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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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/platform/basic.h"
#include "mongo/db/fts/fts_query_impl.h"
#include <memory>
#include "mongo/db/fts/fts_query_parser.h"
#include "mongo/db/fts/fts_spec.h"
#include "mongo/db/fts/fts_tokenizer.h"
#include "mongo/util/str.h"
namespace mongo {
namespace fts {
using std::set;
using std::string;
using std::stringstream;
using std::vector;
Status FTSQueryImpl::parse(TextIndexVersion textIndexVersion) {
const FTSLanguage* ftsLanguage;
try {
ftsLanguage = &FTSLanguage::make(getLanguage(), textIndexVersion);
} catch (const DBException& e) {
return e.toStatus();
}
// Build a space delimited list of words to have the FtsTokenizer tokenize
string positiveTermSentence;
string negativeTermSentence;
bool inNegation = false;
bool inPhrase = false;
unsigned quoteOffset = 0;
FTSQueryParser i(getQuery());
while (i.more()) {
QueryToken t = i.next();
if (t.type == QueryToken::TEXT) {
string s = t.data.toString();
if (inPhrase && inNegation) {
// don't add term
} else {
// A negation should only continue until the next whitespace character. For example,
// "-foo" should negate "foo", "- foo" should not negate "foo", and "-foo-bar"
// should negate both "foo" and "bar".
if (inNegation && t.previousWhiteSpace) {
inNegation = false;
}
if (inNegation) {
negativeTermSentence.append(s);
negativeTermSentence.push_back(' ');
} else {
positiveTermSentence.append(s);
positiveTermSentence.push_back(' ');
}
}
} else if (t.type == QueryToken::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(getQuery()).substr(phraseStart, phraseLength);
if (inNegation) {
_negatedPhrases.push_back(phrase.toString());
} else {
_positivePhrases.push_back(phrase.toString());
}
// Do not reset 'inNegation' here, since a negation should continue until the
// next whitespace character. For example, '-"foo bar"-"baz quux"' should negate
// both the phrase "foo bar" and the phrase "baz quux".
inPhrase = false;
} else {
// start of a phrase
inPhrase = true;
// A "-" should only be treated as a negation if there is no whitespace between
// the "-" and the start of the phrase.
if (inNegation && t.previousWhiteSpace) {
inNegation = false;
}
quoteOffset = t.offset;
}
}
} else {
MONGO_UNREACHABLE;
}
}
std::unique_ptr<FTSTokenizer> tokenizer = ftsLanguage->createTokenizer();
_addTerms(tokenizer.get(), positiveTermSentence, false);
_addTerms(tokenizer.get(), negativeTermSentence, true);
return Status::OK();
}
std::unique_ptr<FTSQuery> FTSQueryImpl::clone() const {
auto clonedQuery = std::make_unique<FTSQueryImpl>();
clonedQuery->setQuery(getQuery());
clonedQuery->setLanguage(getLanguage());
clonedQuery->setCaseSensitive(getCaseSensitive());
clonedQuery->setDiacriticSensitive(getDiacriticSensitive());
clonedQuery->_positiveTerms = _positiveTerms;
clonedQuery->_negatedTerms = _negatedTerms;
clonedQuery->_positivePhrases = _positivePhrases;
clonedQuery->_negatedPhrases = _negatedPhrases;
clonedQuery->_termsForBounds = _termsForBounds;
return std::move(clonedQuery);
}
void FTSQueryImpl::_addTerms(FTSTokenizer* tokenizer, const string& sentence, bool negated) {
tokenizer->reset(sentence.c_str(), FTSTokenizer::kFilterStopWords);
auto& activeTerms = negated ? _negatedTerms : _positiveTerms;
// First, get all the terms for indexing, ie, lower cased words
// If we are case-insensitive, we can also used this for positive, and negative terms
// Some terms may be expanded into multiple words in some non-English languages
while (tokenizer->moveNext()) {
string word = tokenizer->get().toString();
if (!negated) {
_termsForBounds.insert(word);
}
// Compute the string corresponding to 'token' that will be used for the matcher.
// For case and diacritic insensitive queries, this is the same string as 'boundsTerm'
// computed above.
if (!getCaseSensitive() && !getDiacriticSensitive()) {
activeTerms.insert(word);
}
}
if (!getCaseSensitive() && !getDiacriticSensitive()) {
return;
}
FTSTokenizer::Options newOptions = FTSTokenizer::kFilterStopWords;
if (getCaseSensitive()) {
newOptions |= FTSTokenizer::kGenerateCaseSensitiveTokens;
}
if (getDiacriticSensitive()) {
newOptions |= FTSTokenizer::kGenerateDiacriticSensitiveTokens;
}
tokenizer->reset(sentence.c_str(), newOptions);
// If we want case-sensitivity or diacritic sensitivity, get the correct token.
while (tokenizer->moveNext()) {
string word = tokenizer->get().toString();
activeTerms.insert(word);
}
}
BSONObj FTSQueryImpl::toBSON() const {
BSONObjBuilder bob;
bob.append("terms", getPositiveTerms());
bob.append("negatedTerms", getNegatedTerms());
bob.append("phrases", getPositivePhr());
bob.append("negatedPhrases", getNegatedPhr());
return bob.obj();
}
} // namespace fts
} // namespace mongo
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