xapian-core/matcher/andmaybepostlist.cc

   1 /** @file
   2  * @brief Merged postlist; items from one list, weights from both
   3  */
   4 /* Copyright 1999,2000,2001 BrightStation PLC
   5  * Copyright 2002 Ananova Ltd
   6  * Copyright 2003,2004,2005,2008,2009,2011,2017 Olly Betts
   7  * Copyright 2009 Lemur Consulting Ltd
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of the
  12  * License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  22  * USA
  23  */
  24
  25 #include <config.h>
  26 #include "andmaybepostlist.h"
  27
  28 #include "debuglog.h"
  29 #include "multiandpostlist.h"
  30 #include "omassert.h"
  31
  32 PostList *
  33 AndMaybePostList::process_next_or_skip_to(double w_min, PostList *ret)
  34 {
  35     LOGCALL(MATCH, PostList *, "AndMaybePostList::process_next_or_skip_to", w_min | ret);
  36     handle_prune(l, ret);
  37     if (l->at_end()) {
  38         // once l is over, so is the AND MAYBE
  39         lhead = 0;
  40         RETURN(NULL);
  41     }
  42
  43     lhead = l->get_docid();
  44     if (lhead <= rhead) RETURN(NULL);
  45
  46     bool valid;
  47     check_handling_prune(r, lhead, w_min - lmax, matcher, valid);
  48     if (r->at_end()) {
  49         PostList *tmp = l;
  50         l = NULL;
  51         RETURN(tmp);
  52     }
  53     if (valid) {
  54         rhead = r->get_docid();
  55     } else {
  56         rhead = 0;
  57     }
  58     RETURN(NULL);
  59 }
  60
  61 PostList *
  62 AndMaybePostList::sync_rhs(double w_min)
  63 {
  64     LOGCALL(MATCH, PostList *, "AndMaybePostList::sync_rhs", w_min);
  65     bool valid;
  66     check_handling_prune(r, lhead, w_min - lmax, matcher, valid);
  67     if (r->at_end()) {
  68         PostList *tmp = l;
  69         l = NULL;
  70         RETURN(tmp);
  71     }
  72     if (valid) {
  73         rhead = r->get_docid();
  74     } else {
  75         rhead = 0;
  76     }
  77     RETURN(NULL);
  78 }
  79
  80 PostList *
  81 AndMaybePostList::next(double w_min)
  82 {
  83     LOGCALL(MATCH, PostList *, "AndMaybePostList::next", w_min);
  84     if (w_min > lmax) {
  85         // we can replace the AND MAYBE with an AND
  86         PostList *ret;
  87         LOGLINE(MATCH, "AND MAYBE -> AND");
  88         ret = new MultiAndPostList(l, r, lmax, rmax, matcher, dbsize);
  89         l = r = NULL;
  90         skip_to_handling_prune(ret, std::max(lhead, rhead) + 1, w_min, matcher);
  91         RETURN(ret);
  92     }
  93     RETURN(process_next_or_skip_to(w_min, l->next(w_min - rmax)));
  94 }
  95
  96 PostList *
  97 AndMaybePostList::skip_to(Xapian::docid did, double w_min)
  98 {
  99     LOGCALL(MATCH, PostList *, "AndMaybePostList::skip_to", did | w_min);
 100     if (w_min > lmax) {
 101         // we can replace the AND MAYBE with an AND
 102         PostList *ret;
 103         LOGLINE(MATCH, "AND MAYBE -> AND (in skip_to)");
 104         ret = new MultiAndPostList(l, r, lmax, rmax, matcher, dbsize);
 105         did = std::max(did, std::max(lhead, rhead));
 106         l = r = NULL;
 107         skip_to_handling_prune(ret, did, w_min, matcher);
 108         RETURN(ret);
 109     }
 110
 111     // exit if we're already past the skip point (or at it)
 112     if (did <= lhead) RETURN(NULL);
 113
 114     RETURN(process_next_or_skip_to(w_min, l->skip_to(did, w_min - rmax)));
 115 }
 116
 117 Xapian::doccount
 118 AndMaybePostList::get_termfreq_max() const
 119 {
 120     LOGCALL(MATCH, Xapian::doccount, "AndMaybePostList::get_termfreq_max", NO_ARGS);
 121     // Termfreq is exactly that of left hand branch.
 122     RETURN(l->get_termfreq_max());
 123 }
 124
 125 Xapian::doccount
 126 AndMaybePostList::get_termfreq_min() const
 127 {
 128     LOGCALL(MATCH, Xapian::doccount, "AndMaybePostList::get_termfreq_min", NO_ARGS);
 129     // Termfreq is exactly that of left hand branch.
 130     RETURN(l->get_termfreq_min());
 131 }
 132
 133 Xapian::doccount
 134 AndMaybePostList::get_termfreq_est() const
 135 {
 136     LOGCALL(MATCH, Xapian::doccount, "AndMaybePostList::get_termfreq_est", NO_ARGS);
 137     // Termfreq is exactly that of left hand branch.
 138     RETURN(l->get_termfreq_est());
 139 }
 140
 141 TermFreqs
 142 AndMaybePostList::get_termfreq_est_using_stats(
 143         const Xapian::Weight::Internal & stats) const
 144 {
 145     LOGCALL(MATCH, TermFreqs, "AndMaybePostList::get_termfreq_est_using_stats", stats);
 146     // Termfreq is exactly that of left hand branch.
 147     RETURN(l->get_termfreq_est_using_stats(stats));
 148 }
 149
 150 Xapian::docid
 151 AndMaybePostList::get_docid() const
 152 {
 153     LOGCALL(MATCH, Xapian::docid, "AndMaybePostList::get_docid", NO_ARGS);
 154     Assert(lhead != 0); // check we've started
 155     RETURN(lhead);
 156 }
 157
 158 // only called if we are doing a probabilistic AND MAYBE
 159 double
 160 AndMaybePostList::get_weight() const
 161 {
 162     LOGCALL(MATCH, double, "AndMaybePostList::get_weight", NO_ARGS);
 163     Assert(lhead != 0); // check we've started
 164     if (lhead == rhead) RETURN(l->get_weight() + r->get_weight());
 165     RETURN(l->get_weight());
 166 }
 167
 168 // only called if we are doing a probabilistic operation
 169 double
 170 AndMaybePostList::get_maxweight() const
 171 {
 172     LOGCALL(MATCH, double, "AndMaybePostList::get_maxweight", NO_ARGS);
 173     RETURN(lmax + rmax);
 174 }
 175
 176 double
 177 AndMaybePostList::recalc_maxweight()
 178 {
 179     LOGCALL(MATCH, double, "AndMaybePostList::recalc_maxweight", NO_ARGS);
 180     lmax = l->recalc_maxweight();
 181     rmax = r->recalc_maxweight();
 182     RETURN(AndMaybePostList::get_maxweight());
 183 }
 184
 185 bool
 186 AndMaybePostList::at_end() const
 187 {
 188     LOGCALL(MATCH, bool, "AndMaybePostList::at_end", NO_ARGS);
 189     RETURN(lhead == 0);
 190 }
 191
 192 std::string
 193 AndMaybePostList::get_description() const
 194 {
 195     return "(" + l->get_description() + " AndMaybe " + r->get_description() +
 196            ")";
 197 }
 198
 199 Xapian::termcount
 200 AndMaybePostList::get_doclength() const
 201 {
 202     LOGCALL(MATCH, Xapian::termcount, "AndMaybePostList::get_doclength", NO_ARGS);
 203     Assert(lhead != 0); // check we've started
 204     if (lhead == rhead) AssertEq(l->get_doclength(), r->get_doclength());
 205     RETURN(l->get_doclength());
 206 }
 207
 208 Xapian::termcount
 209 AndMaybePostList::get_unique_terms() const
 210 {
 211     LOGCALL(MATCH, Xapian::termcount, "AndMaybePostList::get_unique_terms", NO_ARGS);
 212     Assert(lhead != 0); // check we've started
 213     if (lhead == rhead) AssertEq(l->get_unique_terms(), r->get_unique_terms());
 214     RETURN(l->get_unique_terms());
 215 }
 216
 217 Xapian::termcount
 218 AndMaybePostList::get_wdf() const
 219 {
 220     LOGCALL(MATCH, Xapian::termcount, "AndMaybePostList::get_wdf", NO_ARGS);
 221     if (lhead == rhead) RETURN(l->get_wdf() + r->get_wdf());
 222     RETURN(l->get_wdf());
 223 }
 224
 225 Xapian::termcount
 226 AndMaybePostList::count_matching_subqs() const
 227 {
 228     LOGCALL(MATCH, Xapian::termcount, "AndMaybePostList::count_matching_subqs", NO_ARGS);
 229     if (lhead == rhead)
 230         RETURN(l->count_matching_subqs() + r->count_matching_subqs());
 231     RETURN(l->count_matching_subqs());
 232 }
 233
 234 void
 235 AndMaybePostList::gather_position_lists(OrPositionList* orposlist)
 236 {
 237     l->gather_position_lists(orposlist);
 238     if (lhead == rhead) r->gather_position_lists(orposlist);
 239 }