/Blazing.CMS/Blazing.UI.Cms/Util/ViewstateCompressionHelper.cs

using System;

using System.IO;

using System.IO.Compression;

using System.Web.UI;



namespace Blazing.Web.Util

{

    public class ViewstateCompressionHelper

    {

        public static object LoadPageStateFromPersistenceMedium(Page page)

        {

            string viewState = page.Request.Form["__VSTATE"];

            byte[] bytes = Convert.FromBase64String(viewState);

            bytes = Decompress(bytes);

            LosFormatter formatter = new LosFormatter();

            return formatter.Deserialize(Convert.ToBase64String(bytes));

        }



        public static void SavePageStateToPersistenceMedium(Page page, object viewState)

        {

            LosFormatter formatter = new LosFormatter();

            StringWriter writer = new StringWriter();

            formatter.Serialize(writer, viewState);

            string viewStateString = writer.ToString();

            byte[] bytes = Convert.FromBase64String(viewStateString);

            bytes = Compress(bytes);

            if(ScriptManager.GetCurrent(page) == null)

                page.ClientScript.RegisterHiddenField("__VSTATE", Convert.ToBase64String(bytes));

            else

                ScriptManager.RegisterHiddenField(page, "__VSTATE", Convert.ToBase64String(bytes));

        }



        public static byte[] Compress(byte[] data)

        {

            MemoryStream output = new MemoryStream();

            DeflateStream deflate = new DeflateStream(output,

                              CompressionMode.Compress, true);

            deflate.Write(data, 0, data.Length);

            deflate.Close();

            return output.ToArray();

        }



        public static byte[] Decompress(byte[] data)

        {

            MemoryStream input = new MemoryStream();

            input.Write(data, 0, data.Length);

            input.Position = 0;

            DeflateStream deflate = new DeflateStream(input,

                              CompressionMode.Decompress, true);

            MemoryStream output = new MemoryStream();

            byte[] buff = new byte[512];

            int read = -1;

            read = deflate.Read(buff, 0, buff.Length);

            while (read > 0)

            {

                output.Write(buff, 0, read);

                read = deflate.Read(buff, 0, buff.Length);

            }

            deflate.Close();

            return output.ToArray();

        }

    }

}