MySQLGeometryAdapterType.cs

// Copyright 2016 - Andreas Ravnestad (andreas.ravnestad@gmail.com)
//
// This file is part of NHibernate.Spatial.
// NHibernate.Spatial is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// NHibernate.Spatial is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License
// along with NHibernate.Spatial; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

using MySql.Data.MySqlClient;
using MySql.Data.Types;
using NHibernate.SqlTypes;
using NHibernate.Type;
using System;
using System.Data;
using System.Data.Common;
using NHibernate.Engine;

namespace NHibernate.Spatial.Type
{
    /// <summary>
    /// This class maps MySQLDbType.Geometry to and from Geometry
    /// </summary>
    [Serializable]
    public class MySQLGeometryAdapterType : ImmutableType
    {
        public MySQLGeometryAdapterType()
            : base(SqlTypeFactory.Byte) // Any arbitrary type can be passed as parameter
        { }

        public override string Name => ReturnedClass.Name;

        public override System.Type ReturnedClass => typeof(MySqlGeometry);

        public override object NullSafeGet(DbDataReader rs, string name, ISessionImplementor session)
        {
            object value = base.NullSafeGet(rs, name, session);
            return value ?? default(MySqlGeometry);
        }

        public override object Get(DbDataReader rs, string name, ISessionImplementor session)
        {
            return Get(rs, rs.GetOrdinal(name), session);
        }

        public override object Get(DbDataReader rs, int index, ISessionImplementor session)
        {
            return new MySqlGeometry(MySqlDbType.Geometry, (byte[]) rs[index]);
        }

        public override object NullSafeGet(DbDataReader rs, string[] names, ISessionImplementor session)
        {
            object result = base.NullSafeGet(rs, names, session);

            return result;
        }

        public override void Set(DbCommand cmd, object value, int index, ISessionImplementor session)
        {
            byte[] internalValue = ((MySqlGeometry) value).Value;

            var parameter = cmd.Parameters[index];

            parameter.DbType = DbType.Binary;

            // set the parameter value before the size check, since ODBC changes the size automatically
            parameter.Value = internalValue;

            // Avoid silent truncation which happens in ADO.NET if the parameter size is set.
            if (parameter.Size > 0 && internalValue.Length > parameter.Size)
            {
                throw new HibernateException("The length of the byte[] value exceeds the length configured in the mapping/parameter.");
            }
        }
    }
}