
}
$searchon = wfStrencode( $searchon );
$this->mTitlecond = " MATCH(si_title) AGAINST('$searchon' IN BOOLEAN MODE)";
$this->mTextcond = " (MATCH(si_text) AGAINST('$searchon' IN BOOLEAN MODE) AND cur_is_redirect=0)";
}
function showHit( $row )
{
global $wgUser, $wgOut;
$t = Title::makeName( $row->cur_namespace, $row->cur_title );
$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->mSearchterms ) . ")(.*)/i";
$lineno = 0;
foreach ( $lines as $line ) {
if ( 0 == $contextlines ) { break; }
--$contextlines;
++$lineno;
if ( ! preg_match( $pat1, $line, $m ) ) { continue; }
$pre = $m[1];
if ( 0 == $contextchars ) { $pre = "..."; }
else {
if ( strlen( $pre ) > $contextchars ) {
$pre = "..." . substr( $pre, -$contextchars );
}
}
$pre = wfEscapeHTML( $pre );
if ( count( $m ) < 3 ) { $post = ""; }
else { $post = $m[3]; }
if ( 0 == $contextchars ) { $post = "..."; }
else {
if ( strlen( $post ) > $contextchars ) {
$post = substr( $post, 0, $contextchars ) . "...";
}
}
$post = wfEscapeHTML( $post );
$found = wfEscapeHTML( $m[2] );
$line = "{$pre}{$found}{$post}";
$pat2 = "/(" . implode( "|", $this->mSearchterms ) . ")/i";
$line = preg_replace( $pat2,
"<font color='red'>\\1</font>", $line );
$wgOut->addHTML( "<br /><small>{$lineno}: {$line}</small>\n" );
}
$wgOut->addHTML( "</li>\n" );
}
function goResult()
{
global $wgOut, $wgRequest;
global $wgDisableTextSearch;
$fname = "SearchEngine::goResult";
$search = $wgRequest->getText( "search" );
# First try to go to page as entered.
#
$t = Title::newFromText( $search );
# If the string cannot be used to create a title
if( false == $t ){
$this->showResults();
return;
}
# Exact match? No need to look further.
if ( $t->getNamespace() == NS_SPECIAL || 0 != $t->getArticleID() ) {
$wgOut->redirect( $t->getFullURL() );
return;
}
# Now try all lower case (i.e. first letter capitalized)
#
$t = Title::newFromText( strtolower( $search ) );
if ( 0 != $t->getArticleID() ) {
$wgOut->redirect( $t->getFullURL() );
return;
}
# Now try capitalized string
#
$t = Title::newFromText( ucwords( strtolower( $search ) ) );
if ( 0 != $t->getArticleID() ) {
$wgOut->redirect( $t->getFullURL() );
return;
}
# Now try all upper case
#
$t = Title::newFromText( strtoupper( $search ) );
if ( 0 != $t->getArticleID() ) {
$wgOut->redirect( $t->getFullURL() );
return;
}
# No match, generate an edit URL
$t = Title::newFromText( $this->mUsertext );
$wgOut->addHTML( "<p>" . wfMsg("nogomatch", $t->escapeLocalURL( "action=edit" ) ) . "</p>\n" );
# Try a fuzzy title search
$anyhit = false;
global $wgDisableFuzzySearch;
if(! $wgDisableFuzzySearch ){
foreach( array(NS_MAIN, NS_WP, NS_USER, NS_IMAGE, NS_MEDIAWIKI) as $namespace){
$anyhit |= SearchEngine::doFuzzyTitleSearch( $search, $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;
// to avoid multiple costly SELECTs in case of no memcached
if( $this->all_titles ){
if( isset( $this->all_titles[$aLength][$aNamespace] ) ){
return $this->all_titles[$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 = wfQuery("SELECT cur_title, cur_namespace FROM cur", DB_READ);
$titles = array(); // length, ns, [titles]
while( $obj = wfFetchObject( $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->all_titles = $titles;
if( isset( $titles[$aLength][$aNamespace] ) )
return $titles[$aLength][$aNamespace];
else
return array();
}
}
/* private static */ function SearchEngine_pcmp($a, $b){ return $a[0] - $b[0]; }
?>