W3C home > Mailing lists > Public > www-jigsaw@w3.org > July to August 2000

mark/reset not supported

From: Eamon Dalton <edalton@wilde.cs.tcd.ie>
Date: Fri, 11 Aug 2000 23:07:53 +0100 (BST)
To: www-jigsaw@w3.org
Message-ID: <Pine.GSO.4.10.10008112258320.11006-100000@wilde.cs.tcd.ie>

Hi,

I'm currently running Jigsaw in proxy configuration with a filter that I 
have developed. The filter currently monitors all  http requests and 
associated replies from my browser so that performance can be analysed as
is percieved from an end user prespective, logged to a database and are 
then summarised to give an overview of performance. What I am aiming at is 
to provide a framework to implement Quality of Service(QoS) for services
that are delivered over HTTP.

At the moment, I'm able to measure the time that a request is sent, the
time that it's associated response headers are recieved and the size
and time taken to download the reply entity (if one exists) so kbps 
download for the reply entity are possible to calculate.

I'm trying to extend my ingoing filter which currently only measures the 
time that a request is sent ,to be able to calculate the size and rate of 
upload of a request entity that a POST method typically has.

I'm having a problem with my code shown below which gives me the following 
error for certain POST requests.. It appears that somewhere(I think in
HttpBasicServer), an inputStream is marked and reset which is causing the 
problem but I'm not sure..

Any help would be appreciated..

Eamon.


java.io.IOException: mark/reset not supported
        at java.io.InputStream.reset(InputStream.java:336)
        at org.w3c.www.protocol.http.HttpBasicServer.runRequest(Compile
        at org.w3c.www.protocol.http.HttpManager.runRequest(Compiled Co
        at org.w3c.jigsaw.proxy.ForwardFrame.perform(Compiled Code)
        at org.w3c.tools.resources.FramedResource.performFrames(Compile
        at org.w3c.tools.resources.FramedResource.perform(Compiled Code
        at org.w3c.jigsaw.http.httpd.perform(Compiled Code)
        at org.w3c.jigsaw.http.Client.processRequest(Compiled Code)
        at org.w3c.jigsaw.http.Client.startConnection(Compiled Code)
        at org.w3c.jigsaw.http.socket.SocketClient.run(SocketClient.jav
        at org.w3c.util.CachedThread.run(Compiled Code)


In my ingoingfilter, I am calling the following,

if(request.hasOutputStream()){
	try {
		PipedOutputStream pout = new PipedOutputStream();
		PipedInputStream  pin  = new PipedInputStream(pout);
		new RequestDataMover(request.getOutputStream(),pout);
		request.setOutputStream(pin);
		} catch (Exception ex) {
		ex.printStackTrace();
		}
	}
}

and RequestDataMover(which is similar to what the
org.w3c.jigsaw.filters.GZIPDataMover does except that it's being done on
the request) looks like


class RequestDataMover extends Thread {

    InputStream in = null;
    OutputStream out = null;

    public void run() {
	try {

	    byte buf[] = new byte[1];
	    int  got   = -1;


		//Calcuate some parameter..

		int contentLenght = 0;
	    	while ((got = in.read(buf)) >= 0){
			out.write(buf, 0, got);
			contentLenght = contentLenght + 1;
		}
		
		//Calcuate some more parameter..	
		
		} catch (IOException ex) {
		  ex.printStackTrace();
	} finally {
	    try { in.close(); } catch (Exception ex) {};
	    try { out.close(); } catch (Exception ex) {} ;
	}
    }

    RequestDataMover(InputStream in, OutputStream out ) {
	this.in  = in;
	this.out = out;
	setName("RequestDataMover");
	start();
    }
}
Received on Friday, 11 August 2000 18:08:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 9 April 2012 12:13:34 GMT