// fts_query.cpp
/**
* Copyright (C) 2012 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#include "mongo/pch.h"
#include "mongo/db/fts/fts_query.h"
#include "mongo/db/fts/tokenizer.h"
#include "mongo/util/mongoutils/str.h"
#include "mongo/util/stringutils.h"
namespace mongo {
namespace fts {
using namespace mongoutils;
Status FTSQuery::parse(const string& query, const string& language) {
_search = query;
_language = language;
const StopWords* stopWords = StopWords::getStopWords( language );
Stemmer stemmer( language );
bool inNegation = false;
bool inPhrase = false;
unsigned quoteOffset = 0;
Tokenizer i( _language, query );
while ( i.more() ) {
Token t = i.next();
if ( t.type == Token::TEXT ) {
string s = t.data.toString();
if ( inPhrase && inNegation ) {
// don't add term
}
else {
_addTerm( stopWords, stemmer, s, inNegation );
}
if ( inNegation && !inPhrase )
inNegation = false;
}
else if ( t.type == Token::DELIMITER ) {
char c = t.data[0];
if ( c == '-' ) {
if ( !inPhrase && t.previousWhiteSpace ) {
// phrases can be negated, and terms not in phrases can be negated.
// terms in phrases can not be negated.
inNegation = true;
}
}
else if ( c == '"' ) {
if ( inPhrase ) {
// end of a phrase
unsigned phraseStart = quoteOffset + 1;
unsigned phraseLength = t.offset - phraseStart;
StringData phrase = StringData( query ).substr( phraseStart,
phraseLength );
if ( inNegation )
_negatedPhrases.push_back( tolowerString( phrase ) );
else
_phrases.push_back( tolowerString( phrase ) );
inNegation = false;
inPhrase = false;
}
else {
// start of a phrase
inPhrase = true;
quoteOffset = t.offset;
}
}
}
else {
abort();
}
}
return Status::OK();
}
void FTSQuery::_addTerm( const StopWords* sw, Stemmer& stemmer, const string& term, bool negated ) {
string word = tolowerString( term );
if ( sw->isStopWord( word ) )
return;
word = stemmer.stem( word );
if ( negated )
_negatedTerms.insert( word );
else
_terms.push_back( word );
}
namespace {
void _debugHelp( stringstream& ss, const set& s, const string& sep ) {
bool first = true;
for ( set::const_iterator i = s.begin(); i != s.end(); ++i ) {
if ( first )
first = false;
else
ss << sep;
ss << *i;
}
}
void _debugHelp( stringstream& ss, const vector& v, const string& sep ) {
set s( v.begin(), v.end() );
_debugHelp( ss, s, sep );
}
void _debugHelp( stringstream& ss, const unordered_set& v, const string& sep ) {
set s( v.begin(), v.end() );
_debugHelp( ss, s, sep );
}
}
string FTSQuery::toString() const {
stringstream ss;
ss << "FTSQuery\n";
ss << " terms: ";
_debugHelp( ss, getTerms(), ", " );
ss << "\n";
ss << " negated terms: ";
_debugHelp( ss, getNegatedTerms(), ", " );
ss << "\n";
ss << " phrases: ";
_debugHelp( ss, getPhr(), ", " );
ss << "\n";
ss << " negated phrases: ";
_debugHelp( ss, getNegatedPhr(), ", " );
ss << "\n";
return ss.str();
}
string FTSQuery::debugString() const {
stringstream ss;
_debugHelp( ss, getTerms(), "|" );
ss << "||";
_debugHelp( ss, getNegatedTerms(), "|" );
ss << "||";
_debugHelp( ss, getPhr(), "|" );
ss << "||";
_debugHelp( ss, getNegatedPhr(), "|" );
return ss.str();
}
}
}