How to use vectors to set attributes

Intended audience: developers, Programming language: c++

This page contains examples on how to use C++ vectors to set attribute values on the servers side.

Warning

Tango is optimized not to copy data. For this reason all the attribute set_value() methods only take pointers as input. If you are going to use C++ vectors, you should be aware of the fact that you are going to copy the data! This might slow down execution time when working with large amount of data.

Examples for a vector of short and a vector of string:

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void MyClass::read_Spectrum(Tango::Attribute &attr)
{
    DEBUG_STREAM << "MyClass::read_Spectrum() entering... "<< endl;

    vector<Tango::DevShort> val;
    val.push_back(1);
    val.push_back(2);
    val.push_back(3);

    // data copy !!
    Tango::DevVarShortArray tmp_seq;
    tmp_seq << val;

    attr.set_value (tmp_seq.get_buffer(), tmp_seq.length());
}

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void MyClass::read_StringSpectrum(Tango::Attribute &attr)
{
    DEBUG_STREAM << "MyClass::read_StringSpectrum() entering... "<< endl;

    vector<string> val;
    val.push_back("Hello");
    val.push_back("cruel");
    val.push_back("world!");

    // data copy !!
    Tango::DevVarStringArray tmp_seq;
    tmp_seq << val;

    attr.set_value (tmp_seq.get_buffer(), tmp_seq.length());
}