xapian-core/api/positioniterator.cc

   1 /** @file positioniterator.cc
   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         internal->next();
  48     } catch (...) {
  49         // The destructor only runs if the constructor completes, so we have to
  50         // take care of cleaning up for ourselves here.
  51         decref();
  52         throw;
  53     }
  54     if (internal->at_end()) {
  55         decref();
  56         internal = NULL;
  57     }
  58 }
  59
  60 PositionIterator::PositionIterator(const PositionIterator & o)
  61     : internal(o.internal)
  62 {
  63     LOGCALL_CTOR(API, "PositionIterator", o);
  64     if (internal)
  65         ++internal->_refs;
  66 }
  67
  68 PositionIterator &
  69 PositionIterator::operator=(const PositionIterator & o)
  70 {
  71     LOGCALL(API, PositionIterator &, "PositionIterator::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::termpos
  81 PositionIterator::operator*() const
  82 {
  83     LOGCALL(API, Xapian::termpos, "PositionIterator::operator*", NO_ARGS);
  84     Assert(internal);
  85     RETURN(internal->get_position());
  86 }
  87
  88 PositionIterator &
  89 PositionIterator::operator++()
  90 {
  91     LOGCALL(API, PositionIterator &, "PositionIterator::operator++", NO_ARGS);
  92     Assert(internal);
  93     internal->next();
  94     if (internal->at_end()) {
  95         decref();
  96         internal = NULL;
  97     }
  98     RETURN(*this);
  99 }
 100
 101 void
 102 PositionIterator::skip_to(Xapian::termpos pos)
 103 {
 104     LOGCALL_VOID(API, "PositionIterator::skip_to", pos);
 105     if (internal) {
 106         internal->skip_to(pos);
 107         if (internal->at_end()) {
 108             decref();
 109             internal = NULL;
 110         }
 111     }
 112 }
 113
 114 std::string
 115 PositionIterator::get_description() const
 116 {
 117 #if 0 // FIXME: Add PositionIterator::Internal::get_description() method.
 118     string desc = "PositionIterator(";
 119     if (internal)
 120         desc += internal->get_description();
 121     desc += ')';
 122     return desc;
 123 #else
 124     return "PositionIterator()";
 125 #endif
 126 }
 127
 128 }