I have a pretty great SqlDataReader wrapper in which I can map the output into a strongly typed list.
What I am finding now is that on larger datasets with larger numbers of columns, performance could probably be a bit better if I can optimize my mapping.
In thinking about this there is one section in particular that I am concerned about as it seems to be the heaviest hitter:
while (_Rdr.Read())
{
T newObject = new T();
for (int i = 0; i <= _Rdr.FieldCount - 1; ++i)
{
PropertyInfo info = (PropertyInfo)_ht[_Rdr.GetName(i).ToUpper()];
if ((info != null) && info.CanWrite)
{
info.SetValue(newObject, (_Rdr.GetValue(i) is DBNull) ? default(T) : _Rdr.GetValue(i), null);
}
}
_en.Add(newObject);
}
_Rdr.Close();
What I would really like to know, is if there is a way that I can make this loop asyncronous? I feel that will make all the difference in the world with this beast :)
Here is the entire Map method in case anyone can see where I can make further improvements on it...
IList<T> Map<T>
// Map our datareader object to a strongly typed list
private static IList<T> Map<T>(IDataReader _Rdr) where T : new() {
try {
Type _t = typeof(T);
List<T> _en = new List<T>();
Hashtable _ht = new Hashtable();
PropertyInfo[] _props = _t.GetProperties();
Parallel.ForEach(_props, info =>
{
_ht[info.Name.ToUpper()] = info;
});
while (_Rdr.Read())
{
T newObject = new T();
for (int i = 0; i <= _Rdr.FieldCount - 1; ++i)
{
PropertyInfo info = (PropertyInfo)_ht[_Rdr.GetName(i).ToUpper()];
if ((info != null) && info.CanWrite)
{
info.SetValue(newObject, (_Rdr.GetValue(i) is DBNull) ? default(T) : _Rdr.GetValue(i), null);
}
}
_en.Add(newObject);
}
_Rdr.Close();
return _en;
}catch(Exception ex){
_Msg += "Wrapper.Map Exception: " + ex.Message;
ErrorReporting.WriteEm.WriteItem(ex, "o7th.Class.Library.Data.Wrapper.Map", _Msg);
return default(IList<T>);
}
}
