The Tor Browser / file revision

 # This Source Code Form is subject to the terms of the Mozilla Public

 # License, v. 2.0. If a copy of the MPL was not distributed with this

 # file, You can obtain one at http://mozilla.org/MPL/2.0/.

 // A simple class that encapsulates a request. You'll notice the

 // style here is different from the rest of the extension; that's

 // because this was re-used from really old code we had. At some

 // point it might be nice to replace this with something better

 // (e.g., something that has explicit onerror handler, ability

 // to set headers, and so on).

 /**

  * Because we might be in a component, we can't just assume that

  * XMLHttpRequest exists. So we use this tiny factory function to wrap the

  * XPCOM version.

  *

  * @return XMLHttpRequest object

  */

 function PROT_NewXMLHttpRequest() {

   var Cc = Components.classes;

   var Ci = Components.interfaces;

   var request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]

                 .createInstance(Ci.nsIXMLHttpRequest);

   // Need the following so we get onerror/load/progresschange

   request.QueryInterface(Ci.nsIJSXMLHttpRequest);

   return request;

 }

 /**

  * A helper class that does HTTP GETs and calls back a function with

  * the content it receives. Asynchronous, so uses a closure for the

  * callback.

  *

  * Note, that XMLFetcher is only used for SafeBrowsing, therefore

  * we inherit from nsILoadContext, so we can use the callbacks on the

  * channel to separate the safebrowsing cookie based on a reserved

  * appId.

  * @constructor

  */

 function PROT_XMLFetcher() {

   this.debugZone = "xmlfetcher";

   this._request = PROT_NewXMLHttpRequest();

   // implements nsILoadContext

   this.appId = Ci.nsIScriptSecurityManager.SAFEBROWSING_APP_ID;

   this.isInBrowserElement = false;

   this.usePrivateBrowsing = false;

   this.isContent = false;

 }

 PROT_XMLFetcher.prototype = {

   /**

    * Function that will be called back upon fetch completion.

    */

   _callback: null,

   /**

    * Fetches some content.

    * 

    * @param page URL to fetch

    * @param callback Function to call back when complete.

    */

   get: function(page, callback) {

     this._request.abort();                // abort() is asynchronous, so

     this._request = PROT_NewXMLHttpRequest();

     this._callback = callback;

     var asynchronous = true;

     this._request.open("GET", page, asynchronous);

     this._request.channel.notificationCallbacks = this;

     // Create a closure

     var self = this;

     this._request.addEventListener("readystatechange", function() {

       self.readyStateChange(self);

     }, false);

     this._request.send(null);

   },

   cancel: function() {

     this._request.abort();

     this._request = null;

   },

   /**

    * Called periodically by the request to indicate some state change. 4

    * means content has been received.

    */

   readyStateChange: function(fetcher) {

     if (fetcher._request.readyState != 4)

       return;

     // If the request fails, on trunk we get status set to

     // NS_ERROR_NOT_AVAILABLE.  On 1.8.1 branch we get an exception

     // forwarded from nsIHttpChannel::GetResponseStatus.  To be consistent

     // between branch and trunk, we send back NS_ERROR_NOT_AVAILABLE for

     // http failures.

     var responseText = null;

     var status = Components.results.NS_ERROR_NOT_AVAILABLE;

     try {

       G_Debug(this, "xml fetch status code: \"" + 

               fetcher._request.status + "\"");

       status = fetcher._request.status;

       responseText = fetcher._request.responseText;

     } catch(e) {

       G_Debug(this, "Caught exception trying to read xmlhttprequest " +

               "status/response.");

       G_Debug(this, e);

     }

     if (fetcher._callback)

       fetcher._callback(responseText, status);

   },

   // nsIInterfaceRequestor

   getInterface: function(iid) {

     return this.QueryInterface(iid);

   },

   QueryInterface: XPCOMUtils.generateQI([Ci.nsIInterfaceRequestor,

                                          Ci.nsISupports,

                                          Ci.nsILoadContext])

 };