// $Id$
//
// Copyright (C) 2006
// Fraunhofer Institute for Open Communication Systems (FOKUS)
//
// The contents of this file are subject to the Fraunhofer FOKUS Public License
// Version 1.0 (the "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at 
// http://senf.berlios.de/license.html
//
// The Fraunhofer FOKUS Public License Version 1.0 is based on, 
// but modifies the Mozilla Public License Version 1.1.
// See the full license text for the amendments.
//
// Software distributed under the License is distributed on an "AS IS" basis, 
// WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
// for the specific language governing rights and limitations under the License.
//
// The Original Code is Fraunhofer FOKUS code.
//
// The Initial Developer of the Original Code is Fraunhofer-Gesellschaft e.V. 
// (registered association), Hansastraße 27 c, 80686 Munich, Germany.
// All Rights Reserved.
//
// Contributor(s):
//   Stefan Bund <g0dil@berlios.de>

/** \file
    \brief IntParser internal header */

#ifndef IH_SENF_Packets_IntParser_
#define IH_SENF_Packets_IntParser_ 1

// Custom includes
#include "PacketTypes.hh"

//-/////////////////////////////////////////////////////////////////////////////////////////////////

namespace senf {
namespace detail {
namespace packet {

    //-/////////////////////////////////////////////////////////////////////////////////////////////
    // Integer operators

    /** \brief Internal: Integer operation mixin for integer parsers

        \internal

        This class contains all the integer operations supported by the integer parsers. It is
        inherited by each integer parser.
     */
    template <class Derived, class Value>
    class IntParserOps
    {
    public:
        typedef Value value_type;

        operator Value () const { return derived().value(); }

#       define unary(op) \
            Value operator op () const { return op derived().value(); }
#       define mutator(op) \
            template <class Other> Derived const & operator op ## =  (Other other) \
                { derived().value( derived().value() op other ); return derived(); }

        unary(~)
        unary(!)
        unary(-)

        mutator(+)
        mutator(-)
        mutator(*)
        mutator(/)
        mutator(%)
        mutator(<<)
        mutator(>>)
        mutator(&)
        mutator(|)
        mutator(^)

#       undef unary
#       undef mutator

        Derived const & operator ++ ()
            { derived().value( derived().value()+1 ); return derived(); }
        Derived const & operator -- ()
            { derived().value( derived().value()-1 ); return derived(); }

        Value operator ++ (int)
            { Value v (derived().value()); derived().value( v+1 ); return v; }
        Value operator -- (int)
            { Value v (derived().value()); derived().value( v-1 ); return v; }

    private:
        Derived & derived() { return *static_cast<Derived *>(this); }
        Derived const & derived() const { return *static_cast<Derived const *>(this); };
    };

    //-/////////////////////////////////////////////////////////////////////////////////////////////
    // Network byte order integer extraction

    /** \brief Internal: Extract 16bit network byte order value

        \internal
     */
    inline boost::uint16_t parse_uint16(iterator i)
    {
        return i[1] | i[0]<<8;
    }

    /** \brief Internal: Write 16bit network byte order value

        \internal
     */
    inline void write_uint16(iterator i, boost::uint16_t v)
    {
        i[0] = ( v >>  8 ) & 0xff;
        i[1] = ( v       ) & 0xff;
    }

    /** \brief Internal: Extract 16bit least significant bit order value

        \internal
     */
    inline boost::uint16_t parse_uint16LSB(iterator i)
    {
        return i[0] | i[1]<<8;
    }

    /** \brief Internal: Write 16bit least significant bit order value

        \internal
     */
    inline void write_uint16LSB(iterator i, boost::uint16_t v)
    {
        i[0] = ( v       ) & 0xff;
        i[1] = ( v >>  8 ) & 0xff;
    }

    /** \brief Internal: Extract 24bit network byte order value

        \internal
     */
    inline boost::uint32_t parse_uint24(iterator i)
    {
        return i[2] | i[1]<<8 | i[0]<<16;
    }

    /** \brief Internal: Write 24bit network byte order value

        \internal
     */
    inline void write_uint24(iterator i, boost::uint32_t v)
    {
        i[0] = ( v >> 16 ) & 0xff;
        i[1] = ( v >>  8 ) & 0xff;
        i[2] = ( v       ) & 0xff;
    }

    /** \brief Internal: Extract 32bit network byte order value

        \internal
     */
    inline boost::uint32_t parse_uint32(iterator i)
    {
        return i[3] | i[2]<<8 | i[1]<<16 | i[0]<<24;
    }

    /** \brief Internal: Write 32bit network byte order value

        \internal
     */
    inline void write_uint32(iterator i, boost::uint32_t v)
    {
        i[0] = ( v >> 24 ) & 0xff;
        i[1] = ( v >> 16 ) & 0xff;
        i[2] = ( v >>  8 ) & 0xff;
        i[3] = ( v       ) & 0xff;
    }

    /** \brief Internal: Extract 32bit network byte order value

        \internal
     */
    inline boost::uint32_t parse_uint32LSB(iterator i)
    {
        return i[0] | i[1]<<8 | i[2]<<16 | i[3]<<24;
    }

    /** \brief Internal: Write 32bit network byte order value

        \internal
     */
    inline void write_uint32LSB(iterator i, boost::uint32_t v)
    {
        i[3] = ( v >> 24 ) & 0xff;
        i[2] = ( v >> 16 ) & 0xff;
        i[1] = ( v >>  8 ) & 0xff;
        i[0] = ( v       ) & 0xff;
    }

    /** \brief Internal: Extract 64bit network byte order value

        \internal
     */
    inline boost::uint64_t parse_uint64(iterator i)
    {
        return ((boost::uint64_t)i[7]) | ((boost::uint64_t)i[6])<<8
                | ((boost::uint64_t)i[5])<<16 | ((boost::uint64_t)i[4])<<24
                | ((boost::uint64_t)i[3])<<32 | ((boost::uint64_t)i[2])<<40
                | ((boost::uint64_t)i[1])<<48 | ((boost::uint64_t)i[0])<<56;
    }

    /** \brief Internal: Write 64bit network byte order value

        \internal
     */
    inline void write_uint64(iterator i, boost::uint64_t v)
    {
        i[0] = ( v >> 56 ) & 0xff;
        i[1] = ( v >> 48 ) & 0xff;
        i[2] = ( v >> 40 ) & 0xff;
        i[3] = ( v >> 32 ) & 0xff;
        i[4] = ( v >> 24 ) & 0xff;
        i[5] = ( v >> 16 ) & 0xff;
        i[6] = ( v >> 8  ) & 0xff;
        i[7] = ( v       ) & 0xff;
    }

    /** \brief Internal: Extract 64bit least significant bit order value

        \internal
     */
    inline boost::uint64_t parse_uint64LSB(iterator i)
    {
        return ((boost::uint64_t)i[0]) | ((boost::uint64_t)i[1])<<8
                | ((boost::uint64_t)i[2])<<16 | ((boost::uint64_t)i[3])<<24
                | ((boost::uint64_t)i[4])<<32 | ((boost::uint64_t)i[5])<<40
                | ((boost::uint64_t)i[6])<<48 | ((boost::uint64_t)i[7])<<56;
    }

    /** \brief Internal: Write 64bit least significant bit order value

        \internal
     */
    inline void write_uint64LSB(iterator i, boost::uint64_t v)
    {
        i[0] = ( v       ) & 0xff;
        i[1] = ( v >> 8  ) & 0xff;
        i[2] = ( v >> 16 ) & 0xff;
        i[3] = ( v >> 24 ) & 0xff;
        i[4] = ( v >> 32 ) & 0xff;
        i[5] = ( v >> 40 ) & 0xff;
        i[6] = ( v >> 48 ) & 0xff;
        i[7] = ( v >> 56 ) & 0xff;
    }

    //-/////////////////////////////////////////////////////////////////////////////////////////////
    // bitfield extraction

    // Doxygen doesn't like this stuff ...

#   ifndef DOXYGEN

    template <unsigned offset, unsigned endb, unsigned start, unsigned end>
    struct parse_bitfield_i
    {
        static boost::uint32_t parse(iterator i) {
            return ( ( ( parse_uint32(i+offset+1)>>(40-end) ) // Beware of sign extension !!
                       & boost::low_bits_mask_t<32-(40-end)>::sig_bits )
                     | (i[offset]<<(32-(40-end))) )
                & boost::low_bits_mask_t<end-start>::sig_bits;
        }

        static void write(iterator i, boost::uint32_t v) {
            write_uint32(i+offset+1,
                         (parse_uint32(i+offset+1) & ~(boost::low_bits_mask_t<end-8>::sig_bits<<(40-end)))
                         | ((v & boost::low_bits_mask_t<end-8>::sig_bits) << (40-end)));
            i[offset] = (i[offset] & ~(boost::low_bits_mask_t<8-start>::sig_bits))
                | ((v>>(end-8)) & boost::low_bits_mask_t<8-start>::sig_bits);
        }
    };

    template <unsigned offset, unsigned start, unsigned end>
    struct parse_bitfield_i<offset, 3, start, end>
    {
        static boost::uint32_t parse(iterator i) {
            return ( parse_uint32(i+offset)>>(32-end) )
                & boost::low_bits_mask_t<end-start>::sig_bits;
        }

        static void write(iterator i, boost::uint32_t v) {
            write_uint32(i+offset,
                         (parse_uint32(i+offset) & ~(boost::low_bits_mask_t<end-start>::sig_bits<<(32-end)))
                         | ((v & boost::low_bits_mask_t<end-start>::sig_bits) << (32-end)));
        }
    };

    template <unsigned offset, unsigned start, unsigned end>
    struct parse_bitfield_i<offset, 2, start, end>
    {
        static boost::uint32_t parse(iterator i) {
            return ( parse_uint24(i+offset)>>(24-end) )
                & boost::low_bits_mask_t<end-start>::sig_bits;
        }

        static void write(iterator i, boost::uint32_t v) {
            write_uint24(i+offset,
                         (parse_uint24(i+offset) & ~(boost::low_bits_mask_t<end-start>::sig_bits<<(24-end)))
                         | ((v & boost::low_bits_mask_t<end-start>::sig_bits) << (24-end)));
        }
    };

    template <unsigned offset, unsigned start, unsigned end>
    struct parse_bitfield_i<offset, 1, start, end>
    {
        static boost::uint32_t parse(iterator i) {
            return ( parse_uint16(i+offset)>>(16-end) )
                & boost::low_bits_mask_t<end-start>::sig_bits;
        }

        static void write(iterator i, boost::uint32_t v) {
            write_uint16(i+offset,
                         (parse_uint16(i+offset) & ~(boost::low_bits_mask_t<end-start>::sig_bits<<(16-end)))
                         | ((v & boost::low_bits_mask_t<end-start>::sig_bits) << (16-end)));
        }
    };

    template <unsigned offset, unsigned start, unsigned end>
    struct parse_bitfield_i<offset, 0, start, end>
    {
        static boost::uint32_t parse(iterator i) {
            return ( i[offset]>>(8-end) )
                & boost::low_bits_mask_t<end-start>::sig_bits;
        }

        static void write(iterator i, boost::uint32_t v) {
            i[offset] = (i[offset] & ~(boost::low_bits_mask_t<end-start>::sig_bits<<(8-end)))
                | ((v & boost::low_bits_mask_t<end-start>::sig_bits) << (8-end));
        }
    };

#   endif

    /** \brief Internal: Bitfield read/write helper

        \internal

        Using template specializations, this class provides optimized bitfield parsers and
        writers. For each number of bytes the bitfield covers (from 1 to 5 bytes), a template
        specialization is provided in \c parse_bitfield_i.

        This helper always processes unsigned values. For signed values sign extension still needs
        to be performed.
     */
    template <unsigned start, unsigned end>
    struct parse_bitfield
        : public parse_bitfield_i<start/8,(end-1)/8-start/8,start%8,end-8*(start/8)>
    {};

}}}

//-/////////////////////////////////////////////////////////////////////////////////////////////////
#endif


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// ispell-local-dictionary: "american"
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