I have a class which acts as a file host, in essence you fire up this class with a port number and it hosts a file (in the real world in actually hosts part of a larger file containing many parts - but I've factored that out to try and get to the bottom of some issues). When I host a small file, it's fine and all works as expected, when I host larger files I get some unusual behaviour - specifically when I'm using windows media player to open the url to the listener. It seems like windows media player sends a get request to get everything, then a second request to start collecting chunks - but these always result in an exception "The network specified can no longer found". Fortunately, the original connection remains open and the file is ran in media player - but if I then try and move the slider to a specific point in the file, it fires up another request which errors out - I have managed to get it so windows media simply won't let you move the slider - but that doesn't work for our purposes. I've tried the same file hosted in IIS and it seems fine, and sniffed the packets and the match (well at least until the httplistener dies)... what am I missing.
Here is the code I'm using:
using SWAT.Apps.WebinarRecordingsViewer.Interfaces;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
namespace SWAT.Apps.WebinarRecordingsViewer.Implementation.Common
{
public class FileHost : IFileHost
{
private long Port { get; set; }
private string MimeType { get; set; }
private PointerRecord PointerRecord { get; set; }
public string FileName { get; set; }
public string ResultingFilename { get; set; }
public virtual string Url
{
get
{
return "http://localhost:" + this.Port + "/";
}
}
public Guid Guid { get; set; }
public FileHost(string filename, PointerRecord pointerRecord, string mimeType, long port, string resultingFilename, string realurl)
{
this.Port = port;
this.MimeType = mimeType;
this.FileName = filename;
this.PointerRecord = pointerRecord;
this.ResultingFilename = resultingFilename;
this.RealUrl = realurl;
this.Guid = Guid.NewGuid();
}
public void Dispose()
{
this.Stop();
}
private bool Stopped { get; set; }
private bool Stopping { get; set; }
public void Stop()
{
if (!Stopped)
{
Stopping = true;
if (this.listener!=null)
{
this.listener.Abort();
}
}
this.listener.Close();
}
public HttpListener listener { get; set; }
public void Start()
{
Stopped = false;
Stopping = false;
this.listener = new HttpListener();
this.listener.Prefixes.Add(string.Format("http://localhost:{0}/", this.Port));
this.listener.Start();
IAsyncResult result = listener.BeginGetContext(new AsyncCallback(ListenerCallback), this.listener);
}
public void ListenerCallback(IAsyncResult result)
{
if (this.listener == null)
return;
HttpListenerContext context = this.listener.EndGetContext(result);
// Call EndGetContext to complete the asynchronous operation.
if (!Stopping)
{
this.listener.BeginGetContext(new AsyncCallback(ListenerCallback), this.listener);
this.WriteFile(context.Response, context.Request);
}
if (Stopping)
{
Stopped = true;
Stopping = false;
}
}
public string RealUrl { get; set; }
private void WriteFile(HttpListenerResponse response, HttpListenerRequest request)
{
using (FileStream fs = File.Open(/*this.FileName*/"f:\\work\\download.wmv",FileMode.Open, FileAccess.Read, FileShare.Read))
{
response.KeepAlive = true;
response.SendChunked = true;
bool doingRange = false;
// response.AddHeader("Last-Modified", "Sun, 14 Nov 2010 21:15:21 GMT");
// response.ProtocolVersion = new Version("1.1");
// response.AddHeader("Cache-Control", "max-age=86400");
// response.AddHeader("ETag", string.Format("\"{0}\"", this.Guid.ToString()));
response.AddHeader("Accept-Ranges", "bytes");
response.ContentType = this.MimeType;
long start = 0;
long length = fs.Length;//this.PointerRecord.Length;
Int64 endByte = length-1;
if (request.Headers["range"] != null)
{
doingRange = true;
start = long.Parse(request.Headers["range"].Split('=')[1].Split('-')[0].Trim()) ;
if ((request.Headers["range"].Split('=')[1].Split('-').Length > 1))
{
Int64 endread = 0;
Int64.TryParse(request.Headers["range"].Split('=')[1].Split('-')[1].Trim(), out endread);
if (endread > 0)
{
endByte = endread;
}
}
if ((endByte + 1) > this.PointerRecord.Length)
{
endByte = this.PointerRecord.Length - 1;
}
length = (endByte - start) + 1;
response.AddHeader("Content-Range", "bytes=" + start.ToString() + "-" + endByte.ToString() + "/" + fs.Length.ToString());
response.ContentLength64 = length;
}
else
{
response.ContentLength64 = fs.Length;
}
byte[] buffer = new byte[1024 * 1024 ];
fs.Seek(start, SeekOrigin.Begin);
long read =0;
long runningTotal = 0;
try
{
var stream = response.OutputStream;
while ((length > 0) && ((read = fs.Read(buffer, 0, buffer.Length)) > 0))
{
runningTotal += read;
// if the read overshoots the requested read length
if (runningTotal > length)
{
read = read - (runningTotal - length);
}
stream.Write(buffer, 0, Convert.ToInt32(read));
stream.Flush();
if (runningTotal >= length)
{
break;
}
}
stream.Close();
response.StatusCode = doingRange ? (int)HttpStatusCode.PartialContent : (int)HttpStatusCode.OK;
response.StatusDescription = (doingRange ? HttpStatusCode.PartialContent : HttpStatusCode.OK).ToString();
}
catch (Exception ex)
{
var test = ex.Message;
}
finally
{
fs.Close();
fs.Dispose();
}
}
}
public event EventHandler<FileHostEventArgs> Error;
public void OnError(FileDownloadEventArgs e)
{
throw new NotImplementedException();
}
}
}
I'm not convinced whether this is media player misbehaving, or whether it's something in the server code... any help/suggestions would be great..
