1 | /**********************************************************************
|
---|
2 | *
|
---|
3 | * phrasesearch.cpp -- tools to search for a phrase in a larger text
|
---|
4 | * Copyright (C) 1999 DigiLib Systems Limited
|
---|
5 | *
|
---|
6 | * A component of the Greenstone digital library software
|
---|
7 | * from the New Zealand Digital Library Project at the
|
---|
8 | * University of Waikato, New Zealand.
|
---|
9 | *
|
---|
10 | * This program is free software; you can redistribute it and/or modify
|
---|
11 | * it under the terms of the GNU General Public License as published by
|
---|
12 | * the Free Software Foundation; either version 2 of the License, or
|
---|
13 | * (at your option) any later version.
|
---|
14 | *
|
---|
15 | * This program is distributed in the hope that it will be useful,
|
---|
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
18 | * GNU General Public License for more details.
|
---|
19 | *
|
---|
20 | * You should have received a copy of the GNU General Public License
|
---|
21 | * along with this program; if not, write to the Free Software
|
---|
22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
---|
23 | *
|
---|
24 | * $Id: phrasesearch.cpp 534 1999-09-07 04:57:43Z sjboddie $
|
---|
25 | *
|
---|
26 | *********************************************************************/
|
---|
27 |
|
---|
28 | /*
|
---|
29 | $Log$
|
---|
30 | Revision 1.6 1999/09/07 04:57:23 sjboddie
|
---|
31 | added gpl notice
|
---|
32 |
|
---|
33 | Revision 1.5 1999/08/31 22:45:12 rjmcnab
|
---|
34 | fixed small problem
|
---|
35 |
|
---|
36 | Revision 1.4 1999/07/16 00:15:48 sjboddie
|
---|
37 | changed to use termfreqclassarray type
|
---|
38 |
|
---|
39 | Revision 1.3 1999/07/07 06:19:45 rjmcnab
|
---|
40 | Added ability to combine two or more independant queries.
|
---|
41 |
|
---|
42 | Revision 1.2 1999/07/01 09:25:54 rjmcnab
|
---|
43 | fixed bug :-^
|
---|
44 |
|
---|
45 | Revision 1.1 1999/07/01 04:01:46 rjmcnab
|
---|
46 | Initial revision.
|
---|
47 |
|
---|
48 | */
|
---|
49 |
|
---|
50 |
|
---|
51 | #include "phrasesearch.h"
|
---|
52 | #include "gsdlunicode.h"
|
---|
53 |
|
---|
54 | inline unsigned char *parse_nonword_word (unsigned char *here, unsigned char *end,
|
---|
55 | text_t &word) {
|
---|
56 | int c_len = 0;
|
---|
57 | unsigned short c = 0;
|
---|
58 |
|
---|
59 | word.clear();
|
---|
60 |
|
---|
61 | // parse non word
|
---|
62 | while (here <= end) {
|
---|
63 | c_len = parse_utf8_char (here, end, &c);
|
---|
64 | if (c == '(') {
|
---|
65 | // found a note, look for '}'
|
---|
66 | while (here <= end && c != ')') {
|
---|
67 | c_len = parse_utf8_char (here, end, &c);
|
---|
68 | here += c_len;
|
---|
69 | }
|
---|
70 | }
|
---|
71 | if (c == '{') {
|
---|
72 | // found a composite character, look for '}'
|
---|
73 | while (here <= end && c != '}') {
|
---|
74 | c_len = parse_utf8_char (here, end, &c);
|
---|
75 | here += c_len;
|
---|
76 | }
|
---|
77 | }
|
---|
78 | if (is_unicode_letdig(c)) {
|
---|
79 | while (c_len > 0) {
|
---|
80 | // this is in a word
|
---|
81 | word.push_back(*here);
|
---|
82 | here++; c_len--;
|
---|
83 | }
|
---|
84 | break;
|
---|
85 | }
|
---|
86 | here += c_len;
|
---|
87 | }
|
---|
88 |
|
---|
89 | // parse word
|
---|
90 | while (here <= end) {
|
---|
91 | c_len = parse_utf8_char (here, end, &c);
|
---|
92 | if (!is_unicode_letdig(c)) {
|
---|
93 | here += c_len; // it is ok to skip a nonword character
|
---|
94 | break;
|
---|
95 | }
|
---|
96 | while (c_len > 0) {
|
---|
97 | word.push_back(*here);
|
---|
98 | here++; c_len--;
|
---|
99 | }
|
---|
100 | }
|
---|
101 |
|
---|
102 | return here;
|
---|
103 | }
|
---|
104 |
|
---|
105 |
|
---|
106 | bool doc_phrase_search (unsigned char *doc, int doclen,
|
---|
107 | const termfreqclassarray &phrase) {
|
---|
108 | // note: this uses the most braindead search routine :-)
|
---|
109 | // however its not so bad as there shouldn't be many partial
|
---|
110 | // matches
|
---|
111 |
|
---|
112 | // a null phrase matches anything
|
---|
113 | if (phrase.empty()) return true;
|
---|
114 |
|
---|
115 | // if there is nothing then there can't be a match
|
---|
116 | if (doc == NULL || doclen == 0) return false;
|
---|
117 |
|
---|
118 | text_t doc_word;
|
---|
119 | doc_word.reserve (16);
|
---|
120 |
|
---|
121 | bool first = true;
|
---|
122 |
|
---|
123 | unsigned char *doc_here = doc;
|
---|
124 | unsigned char *doc_herefirstword = doc;
|
---|
125 | unsigned char *doc_end = doc+doclen-1; // unitool conventions :-/
|
---|
126 |
|
---|
127 | while (doc_here <= doc_end) {
|
---|
128 | first = true;
|
---|
129 |
|
---|
130 | // there will be at least one member of phrase (see above)
|
---|
131 | termfreqclassarray::const_iterator phrase_here = phrase.begin();
|
---|
132 | termfreqclassarray::const_iterator phrase_end = phrase.end();
|
---|
133 | do {
|
---|
134 | // get the next non-word ... and ignore it, then get the next word
|
---|
135 | doc_here = parse_nonword_word (doc_here, doc_end, doc_word);
|
---|
136 | if (first) {doc_herefirstword = doc_here; first = false;}
|
---|
137 |
|
---|
138 | // break if this word is not the next in the phrase
|
---|
139 | if ((*phrase_here).utf8equivterms.find (doc_word) ==
|
---|
140 | (*phrase_here).utf8equivterms.end()) break;
|
---|
141 |
|
---|
142 | phrase_here++;
|
---|
143 | } while (doc_here <= doc_end && phrase_here != phrase_end);
|
---|
144 |
|
---|
145 | // see if we found a phrase
|
---|
146 | if (phrase_here == phrase_end) return true;
|
---|
147 |
|
---|
148 | doc_here = doc_herefirstword; // set the counter back
|
---|
149 | }
|
---|
150 |
|
---|
151 | return false;
|
---|
152 | }
|
---|
153 |
|
---|
154 |
|
---|
155 | // looks for the stemmed phrase in the metadata or text associated with
|
---|
156 | // an OID. This function has not been coded with all situations in mind
|
---|
157 | bool OID_phrase_search (mgsearchclass &mgsearch,
|
---|
158 | gdbmclass &gdbm,
|
---|
159 | const text_t &index,
|
---|
160 | const text_t &subcollection,
|
---|
161 | const text_t &language,
|
---|
162 | const text_t &longindex,
|
---|
163 | const text_t &collection,
|
---|
164 | const termfreqclassarray &phrase,
|
---|
165 | int docnum) {
|
---|
166 | // disect the long index to find out where the text should come from
|
---|
167 | text_t level, gran;
|
---|
168 | text_t::const_iterator longindex_here = longindex.begin();
|
---|
169 | text_t::const_iterator longindex_end = longindex.end();
|
---|
170 | longindex_here = getdelimitstr (longindex_here, longindex_end, ':', level);
|
---|
171 | longindex_here = getdelimitstr (longindex_here, longindex_end, ':', gran);
|
---|
172 |
|
---|
173 | if (gran.empty()) return false;
|
---|
174 |
|
---|
175 | if (gran == "text") {
|
---|
176 | char *doc = NULL;
|
---|
177 | int doclen = 0;
|
---|
178 |
|
---|
179 | // get text from mg.
|
---|
180 | if (!mgsearch.mgdocument (index, subcollection, language, collection,
|
---|
181 | docnum, doc, doclen)) return false;
|
---|
182 | return doc_phrase_search ((unsigned char *)doc, doclen, phrase);
|
---|
183 | }
|
---|
184 |
|
---|
185 | // get OID
|
---|
186 | char *metadata = NULL;
|
---|
187 | text_t::size_type metadata_len = 0;
|
---|
188 | infodbclass docnum_info;
|
---|
189 | infodbclass OID_info;
|
---|
190 |
|
---|
191 | if (!gdbm.getinfo (docnum, docnum_info)) return false;
|
---|
192 | text_t &OID = docnum_info["section"];
|
---|
193 | if (OID.empty()) return false;
|
---|
194 |
|
---|
195 | // get field
|
---|
196 | if (!gdbm.getinfo (OID, OID_info)) return false;
|
---|
197 |
|
---|
198 | bool result = false;
|
---|
199 | text_tarray *tarr_ptr = OID_info.getmultinfo (gran);
|
---|
200 | if (tarr_ptr != NULL ) {
|
---|
201 | text_tarray::const_iterator subvalue_here = (*tarr_ptr).begin();
|
---|
202 | text_tarray::const_iterator subvalue_end = (*tarr_ptr).end();
|
---|
203 | while (subvalue_here != subvalue_end) {
|
---|
204 | if (subvalue_here != NULL) {
|
---|
205 | metadata = (to_utf8(*subvalue_here)).getcarr(metadata_len);
|
---|
206 | result = doc_phrase_search ((unsigned char *)metadata, metadata_len, phrase);
|
---|
207 | delete [] metadata;
|
---|
208 |
|
---|
209 | if (result) return true;
|
---|
210 | }
|
---|
211 |
|
---|
212 | subvalue_here++;
|
---|
213 | }
|
---|
214 | }
|
---|
215 |
|
---|
216 | return result;
|
---|
217 | }
|
---|