split byte[] array

Question

private Arraylist split(byte[] filebytes, int range)
{
}

how to split this filebytes by given range i.e if range is 100 it should split the filebytes by 100kb and put this into the arraylist untill the eof. i have .net framework 1.1 only... thanks in advance.

Answer 1

So, if I understand this correctly, you want and ArrayList of byte[] of size 100000? I can't write the code for you (don't have VS here at the moment), but the most efficient way is to create new array objects and use Array.Copy() to copy the data from your big array into the bunch of smaller arrays.

Answer 2

If I understand the question correctly, you want to chop the existing array into arrays of (at most) 100k elements, and put those arrays in the array list?

ArrayList Split(byte[] filebytes, int range)
{
    range *= 1000;
    int pos = 0;
    int remaining;

    ArrayList result = new ArrayList();

    while ((remaining = filebytes.Length - pos) > 0)
    {
        byte[] block = new byte[Math.Min(remaining, range)];

        Array.Copy(filebytes, pos, block, 0, block.Length);
        result.Add(block);

        pos += block.Length;
    }

    return result;
}

Change 1000 to 1024 if that was your intention :)

I can't really think of a reason why you'd want to do something like this though. Loading one huge array of bytes and then splitting into blocks is rather inefficient if you could have split them into 100k blocks while reading your data.

---

Regarding your comment: sending an entire file to a socket should be much simpler than you're making it to be. I have no way of testing, but this should work in .NET 1.1.

private void SendFileToSocket(string fileName)
{
    Socket socket = new Socket(
        AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

    using (socket)
    {
        socket.Connect("server.domain.com", 12345);

        using (NetworkStream networkStream = new NetworkStream(socket))
        using (FileStream fileStream = File.OpenRead(fileName))
        {
            byte[] buffer = new byte[32768];

            while (true)
            {
                int bytesRead = fileStream.Read(buffer, 0, buffer.Length);
                if (bytesRead == 0)
                    break;

                networkStream.Write(buffer, 0, bytesRead);
            }
        }
    }
}

The buffer size is a little arbitrary, but it should be large enough.

Answer 3

The idea suggested by Thorarin is a good solution. However I would make a small change regarding the declaration of the byte[] block. It is better to place the declaration outside the while. As far as I know that is better for your performance. You won't notice very much (especially not on small versions of the filebytes array), but software like FXCop will warn you about declarations within while/for constructions (at least as far as I know). So the code would look like this:

ArrayList Split(byte[] filebytes, int range)
{
    range *= 1000;
    int pos = 0;
    int remaining;

    ArrayList result = new ArrayList();

    //Placed the declaration of block outside the while. 
    byte[] block = null; 
    while ((remaining = filebytes.Length - pos) > 0)
    {
        block = new byte[Math.Min(remaining, range)];

        Array.Copy(filebytes, pos, block, 0, block.Length);
        result.Add(block);

        pos += block.Length;
    }

    return result;
}

For more details look at: Declare variable inside or outside the [email protected]