PacketData.hh 9.80 KiB
// Copyright (C) 2007
// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
// Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
// Stefan Bund <g0dil@berlios.de>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the
// Free Software Foundation, Inc.,
// 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
/** \file
\brief PacketData public header */
#ifndef HH_PacketData_
#define HH_PacketData_ 1
// Custom includes
#include <boost/utility.hpp>
#include <boost/type_traits.hpp>
#include <boost/iterator/iterator_facade.hpp>
#include "../Utils/safe_bool.hh"
#include "PacketTypes.hh"
//#include "PacketData.mpp"
///////////////////////////////hh.p////////////////////////////////////////
namespace senf {
/** \brief Packet data STL-sequence view
The PacketData class provides an STL-sequence compatible view of the raw packet data. Each
packet/header/interpreter in the chain references the same storage area, presenting a
different (but nested/overlapping) section of the data.
Whenever the data is manipulated through PacketData, the change is assumed to be within the
data range of that packet: All insertions take place \e inside \c this packet and \e outside
any following packets in the packet chain.
\warning It is not permissible to change data belonging to a following
packet/header/interpreter even though this data is part of \c this sequence. Doing so
will corrupt the packet data.
\par
\warning When accessing packet data via the PacketData interface you are on your own: The
packet is not validated in any way, you bypass all parsers.
All public members are those of an STL random-access sequence.
\implementation This class is very tightly integrated with PacketInterpreterBase /
PacketInterpreter. It is separated out of those classes primarily to provide a clean
sequence interface to the library user and not for implementation reasons (it would have
been simpler to implement all these members in PacketInterpreterBase).
\ingroup packet_module
*/
class PacketData
: boost::noncopyable
{
public: ///////////////////////////////////////////////////////////////////////////
// Types
typedef senf::detail::packet::iterator iterator;
typedef senf::detail::packet::const_iterator const_iterator;
typedef senf::detail::packet::size_type size_type;
typedef senf::detail::packet::difference_type difference_type;
typedef senf::detail::packet::byte byte;
typedef byte value_type;
typedef byte & reference;
typedef byte const & const_reference;
typedef byte * pointer;
typedef byte const * const_pointer;
///////////////////////////////////////////////////////////////////////////
///\name Structors and default members
///@{
// no public constructors
// no conversion constructors
///@}
///////////////////////////////////////////////////////////////////////////
///\name Sequence interface to raw data
///@{
iterator begin() const; /**< Returns an <em>random access iterator</em> referring
to the first byte of the packet data. */
iterator end() const; /**< Returns an <em>random access iterator</em> referring to the
element past the end of the packet data. */
size_type size() const; ///< Returns the number of bytes in the packet data.
bool empty() const; ///< Test whether the packet data is empty.
/**< Returns whether the packet data is empty, i.e.
whether its size is 0. This function does not modify
the content of the packet data in any way. To clear
the content use clear() */
byte operator[](size_type n) const;
byte & operator[](size_type n);
// Modifying the raw packet data
// IMPORTANT NOTE: It is not possible to insert data AFTER an empty packet
// since for an empty packet begin() == end(). However, I hope this problem is
// only academic since what should an empty packet be good for ?
void insert(iterator pos, byte v);
void insert(iterator pos, size_type n, byte v);
# ifndef DOXYGEN
template <class InputIterator>
void insert(iterator pos, InputIterator f, InputIterator l,
typename boost::disable_if< boost::is_convertible<InputIterator,size_type> >::type * = 0);
# else
template <class InputIterator>
void insert(iterator pos, InputIterator f, InputIterator l);
# endif
void erase(iterator pos);
void erase(iterator first, iterator last);
void clear(); /**< All bytes of the packet data dropped,
leaving the container with a size of 0. */
void resize(size_type n, byte v=0);
///@}
protected:
PacketData(size_type b, size_type e);
/// Need to make this protected so we can change it in the derived class
detail::PacketImpl * impl_;
detail::PacketImpl & impl() const;
bool valid();
private:
size_type begin_;
size_type end_;
friend class detail::PacketImpl;
};
class PacketParserBase;
/** \brief Invalid packet data access
This exception is signaled whenever an operation tries to access an out-of-bounds data
byte. If the packet has been implemented correctly, this signals a malformed packet.
*/
struct TruncatedPacketException : public std::exception
{ virtual char const * what() const throw() { return "truncated packet"; } };
/** \brief Re-validating data iterator
This class is a wrapper around a PacketData::iterator instance. It will revalidate the
iterator on every access. This keeps the iterator valid even when the data container is
resized and thereby possibly relocated. The iterator will always point to the byte at the
same offset from the packets beginning. If data is inserted before this iterators position,
the data pointed to will of course change.
For this to work, the safe_data_iterator must be initialized with the container to which the
iterator belongs. After this initialization it can be used like any other iterator.
*/
class safe_data_iterator
: public boost::iterator_facade< safe_data_iterator,
PacketData::value_type,
boost::random_access_traversal_tag >,
public comparable_safe_bool<safe_data_iterator>
{
public:
typedef PacketData::size_type size_type;
safe_data_iterator(); ///< Make uninitialized iterator
explicit safe_data_iterator(PacketData & data);
///< Construct iterator only setting the data container
safe_data_iterator(PacketData & data, PacketData::iterator i);
///< Initialize iterator to given position
explicit safe_data_iterator(PacketParserBase const & parser);
///< Initialize iterator from parser
/**< The iterator will point to the parsers start
position. */
safe_data_iterator & operator=(PacketData::iterator i); ///< Assign iterator
/**< The iteator \a i must be from the container wo which \c
this iterator has been initialized. */
safe_data_iterator & operator=(PacketParserBase const & parser);
///< Assign iterator from parser
/**< The iterator will point to the parser start
position. */
operator PacketData::iterator() const; ///< Convert to iterator
bool boolean_test() const; ///< Check, if iterator is initialized
PacketData & data() const; ///< Access data container
private:
friend class boost::iterator_core_access;
// iterator_facade interface
value_type & dereference() const;
bool equal(safe_data_iterator const & other) const;
difference_type distance_to(safe_data_iterator const & other) const;
void increment();
void decrement();
void advance(difference_type n);
PacketData::iterator i() const;
PacketData * data_;
size_type i_;
};
}
///////////////////////////////hh.e////////////////////////////////////////
#endif
#if !defined(HH_Packets__decls_) && !defined(HH_PacketData_i_)
#define HH_PacketData_i_
#include "PacketData.cci"
//#include "PacketData.ct"
#include "PacketData.cti"
#endif
// Local Variables:
// mode: c++
// fill-column: 100
// c-file-style: "senf"
// indent-tabs-mode: nil
// ispell-local-dictionary: "american"
// compile-command: "scons -u test"
// comment-column: 40
// End: