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Caching strategy - usage on both WinForms and ASP.NET

Hi

I have a Class which i chose to implement like attached in my Winforms Application.
This works very and gives a great performance.

The problem now however is that we are building an ASP.NET application where i would like to reuse this code.
However the web application could be accessing different Data on each request, meaning the data stored in this Singleton would be invalid and the correct data should be loaded.

How can i implement this in a way where i get the performance from using singleton in my Windows Application but on my Web application i would like nothing to be stored for more than the current request

The Idea behind doing this is to enable very fast lazy loading on objects refering to these ShiftGroups.
Should i do this in some other way ?

using System;
using System.ComponentModel;
using System.Linq;
using System.Data.SqlClient;
namespace FlexyBook.Business.Shift
{
    public class ShiftGroups
    {
        static BindingList<ShiftGroup> m_loaded_groups;
        public static BindingList<ShiftGroup> GetShiftGroups()
        {
 
            if (m_loaded_groups == null)
            {
                LoadGroups();
            }
            return m_loaded_groups;
        }
        public static ShiftGroup GetShiftGroup(int groupID)
        {
            return GetShiftGroups().Where(mGroup => mGroup.ID == groupID).FirstOrDefault();
        }
        private static void LoadGroups()
        {
            m_loaded_groups = new BindingList<ShiftGroup>();
 
            using (SqlConnection cnx = Data.Connection)
            {
                cnx.Open();
                using (SqlCommand command = new SqlCommand("SELECT * FROM vagtgruppe_db;", cnx))
                {
                    SqlDataReader reader = command.ExecuteReader();
                    while (reader.Read())
                    {
                        int id = (int)reader["vagtgruppe_id"];
                        string name = (string)reader["vagtgruppe_navn"];
                        int area = (int)reader["vagtgruppe_area"];
                        int order = (int)reader["vagtgruppe_order"];
                        bool doPrint = ((int)reader["vagtgruppe_print"]) == 1;
                        ShiftGroup mGroup = new ShiftGroup(name, area, id, order, doPrint);
                        m_loaded_groups.Add(mGroup);
                    }
                    reader.Close();
                }
            }
        }
    }
}

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OblivionSY

When i have implemented caching for both windows and web, I have generally implemented a new class for example "CacheHandler" and put a mehod in this class to GetShiftGroups.

This class then decides whether to serve up a windows cached item or a web cached item.

If the group list depends on the user (ie each web user has a different set of groups) this information will need to be passed into the CacheHandler.

Assuming there are not hundreds of users, you could store the lists in session which would be catered for each user automatically

Hope that helps

mSchmidt

ASKER

That was what i had in mind, however could you show how you implemented this ?

OblivionSY

It can be as complex as you want it to be really. In my implementation I created an Interface which defined all the methods a cache handler was suppose to be able to do (insert and retrieve) then created two implementations of this interface, one for windows and one for web. My cache handler merely instantiated the correct implementation class based on whether it was for windows or web. Your application just works with the interface, so doesnt care how the data is returned, merely that whatever implements those interfaces will guarantee to return something.

This could be incoporated into one file if you wanted to. How large scale is the project?

One file is simpler, but you have lots of "if online, then x else y" stuff all over the place. But the interface options (although IMO better) does take a little bit of setting up

mSchmidt

ASKER

Ahh okay,

How did you check whether your application was online or not ?

ASKER CERTIFIED SOLUTION

OblivionSY

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