netreqpacket.h

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#ifndef netreqpacket_h
#define netreqpacket_h

/*+
________________________________________________________________________

 (C) dGB Beheer B.V.; (LICENSE) http://opendtect.org/OpendTect_license.txt
 Author:        K. Tingdahl
 Date:          August 2014
 RCS:           $Id$
________________________________________________________________________

-*/

#include "networkmod.h"
#include "bufstringset.h"

#define mRequestPacketHeaderSize                10


namespace Network
{

/*\brief Standardized packet that can be sent over a Tcp connection

  The request header contains a unique (int) request ID and a (short) sub-ID.
  The sub-ID is a flag that can be used to implement your protocol. Negative
  sub-IDs are special and cannot be freely used.

  Servers will not send Begin packets as they don't initiate requests. Replies
  are never Begin packets. Error always implies End.

  Request IDs are obtained by using setIsNewRequest().

  At the end of the class there is a public section for expert usage.

  */

mExpClass(Network) RequestPacket
{
public:
                        RequestPacket(od_int32 payloadsize=0);
                        ~RequestPacket();

    od_int32            requestID() const;
    bool                isNewRequest() const { return subID()==cBeginSubID(); }
    bool                isRequestEnd() const { return subID()<cMoreSubID(); }
    bool                isError() const      { return subID()==cErrorSubID(); }
    od_int32            payloadSize() const;
    const void*         payload() const;
    void                getStringPayload(BufferString&) const;
    od_int32            totalSize() const
                        { return payloadSize() + mRequestPacketHeaderSize; }

    int                 setIsNewRequest();   
    void                setRequestID(od_int32); 
    void                setIsError()         { setSubID( cErrorSubID() ); }
    void                setIsLast()          { setSubID( cEndSubID() ); }

    void*               allocPayload(od_int32 size);
    void                setPayload(void*,od_int32 size); 
    void                setStringPayload(const char*);

    void                addErrMsg(BufferString&) const;

                        // essentially, there is no limit unless user sets it
    static od_int32     systemSizeLimit();              //< if < 1 no limit
    static void         setSystemSizeLimit(od_int32);   //< no limit set to 0

protected:

    union Header
    {
        od_int32        int32s_[2];
        od_int16        int16s_[5]; 
    };


    Header              header_;
    char*               payload_;

    static od_int16     cBeginSubID()           { return -1; }
    static od_int16     cMoreSubID()            { return -2; }
    static od_int16     cEndSubID()             { return -4; }
    static od_int16     cErrorSubID()           { return -8; }

    friend class        PacketFiller;
    friend class        PacketInterpreter;

public:

    bool                isOK() const;
    od_int16            subID() const;

    void                setSubID(od_int16);

    static od_int32     headerSize() { return mRequestPacketHeaderSize; }
    static od_int32     getPayloadSize(const void*);

    void*               payload(bool takeover=false);
    void*               getRawHeader()          { return header_.int32s_; }
    const void*         getRawHeader() const    { return header_.int32s_; }
};


/*\brief fills a packet's payload.

  Use the sizeFor() functions to calculate the total payload size.

*/

mExpClass(Network) PacketFiller
{
public:
                        PacketFiller( RequestPacket& p, int startpos=0 )
                            : pkt_(p)
                            , curpos_(startpos) {}

#   define              mNPFSizeFor(v) Network::PacketFiller::sizeFor(v)
#   define              mNPFSizeForArr(a,s) Network::PacketFiller::sizeFor(a,s)
    template <class T>
    static int          sizeFor(const T&);
    template <class T>
    static int          sizeFor(const T*,int nrelems,bool rawmode=false);
    static int          sizeFor(bool);
    static int          sizeFor(const char*);
    static int          sizeFor(const OD::String&);
    static int          sizeFor(const BufferStringSet&);

    template <class T> const PacketFiller&
                        put(const T&) const;
    template <class T> const PacketFiller&
                        put(const T*,int nrelems,bool rawmode=false) const;
    const PacketFiller& put(const char*) const;
    const PacketFiller& put(bool) const;
    const PacketFiller& put(const OD::String&) const;
    const PacketFiller& put(const BufferStringSet&) const;

    const PacketFiller& putBytes(const void*,int nrbytes) const;

protected:

    RequestPacket&      pkt_;
    mutable int         curpos_;

};


/*\brief interprets what is in a packet.

  You need to know what should be in there. Arrays/sets are always
  preceeded by their size.

*/

mExpClass(Network) PacketInterpreter
{
public:
                                PacketInterpreter( const RequestPacket& p,
                                                 int startpos=0 )
                                    : pkt_(p)
                                    , curpos_(startpos) {}

    template <class T> void     get(T&) const;
    inline bool                 getBool() const;
    inline int                  getInt() const;
    inline float                getFloat() const;
    inline double               getDouble() const;
    inline BufferString         getString() const;

    template <class T> void     getArr(T*,int maxsz,bool rawmode=false) const;
    template <class T> void     getSet(TypeSet<T>&,int maxsz=-1,
                                        bool rawmode=false) const;
    inline void                 getSet(BufferStringSet&,int maxsz=-1) const;

    inline void                 move( int nrb ) const   { curpos_ += nrb; }
    inline void                 moveTo( int pos ) const { curpos_ = pos; }
    template <class T> void     peek(T&) const;
    inline int                  peekInt() const;
    void                        getBytes(void*,int nrbytes) const;

    inline bool                 atEndOfPkt() const;

protected:

    const RequestPacket&        pkt_;
    mutable int                 curpos_;

};


template <class T>
inline int PacketFiller::sizeFor( const T& var )
{
    return sizeof(T);
}
inline int PacketFiller::sizeFor( bool var )
{
    return sizeFor( ((int)var) );
}

template <class T>
inline int PacketFiller::sizeFor( const T* arr, int nrelems, bool rawmode )
{
    return (rawmode ? 0 : sizeof(int)) + nrelems * sizeof(T);
}

inline int PacketFiller::sizeFor( const char* str )
{
    return sizeFor( FixedString(str) );
}

inline int PacketFiller::sizeFor( const OD::String& str )
{
    return sizeof(int) + str.size();
}

inline int PacketFiller::sizeFor( const BufferStringSet& bss )
{
    int ret = sizeof(int);
    for ( int idx=0; idx<bss.size(); idx++ )
        ret += sizeFor( bss.get(idx) );
    return ret;
}


inline const PacketFiller& PacketFiller::put( bool var ) const
{
    const int toput = var ? 1 : 0;
    return put( toput );
}


template <class T>
inline const PacketFiller& PacketFiller::put( const T& var ) const
{
    return putBytes( &var, sizeof(T) );
}

template <class T>
inline const PacketFiller& PacketFiller::put( const T* arr, int nrelems,
                                                bool rawmode ) const
{
    if ( !rawmode )
        put( nrelems );
    return putBytes( arr, nrelems * sizeof(T) );
}

inline const PacketFiller& PacketFiller::put( const char* str ) const
{
    return put( FixedString(str) );
}

inline const PacketFiller& PacketFiller::put( const OD::String& str ) const
{
    const int sz = str.size();
    put( sz );
    return putBytes( str.str(), sz );
}

inline const PacketFiller& PacketFiller::put( const BufferStringSet& bss ) const
{
    const int sz = bss.size();
    put( sz );
    for ( int idx=0; idx<sz; idx++ )
        put( bss.get(idx) );
    return *this;
}

inline const PacketFiller& PacketFiller::putBytes( const void* ptr,
                                                   int sz ) const
{
    if ( sz > 0 )
    {
        OD::memCopy( pkt_.payload_+curpos_, ptr, sz );
        curpos_ += sz;
    }
    return *this;
}




template <class T>
inline void PacketInterpreter::peek( T& var ) const
{
    OD::memCopy( &var, pkt_.payload_+curpos_, sizeof(T) );
}

template <class T>
inline void PacketInterpreter::get( T& var ) const
{
    getBytes( &var, sizeof(T) );
}

template <>
inline void PacketInterpreter::get( BufferString& var ) const
{
    int sz; get( sz );
    if ( sz < 1 )
    {
        if ( sz < 0 )
            { pErrMsg("Invalid string size"); }
        var.setEmpty();
        return;
    }
    var.setBufSize( sz+1 );
    char* cstr = var.getCStr();
    getBytes( cstr, sz );
    cstr[sz] = '\0';
}

inline int PacketInterpreter::peekInt() const
{ int ret = 0; peek(ret); return ret; }
inline bool PacketInterpreter::getBool() const
{ int ret = 0; get(ret); return ret != 0; }
inline int PacketInterpreter::getInt() const
{ int ret = 0; get(ret); return ret; }
inline float PacketInterpreter::getFloat() const
{ float ret = 0.f; get(ret); return ret; }
inline double PacketInterpreter::getDouble() const
{ double ret = 0.; get(ret); return ret; }
inline BufferString PacketInterpreter::getString() const
{ BufferString ret; get(ret); return ret; }

template <class T>
inline void PacketInterpreter::getArr( T* arr, int maxsz, bool rawmode ) const
{
    int arrsz = maxsz;
    if ( !rawmode )
        get( arrsz );
    int sz = arrsz;
    if ( sz > maxsz )
        sz = maxsz;
    if ( arrsz < 1 )
        return;

    getBytes( arr, sz*sizeof(T) );
}

template <class T>
inline void PacketInterpreter::getSet( TypeSet<T>& ts, int maxsz,
                                        bool rawmode ) const
{
    int arrsz = maxsz;
    if ( !rawmode )
        get( arrsz );
    int sz = arrsz;
    if ( maxsz >= 0 && sz > maxsz )
        sz = maxsz;
    if ( arrsz < 1 )
        { ts.setEmpty(); return; }

    ts.setSize( sz );
    getBytes( ts.arr(), sz*sizeof(T) );
}

inline void PacketInterpreter::getSet( BufferStringSet& bss,
                                                int maxsz ) const
{
    int setsz; get( setsz );
    int sz = setsz;
    if ( maxsz >= 0 && sz > maxsz )
        sz = maxsz;
    bss.setEmpty();
    if ( setsz < 1 )
        return;

    for ( int idx=0; idx<sz; idx++ )
    {
        BufferString* bs = new BufferString;
        get( *bs );
        bss += bs;
    }

    for ( int idx=sz; idx<setsz; idx++ )
        getString();
}

inline void PacketInterpreter::getBytes( void* ptr, int nrbytes ) const
{
    if ( nrbytes > 0 )
    {
        OD::memCopy( ptr, pkt_.payload_+curpos_, nrbytes );
        curpos_ += nrbytes;
    }
}

inline bool PacketInterpreter::atEndOfPkt() const
{ return curpos_ >= pkt_.payloadSize(); }

}; //Namespace Network


#endif