Class compressed/decompressed with. NET 2.0)

The main function is to reduce the amount of data transmitted over the network,

Using System;
Using System. Collections. Generic;
Using System. Collections;
Using System. Text;
Using System. IO;
Using System. IO. Compression;

Namespace CompressionService
{
Public class Compression
{

// Compression
Public int Compress (byte [] source, ref byte [] dest)
{
Int resultcode;
Try
{
Memorystream MS = new memorystream ();

// Use the newly created memory stream for the compressed data.
Gzipstream compressedzipstream = new gzipstream (MS, compressionmode. Compress, true );

Compressedzipstream. Write (source, 0, source. Length );
Compressedzipstream. Close ();

Ms. Position = 0;
Dest = ms. ToArray ();

Ms. Close ();
Resultcode = 1;
}
Catch
{
Resultcode = 0;
}
Return resultcode;

}

// Extract

Public int UnCompress (byte [] source, ref byte [] dest)
{
Int resultcode;

Try
{
MemoryStream tempms = new MemoryStream (source );
Tempms. Position = 0;
GZipStream tempzip = new GZipStream (tempms, CompressionMode. Decompress );

Dest = GetDeData (tempzip, source );
Tempzip. Close ();
// Tempms. Close ();
// Console. WriteLine ("temporarily decoded data: {0}", System. Text. Encoding. Default. GetString (dest ));
Resultcode = 1;
}
Catch
{
Resultcode = 0;
}
Return resultcode;
}

Public byte [] GetDeData (Stream stream, byte [] temp) // obtain the decompressed file data
{

Int totalcount = 0;
Int datalen = temp. Length;
Int bytecount = datalen;

While (true)
{

Byte [] tempdata = new byte [bytecount];
Int bytesread = stream. Read (tempdata, 0, bytecount );
If (bytesread = 0)
Break;
Totalcount + = bytesread;
Bytecount = totalcount + bytesread;
}
Stream. Close ();

MemoryStream MS = new MemoryStream (temp );
GZipStream gs = new GZipStream (MS, CompressionMode. Decompress );
Byte [] alltempdata = new byte [totalcount];
Gs. Read (alltempdata, 0, alltempdata. Length );
Gs. Close ();
Return alltempdata;
}
}
}

The call class P is as follows:

Public static void Main ()
{
CompressionService. Compression ct = new CompressionService. Compression ();
Byte [] origialdata = OpenFile ();
Console. WriteLine ("Raw Data Length: {0}", origialdata. Length );
Byte [] test = NULL;
Ct. Compress (origialdata, ref test );
Console. writeline ("Compressed Data Length: {0}", test. Length );
Byte [] uncompressdata = NULL;
Ct. uncompress (test, ref uncompressdata );
Console. writeline ("decompress data: {0}, size: {1}", system. text. encoding. default. getstring (uncompressdata ). tostring (), uncompressdata. length );
}

Public static byte [] openfile ()
{
// String test = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzddafdsfsfsdafdfa, We are Chinese ";
Filestream infile = new filestream ("C: \ test.txt", filemode. Open, fileaccess. Read, fileshare. Read );
Byte [] buffer = new byte [infile. Length];
Infile. Read (buffer, 0, buffer. Length );

Console. writeline ("Raw data: {0}", system. Text. encoding. Default. getstring (buffer ));

// System. Text. encoding. ASCII. getstring (TEST ));
Return buffer;
}

 

For online File compression and decompression:

Public void CompressFile (string sourceFile, string destinationFile)
{
// Make sure the source file is there
If (File. Exists (sourceFile) = false)
Throw new FileNotFoundException ();

// Create the streams and byte arrays needed
Byte [] buffer = null;
Filestream sourcestream = NULL;
Filestream destinationstream = NULL;
Gzipstream compressedstream = NULL;

Try
{
// Read the bytes from the source file into a byte array
Sourcestream = new filestream (sourcefile, filemode. Open, fileaccess. Read, fileshare. Read );

// Read the source stream values into the buffer
Buffer = new byte [sourceStream. Length];
Int checkCounter = sourceStream. Read (buffer, 0, buffer. Length );

If (checkCounter! = Buffer. Length)
{
Throw new ApplicationException ();
}

// Open the filestream to write
Destinationstream = new filestream (destinationfile, filemode. openorcreate, fileaccess. Write );

// Create a compression stream pointing to the destiantion stream
Compressedstream = new gzipstream (destinationstream, compressionmode. Compress, true );

// Now write the compressed data to the destination file
CompressedStream. Write (buffer, 0, buffer. Length );
}
Catch (ApplicationException ex)
{
// MessageBox. Show (ex. Message, "An Error occurred when compressing the file:", MessageBoxButtons. OK, MessageBoxIcon. Error );
}
Finally
{
// Make sure we allways close all streams
If (sourcestream! = NULL)
Sourcestream. Close ();

If (compressedstream! = NULL)
Compressedstream. Close ();

If (destinationstream! = NULL)
DestinationStream. Close ();
}
}

Public void DecompressFile (string sourceFile, string destinationFile)
{
// Make sure the source file is there
If (File. Exists (sourceFile) = false)
Throw new FileNotFoundException ();

// Create the streams and byte arrays needed
Filestream sourcestream = NULL;
Filestream destinationstream = NULL;
Gzipstream decompressedstream = NULL;
Byte [] quartetbuffer = NULL;

Try
{
// Read in the compressed source stream
Sourcestream = new filestream (sourcefile, filemode. Open );

// Create a compression stream pointing to the destiantion stream
Decompressedstream = new gzipstream (sourcestream, compressionmode. decompress, true );

// Read the footer to determine the length of the destiantion File
Quartetbuffer = new byte [4];
Int position = (INT) sourcestream. Length-4;
SourceStream. Position = position;
SourceStream. Read (quartetBuffer, 0, 4 );
SourceStream. Position = 0;
Int checkLength = BitConverter. ToInt32 (quartetBuffer, 0 );

Byte [] buffer = new byte [checkLength + 100];

Int offset = 0;
Int total = 0;

// Read the compressed data into the buffer
While (true)
{
Int bytesRead = decompressedStream. Read (buffer, offset, 100 );

If (bytesRead = 0)
Break;

Offset + = bytesRead;
Total + = bytesRead;
}

// Now write everything to the destination file
DestinationStream = new FileStream (destinationFile, FileMode. Create );
DestinationStream. Write (buffer, 0, total );

// And flush everyhting to clean out the buffer
DestinationStream. Flush ();
}
Catch (ApplicationException ex)
{
// MessageBox. Show (ex. Message, "An Error occurred when extracting the file:", MessageBoxButtons. OK, MessageBoxIcon. Error );
}
Finally
{
// Make sure we allways close all streams
If (sourceStream! = Null)
SourceStream. Close ();

If (decompressedStream! = Null)
DecompressedStream. Close ();

If (destinationStream! = Null)
DestinationStream. Close ();
}

}