summaryrefslogtreecommitdiff
path: root/src/mongo/db/fts/fts_matcher.cpp
blob: 337772b4a6c5d3622a2387b9eb4b75964ab4bcf6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
// fts_matcher.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 <http://www.gnu.org/licenses/>.
*
*    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_matcher.h"
#include "mongo/db/fts/fts_element_iterator.h"
#include "mongo/platform/strcasestr.h"

namespace mongo {

    namespace fts {

        FTSMatcher::FTSMatcher( const FTSQuery& query, const FTSSpec& spec )
            : _query( query ),
              _spec( spec ) {
        }

        /*
         * Checks if the obj contains any of the negTerms, if so returns true, otherwise false
         * @param obj, object to be checked
         */
        bool FTSMatcher::hasNegativeTerm(const BSONObj& obj ) const {
            // called during search. deals with the case in which we have a term
            // flagged for exclusion, i.e. "hello -world" we want to remove all
            // results that include "world"

            if ( _query.getNegatedTerms().size() == 0 ) {
                return false;
            }

            FTSElementIterator it( _spec, obj);

            while ( it.more() ) {
                FTSIteratorValue val = it.next();
                if (_hasNegativeTerm_string( val._language, val._text )) {
                    return true;
                }
            }

            return false;
        }

        /*
         * Checks if any of the negTerms is in the tokenized string
         * @param raw, the raw string to be tokenized
         */
        bool FTSMatcher::_hasNegativeTerm_string( const FTSLanguage* language,
                                                  const string& raw ) const {

            Tokenizer i( *language, raw );
            Stemmer stemmer( *language );
            while ( i.more() ) {
                Token t = i.next();
                if ( t.type != Token::TEXT )
                    continue;
                string word = stemmer.stem( tolowerString( t.data ) );
                if ( _query.getNegatedTerms().count( word ) > 0 )
                    return true;
            }
            return false;
        }

        bool FTSMatcher::phrasesMatch( const BSONObj& obj ) const {
            for (unsigned i = 0; i < _query.getPhr().size(); i++ ) {
                if ( !phraseMatch( _query.getPhr()[i], obj ) ) {
                    return false;
                }
            }

            for (unsigned i = 0; i < _query.getNegatedPhr().size(); i++ ) {
                if ( phraseMatch( _query.getNegatedPhr()[i], obj ) ) {
                    return false;
                }
            }

            return true;
        }

        /**
         * Checks if phrase is exactly matched in obj, returns true if so, false otherwise
         * @param phrase, the string to be matched
         * @param obj, document in the collection to match against
         */
        bool FTSMatcher::phraseMatch( const string& phrase, const BSONObj& obj ) const {
            FTSElementIterator it( _spec, obj);

            while ( it.more() ) {
                FTSIteratorValue val = it.next();
                if (_phraseMatches( phrase, val._text )) {
                    return true;
                }
            }

            return false;
        }

        /*
         * Looks for phrase in a raw string
         * @param phrase, phrase to match
         * @param haystack, raw string to be parsed
         */
        bool FTSMatcher::_phraseMatches( const string& phrase, const string& haystack ) const {
            return strcasestr( haystack.c_str(), phrase.c_str() ) != NULL;
        }
    }
}