xapian-core/matcher/mergepostlist.cc

   1 /** @file mergepostlist.cc
   2  * @brief PostList class implementing Query::OP_AND_NOT
   3  */
   4 /* Copyright 2017 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <config.h>
  22
  23 #include "mergepostlist.h"
  24
  25 #include "backends/multi.h"
  26 #include "valuestreamdocument.h"
  27
  28 using namespace std;
  29
  30 MergePostList::~MergePostList()
  31 {
  32     pl = NULL;
  33     for (Xapian::doccount i = 0; i != n_shards; ++i)
  34         delete shard_pls[i];
  35 }
  36
  37 Xapian::doccount
  38 MergePostList::get_termfreq_min() const
  39 {
  40     Xapian::doccount result = 0;
  41     for (Xapian::doccount i = 0; i != n_shards; ++i)
  42         result += shard_pls[i]->get_termfreq_min();
  43     return result;
  44 }
  45
  46 Xapian::doccount
  47 MergePostList::get_termfreq_max() const
  48 {
  49     Xapian::doccount result = 0;
  50     for (Xapian::doccount i = 0; i != n_shards; ++i)
  51         result += shard_pls[i]->get_termfreq_max();
  52     return result;
  53 }
  54
  55 Xapian::doccount
  56 MergePostList::get_termfreq_est() const
  57 {
  58     Xapian::doccount result = 0;
  59     for (Xapian::doccount i = 0; i != n_shards; ++i)
  60         result += shard_pls[i]->get_termfreq_est();
  61     return result;
  62 }
  63
  64 Xapian::docid
  65 MergePostList::get_docid() const
  66 {
  67     return unshard(WrapperPostList::get_docid(), shard, n_shards);
  68 }
  69
  70 const string*
  71 MergePostList::get_sort_key() const
  72 {
  73     return pl->get_sort_key();
  74 }
  75
  76 const string*
  77 MergePostList::get_collapse_key() const
  78 {
  79     return pl->get_collapse_key();
  80 }
  81
  82 bool
  83 MergePostList::at_end() const
  84 {
  85     return shard == n_shards;
  86 }
  87
  88 double
  89 MergePostList::recalc_maxweight()
  90 {
  91     double result = 0;
  92     for (Xapian::doccount i = 0; i != n_shards; ++i) {
  93         result = max(result, shard_pls[i]->recalc_maxweight());
  94     }
  95     return result;
  96 }
  97
  98 TermFreqs
  99 MergePostList::get_termfreq_est_using_stats(const Xapian::Weight::Internal&) const
 100 {
 101     // We're only called by PostListTree which never calls this method.
 102     Assert(false);
 103     return TermFreqs();
 104 }
 105
 106 PostList*
 107 MergePostList::next(double w_min)
 108 {
 109     while (true) {
 110         PostList* result = pl->next(w_min);
 111         if (result) {
 112             delete pl;
 113             pl = result;
 114             shard_pls[shard] = pl;
 115         }
 116         if (!pl->at_end() || ++shard == n_shards) {
 117             break;
 118         }
 119         // Move on to the next shard.
 120         vsdoc.new_shard(shard);
 121         pl = shard_pls[shard];
 122     }
 123     return NULL;
 124 }
 125
 126 PostList*
 127 MergePostList::skip_to(Xapian::docid, double)
 128 {
 129     // We're only called by PostListTree which never calls this method.
 130     Assert(false);
 131     return NULL;
 132 }
 133
 134 string
 135 MergePostList::get_description() const
 136 {
 137     string desc = "MergePostList(";
 138     for (Xapian::doccount i = 0; i != n_shards; ++i) {
 139         desc += shard_pls[i]->get_description();
 140         desc += ',';
 141     }
 142     desc.back() = ')';
 143     return desc;
 144 }