1 /* mergepostlist.cc: merge postlists from different databases
2 *
3 * Copyright 1999,2000,2001 BrightStation PLC
4 * Copyright 2002 Ananova Ltd
5 * Copyright 2002,2003,2004,2006,2008,2009,2011,2015,2016 Olly Betts
6 * Copyright 2007,2009 Lemur Consulting Ltd
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
21 * USA
22 */
23
24 #include <config.h>
25 #include "mergepostlist.h"
26
27 #include "multimatch.h"
28 #include "api/emptypostlist.h"
29 #include "branchpostlist.h"
30 #include "debuglog.h"
31 #include "omassert.h"
32 #include "valuestreamdocument.h"
33
34 #include "xapian/error.h"
35
36 // NB don't prune - even with one sublist we still translate docids...
37
~MergePostList()38 MergePostList::~MergePostList()
39 {
40 LOGCALL_DTOR(MATCH, "MergePostList");
41 std::vector<PostList *>::const_iterator i;
42 for (i = plists.begin(); i != plists.end(); ++i) {
43 delete *i;
44 }
45 }
46
47 PostList *
next(double w_min)48 MergePostList::next(double w_min)
49 {
50 LOGCALL(MATCH, PostList *, "MergePostList::next", w_min);
51 LOGVALUE(MATCH, current);
52 if (current == -1) current = 0;
53 while (true) {
54 // FIXME: should skip over Remote matchers which aren't ready yet
55 // and come back to them later...
56 next_handling_prune(plists[current], w_min, matcher);
57 if (!plists[current]->at_end()) break;
58 ++current;
59 if (unsigned(current) >= plists.size()) break;
60 vsdoc.new_subdb(current);
61 if (matcher) matcher->recalc_maxweight();
62 }
63 LOGVALUE(MATCH, current);
64 RETURN(NULL);
65 }
66
67 PostList *
skip_to(Xapian::docid did,double w_min)68 MergePostList::skip_to(Xapian::docid did, double w_min)
69 {
70 LOGCALL(MATCH, PostList *, "MergePostList::skip_to", did | w_min);
71 (void)did;
72 (void)w_min;
73 // MergePostList doesn't return documents in docid order, so skip_to
74 // isn't a meaningful operation.
75 throw Xapian::InvalidOperationError("MergePostList doesn't support skip_to");
76 }
77
78 Xapian::termcount
get_wdf() const79 MergePostList::get_wdf() const
80 {
81 LOGCALL(MATCH, Xapian::termcount, "MergePostList::get_wdf", NO_ARGS);
82 RETURN(plists[current]->get_wdf());
83 }
84
85 Xapian::doccount
get_termfreq_max() const86 MergePostList::get_termfreq_max() const
87 {
88 LOGCALL(MATCH, Xapian::doccount, "MergePostList::get_termfreq_max", NO_ARGS);
89 // sum of termfreqs for all children
90 Xapian::doccount total = 0;
91 vector<PostList *>::const_iterator i;
92 for (i = plists.begin(); i != plists.end(); ++i) {
93 total += (*i)->get_termfreq_max();
94 }
95 RETURN(total);
96 }
97
98 Xapian::doccount
get_termfreq_min() const99 MergePostList::get_termfreq_min() const
100 {
101 LOGCALL(MATCH, Xapian::doccount, "MergePostList::get_termfreq_min", NO_ARGS);
102 // sum of termfreqs for all children
103 Xapian::doccount total = 0;
104 vector<PostList *>::const_iterator i;
105 for (i = plists.begin(); i != plists.end(); ++i) {
106 total += (*i)->get_termfreq_min();
107 }
108 RETURN(total);
109 }
110
111 Xapian::doccount
get_termfreq_est() const112 MergePostList::get_termfreq_est() const
113 {
114 LOGCALL(MATCH, Xapian::doccount, "MergePostList::get_termfreq_est", NO_ARGS);
115 // sum of termfreqs for all children
116 Xapian::doccount total = 0;
117 vector<PostList *>::const_iterator i;
118 for (i = plists.begin(); i != plists.end(); ++i) {
119 total += (*i)->get_termfreq_est();
120 }
121 RETURN(total);
122 }
123
124 Xapian::docid
get_docid() const125 MergePostList::get_docid() const
126 {
127 LOGCALL(MATCH, Xapian::docid, "MergePostList::get_docid", NO_ARGS);
128 Assert(current != -1);
129 // FIXME: this needs fixing so we can prune plists - see MultiPostlist
130 // for code which does this...
131 RETURN((plists[current]->get_docid() - 1) * plists.size() + current + 1);
132 }
133
134 double
get_weight() const135 MergePostList::get_weight() const
136 {
137 LOGCALL(MATCH, double, "MergePostList::get_weight", NO_ARGS);
138 Assert(current != -1);
139 RETURN(plists[current]->get_weight());
140 }
141
142 const string *
get_sort_key() const143 MergePostList::get_sort_key() const
144 {
145 LOGCALL(MATCH, const string *, "MergePostList::get_sort_key", NO_ARGS);
146 Assert(current != -1);
147 RETURN(plists[current]->get_sort_key());
148 }
149
150 const string *
get_collapse_key() const151 MergePostList::get_collapse_key() const
152 {
153 LOGCALL(MATCH, const string *, "MergePostList::get_collapse_key", NO_ARGS);
154 Assert(current != -1);
155 RETURN(plists[current]->get_collapse_key());
156 }
157
158 double
get_maxweight() const159 MergePostList::get_maxweight() const
160 {
161 LOGCALL(MATCH, double, "MergePostList::get_maxweight", NO_ARGS);
162 RETURN(w_max);
163 }
164
165 double
recalc_maxweight()166 MergePostList::recalc_maxweight()
167 {
168 LOGCALL(MATCH, double, "MergePostList::recalc_maxweight", NO_ARGS);
169 w_max = 0;
170 vector<PostList *>::iterator i;
171 for (i = plists.begin(); i != plists.end(); ++i) {
172 double w = (*i)->recalc_maxweight();
173 if (w > w_max) w_max = w;
174 }
175 RETURN(w_max);
176 }
177
178 bool
at_end() const179 MergePostList::at_end() const
180 {
181 LOGCALL(MATCH, bool, "MergePostList::at_end", NO_ARGS);
182 Assert(current != -1);
183 RETURN(unsigned(current) >= plists.size());
184 }
185
186 string
get_description() const187 MergePostList::get_description() const
188 {
189 string desc = "( Merge ";
190 vector<PostList *>::const_iterator i;
191 for (i = plists.begin(); i != plists.end(); ++i) {
192 desc += (*i)->get_description() + " ";
193 }
194 return desc + ")";
195 }
196
197 Xapian::termcount
get_doclength() const198 MergePostList::get_doclength() const
199 {
200 LOGCALL(MATCH, Xapian::termcount, "MergePostList::get_doclength", NO_ARGS);
201 Assert(current != -1);
202 RETURN(plists[current]->get_doclength());
203 }
204
205 Xapian::termcount
get_unique_terms() const206 MergePostList::get_unique_terms() const
207 {
208 LOGCALL(MATCH, Xapian::termcount, "MergePostList::get_unique_terms", NO_ARGS);
209 Assert(current != -1);
210 RETURN(plists[current]->get_unique_terms());
211 }
212
213 Xapian::termcount
count_matching_subqs() const214 MergePostList::count_matching_subqs() const
215 {
216 LOGCALL(MATCH, Xapian::termcount, "MergePostList::count_matching_subqs", NO_ARGS);
217 RETURN(plists[current]->count_matching_subqs());
218 }
219