atom.hpp

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//            Copyright Paul Colby 2013 - 2015.
// Distributed under the Boost Software License, Version 1.0.
//       (See accompanying file LICENSE.md or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

/**
 * @file
 * @brief Defines the pcp::atom template class.
 */

#ifndef __PCP_CPP_ATOM_HPP__
#define __PCP_CPP_ATOM_HPP__

#include "config.hpp"
#include "exception.hpp"
#include "types.hpp"

PCP_CPP_BEGIN_NAMESPACE

namespace pcp {

/**
 * @brief Caset a value to a PCP pmAtomValue.
 *
 * This base template definition handles most numeric types.
 *
 * @param type  The atom type to set.
 * @param value The atom value to set.
 *
 * @tparam ValueType Type of value to set.
 *
 * @return A `pmAtomValue` containing \c value of type \c type.
 */
template <typename ValueType>
pmAtomValue atom(const atom_type_type type, ValueType value)
{
    pmAtomValue atom;
    switch (type) {
        case PM_TYPE_32:               atom.l   = static_cast< int32_t>(value); break;
        case PM_TYPE_U32:              atom.ul  = static_cast<uint32_t>(value); break;
        case PM_TYPE_64:               atom.ll  = static_cast< int64_t>(value); break;
        case PM_TYPE_U64:              atom.ull = static_cast<uint64_t>(value); break;
        case PM_TYPE_FLOAT:            atom.f   = static_cast<float   >(value); break;
        case PM_TYPE_DOUBLE:           atom.d   = static_cast<double  >(value); break;
      //case PM_TYPE_STRING:           atom.cp  = value; break;
      //case PM_TYPE_AGGREGATE:        atom.vbp = value; break;
      //case PM_TYPE_AGGREGATE_STATIC: atom.vbp = value; break;
      //case PM_TYPE_EVENT:            atom.vbp = value; break;
      //case PM_TYPE_HIGHRES_EVENT:    atom.vbp = value; break;
        default:
            throw pcp::exception(PM_ERR_TYPE);
    }
    return atom;
}

/**
 * @brief Caset a value to a PCP pmAtomValue.
 *
 * This template specialisation hanldes `char *` strings.
 *
 * @note We do not provide a `const char *` template specialisation, since that
 *       would require us to `const_cast` the value, which is something the
 *       caller ought to be very clear about / aware is happening. Hence, if you
 *       want to use a `const char *`, use something like:
 *       `pcp::atom(PM_TYPE_STRING, const_cast<char *>(value)`
 *
 * @param type  The atom type to set.
 * @param value The atom value to set.
 *
 * @return A `pmAtomValue` containing \c value of type \c type.
 */
template <>
inline pmAtomValue atom<char *>(const atom_type_type type, char * value)
{
    pmAtomValue atom;
    switch (type) {
      //case PM_TYPE_32:               atom.l   = value; break;
      //case PM_TYPE_U32:              atom.ul  = value; break;
      //case PM_TYPE_64:               atom.ll  = value; break;
      //case PM_TYPE_U64:              atom.ull = value; break;
      //case PM_TYPE_FLOAT:            atom.f   = value; break;
      //case PM_TYPE_DOUBLE:           atom.d   = value; break;
        case PM_TYPE_STRING:           atom.cp  = value; break;
      //case PM_TYPE_AGGREGATE:        atom.vbp = value; break;
      //case PM_TYPE_AGGREGATE_STATIC: atom.vbp = value; break;
      //case PM_TYPE_EVENT:            atom.vbp = value; break;
      //case PM_TYPE_HIGHRES_EVENT:    atom.vbp = value; break;
        default:
            throw pcp::exception(PM_ERR_TYPE);
    }
    return atom;
}

/**
 * @brief Caset a value to a PCP pmAtomValue.
 *
 * This template specialisation hanldes `pmValueBlock` values.
 *
 * @param type  The atom type to set.
 * @param value The atom value to set.
 *
 * @return A `pmAtomValue` containing \c value of type \c type.
 */
template <>
inline pmAtomValue atom<pmValueBlock *>(const atom_type_type type, pmValueBlock * value)
{
    pmAtomValue atom;
    switch (type) {
      //case PM_TYPE_32:               atom.l   = value; break;
      //case PM_TYPE_U32:              atom.ul  = value; break;
      //case PM_TYPE_64:               atom.ll  = value; break;
      //case PM_TYPE_U64:              atom.ull = value; break;
      //case PM_TYPE_FLOAT:            atom.f   = value; break;
      //case PM_TYPE_DOUBLE:           atom.d   = value; break;
      //case PM_TYPE_STRING:           atom.cp  = value; break;
        case PM_TYPE_AGGREGATE:        atom.vbp = value; break;
        case PM_TYPE_AGGREGATE_STATIC: atom.vbp = value; break;
        case PM_TYPE_EVENT:            atom.vbp = value; break;
#ifdef PM_TYPE_HIGHRES_EVENT // PM_TYPE_HIGHRES_EVENT added in PCP 3.9.10.
        case PM_TYPE_HIGHRES_EVENT:    atom.vbp = value; break;
#endif
        default:
            throw pcp::exception(PM_ERR_TYPE);
    }
    return atom;
}

} // pcp namespace.

PCP_CPP_END_NAMESPACE

#endif