1 /** @file weight.cc
2 * @brief Xapian::Weight base class
3 */
4 /* Copyright (C) 2007,2008,2009 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 "debuglog.h"
29
30 #include "xapian/error.h"
31
32 using namespace std;
33
34 namespace Xapian {
35
36 void
init_(const Internal & stats,Xapian::termcount query_length)37 Weight::init_(const Internal & stats, Xapian::termcount query_length)
38 {
39 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length);
40 collection_size_ = stats.collection_size;
41 rset_size_ = stats.rset_size;
42 if (stats_needed & AVERAGE_LENGTH)
43 average_length_ = stats.get_average_length();
44 if (stats_needed & DOC_LENGTH_MAX)
45 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
46 if (stats_needed & DOC_LENGTH_MIN)
47 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
48 wdf_upper_bound_ = 0;
49 termfreq_ = 0;
50 reltermfreq_ = 0;
51 query_length_ = query_length;
52 wqf_ = 1;
53 init(0.0);
54 }
55
56 void
init_(const Internal & stats,Xapian::termcount query_length,const string & term,Xapian::termcount wqf,double factor)57 Weight::init_(const Internal & stats, Xapian::termcount query_length,
58 const string & term, Xapian::termcount wqf, double factor)
59 {
60 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length | term | wqf | factor);
61 collection_size_ = stats.collection_size;
62 rset_size_ = stats.rset_size;
63 if (stats_needed & AVERAGE_LENGTH)
64 average_length_ = stats.get_average_length();
65 if (stats_needed & DOC_LENGTH_MAX)
66 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
67 if (stats_needed & DOC_LENGTH_MIN)
68 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
69 if (stats_needed & WDF_MAX)
70 wdf_upper_bound_ = stats.db.get_wdf_upper_bound(term);
71 if (stats_needed & TERMFREQ)
72 termfreq_ = stats.get_termfreq(term);
73 if (stats_needed & RELTERMFREQ)
74 reltermfreq_ = stats.get_reltermfreq(term);
75 query_length_ = query_length;
76 wqf_ = wqf;
77 init(factor);
78 }
79
80 void
init_(const Internal & stats,Xapian::termcount query_length,double factor,Xapian::doccount termfreq,Xapian::doccount reltermfreq)81 Weight::init_(const Internal & stats, Xapian::termcount query_length,
82 double factor, Xapian::doccount termfreq,
83 Xapian::doccount reltermfreq)
84 {
85 LOGCALL_VOID(MATCH, "Weight::init_", stats | query_length | factor | termfreq | reltermfreq);
86 // Synonym case.
87 collection_size_ = stats.collection_size;
88 rset_size_ = stats.rset_size;
89 if (stats_needed & AVERAGE_LENGTH)
90 average_length_ = stats.get_average_length();
91 if (stats_needed & DOC_LENGTH_MAX)
92 doclength_upper_bound_ = stats.db.get_doclength_upper_bound();
93 if (stats_needed & DOC_LENGTH_MIN)
94 doclength_lower_bound_ = stats.db.get_doclength_lower_bound();
95
96 // The doclength is an upper bound on the wdf. This is obviously true for
97 // normal terms, but SynonymPostList ensures that it is also true for
98 // synonym terms by clamping the wdf values returned to the doclength.
99 //
100 // (This clamping is only actually necessary in cases where a constituent
101 // term of the synonym is repeated.)
102 if (stats_needed & WDF_MAX)
103 wdf_upper_bound_ = stats.db.get_doclength_upper_bound();
104
105 termfreq_ = termfreq;
106 reltermfreq_ = reltermfreq;
107 query_length_ = query_length;
108 wqf_ = 1;
109 init(factor);
110 }
111
~Weight()112 Weight::~Weight() { }
113
114 string
name() const115 Weight::name() const
116 {
117 return string();
118 }
119
120 string
serialise() const121 Weight::serialise() const
122 {
123 throw Xapian::UnimplementedError("serialise() not supported for this Xapian::Weight subclass");
124 }
125
126 Weight *
unserialise(const string &) const127 Weight::unserialise(const string &) const
128 {
129 throw Xapian::UnimplementedError("unserialise() not supported for this Xapian::Weight subclass");
130 }
131
132 }
133