query_results.h

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/*
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#ifndef MONGO_ROS_QUERY_RESULTS_H
#define MONGO_ROS_QUERY_RESULTS_H

#include <mongo_ros/message_with_metadata.h>
#include <boost/optional.hpp>

namespace mongo_ros
{

// To avoid some const-correctness issues we wrap Mongo's returned auto_ptr in
// another pointer
typedef std::auto_ptr<mongo::DBClientCursor> Cursor;
typedef boost::shared_ptr<Cursor> CursorPtr;

template <class M>
class ResultIterator :
    public boost::iterator_facade<ResultIterator<M>,
                                  typename MessageWithMetadata<M>::ConstPtr,
                                  boost::single_pass_traversal_tag,
                                  typename MessageWithMetadata<M>::ConstPtr >
{
public:

  ResultIterator (boost::shared_ptr<mongo::DBClientConnection> conn,
                  const std::string& ns,
                  const mongo::Query& query,
                  boost::shared_ptr<mongo::GridFS> gfs,
                  bool metadata_only);

  ResultIterator (const ResultIterator& rhs);

  ResultIterator ();

private:

  friend class boost::iterator_core_access;

  // Member functions needed to be an iterator
  void increment ();
  typename MessageWithMetadata<M>::ConstPtr dereference () const;
  bool equal (const ResultIterator<M>& other) const;

  const bool metadata_only_;
  CursorPtr cursor_;
  boost::optional<mongo::BSONObj> next_;
  boost::shared_ptr<mongo::GridFS> gfs_;
};

template <class M>
struct QueryResults
{
  typedef std::pair<ResultIterator<M>, ResultIterator<M> > range_t;
};



} // namespace

#include "impl/query_results_impl.hpp"

#endif // include guard