Today was the most surprising day, it all happened when I opened my inbox to find this email from Microsoft that informed me being Microsoft Community Contributor Award recipient. This is a proud moment and was rather a great feel to get this recognition from Microsoft. Very encouraging for me for all the participation. If you would like to know more about this award, please follow this link.

What is the difference between String and StringBuilder?

Why? because they are similar in concept. A Uri/String is immutable (read-only, if you will). A UriBuilder/StringBuilder provides a mechanish to modify the contents of a Uri/String without having to destroy and recreate a Uri/String each time (which, if done often enough, could hurt performance).

String scheme = "http";
String target = "balaji.com";
int port = 8080;
String path = sample/page1.aspx";
String query = "?query=search text";
UriBuilder u = new UriBuilder(scheme, target, port, path, query);

Report Server: http://localhost/ReportServer
Report Manager: http://localhost/Reports/Pages/Folder.aspx

The page took more time to load, however gave me the following error even thou I was sure that I gave windows authentication for security during installation.

Microsoft.ReportingServices.Diagnostics.Utilities.ErrorStrings
The permissions granted to user ‘mydomain\myAccount’ are insufficient for performing this operation. (rsAccessDenied) (ReportingServicesLibrary)

After a long research, I finally discovered that you have to open Internet Explorer in administrator mode (Right-Click and Open as Administrator) and try navigating to the above URLs. This is because initially the SSRS will have the following group “BUILTIN\Administrators” as “System Administrator” and you have to explicitly open as administrator when using Internet Explorer.

You will discover that this time you are able to load the pages and the first thing for me to do was to click on the “Site Settings” and under the Security option added my username as “System Administrator” under “New Role Assignment”.

After this done, you will notice that you can open up the Report Server / Manager URL’s under normal mode (without opening it as Administrator)

More Info from MSDN: http://msdn.microsoft.com/en-us/library/aa337279.aspx

Hope this is of help to somebody who is caught up with this issue.

Do you know?
CAPTCHA considers the human to be a hero, while computers to be a villain even thou it’s the human who drives the computer to do all evil stuff and the computer finally takes the blame! I hope with the advancement of “Artificial Intelligence”, computers one day can sue for this discrimination. Anyway the real definition could be, “Process of determining good guys from bad guys.”

CAPTCHA has grown over the years with all the experience having dealt with SPAM attacks and HACKS. However what I have found recently encouraged to write this blog, have a look at this image below:

This CAPTCHA is meaningless and I myself don’t know how to pass this challenge! Even thou I can refresh and get a new CAPTCHA I was concerned about the users with disability and how tough and annoying it would be for them.

Arguably thou the need for CAPTCHA has to be much complex these days, this kind of complexity would prove worthless and thats when I thought, why not CAPTCHA implement this? Have a look at the image below:

For most of the readers you might not understand what this means ”அம்மா அப்பா”, but this is written in Tamil language which means “mother father”. I guess you should have got the point already now. In todays world every user is tied to atleast one registration process, could be an open id or from any other services like facebook, google, yahoo, etc. During the registration, information like country / language are captured from the user. The system could use this information and offer challenges based on the user’s language (during registration), a sample question could be:

Translate “அம்மா” in English.

This way you will be reducing attacks enormously. Remember if it was english language alone, then maintaining one dictionary for english would be more than enought to compromise the CAPTCHA system.

Thou this implementation offers primarily one challenge which is to support the script for a given language, on the other hand this could be a first level filter / test that would be even more challenging.

Well, coming to my blog world, I always wanted to investigate a bit on how GMAIL has been smartly displaying related links / products / ads when reading my email, thou it looks to be fascinating at the beginning, a little thought has provoked my mind urging the need to find the smoking gun behind this, most importantly does GOOGLE read my email contents? So that’s what my next post is going to be!

I have named it “Byte Player” and according to the name the application would be playing the music when data is fed into as byte arrays. The database is designed using the same strategy that’s designed to store normal files.

Add the following DLL reference: “irrKlang.NET4″ and put the following DLLs to your bin folder:
~ ikpFlac.dll
~ ikpMP3.dll
~ irrKlang.NET4.dll

Use the following reference:

using IrrKlang;

Generated Database Script to Create Table:

CREATE TABLE [dbo].[MusicLibrary](
	[FileID] [uniqueidentifier] ROWGUIDCOL  NOT NULL,
	[FileName] [nvarchar](50) NOT NULL,
	[FileContent] [varbinary](max) NOT NULL,
	[FileType] [nvarchar](50) NOT NULL,
	[CreateBy] [nvarchar](128) NULL,
	[CreatedOn] [datetime] NULL,
	[ModifiedBy] [nvarchar](128) NULL,
	[ModifiedOn] [datetime] NULL,
 CONSTRAINT [PK_MusicLibrary] PRIMARY KEY CLUSTERED 
(
	[FileID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

SET ANSI_PADDING OFF
GO

ALTER TABLE [dbo].[MusicLibrary] ADD  CONSTRAINT [DF_MusicLibrary_FileID]  DEFAULT (newid()) FOR [FileID]
GO

ALTER TABLE [dbo].[MusicLibrary] ADD  CONSTRAINT [DF_MusicLibrary_CreateBy]  DEFAULT (user_name(user_id(user_name()))) FOR [CreateBy]
GO

ALTER TABLE [dbo].[MusicLibrary] ADD  CONSTRAINT [DF_MusicLibrary_CreatedOn]  DEFAULT (getdate()) FOR [CreatedOn]
GO

ALTER TABLE [dbo].[MusicLibrary] ADD  CONSTRAINT [DF_MusicLibrary_ModifiedBy]  DEFAULT (user_name(user_id(user_name()))) FOR [ModifiedBy]
GO

ALTER TABLE [dbo].[MusicLibrary] ADD  CONSTRAINT [DF_MusicLibrary_ModifiedOn]  DEFAULT (getdate()) FOR [ModifiedOn]
GO

The C# application will hold the following methods to interact with the database.

const string connectionString = @"Server=KRISHNA\SQLEXPRESS;Database=music;Trusted_Connection=True;";

/// <summary>
/// Function to select files from the computer to be saved in the database.
/// </summary>
private void OpenMP3Files()
{
    OpenFileDialog dialog = new OpenFileDialog();
    dialog.Filter = "MP3 files|*.mp3";
    dialog.FilterIndex = 1;
    dialog.InitialDirectory = @"C:\\";
    dialog.RestoreDirectory = true;
    dialog.CheckFileExists = true;
    dialog.CheckPathExists = true;
    dialog.Multiselect = true;
    if (dialog.ShowDialog() == DialogResult.OK)
    {
        Cursor.Current = Cursors.WaitCursor;
        foreach (string filename in dialog.FileNames)
        {
            FileStream stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
            using (BinaryReader reader = new BinaryReader(stream))
            {
                long length = new FileInfo(filename).Length;
                InsertMP3File(Path.GetFileName(filename), reader.ReadBytes((int)length));
            }
        }
        GetAllMP3();
    }
}

/// <summary>
/// Retrieves entire MP3 list from database (excludes the file content)
/// </summary>
private void GetAllMP3()
{
    string queryString = "SELECT [FileID], [FileName] FROM [MusicLibrary]";
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        SqlDataAdapter adapter = new SqlDataAdapter();
        adapter.SelectCommand = new SqlCommand(queryString, connection);
        DataSet dataset = new DataSet();
        adapter.Fill(dataset);
        if (dataset.Tables.Count > 0)
        {
            gridMusic.DataSource = dataset.Tables[0];
            gridMusic.Columns[0].Visible = false;
            gridMusic.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;
        }
    }
}

/// <summary>
/// Individual files are stored in the database.
/// </summary>
/// <param name="filename"></param>
/// <param name="data"></param>
private void InsertMP3File(string filename, byte[] data)
{
    string filetype = @"audio / mpeg";
    string queryString = "INSERT INTO [MusicLibrary] ([FileName] ,[FileContent] ,[FileType]) VALUES (@FileName, @FileContent, @FileType)";
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        SqlCommand command = new SqlCommand(queryString, connection);
        command.Parameters.Add(new SqlParameter("@FileName", (object)filename));
        command.Parameters.Add(new SqlParameter("@FileContent", (object)data));
        command.Parameters.Add(new SqlParameter("@FileType", (object)filetype));
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();
    }
}

Inorder to play the MP3 file I had some initial consideration and based on some strong reviews started of with the “NAudio” library [Ref: http://naudio.codeplex.com] but i faced some issues while trying to play the file from stream and upon searching through discussion forums I discovered that these issues are currently being worked upon and would have a fix in future releases; Therefore i was forced to consider my second choice “irrKlang” sound library [Ref: http://www.ambiera.com/irrklang/] and it worked out to be more simple and brilliant! The code illustrated below shows the fine integration between this library api and the database.

const string sound = "static.mp3";
ISoundEngine engine = new ISoundEngine();

/// <summary>
/// Retrieve individual file content from database
/// </summary>
/// <param name="fileID"></param>
private void GetMP3Data(string fileID)
{
    string queryString = "SELECT [FileContent] FROM [MusicLibrary] WHERE [FileID] = @FileID";
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        SqlCommand command = new System.Data.SqlClient.SqlCommand(queryString, connection);
        command.Parameters.Add(new SqlParameter("@FileID", (object)fileID));
        command.Connection.Open();
        byte[] buffer = (byte[])command.ExecuteScalar();
        if (engine.IsCurrentlyPlaying(sound))
        {
            engine.RemoveAllSoundSources();
        }
        PlayMP3(buffer, sound);
        command.Connection.Close();
    }
}

/// <summary>
/// Play a single MP3 file
/// </summary>
/// <param name="data"></param>
/// <param name="filename"></param>
private void PlayMP3(byte[] data, string filename)
{
    ISoundSource source = engine.AddSoundSourceFromMemory(data, filename);
    engine.Play2D(filename);
}

I am so much interested in improving this and building a full-fledged player that would support right from ripping CD’s and expanding the database to include more information about the music albums and MP3 tags.

Case 1: Sample1.xsd

<?xml version="1.0" encoding="ISO-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
  <xs:simpleType name="PropertyNames">
    <xs:restriction base="xs:string">
      <xs:enumeration value="prop1"></xs:enumeration>
      <xs:enumeration value="prop2"></xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:element name="Items">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="Item" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="name" type="xs:string"/>
              <xs:element name="properties" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

When you use the dataset’s “ReadXmlSchema” method you will find that the dataset will contain 2 tables!

// Create the DataSet to read the schema into.
DataSet ds = new DataSet();
// Invoke the ReadXmlSchema method with the file name.
ds.ReadXmlSchema(@"C:\\test\\Sample1.xsd");

A XML instance representation for this schema will be:

<Items>
  <Item> [1..*]
    <name> xs:string </name> [1]
    <properties> xs:string </properties> [0..*]
  </Item>
</Items>

Case 2: Sample2.xsd

<?xml version="1.0" encoding="iso-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
  <xs:simpleType name="PropertyNames">
    <xs:restriction base="xs:string">
      <xs:enumeration value="prop1"></xs:enumeration>
      <xs:enumeration value="prop2"></xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:element name="Items">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="Item" maxOccurs="unbounded">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="name" type="xs:string"/>
              <xs:element name="properties" type="PropertyNames" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

This time when you execute the following code you will find that the dataset will contain 1 table!

// Create the DataSet to read the schema into.
DataSet ds = new DataSet();
// Invoke the ReadXmlSchema method with the file name.
ds.ReadXmlSchema(@"C:\\test\\Sample1.xsd");

Whereas the XML instance representation for this schema will be:

<Items>
  <Item> [1..*]
    <name> xs:string </name> [1]
    <properties> PropertyNames </properties> [0..*]
  </Item>
</Items>

Actually, you should have noted that thou the XML instance representation for this schema (Case 2) is similar to the one in (Case 1), the dataset had only one table instead of two; After several hours of investigation and read through, I happen to discover (atleast lucky) thats there is a “Microsoft Support Article” which explains the “Limitations for DataSet Schema Files (XSD)”.

Please find the references to the file at the following location: http://support.microsoft.com/kb/319372

Question: How does this article applies to my scenario?
Answer: Use of Restriction Element Is Mostly Ignored
You can derive a new simple type by restricting an existing simple type with the restriction element. When you use the restriction element in simple types, the restriction element is ignored. Therefore, all the sub-elements of that restriction element are ignored also.

All restriction elements are ignored except the XSD simple type “string”, and its facets as follows:
> length
> minlength
> maxlength

In your .NET project add references to the following DLLs:
Microsoft.Deployment.Compression.dll
Microsoft.Deployment.Compression.Zip.dll

And we will be using this library (Microsoft.Deployment.Compression.Zip) for creating CAB (cabinet) files.

using Microsoft.Deployment.Compression.Zip;

In our example we will see how to add individual files to the ZIP file and how to add a folder (directory) to the ZIP file and finally how to extract (unpack) the ZIP file.

// CREATING ZIP FILE BY ADDING LIST OF FILES
ZipInfo zip = new ZipInfo(@"C:\testarchive1.zip");
List<string> files = new List<string>();
files.Add(@"C:\test1.txt");
files.Add(@"C:\test2.txt");
files.Add(@"C:\test3.txt");
zip.PackFiles(null, files, null);

// CREATING ZIP FILE BY ADDING FOLDER (WITH SUB-FOLDERS) USING MAXIMUM COMPRESSION
zip = new ZipInfo(@"C:\testarchive2.zip");
zip.Pack(@"C:\Balaji", true, Microsoft.Deployment.Compression.CompressionLevel.Max, null);

// EXTRACTING (UNPACKING) FILES FROM ZIP FILE
zip = new ZipInfo(@"C:\testarchive2.zip");
zip.Unpack(@"C:\ArchiveDir");

In your .NET project add references to the following DLLs:
Microsoft.Deployment.Compression.dll
Microsoft.Deployment.Compression.Cab.dll

And we will be using this library (Microsoft.Deployment.Compression.Cab) for creating CAB (cabinet) files.

using Microsoft.Deployment.Compression.Cab;

In our example we will see how to add individual files to the CAB file and how to add a folder (directory) to the CAB file and finally how to extract (unpack) the CAB file.

// CREATING CAB FILE BY ADDING LIST OF FILES
CabInfo cab = new CabInfo(@"C:\testarchive1.cab");
List files = new List();
files.Add(@"C:\test1.txt");
files.Add(@"C:\test2.txt");
files.Add(@"C:\test3.txt");
cab.PackFiles(null,files,null);

// CREATING CAB FILE BY ADDING FOLDER (WITH SUB-FOLDERS) USING MINIMUM COMPRESSION
cab = new CabInfo(@"C:\testarchive2.cab");
cab.Pack(@"C:\Balaji", true, Microsoft.Deployment.Compression.CompressionLevel.Min, null);

// EXTRACTING (UNPACKING) FILES FROM CAB FILE
cab = new CabInfo(@"C:\testarchive1.cab");
cab.Unpack(@"C:\ArchieveDir");