xapian-core/api/postingiterator.cc

   1 /** @file postingiterator.cc
   2  *  @brief Class for iterating over a list of document ids.
   3  */
   4 /* Copyright (C) 2008,2009,2010,2011,2013,2017 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (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 "xapian/postingiterator.h"
  24
  25 #include "api/postingiteratorinternal.h"
  26 #include "debuglog.h"
  27 #include "omassert.h"
  28 #include "postlist.h"
  29
  30 using namespace std;
  31
  32 namespace Xapian {
  33
  34 void
  35 PostingIterator::decref()
  36 {
  37     Assert(internal);
  38     if (--internal->_refs == 0)
  39         delete internal;
  40 }
  41
  42 PostingIterator::PostingIterator(Internal *internal_) : internal(internal_)
  43 {
  44     LOGCALL_CTOR(API, "PostingIterator", internal_);
  45     if (!internal) return;
  46     try {
  47         ++internal->_refs;
  48         if (!internal->next()) {
  49             decref();
  50             internal = NULL;
  51         }
  52     } catch (...) {
  53         // The destructor only runs if the constructor completes, so we have to
  54         // take care of cleaning up for ourselves here.
  55         decref();
  56         throw;
  57     }
  58 }
  59
  60 PostingIterator::PostingIterator(const PostingIterator & o)
  61     : internal(o.internal)
  62 {
  63     LOGCALL_CTOR(API, "PostingIterator", o);
  64     if (internal)
  65         ++internal->_refs;
  66 }
  67
  68 PostingIterator &
  69 PostingIterator::operator=(const PostingIterator & o)
  70 {
  71     LOGCALL(API, PostingIterator &, "PostingIterator::operator=", o);
  72     if (o.internal)
  73         ++o.internal->_refs;
  74     if (internal)
  75         decref();
  76     internal = o.internal;
  77     RETURN(*this);
  78 }
  79
  80 Xapian::docid
  81 PostingIterator::operator*() const
  82 {
  83     LOGCALL(API, Xapian::docid, "PostingIterator::operator*", NO_ARGS);
  84     Assert(internal);
  85     RETURN(internal->get_docid());
  86 }
  87
  88 PostingIterator &
  89 PostingIterator::operator++()
  90 {
  91     LOGCALL(API, PostingIterator &, "PostingIterator::operator++", NO_ARGS);
  92     Assert(internal);
  93     if (!internal->next()) {
  94         decref();
  95         internal = NULL;
  96     }
  97     RETURN(*this);
  98 }
  99
 100 Xapian::termcount
 101 PostingIterator::get_wdf() const
 102 {
 103     LOGCALL(API, Xapian::termcount, "PostingIterator::get_wdf", NO_ARGS);
 104     Assert(internal);
 105     RETURN(internal->get_wdf());
 106 }
 107
 108 Xapian::termcount
 109 PostingIterator::get_doclength() const
 110 {
 111     LOGCALL(API, Xapian::termcount, "PostingIterator::get_doclength", NO_ARGS);
 112     Assert(internal);
 113     RETURN(internal->get_doclength());
 114 }
 115
 116 Xapian::termcount
 117 PostingIterator::get_unique_terms() const
 118 {
 119     LOGCALL(API, Xapian::termcount, "PostingIterator::get_unique_terms", NO_ARGS);
 120     Assert(internal);
 121     RETURN(internal->get_unique_terms());
 122 }
 123
 124 #if 0 // FIXME: TermIterator supports this, so PostingIterator really ought to.
 125 Xapian::termcount
 126 PostingIterator::positionlist_count() const
 127 {
 128     LOGCALL(API, Xapian::termcount, "PostingIterator::positionlist_count", NO_ARGS);
 129     Assert(internal);
 130     RETURN(internal->positionlist_count());
 131 }
 132 #endif
 133
 134 PositionIterator
 135 PostingIterator::positionlist_begin() const
 136 {
 137     LOGCALL(API, PositionIterator, "PostingIterator::positionlist_begin", NO_ARGS);
 138     Assert(internal);
 139     RETURN(PositionIterator(internal->open_position_list()));
 140 }
 141
 142 void
 143 PostingIterator::skip_to(Xapian::docid did)
 144 {
 145     LOGCALL_VOID(API, "PostingIterator::skip_to", did);
 146     if (internal) {
 147         if (!internal->skip_to(did)) {
 148             decref();
 149             internal = NULL;
 150         }
 151     }
 152 }
 153
 154 std::string
 155 PostingIterator::get_description() const
 156 {
 157     string desc = "PostingIterator(";
 158     if (internal)
 159         desc += internal->get_description();
 160     desc += ')';
 161     return desc;
 162 }
 163
 164 }