ntunion.h

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/* ntunion.h */
/*
 * Copyright information and license terms for this software can be
 * found in the file LICENSE that is included with the distribution
 */
#ifndef NTUNION_H
#define NTUNION_H

#ifdef epicsExportSharedSymbols
#   define ntunionEpicsExportSharedSymbols
#   undef epicsExportSharedSymbols
#endif

#ifdef ntunionEpicsExportSharedSymbols
#   define epicsExportSharedSymbols
#   undef ntunionEpicsExportSharedSymbols
#endif

#include <pv/ntfield.h>

#include <shareLib.h>

namespace epics { namespace nt {

class NTUnion;
typedef std::tr1::shared_ptr<NTUnion> NTUnionPtr;

namespace detail {

    class epicsShareClass NTUnionBuilder :
        public std::tr1::enable_shared_from_this<NTUnionBuilder>
    {
    public:
        POINTER_DEFINITIONS(NTUnionBuilder);

        shared_pointer value(epics::pvData::UnionConstPtr unionType);

        shared_pointer addDescriptor();

        shared_pointer addAlarm();

        shared_pointer addTimeStamp();

        epics::pvData::StructureConstPtr createStructure();

        epics::pvData::PVStructurePtr createPVStructure();

        NTUnionPtr create();
        shared_pointer add(std::string const & name, epics::pvData::FieldConstPtr const & field);

    private:
        NTUnionBuilder();

        epics::pvData::UnionConstPtr valueType;

        void reset();

        bool descriptor;
        bool alarm;
        bool timeStamp;

        // NOTE: this preserves order, however it does not handle duplicates
        epics::pvData::StringArray extraFieldNames;
        epics::pvData::FieldConstPtrArray extraFields;

        friend class ::epics::nt::NTUnion;
    };

}

typedef std::tr1::shared_ptr<detail::NTUnionBuilder> NTUnionBuilderPtr;



class epicsShareClass NTUnion
{
public:
    POINTER_DEFINITIONS(NTUnion);

    static const std::string URI;

    static shared_pointer wrap(epics::pvData::PVStructurePtr const & pvStructure);

    static shared_pointer wrapUnsafe(epics::pvData::PVStructurePtr const & pvStructure);

    static bool is_a(epics::pvData::StructureConstPtr const & structure);

    static bool is_a(epics::pvData::PVStructurePtr const & pvStructure);

    static bool isCompatible(
        epics::pvData::StructureConstPtr const &structure);

    static bool isCompatible(
        epics::pvData::PVStructurePtr const &pvStructure);

    bool isValid();

    static NTUnionBuilderPtr createBuilder();

    ~NTUnion() {}

    bool attachTimeStamp(epics::pvData::PVTimeStamp &pvTimeStamp) const;

    bool attachAlarm(epics::pvData::PVAlarm &pvAlarm) const;

    epics::pvData::PVStructurePtr getPVStructure() const;

    epics::pvData::PVStringPtr getDescriptor() const;

    epics::pvData::PVStructurePtr getTimeStamp() const;

    epics::pvData::PVStructurePtr getAlarm() const;

    epics::pvData::PVUnionPtr getValue() const;

private:
    NTUnion(epics::pvData::PVStructurePtr const & pvStructure);
    epics::pvData::PVStructurePtr pvNTUnion;
    epics::pvData::PVUnionPtr pvValue;

    friend class detail::NTUnionBuilder;
};

}}
#endif  /* NTUNION_H */