hdftype.hh

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#ifndef UTOPIA_DATAIO_HDFTYPEFACTORY_HH
#define UTOPIA_DATAIO_HDFTYPEFACTORY_HH
 
#include <variant>
 
#include <hdf5.h>
#include <hdf5_hl.h>
 
#include <utopia/core/type_traits.hh>
 
#include "hdfobject.hh"
#include "hdfutilities.hh"
 
namespace Utopia
{
namespace DataIO
{
 
namespace Detail
{
 
template < typename T >
hid_t inline get_type()
{
    return 0;
}
// bunch of overloads of get_type for getting hdf5 types for different c++
// types
template <>
hid_t
get_type< float >()
{
    return H5T_NATIVE_FLOAT;
}
 
template <>
hid_t
get_type< double >()
{
    return H5T_NATIVE_DOUBLE;
}
template <>
hid_t
get_type< long double >()
{
    return H5T_NATIVE_LDOUBLE;
}
template <>
hid_t
get_type< int >()
{
    return H5T_NATIVE_INT;
}
 
template <>
hid_t
get_type< short int >()
{
    return H5T_NATIVE_SHORT;
}
template <>
hid_t
get_type< long int >()
{
    return H5T_NATIVE_LONG;
}
template <>
hid_t
get_type< long long int >()
{
    return H5T_NATIVE_LLONG;
}
template <>
hid_t
get_type< unsigned int >()
{
    return H5T_NATIVE_UINT;
}
template <>
hid_t
get_type< unsigned short int >()
{
    return H5T_NATIVE_UINT16;
}
template <>
hid_t
get_type< std::size_t >()
{
    return H5T_NATIVE_ULLONG;
}
 
template <>
hid_t
get_type< unsigned long long >()
{
    return H5T_NATIVE_ULLONG;
}
 
template <>
hid_t
get_type< bool >()
{
    return H5T_NATIVE_HBOOL;
}
template <>
hid_t
get_type< char >()
{
    return H5T_NATIVE_CHAR;
}
 
}
 
class HDFType final : public HDFObject< HDFCategory::datatype >
{
  private:
    // identify if the type is mutable or not. Unfortunatelly there is no
    // HDF5-intrinsic way to check this...
    bool _mutable = false;
 
    // enumeration telling what class the type belongs to
    H5T_class_t _classid;
 
  public:
    using Base = HDFObject< HDFCategory::datatype >;
 
    // typedef for variant type to store attributes in
    // all supported types are assembled into one variant here
    using Variant = std::variant< float,
                                  double,
                                  long double,
                                  int,
                                  short int,
                                  long int,
                                  long long int,
                                  unsigned int,
                                  unsigned short int,
                                  std::size_t,
                                  unsigned long long,
                                  bool,
                                  char,
                                  std::vector< float >,
                                  std::vector< double >,
                                  std::vector< long double >,
                                  std::vector< int >,
                                  std::vector< short int >,
                                  std::vector< long int >,
                                  std::vector< long long int >,
                                  std::vector< unsigned int >,
                                  std::vector< unsigned short int >,
                                  std::vector< std::size_t >,
                                  std::vector< unsigned long long >,
                                  // std::vector<bool>,
                                  std::vector< char >,
                                  std::vector< std::string >,
                                  std::string,
                                  const char* >;
 
    inline bool
    is_mutable() const
    {
        return _mutable;
    }
 
    inline auto
    type_category() const
    {
        return _classid;
    }
 
    inline std::size_t
    size() const
    {
        return H5Tget_size(get_C_id());
    }
 
    template < typename T >
    void
    open(T&& object)
    {
        this->_log->debug("Opening HDFType from existing object {}",
                          object.get_path());
 
        if (is_valid())
        {
            throw std::runtime_error(
                "Error, cannot open HDFType while it's still bound to another "
                "valid type object, close it first");
        }
 
        bind_to(open_type(object),
                &H5Tclose, // we lock the type, hence no H5Tclose needed
                "datatype of " + object.get_path());
 
        _mutable = true;
        _classid = H5Tget_class(get_C_id());
    }
 
    template < typename T >
    void
    open(std::string name, hsize_t typesize)
    {
        this->_log->debug("Opening HDFType from scratch");
 
        if (is_valid())
        {
            throw std::runtime_error(
                "Error, cannot open HDFType '" + name + "' while it's still bound "
                "to another valid type object! Close it first.");
        }
 
        // include const char* which is a  c-string
        if constexpr (Utils::is_container_v< T >)
        {
            if (typesize == 0ul)
            {
                bind_to(H5Tvlen_create(
                            Detail::get_type< typename T::value_type >()),
                        &H5Tclose,
                        name);
            }
            else
            {
                hsize_t dim[1] = { typesize };
                bind_to(
                    H5Tarray_create(
                        Detail::get_type< typename T::value_type >(), 1, dim),
                    &H5Tclose,
                    name);
            }
            _mutable = true;
        }
        else if constexpr (Utils::is_string_v< T >)
        {
            hid_t type = H5Tcopy(H5T_C_S1);
 
            if (typesize == 0)
            {
                H5Tset_size(type, H5T_VARIABLE);
            }
            else
            {
                H5Tset_size(type, typesize);
            }
            bind_to(std::move(type), &H5Tclose, name);
 
            _mutable = true;
        }
        else
        {
            // native type objects like H5T_NATIVE_INT are interpreted as
            // invalid by H5Iis_valid, hence at this point the `bind_to`
            // function is not used, because it checks validity
            _id.open(Detail::get_type< T >(),
                     [](hid_t) -> herr_t { return 0; });
            _path    = name;
            _mutable = false;
        }
 
        _classid = H5Tget_class(get_C_id());
    }
 
     void
    close() 
    {
 
        // everything that is obtained via H5Tcopy, H5Topen or H5Tcreate
        // needs to be released explicitly. This is given by the _mutable
        // flag
        Base::close();
        _mutable = false;
        _classid = H5T_NO_CLASS;
    }
 
    virtual bool
    is_valid() const override
    {
        // this distinction is important because identifiers are not always
        // checkable via H5Iis_valid
        if (not(_classid == H5T_VLEN or _classid == H5T_ARRAY or
                _classid == H5T_STRING) and
            not(get_C_id() == -1))
        {
            return true;
        }
        else
        {
            return Base::is_valid();
        }
    }
 
    HDFType(HDFType&& other) : Base(static_cast< Base&& >(other))
    {
        _mutable = std::move(other._mutable);
        _classid = std::move(other._classid);
 
        other._mutable = false;
        other._classid = H5T_NO_CLASS;
    }
 
    HDFType&
    operator=(HDFType&& other)
    {
        static_cast<Base&>(*this) = static_cast< Base&& >(other);
        _mutable = std::move(other._mutable);
        _classid = std::move(other._classid);
 
        other._mutable = false;
        other._classid = H5T_NO_CLASS;
 
        return *this;
    }
 
    HDFType(const HDFType& other) =  default;
 
    HDFType&
    operator=(const HDFType& other) = default;
 
    virtual ~HDFType()
    {
        close();
    }
 
    HDFType() : Base(), _mutable(false), _classid(H5T_NO_CLASS)
    {
    }
 
    template < typename T >
    HDFType(T&& object_or_size,
            std::enable_if_t< not std::is_same_v< HDFType, std::decay_t< T > >, int > = 0):
    HDFType()
    {
        open(object_or_size);
    }
};
 
bool
operator==(const HDFType& lhs, const HDFType& rhs)
{
    auto equal = H5Tequal(lhs.get_C_id(), rhs.get_C_id()) &&
                 lhs.type_category() == rhs.type_category();
    if (equal > 0)
    {
        return true;
    }
    else if (equal == 0)
    {
        return false;
    }
    else
    {
        throw std::runtime_error("Error when comparing dataspaces");
        return false;
    }
}
 
bool
operator!=(const HDFType& lhs, const HDFType& rhs)
{
    return not(lhs == rhs);
}
 // end of group HDF5 // end of group DataIO
 
} // namespace DataIO
} // namespace Utopia
 
#endif