1 /** @file
2 * @brief Xapian::Weight base class
3 */
4 /* Copyright (C) 2007,2008,2009,2014,2017,2019 Olly Betts
5 * Copyright (C) 2009 Lemur Consulting Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <config.h>
23
24 #include "xapian/weight.h"
25
26 #include "weightinternal.h"
27
28 #include "omassert.h"
29 #include "debuglog.h"
30
31 #include "xapian/error.h"
32
33 using namespace std;
34
35 namespace Xapian {
36
37 void
init_(const Internal & stats,Xapian::termcount query_length)38 Weight::init_(const Internal & stats, Xapian::termcount query_length)
39 {
40 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length);
41 collection_size_ = stats.collection_size;
42 rset_size_ = stats.rset_size;
43 if (stats_needed & AVERAGE_LENGTH)
44 average_length_ = stats.get_average_length();
45 if (stats_needed & DOC_LENGTH_MAX)
46 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
47 if (stats_needed & DOC_LENGTH_MIN)
48 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
49 collectionfreq_ = 0;
50 wdf_upper_bound_ = 0;
51 termfreq_ = 0;
52 reltermfreq_ = 0;
53 query_length_ = query_length;
54 wqf_ = 1;
55 init(0.0);
56 }
57
58 void
init_(const Internal & stats,Xapian::termcount query_length,const string & term,Xapian::termcount wqf,double factor)59 Weight::init_(const Internal & stats, Xapian::termcount query_length,
60 const string & term, Xapian::termcount wqf, double factor)
61 {
62 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length | term | wqf | factor);
63 collection_size_ = stats.collection_size;
64 rset_size_ = stats.rset_size;
65 if (stats_needed & AVERAGE_LENGTH)
66 average_length_ = stats.get_average_length();
67 if (stats_needed & DOC_LENGTH_MAX)
68 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
69 if (stats_needed & DOC_LENGTH_MIN)
70 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
71 if (stats_needed & WDF_MAX)
72 wdf_upper_bound_ = stats.db.get_wdf_upper_bound(term);
73 if (stats_needed & (TERMFREQ | RELTERMFREQ | COLLECTION_FREQ)) {
74 bool ok = stats.get_stats(term,
75 termfreq_, reltermfreq_, collectionfreq_);
76 (void)ok;
77 Assert(ok);
78 }
79 query_length_ = query_length;
80 wqf_ = wqf;
81 init(factor);
82 }
83
84 void
init_(const Internal & stats,Xapian::termcount query_length,double factor,Xapian::doccount termfreq,Xapian::doccount reltermfreq,Xapian::termcount collection_freq)85 Weight::init_(const Internal & stats, Xapian::termcount query_length,
86 double factor, Xapian::doccount termfreq,
87 Xapian::doccount reltermfreq, Xapian::termcount collection_freq)
88 {
89 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length | factor | termfreq | reltermfreq | collection_freq);
90 // Synonym case.
91 collection_size_ = stats.collection_size;
92 rset_size_ = stats.rset_size;
93 if (stats_needed & AVERAGE_LENGTH)
94 average_length_ = stats.get_average_length();
95 if (stats_needed & (DOC_LENGTH_MAX | WDF_MAX)) {
96 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
97 // The doclength is an upper bound on the wdf. This is obviously true
98 // for normal terms, but SynonymPostList ensures that it is also true
99 // for synonym terms by clamping the wdf values returned to the
100 // doclength.
101 //
102 // (This clamping is only actually necessary in cases where a constituent
103 // term of the synonym is repeated.)
104 wdf_upper_bound_ = doclength_upper_bound_;
105 }
106 if (stats_needed & DOC_LENGTH_MIN)
107 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
108
109 termfreq_ = termfreq;
110 reltermfreq_ = reltermfreq;
111 query_length_ = query_length;
112 collectionfreq_ = collection_freq;
113 wqf_ = 1;
114 init(factor);
115 }
116
~Weight()117 Weight::~Weight() { }
118
119 string
name() const120 Weight::name() const
121 {
122 return string();
123 }
124
125 string
serialise() const126 Weight::serialise() const
127 {
128 throw Xapian::UnimplementedError("serialise() not supported for this Xapian::Weight subclass");
129 }
130
131 Weight *
unserialise(const string &) const132 Weight::unserialise(const string &) const
133 {
134 throw Xapian::UnimplementedError("unserialise() not supported for this Xapian::Weight subclass");
135 }
136
137 }
138