xapian-core/api/positioniterator.cc

   1 /** @file
   2  *  @brief Class for iterating over term positions.
   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/positioniterator.h"
  24
  25 #include "debuglog.h"
  26 #include "omassert.h"
  27 #include "backends/positionlist.h"
  28
  29 using namespace std;
  30
  31 namespace Xapian {
  32
  33 void
  34 PositionIterator::decref()
  35 {
  36     Assert(internal);
  37     if (--internal->_refs == 0)
  38         delete internal;
  39 }
  40
  41 PositionIterator::PositionIterator(Internal *internal_) : internal(internal_)
  42 {
  43     LOGCALL_CTOR(API, "PositionIterator", internal_);
  44     Assert(internal);
  45     ++internal->_refs;
  46     try {
  47         if (!internal->next()) {
  48             decref();
  49             internal = NULL;
  50         }
  51     } catch (...) {
  52         // The destructor only runs if the constructor completes, so we have to
  53         // take care of cleaning up for ourselves here.
  54         decref();
  55         throw;
  56     }
  57 }
  58
  59 PositionIterator::PositionIterator(const PositionIterator & o)
  60     : internal(o.internal)
  61 {
  62     LOGCALL_CTOR(API, "PositionIterator", o);
  63     if (internal)
  64         ++internal->_refs;
  65 }
  66
  67 PositionIterator &
  68 PositionIterator::operator=(const PositionIterator & o)
  69 {
  70     LOGCALL(API, PositionIterator &, "PositionIterator::operator=", o);
  71     if (o.internal)
  72         ++o.internal->_refs;
  73     if (internal)
  74         decref();
  75     internal = o.internal;
  76     RETURN(*this);
  77 }
  78
  79 Xapian::termpos
  80 PositionIterator::operator*() const
  81 {
  82     LOGCALL(API, Xapian::termpos, "PositionIterator::operator*", NO_ARGS);
  83     Assert(internal);
  84     RETURN(internal->get_position());
  85 }
  86
  87 PositionIterator &
  88 PositionIterator::operator++()
  89 {
  90     LOGCALL(API, PositionIterator &, "PositionIterator::operator++", NO_ARGS);
  91     Assert(internal);
  92     if (!internal->next()) {
  93         decref();
  94         internal = NULL;
  95     }
  96     RETURN(*this);
  97 }
  98
  99 void
 100 PositionIterator::skip_to(Xapian::termpos pos)
 101 {
 102     LOGCALL_VOID(API, "PositionIterator::skip_to", pos);
 103     if (internal) {
 104         if (!internal->skip_to(pos)) {
 105             decref();
 106             internal = NULL;
 107         }
 108     }
 109 }
 110
 111 std::string
 112 PositionIterator::get_description() const
 113 {
 114 #if 0 // FIXME: Add PositionIterator::Internal::get_description() method.
 115     string desc = "PositionIterator(";
 116     if (internal)
 117         desc += internal->get_description();
 118     desc += ')';
 119     return desc;
 120 #else
 121     return "PositionIterator()";
 122 #endif
 123 }
 124
 125 }