IPstream.H

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/*---------------------------------------------------------------------------*\
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    Copyright (C) 2021-2025 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
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    the Free Software Foundation, either version 3 of the License, or
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    You should have received a copy of the GNU General Public License
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Class
    Foam::IPstream

Description
    Input inter-processor communications stream.

SourceFiles
    IPstreams.C

\*---------------------------------------------------------------------------*/

#include "Pstream.H"

#ifndef Foam_IPstream_H
#define Foam_IPstream_H

#include "UIPstream.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

/*---------------------------------------------------------------------------*\
                           Class IPstream Declaration
\*---------------------------------------------------------------------------*/

class IPstream
:
    public Pstream,
    public UIPstream
{
public:

    // Constructors

        //- Construct given process index to read from
        IPstream
        (
            const UPstream::commsTypes commsType,
            const int fromProcNo,
            const int bufferSize = 0,  
            const int tag = UPstream::msgType(),
            const int communicator = UPstream::worldComm,
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        );


    // Static Functions

        //- Receive and deserialize a value.
        //- Uses \c operator>> for de-serialization
        template<class Type>
        static void recv
        (
            Type& value,
            const int fromProcNo,
            const int tag = UPstream::msgType(),
            const int communicator = UPstream::worldComm,
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        )
        {
            IPstream is
            (
                UPstream::commsTypes::scheduled,  // ie, MPI_Recv()
                fromProcNo,
                0,  // bufferSize
                tag,
                communicator,
                fmt
            );
            is >> value;
        }
};


/*---------------------------------------------------------------------------*\
                          Class IPBstream Declaration
\*---------------------------------------------------------------------------*/

//- Input inter-processor communications stream
//- using MPI broadcast.
class IPBstream
:
    public Pstream,
    public UIPBstream
{
public:

    // Constructors

        //- Construct with optional communicator and read format.
        //- Uses UPstream::masterNo() root
        explicit IPBstream
        (
            const int communicator = UPstream::worldComm,
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        );


    // Static Functions

        //- Receive (from broadcast, root == UPstream::masterNo())
        //- and deserialize a value.
        //- Uses \c operator>> for de-serialization
        template<class Type>
        static void recv
        (
            Type& value,
            const int communicator = UPstream::worldComm
        )
        {
            IPBstream is(communicator);
            {
                is >> value;
            }
        }

        //- Receive (from broadcast) a buffer and deserialize
        //- multiple items.
        //- Uses \c operator>> for de-serialization
        template<class Type, class... Args>
        static void recvs
        (
            const int communicator,
            Type& value,
            Args&&... values
        )
        {
            IPBstream is(communicator);
            {
                Detail::inputLoop(is, value, std::forward<Args>(values)...);
                // Depending on compiler support:
                // Unpack via fold expression
                // (((is >> value) >> std::forward<Args>(values)), ...);
            }
        }
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //