xapian-core/api/termiterator.cc

   1 /** @file
   2  *  @brief Class for iterating over a list of terms.
   3  */
   4 /* Copyright (C) 2008,2009,2010,2011,2013 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/termiterator.h"
  24
  25 #include "debuglog.h"
  26 #include "omassert.h"
  27 #include "termlist.h"
  28
  29 using namespace std;
  30
  31 namespace Xapian {
  32
  33 void
  34 TermIterator::decref()
  35 {
  36     Assert(internal);
  37     if (--internal->_refs == 0)
  38         delete internal;
  39 }
  40
  41 void
  42 TermIterator::post_advance(Internal * res)
  43 {
  44     if (res) {
  45         // This can happen with iterating allterms from multiple databases.
  46         ++res->_refs;
  47         decref();
  48         internal = res;
  49     }
  50     if (internal->at_end()) {
  51         decref();
  52         internal = NULL;
  53     }
  54 }
  55
  56 TermIterator::TermIterator(Internal *internal_) : internal(internal_)
  57 {
  58     LOGCALL_CTOR(API, "TermIterator", internal_);
  59     if (!internal) return;
  60     try {
  61         ++internal->_refs;
  62         post_advance(internal->next());
  63     } catch (...) {
  64         // The destructor only runs if the constructor completes, so we have to
  65         // take care of cleaning up for ourselves here.
  66         decref();
  67         throw;
  68     }
  69 }
  70
  71 TermIterator::TermIterator(const TermIterator & o)
  72     : internal(o.internal)
  73 {
  74     LOGCALL_CTOR(API, "TermIterator", o);
  75     if (internal)
  76         ++internal->_refs;
  77 }
  78
  79 TermIterator &
  80 TermIterator::operator=(const TermIterator & o)
  81 {
  82     LOGCALL(API, TermIterator &, "TermIterator::operator=", o);
  83     if (o.internal)
  84         ++o.internal->_refs;
  85     if (internal)
  86         decref();
  87     internal = o.internal;
  88     RETURN(*this);
  89 }
  90
  91 string
  92 TermIterator::operator*() const
  93 {
  94     LOGCALL(API, string, "TermIterator::operator*", NO_ARGS);
  95     Assert(internal);
  96     RETURN(internal->get_termname());
  97 }
  98
  99 TermIterator &
 100 TermIterator::operator++()
 101 {
 102     LOGCALL(API, TermIterator &, "TermIterator::operator++", NO_ARGS);
 103     Assert(internal);
 104     post_advance(internal->next());
 105     RETURN(*this);
 106 }
 107
 108 Xapian::termcount
 109 TermIterator::get_wdf() const
 110 {
 111     LOGCALL(API, Xapian::termcount, "TermIterator::get_wdf", NO_ARGS);
 112     Assert(internal);
 113     RETURN(internal->get_wdf());
 114 }
 115
 116 Xapian::doccount
 117 TermIterator::get_termfreq() const
 118 {
 119     LOGCALL(API, Xapian::doccount, "TermIterator::get_termfreq", NO_ARGS);
 120     Assert(internal);
 121     RETURN(internal->get_termfreq());
 122 }
 123
 124 Xapian::termcount
 125 TermIterator::positionlist_count() const
 126 {
 127     LOGCALL(API, Xapian::termcount, "TermIterator::positionlist_count", NO_ARGS);
 128     Assert(internal);
 129     RETURN(internal->positionlist_count());
 130 }
 131
 132 PositionIterator
 133 TermIterator::positionlist_begin() const
 134 {
 135     LOGCALL(API, PositionIterator, "TermIterator::positionlist_begin", NO_ARGS);
 136     Assert(internal);
 137     RETURN(internal->positionlist_begin());
 138 }
 139
 140 void
 141 TermIterator::skip_to(const string & term)
 142 {
 143     LOGCALL_VOID(API, "TermIterator::skip_to", term);
 144     if (internal)
 145         post_advance(internal->skip_to(term));
 146 }
 147
 148 std::string
 149 TermIterator::get_description() const
 150 {
 151 #if 0 // FIXME: Add TermIterator::Internal::get_description() method.
 152     string desc = "TermIterator(";
 153     if (internal)
 154         desc += internal->get_description();
 155     desc += ')';
 156     return desc;
 157 #else
 158     return "TermIterator()";
 159 #endif
 160 }
 161
 162 }