The Tor Browser / file revision

 const Cc = Components.classes;

 const Ci = Components.interfaces;

 const TIMEOUT_INTERVAL_MS = 100;

 function handleRequest(request, response) {

   // Allow us to asynchronously construct the response with timeouts

   // rather than forcing us to make the whole thing in one call. See

   // bug 396226.

   response.processAsync();

   // Figure out whether the client wants to load the image, or just

   // to tell us to finish the previous load

   var query = {};

   request.queryString.split('&').forEach(function (val) {

     var [name, value] = val.split('=');

     query[name] = unescape(value);

   });

   if (query["continue"] == "true") {

     // Debugging information so we can figure out the hang

     dump("file_IconTestServer.js DEBUG - Got continue command\n");

     // Get the context structure and finish the old request

     getObjectState("context", function(obj) {

       // magic or goop, depending on how you look at it

       savedCtx = obj.wrappedJSObject;

       // Write the rest of the data

       savedCtx.ostream.writeFrom(savedCtx.istream, savedCtx.istream.available());

       // Close the streams

       savedCtx.ostream.close();

       savedCtx.istream.close();

       // Finish off 'the old response'

       savedCtx.response.finish();

     });

     // Finish off 'the current response'

     response.finish();

     return;

   }

   // Debugging information so we can figure out the hang

   dump("file_IconTestServer.js DEBUG - Got initial request\n");

   // Context structure - we need to set this up properly to pass to setObjectState

   var ctx = {

     QueryInterface: function(iid) {

       if (iid.equals(Components.interfaces.nsISupports))

         return this;

       throw Components.results.NS_ERROR_NO_INTERFACE;

     }

   };

   ctx.wrappedJSObject = ctx;

   // Save the response

   ctx.response = response;

   // We're serving up a png

   response.setHeader("Content-Type", "image/png", false);

   // Get the output stream

   ctx.ostream = response.bodyOutputStream;

   // Ugly hack, but effective - copied from content/media/test/contentDuration1.sjs

   var pngFile = Components.classes["@mozilla.org/file/directory_service;1"].

                            getService(Components.interfaces.nsIProperties).

                            get("CurWorkD", Components.interfaces.nsILocalFile);

   var paths = "tests/layout/generic/test/file_Dolske.png";

   var split = paths.split("/");

   for(var i = 0; i < split.length; ++i) {

     pngFile.append(split[i]);

   }

   // Get an input stream for the png data

   ctx.istream = Cc["@mozilla.org/network/file-input-stream;1"].

                       createInstance(Components.interfaces.nsIFileInputStream);

   ctx.istream.init(pngFile, -1, 0, 0);

   // Write the first 10 bytes, which is just boilerplate/magic bytes

   ctx.ostream.writeFrom(ctx.istream, 10);

   // Save the context structure for retrieval when we get pinged

   setObjectState("context", ctx);

   // Now we play the waiting game...

   // Debugging information so we can figure out the hang

   dump("file_IconTestServer.js DEBUG - Playing the waiting game\n");

 }