Dictionary VS Hash Table

8. January 2008
Comments (3)

We all know how useful a hash table can be, but if you are using the .NET Framework 2.0 you should be using a Dictionary instead. A dictionary and a hash table in .NET 2.0 are very similar but with 1 main difference, a dictionary is faster because it does not need to box and unbox the data as a hash table would.

 

I made a simple program to see just how much faster a dictionary is than a hash table. I ran the test 20 times for each data set and the results were close each time. A GUID as the key and a boolean as the data.

This is the results of the last test for each dataset.

Time in Milliseconds for 100,000 keys Dictionary Hash Table
Inserting 34.41264 76.0970
Reading 18.9005 31.1648
Deleting 21.2474 30.4655

 

Time in Seconds for 10,000,000 keys Dictionary Hash Table
Inserting 6.5704143 26.9096540
Reading 3.1362891 5.6670613
Deleting 3.4623316 4.8830676

 

My comp specs

Vista Business 32bit, AMD 64 x2 5000+, 2GB ram

 

and now for the code I used. You can also download the project.  

 

 

 

 

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
 
namespace hashVsDictionary
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            #region init
 
            int num = 10000000;
            Guid[] guids = new Guid[num];
 
            Stopwatch s = new Stopwatch();
            s.Start();
 
            for (int i = 0; i < num; i++)
            {
                guids[i] = Guid.NewGuid();
            }
 
            s.Stop();
            Console.WriteLine("Data Creation = " + s.Elapsed);
            s.Reset();
 
            #endregion
 
            #region hash
 
            Hashtable hash = new Hashtable();
            s.Start();
            for (int i = 0; i < num; i++)
            {
                hash.Add(guids[i], true);
            }
            s.Stop();
            Console.WriteLine("Insert Hash = " + s.Elapsed);
            s.Reset();
 
            s.Start();
            for (int i = 0; i < num; i++)
            {
                bool b = Convert.ToBoolean(hash[guids[i]]);
            }
            Console.WriteLine("Extracting Hash = " + s.Elapsed);
            s.Reset();
 
            s.Start();
            for (int i = 0; i < num; i++)
            {
                hash.Remove(guids[i]);
            }
 
            Console.WriteLine("Removing Hash = " + s.Elapsed);
            s.Reset();
 
            #endregion
 
            #region dict
 
            Dictionary<Guid, bool> dict = new Dictionary<Guid, bool>();
            s.Start();
            for (int i = 0; i < num; i++)
            {
                dict.Add(guids[i], true);
            }
            s.Stop();
            Console.WriteLine("Insert Dictionary = " + s.Elapsed);
            s.Reset();
 
            s.Start();
            for (int i = 0; i < num; i++)
            {
                bool b = dict[guids[i]];
            }
            Console.WriteLine("Extracting Dict = " + s.Elapsed);
            s.Reset();
 
            s.Start();
            for (int i = 0; i < num; i++)
            {
                dict.Remove(guids[i]);
            }
            Console.WriteLine("Removing Dict = " + s.Elapsed);
            s.Reset();
 
            #endregion
 
            Console.ReadLine();
        }
    }
}

ASP.NET, Generics ,

ASP.NET Google Map Control

4. January 2008
Comments (5)

If you are looking for a ASP.NET Google Map Control, your search is now over.

Jacob Reimers from http://www.reimers.dk/ offers a great asp.net control in 2 flavors.

The free version which lets you easily display a map with markers and/or lines and a licensed version which gives you the full power of Google Maps.

 

I have used this control on a few of Web Solutions clients sites. Two of the better implementations are Low Index and Seville Homes.

 

*The deals listed below are entirely fictional. They were created for presentation purposes only.

 

lowIndex

seville

 

 

 

To use this great control, head over to http://www.reimers.dk/, download the free control, unzip it to your Bin folder in your web app and add a reference to it.

 

This is a sample asp.net page

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register Assembly="GoogleMap" Namespace="Reimers.Map" TagPrefix="Reimers" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

    <title>Google Map test</title>

</head>

<body>

    <form id="form1" runat="server">

        <div>

            <reimers:googlemap id="GMap" runat="server" width="349" height="354" onmarkerclick="GMap_MarkerClick"  />

        </div>

    </form>

</body>

</html>

 

and the code behind

 

using System;

using System.Web.UI;

using Reimers.Map;

 

public partial class _Default : Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        GMap.GoogleKey = "Your API Code here";

        GMap.MapType = MapType.Map;

        GMap.TypeControl = MapTypeControl.None;

        GMap.MapControl = ControlType.Small;

 

        GoogleMarker testMarker = new GoogleMarker("newMarker", new GoogleLatLng(43.611611, -88.952931));

        testMarker.MarkerText = "Test Marker";

        GMap.Markers.Add(testMarker);

 

        GMap.Latitude = testMarker.Latitude;

        GMap.Longitude = testMarker.Longitude;

        GMap.Zoom = 10;

    }

 

    protected void GMap_MarkerClick(GoogleMap GMap, GoogleMarker Marker, ref String MapCommand)

    {

        MapCommand = Marker.OpenInfoWindowHTML(GMap, Marker.MarkerText);

    }

}

ASP.NET, Google Maps ,