gziphelper.cs

破解的飞信源代码

namespace Imps.Utils
{
    using System;
    using System.IO;
    using System.IO.Compression;
    using System.Text;

    public class GZipHelper
    {
        private static Encoding encode = Encoding.UTF8;

        public static void CompressFile(string sourceFile, string destinationFile)
        {
            if (!File.Exists(sourceFile))
            {
                throw new FileNotFoundException();
            }
            byte[] buffer = null;
            FileStream stream = null;
            FileStream stream2 = null;
            GZipStream stream3 = null;
            try
            {
                stream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read);
                buffer = new byte[stream.Length];
                if (stream.Read(buffer, 0, buffer.Length) != buffer.Length)
                {
                    throw new ApplicationException();
                }
                stream2 = new FileStream(destinationFile, FileMode.OpenOrCreate, FileAccess.Write);
                stream3 = new GZipStream(stream2, 1, true);
                stream3.Write(buffer, 0, buffer.Length);
            }
            finally
            {
                if (stream != null)
                {
                    stream.Close();
                }
                if (stream3 != null)
                {
                    stream3.Close();
                }
                if (stream2 != null)
                {
                    stream2.Close();
                }
            }
        }

        public static string CompressString(string input)
        {
            if (input.Length == 0)
            {
                return string.Empty;
            }
            string text = string.Empty;
            MemoryStream stream = null;
            GZipStream stream2 = null;
            try
            {
                byte[] bytes = encode.GetBytes(input);
                stream = new MemoryStream();
                using (stream2 = new GZipStream(stream, 1, true))
                {
                    stream2.Write(bytes, 0, bytes.Length);
                }
                text = Convert.ToBase64String(stream.ToArray());
            }
            catch
            {
            }
            finally
            {
                if (stream != null)
                {
                    stream.Dispose();
                }
                if (stream2 != null)
                {
                    stream2.Dispose();
                }
            }
            return text;
        }

        public static void DecompressFile(string sourceFile, string destinationFile)
        {
            if (!File.Exists(sourceFile))
            {
                throw new FileNotFoundException();
            }
            FileStream stream = null;
            FileStream stream2 = null;
            GZipStream stream3 = null;
            byte[] buffer = null;
            try
            {
                stream = new FileStream(sourceFile, FileMode.Open);
                stream3 = new GZipStream(stream, 0, true);
                buffer = new byte[4];
                int num = ((int) stream.Length) - 4;
                stream.Position = num;
                stream.Read(buffer, 0, 4);
                stream.Position = 0;
                byte[] buffer2 = new byte[BitConverter.ToInt32(buffer, 0) + 100];
                int offset = 0;
                int count = 0;
                while (true)
                {
                    int num5 = stream3.Read(buffer2, offset, 100);
                    if (num5 == 0)
                    {
                        break;
                    }
                    offset += num5;
                    count += num5;
                }
                stream2 = new FileStream(destinationFile, FileMode.Create);
                stream2.Write(buffer2, 0, count);
                stream2.Flush();
            }
            finally
            {
                if (stream != null)
                {
                    stream.Close();
                }
                if (stream3 != null)
                {
                    stream3.Close();
                }
                if (stream2 != null)
                {
                    stream2.Close();
                }
            }
        }

        public static string DecompressString(string base64String)
        {
            if (base64String.Length == 0)
            {
                return string.Empty;
            }
            string text = string.Empty;
            try
            {
                byte[] buffer = Convert.FromBase64String(base64String);
                int count = BitConverter.ToInt32(new byte[] { buffer[buffer.Length - 4], buffer[buffer.Length - 3], buffer[buffer.Length - 2], buffer[buffer.Length - 1] }, 0);
                using (MemoryStream stream = new MemoryStream(buffer, 0, buffer.Length))
                {
                    using (GZipStream stream2 = new GZipStream(stream, 0))
                    {
                        byte[] buffer3 = new byte[count];
                        stream2.Read(buffer3, 0, count);
                        return encode.GetString(buffer3);
                    }
                }
            }
            catch
            {
            }
            return text;
        }
    }
}