Bug 1222690 - Test SDK Content Scripts are not frozen before document.readyState complete. r?krizsa draft
authorLuca Greco <lgreco@mozilla.com>
Mon, 20 Jun 2016 16:12:33 +0200
changeset 380053 556ed588b07da256163763f0dc8ccd3d77c34ced
parent 380052 710c53362b5972434a13ca2969159a69c0d666b2
child 523629 66a572eba33c93f90bc70112f4ef6bc8e6e0cbd4
push id21119
push userluca.greco@alcacoop.it
push dateMon, 20 Jun 2016 14:36:28 +0000
reviewerskrizsa
bugs1222690
milestone50.0a1
Bug 1222690 - Test SDK Content Scripts are not frozen before document.readyState complete. r?krizsa MozReview-Commit-ID: DZSFb7tS2YQ
addon-sdk/moz.build
addon-sdk/source/test/addons/content-script-messages-latency/httpd.js
addon-sdk/source/test/addons/content-script-messages-latency/main.js
addon-sdk/source/test/addons/content-script-messages-latency/package.json
addon-sdk/source/test/addons/jetpack-addon.ini
--- a/addon-sdk/moz.build
+++ b/addon-sdk/moz.build
@@ -17,16 +17,17 @@ JETPACK_PACKAGE_MANIFESTS += ['source/te
 JETPACK_ADDON_MANIFESTS += ['source/test/addons/jetpack-addon.ini']
 
 addons = [
     'addon-manager',
     'author-email',
     'child_process',
     'chrome',
     'content-permissions',
+    'content-script-messages-latency',
     'contributors',
     'curly-id',
     'developers',
     'e10s-content',
     'e10s-l10n',
     'e10s-remote',
     'e10s-tabs',
     'e10s',
new file mode 100644
--- /dev/null
+++ b/addon-sdk/source/test/addons/content-script-messages-latency/httpd.js
@@ -0,0 +1,5211 @@
+/* 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/. */
+
+/*
+*  NOTE: do not edit this file, this is copied from:
+*  https://github.com/mozilla/addon-sdk/blob/master/test/lib/httpd.js
+*/
+
+module.metadata = {
+  "stability": "experimental"
+};
+
+const { components, CC, Cc, Ci, Cr, Cu } = require("chrome");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+
+const PR_UINT32_MAX = Math.pow(2, 32) - 1;
+
+/** True if debugging output is enabled, false otherwise. */
+var DEBUG = false; // non-const *only* so tweakable in server tests
+
+/** True if debugging output should be timestamped. */
+var DEBUG_TIMESTAMP = false; // non-const so tweakable in server tests
+
+var gGlobalObject = Cc["@mozilla.org/systemprincipal;1"].createInstance();
+
+/**
+* Asserts that the given condition holds. If it doesn't, the given message is
+* dumped, a stack trace is printed, and an exception is thrown to attempt to
+* stop execution (which unfortunately must rely upon the exception not being
+* accidentally swallowed by the code that uses it).
+*/
+function NS_ASSERT(cond, msg)
+{
+  if (DEBUG && !cond)
+  {
+    dumpn("###!!!");
+    dumpn("###!!! ASSERTION" + (msg ? ": " + msg : "!"));
+    dumpn("###!!! Stack follows:");
+
+    var stack = new Error().stack.split(/\n/);
+    dumpn(stack.map(function(val) { return "###!!! " + val; }).join("\n"));
+
+    throw Cr.NS_ERROR_ABORT;
+  }
+}
+
+/** Constructs an HTTP error object. */
+function HttpError(code, description)
+{
+  this.code = code;
+  this.description = description;
+}
+HttpError.prototype =
+{
+  toString: function()
+  {
+    return this.code + " " + this.description;
+  }
+};
+
+/**
+* Errors thrown to trigger specific HTTP server responses.
+*/
+const HTTP_400 = new HttpError(400, "Bad Request");
+const HTTP_401 = new HttpError(401, "Unauthorized");
+const HTTP_402 = new HttpError(402, "Payment Required");
+const HTTP_403 = new HttpError(403, "Forbidden");
+const HTTP_404 = new HttpError(404, "Not Found");
+const HTTP_405 = new HttpError(405, "Method Not Allowed");
+const HTTP_406 = new HttpError(406, "Not Acceptable");
+const HTTP_407 = new HttpError(407, "Proxy Authentication Required");
+const HTTP_408 = new HttpError(408, "Request Timeout");
+const HTTP_409 = new HttpError(409, "Conflict");
+const HTTP_410 = new HttpError(410, "Gone");
+const HTTP_411 = new HttpError(411, "Length Required");
+const HTTP_412 = new HttpError(412, "Precondition Failed");
+const HTTP_413 = new HttpError(413, "Request Entity Too Large");
+const HTTP_414 = new HttpError(414, "Request-URI Too Long");
+const HTTP_415 = new HttpError(415, "Unsupported Media Type");
+const HTTP_417 = new HttpError(417, "Expectation Failed");
+
+const HTTP_500 = new HttpError(500, "Internal Server Error");
+const HTTP_501 = new HttpError(501, "Not Implemented");
+const HTTP_502 = new HttpError(502, "Bad Gateway");
+const HTTP_503 = new HttpError(503, "Service Unavailable");
+const HTTP_504 = new HttpError(504, "Gateway Timeout");
+const HTTP_505 = new HttpError(505, "HTTP Version Not Supported");
+
+/** Creates a hash with fields corresponding to the values in arr. */
+function array2obj(arr)
+{
+  var obj = {};
+  for (var i = 0; i < arr.length; i++)
+    obj[arr[i]] = arr[i];
+  return obj;
+}
+
+/** Returns an array of the integers x through y, inclusive. */
+function range(x, y)
+{
+  var arr = [];
+  for (var i = x; i <= y; i++)
+    arr.push(i);
+  return arr;
+}
+
+/** An object (hash) whose fields are the numbers of all HTTP error codes. */
+const HTTP_ERROR_CODES = array2obj(range(400, 417).concat(range(500, 505)));
+
+
+/**
+* The character used to distinguish hidden files from non-hidden files, a la
+* the leading dot in Apache. Since that mechanism also hides files from
+* easy display in LXR, ls output, etc. however, we choose instead to use a
+* suffix character. If a requested file ends with it, we append another
+* when getting the file on the server. If it doesn't, we just look up that
+* file. Therefore, any file whose name ends with exactly one of the character
+* is "hidden" and available for use by the server.
+*/
+const HIDDEN_CHAR = "^";
+
+/**
+* The file name suffix indicating the file containing overridden headers for
+* a requested file.
+*/
+const HEADERS_SUFFIX = HIDDEN_CHAR + "headers" + HIDDEN_CHAR;
+
+/** Type used to denote SJS scripts for CGI-like functionality. */
+const SJS_TYPE = "sjs";
+
+/** Base for relative timestamps produced by dumpn(). */
+var firstStamp = 0;
+
+/** dump(str) with a trailing "\n" -- only outputs if DEBUG. */
+function dumpn(str)
+{
+  if (DEBUG)
+  {
+    var prefix = "HTTPD-INFO | ";
+    if (DEBUG_TIMESTAMP)
+    {
+      if (firstStamp === 0)
+        firstStamp = Date.now();
+
+      var elapsed = Date.now() - firstStamp; // milliseconds
+      var min = Math.floor(elapsed / 60000);
+      var sec = (elapsed % 60000) / 1000;
+
+      if (sec < 10)
+        prefix += min + ":0" + sec.toFixed(3) + " | ";
+      else
+        prefix += min + ":" + sec.toFixed(3) + " | ";
+    }
+
+    dump(prefix + str + "\n");
+  }
+}
+
+/** Dumps the current JS stack if DEBUG. */
+function dumpStack()
+{
+  // peel off the frames for dumpStack() and Error()
+  var stack = new Error().stack.split(/\n/).slice(2);
+  stack.forEach(dumpn);
+}
+
+
+/** The XPCOM thread manager. */
+var gThreadManager = null;
+
+/** The XPCOM prefs service. */
+var gRootPrefBranch = null;
+function getRootPrefBranch()
+{
+  if (!gRootPrefBranch)
+  {
+    gRootPrefBranch = Cc["@mozilla.org/preferences-service;1"]
+                        .getService(Ci.nsIPrefBranch);
+  }
+  return gRootPrefBranch;
+}
+
+/**
+* JavaScript constructors for commonly-used classes; precreating these is a
+* speedup over doing the same from base principles. See the docs at
+* http://developer.mozilla.org/en/docs/components.Constructor for details.
+*/
+const ServerSocket = CC("@mozilla.org/network/server-socket;1",
+                        "nsIServerSocket",
+                        "init");
+const ScriptableInputStream = CC("@mozilla.org/scriptableinputstream;1",
+                                 "nsIScriptableInputStream",
+                                 "init");
+const Pipe = CC("@mozilla.org/pipe;1",
+                "nsIPipe",
+                "init");
+const FileInputStream = CC("@mozilla.org/network/file-input-stream;1",
+                           "nsIFileInputStream",
+                           "init");
+const ConverterInputStream = CC("@mozilla.org/intl/converter-input-stream;1",
+                                "nsIConverterInputStream",
+                                "init");
+const WritablePropertyBag = CC("@mozilla.org/hash-property-bag;1",
+                               "nsIWritablePropertyBag2");
+const SupportsString = CC("@mozilla.org/supports-string;1",
+                          "nsISupportsString");
+
+/* These two are non-const only so a test can overwrite them. */
+var BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",
+                           "nsIBinaryInputStream",
+                           "setInputStream");
+var BinaryOutputStream = CC("@mozilla.org/binaryoutputstream;1",
+                            "nsIBinaryOutputStream",
+                            "setOutputStream");
+
+/**
+* Returns the RFC 822/1123 representation of a date.
+*
+* @param date : Number
+* the date, in milliseconds from midnight (00:00:00), January 1, 1970 GMT
+* @returns string
+* the representation of the given date
+*/
+function toDateString(date)
+{
+  //
+  // rfc1123-date = wkday "," SP date1 SP time SP "GMT"
+  // date1 = 2DIGIT SP month SP 4DIGIT
+  // ; day month year (e.g., 02 Jun 1982)
+  // time = 2DIGIT ":" 2DIGIT ":" 2DIGIT
+  // ; 00:00:00 - 23:59:59
+  // wkday = "Mon" | "Tue" | "Wed"
+  // | "Thu" | "Fri" | "Sat" | "Sun"
+  // month = "Jan" | "Feb" | "Mar" | "Apr"
+  // | "May" | "Jun" | "Jul" | "Aug"
+  // | "Sep" | "Oct" | "Nov" | "Dec"
+  //
+
+  const wkdayStrings = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
+  const monthStrings = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
+                        "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
+
+  /**
+* Processes a date and returns the encoded UTC time as a string according to
+* the format specified in RFC 2616.
+*
+* @param date : Date
+* the date to process
+* @returns string
+* a string of the form "HH:MM:SS", ranging from "00:00:00" to "23:59:59"
+*/
+  function toTime(date)
+  {
+    var hrs = date.getUTCHours();
+    var rv = (hrs < 10) ? "0" + hrs : hrs;
+
+    var mins = date.getUTCMinutes();
+    rv += ":";
+    rv += (mins < 10) ? "0" + mins : mins;
+
+    var secs = date.getUTCSeconds();
+    rv += ":";
+    rv += (secs < 10) ? "0" + secs : secs;
+
+    return rv;
+  }
+
+  /**
+* Processes a date and returns the encoded UTC date as a string according to
+* the date1 format specified in RFC 2616.
+*
+* @param date : Date
+* the date to process
+* @returns string
+* a string of the form "HH:MM:SS", ranging from "00:00:00" to "23:59:59"
+*/
+  function toDate1(date)
+  {
+    var day = date.getUTCDate();
+    var month = date.getUTCMonth();
+    var year = date.getUTCFullYear();
+
+    var rv = (day < 10) ? "0" + day : day;
+    rv += " " + monthStrings[month];
+    rv += " " + year;
+
+    return rv;
+  }
+
+  date = new Date(date);
+
+  const fmtString = "%wkday%, %date1% %time% GMT";
+  var rv = fmtString.replace("%wkday%", wkdayStrings[date.getUTCDay()]);
+  rv = rv.replace("%time%", toTime(date));
+  return rv.replace("%date1%", toDate1(date));
+}
+
+/**
+* Prints out a human-readable representation of the object o and its fields,
+* omitting those whose names begin with "_" if showMembers != true (to ignore
+* "private" properties exposed via getters/setters).
+*/
+function printObj(o, showMembers)
+{
+  var s = "******************************\n";
+  s += "o = {\n";
+  for (var i in o)
+  {
+    if (typeof(i) != "string" ||
+        (showMembers || (i.length > 0 && i[0] != "_")))
+      s+= " " + i + ": " + o[i] + ",\n";
+  }
+  s += " };\n";
+  s += "******************************";
+  dumpn(s);
+}
+
+/**
+* Instantiates a new HTTP server.
+*/
+function nsHttpServer()
+{
+  if (!gThreadManager)
+    gThreadManager = Cc["@mozilla.org/thread-manager;1"].getService();
+
+  /** The port on which this server listens. */
+  this._port = undefined;
+
+  /** The socket associated with this. */
+  this._socket = null;
+
+  /** The handler used to process requests to this server. */
+  this._handler = new ServerHandler(this);
+
+  /** Naming information for this server. */
+  this._identity = new ServerIdentity();
+
+  /**
+* Indicates when the server is to be shut down at the end of the request.
+*/
+  this._doQuit = false;
+
+  /**
+* True if the socket in this is closed (and closure notifications have been
+* sent and processed if the socket was ever opened), false otherwise.
+*/
+  this._socketClosed = true;
+
+  /**
+* Used for tracking existing connections and ensuring that all connections
+* are properly cleaned up before server shutdown; increases by 1 for every
+* new incoming connection.
+*/
+  this._connectionGen = 0;
+
+  /**
+* Hash of all open connections, indexed by connection number at time of
+* creation.
+*/
+  this._connections = {};
+}
+nsHttpServer.prototype =
+{
+  classID: components.ID("{54ef6f81-30af-4b1d-ac55-8ba811293e41}"),
+
+  // NSISERVERSOCKETLISTENER
+
+  /**
+* Processes an incoming request coming in on the given socket and contained
+* in the given transport.
+*
+* @param socket : nsIServerSocket
+* the socket through which the request was served
+* @param trans : nsISocketTransport
+* the transport for the request/response
+* @see nsIServerSocketListener.onSocketAccepted
+*/
+  onSocketAccepted: function(socket, trans)
+  {
+    dumpn("*** onSocketAccepted(socket=" + socket + ", trans=" + trans + ")");
+
+    dumpn(">>> new connection on " + trans.host + ":" + trans.port);
+
+    const SEGMENT_SIZE = 8192;
+    const SEGMENT_COUNT = 1024;
+    try
+    {
+      var input = trans.openInputStream(0, SEGMENT_SIZE, SEGMENT_COUNT)
+                       .QueryInterface(Ci.nsIAsyncInputStream);
+      var output = trans.openOutputStream(0, 0, 0);
+    }
+    catch (e)
+    {
+      dumpn("*** error opening transport streams: " + e);
+      trans.close(Cr.NS_BINDING_ABORTED);
+      return;
+    }
+
+    var connectionNumber = ++this._connectionGen;
+
+    try
+    {
+      var conn = new Connection(input, output, this, socket.port, trans.port,
+                                connectionNumber);
+      var reader = new RequestReader(conn);
+
+      // XXX add request timeout functionality here!
+
+      // Note: must use main thread here, or we might get a GC that will cause
+      // threadsafety assertions. We really need to fix XPConnect so that
+      // you can actually do things in multi-threaded JS. :-(
+      input.asyncWait(reader, 0, 0, gThreadManager.mainThread);
+    }
+    catch (e)
+    {
+      // Assume this connection can't be salvaged and bail on it completely;
+      // don't attempt to close it so that we can assert that any connection
+      // being closed is in this._connections.
+      dumpn("*** error in initial request-processing stages: " + e);
+      trans.close(Cr.NS_BINDING_ABORTED);
+      return;
+    }
+
+    this._connections[connectionNumber] = conn;
+    dumpn("*** starting connection " + connectionNumber);
+  },
+
+  /**
+* Called when the socket associated with this is closed.
+*
+* @param socket : nsIServerSocket
+* the socket being closed
+* @param status : nsresult
+* the reason the socket stopped listening (NS_BINDING_ABORTED if the server
+* was stopped using nsIHttpServer.stop)
+* @see nsIServerSocketListener.onStopListening
+*/
+  onStopListening: function(socket, status)
+  {
+    dumpn(">>> shutting down server on port " + socket.port);
+    this._socketClosed = true;
+    if (!this._hasOpenConnections())
+    {
+      dumpn("*** no open connections, notifying async from onStopListening");
+
+      // Notify asynchronously so that any pending teardown in stop() has a
+      // chance to run first.
+      var self = this;
+      var stopEvent =
+        {
+          run: function()
+          {
+            dumpn("*** _notifyStopped async callback");
+            self._notifyStopped();
+          }
+        };
+      gThreadManager.currentThread
+                    .dispatch(stopEvent, Ci.nsIThread.DISPATCH_NORMAL);
+    }
+  },
+
+  // NSIHTTPSERVER
+
+  //
+  // see nsIHttpServer.start
+  //
+  start: function(port)
+  {
+    this._start(port, "localhost")
+  },
+
+  _start: function(port, host)
+  {
+    if (this._socket)
+      throw Cr.NS_ERROR_ALREADY_INITIALIZED;
+
+    this._port = port;
+    this._doQuit = this._socketClosed = false;
+
+    this._host = host;
+
+    // The listen queue needs to be long enough to handle
+    // network.http.max-persistent-connections-per-server concurrent connections,
+    // plus a safety margin in case some other process is talking to
+    // the server as well.
+    var prefs = getRootPrefBranch();
+    var maxConnections;
+    try {
+      // Bug 776860: The original pref was removed in favor of this new one:
+      maxConnections = prefs.getIntPref("network.http.max-persistent-connections-per-server") + 5;
+    }
+    catch(e) {
+      maxConnections = prefs.getIntPref("network.http.max-connections-per-server") + 5;
+    }
+
+    try
+    {
+      var loopback = true;
+      if (this._host != "127.0.0.1" && this._host != "localhost") {
+        var loopback = false;
+      }
+
+      var socket = new ServerSocket(this._port,
+                                    loopback, // true = localhost, false = everybody
+                                    maxConnections);
+      dumpn(">>> listening on port " + socket.port + ", " + maxConnections +
+            " pending connections");
+      socket.asyncListen(this);
+      this._identity._initialize(socket.port, host, true);
+      this._socket = socket;
+    }
+    catch (e)
+    {
+      dumpn("!!! could not start server on port " + port + ": " + e);
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+    }
+  },
+
+  //
+  // see nsIHttpServer.stop
+  //
+  stop: function(callback)
+  {
+    if (!callback)
+      throw Cr.NS_ERROR_NULL_POINTER;
+    if (!this._socket)
+      throw Cr.NS_ERROR_UNEXPECTED;
+
+    this._stopCallback = typeof callback === "function"
+                       ? callback
+                       : function() { callback.onStopped(); };
+
+    dumpn(">>> stopping listening on port " + this._socket.port);
+    this._socket.close();
+    this._socket = null;
+
+    // We can't have this identity any more, and the port on which we're running
+    // this server now could be meaningless the next time around.
+    this._identity._teardown();
+
+    this._doQuit = false;
+
+    // socket-close notification and pending request completion happen async
+  },
+
+  //
+  // see nsIHttpServer.registerFile
+  //
+  registerFile: function(path, file)
+  {
+    if (file && (!file.exists() || file.isDirectory()))
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    this._handler.registerFile(path, file);
+  },
+
+  //
+  // see nsIHttpServer.registerDirectory
+  //
+  registerDirectory: function(path, directory)
+  {
+    // XXX true path validation!
+    if (path.charAt(0) != "/" ||
+        path.charAt(path.length - 1) != "/" ||
+        (directory &&
+         (!directory.exists() || !directory.isDirectory())))
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    // XXX determine behavior of nonexistent /foo/bar when a /foo/bar/ mapping
+    // exists!
+
+    this._handler.registerDirectory(path, directory);
+  },
+
+  //
+  // see nsIHttpServer.registerPathHandler
+  //
+  registerPathHandler: function(path, handler)
+  {
+    this._handler.registerPathHandler(path, handler);
+  },
+
+  //
+  // see nsIHttpServer.registerPrefixHandler
+  //
+  registerPrefixHandler: function(prefix, handler)
+  {
+    this._handler.registerPrefixHandler(prefix, handler);
+  },
+
+  //
+  // see nsIHttpServer.registerErrorHandler
+  //
+  registerErrorHandler: function(code, handler)
+  {
+    this._handler.registerErrorHandler(code, handler);
+  },
+
+  //
+  // see nsIHttpServer.setIndexHandler
+  //
+  setIndexHandler: function(handler)
+  {
+    this._handler.setIndexHandler(handler);
+  },
+
+  //
+  // see nsIHttpServer.registerContentType
+  //
+  registerContentType: function(ext, type)
+  {
+    this._handler.registerContentType(ext, type);
+  },
+
+  //
+  // see nsIHttpServer.serverIdentity
+  //
+  get identity()
+  {
+    return this._identity;
+  },
+
+  //
+  // see nsIHttpServer.getState
+  //
+  getState: function(path, k)
+  {
+    return this._handler._getState(path, k);
+  },
+
+  //
+  // see nsIHttpServer.setState
+  //
+  setState: function(path, k, v)
+  {
+    return this._handler._setState(path, k, v);
+  },
+
+  //
+  // see nsIHttpServer.getSharedState
+  //
+  getSharedState: function(k)
+  {
+    return this._handler._getSharedState(k);
+  },
+
+  //
+  // see nsIHttpServer.setSharedState
+  //
+  setSharedState: function(k, v)
+  {
+    return this._handler._setSharedState(k, v);
+  },
+
+  //
+  // see nsIHttpServer.getObjectState
+  //
+  getObjectState: function(k)
+  {
+    return this._handler._getObjectState(k);
+  },
+
+  //
+  // see nsIHttpServer.setObjectState
+  //
+  setObjectState: function(k, v)
+  {
+    return this._handler._setObjectState(k, v);
+  },
+
+
+  // NSISUPPORTS
+
+  //
+  // see nsISupports.QueryInterface
+  //
+  QueryInterface: function(iid)
+  {
+    if (iid.equals(Ci.nsIServerSocketListener) || iid.equals(Ci.nsISupports))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // NON-XPCOM PUBLIC API
+
+  /**
+* Returns true iff this server is not running (and is not in the process of
+* serving any requests still to be processed when the server was last
+* stopped after being run).
+*/
+  isStopped: function()
+  {
+    return this._socketClosed && !this._hasOpenConnections();
+  },
+
+  // PRIVATE IMPLEMENTATION
+
+  /** True if this server has any open connections to it, false otherwise. */
+  _hasOpenConnections: function()
+  {
+    //
+    // If we have any open connections, they're tracked as numeric properties on
+    // |this._connections|. The non-standard __count__ property could be used
+    // to check whether there are any properties, but standard-wise, even
+    // looking forward to ES5, there's no less ugly yet still O(1) way to do
+    // this.
+    //
+    for (var n in this._connections)
+      return true;
+    return false;
+  },
+
+  /** Calls the server-stopped callback provided when stop() was called. */
+  _notifyStopped: function()
+  {
+    NS_ASSERT(this._stopCallback !== null, "double-notifying?");
+    NS_ASSERT(!this._hasOpenConnections(), "should be done serving by now");
+
+    //
+    // NB: We have to grab this now, null out the member, *then* call the
+    // callback here, or otherwise the callback could (indirectly) futz with
+    // this._stopCallback by starting and immediately stopping this, at
+    // which point we'd be nulling out a field we no longer have a right to
+    // modify.
+    //
+    var callback = this._stopCallback;
+    this._stopCallback = null;
+    try
+    {
+      callback();
+    }
+    catch (e)
+    {
+      // not throwing because this is specified as being usually (but not
+      // always) asynchronous
+      dump("!!! error running onStopped callback: " + e + "\n");
+    }
+  },
+
+  /**
+* Notifies this server that the given connection has been closed.
+*
+* @param connection : Connection
+* the connection that was closed
+*/
+  _connectionClosed: function(connection)
+  {
+    NS_ASSERT(connection.number in this._connections,
+              "closing a connection " + this + " that we never added to the " +
+              "set of open connections?");
+    NS_ASSERT(this._connections[connection.number] === connection,
+              "connection number mismatch? " +
+              this._connections[connection.number]);
+    delete this._connections[connection.number];
+
+    // Fire a pending server-stopped notification if it's our responsibility.
+    if (!this._hasOpenConnections() && this._socketClosed)
+      this._notifyStopped();
+  },
+
+  /**
+* Requests that the server be shut down when possible.
+*/
+  _requestQuit: function()
+  {
+    dumpn(">>> requesting a quit");
+    dumpStack();
+    this._doQuit = true;
+  }
+};
+
+
+//
+// RFC 2396 section 3.2.2:
+//
+// host = hostname | IPv4address
+// hostname = *( domainlabel "." ) toplabel [ "." ]
+// domainlabel = alphanum | alphanum *( alphanum | "-" ) alphanum
+// toplabel = alpha | alpha *( alphanum | "-" ) alphanum
+// IPv4address = 1*digit "." 1*digit "." 1*digit "." 1*digit
+//
+
+const HOST_REGEX =
+  new RegExp("^(?:" +
+               // *( domainlabel "." )
+               "(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)*" +
+               // toplabel
+               "[a-z](?:[a-z0-9-]*[a-z0-9])?" +
+             "|" +
+               // IPv4 address
+               "\\d+\\.\\d+\\.\\d+\\.\\d+" +
+             ")$",
+             "i");
+
+
+/**
+* Represents the identity of a server. An identity consists of a set of
+* (scheme, host, port) tuples denoted as locations (allowing a single server to
+* serve multiple sites or to be used behind both HTTP and HTTPS proxies for any
+* host/port). Any incoming request must be to one of these locations, or it
+* will be rejected with an HTTP 400 error. One location, denoted as the
+* primary location, is the location assigned in contexts where a location
+* cannot otherwise be endogenously derived, such as for HTTP/1.0 requests.
+*
+* A single identity may contain at most one location per unique host/port pair;
+* other than that, no restrictions are placed upon what locations may
+* constitute an identity.
+*/
+function ServerIdentity()
+{
+  /** The scheme of the primary location. */
+  this._primaryScheme = "http";
+
+  /** The hostname of the primary location. */
+  this._primaryHost = "127.0.0.1"
+
+  /** The port number of the primary location. */
+  this._primaryPort = -1;
+
+  /**
+* The current port number for the corresponding server, stored so that a new
+* primary location can always be set if the current one is removed.
+*/
+  this._defaultPort = -1;
+
+  /**
+* Maps hosts to maps of ports to schemes, e.g. the following would represent
+* https://example.com:789/ and http://example.org/:
+*
+* {
+* "xexample.com": { 789: "https" },
+* "xexample.org": { 80: "http" }
+* }
+*
+* Note the "x" prefix on hostnames, which prevents collisions with special
+* JS names like "prototype".
+*/
+  this._locations = { "xlocalhost": {} };
+}
+ServerIdentity.prototype =
+{
+  // NSIHTTPSERVERIDENTITY
+
+  //
+  // see nsIHttpServerIdentity.primaryScheme
+  //
+  get primaryScheme()
+  {
+    if (this._primaryPort === -1)
+      throw Cr.NS_ERROR_NOT_INITIALIZED;
+    return this._primaryScheme;
+  },
+
+  //
+  // see nsIHttpServerIdentity.primaryHost
+  //
+  get primaryHost()
+  {
+    if (this._primaryPort === -1)
+      throw Cr.NS_ERROR_NOT_INITIALIZED;
+    return this._primaryHost;
+  },
+
+  //
+  // see nsIHttpServerIdentity.primaryPort
+  //
+  get primaryPort()
+  {
+    if (this._primaryPort === -1)
+      throw Cr.NS_ERROR_NOT_INITIALIZED;
+    return this._primaryPort;
+  },
+
+  //
+  // see nsIHttpServerIdentity.add
+  //
+  add: function(scheme, host, port)
+  {
+    this._validate(scheme, host, port);
+
+    var entry = this._locations["x" + host];
+    if (!entry)
+      this._locations["x" + host] = entry = {};
+
+    entry[port] = scheme;
+  },
+
+  //
+  // see nsIHttpServerIdentity.remove
+  //
+  remove: function(scheme, host, port)
+  {
+    this._validate(scheme, host, port);
+
+    var entry = this._locations["x" + host];
+    if (!entry)
+      return false;
+
+    var present = port in entry;
+    delete entry[port];
+
+    if (this._primaryScheme == scheme &&
+        this._primaryHost == host &&
+        this._primaryPort == port &&
+        this._defaultPort !== -1)
+    {
+      // Always keep at least one identity in existence at any time, unless
+      // we're in the process of shutting down (the last condition above).
+      this._primaryPort = -1;
+      this._initialize(this._defaultPort, host, false);
+    }
+
+    return present;
+  },
+
+  //
+  // see nsIHttpServerIdentity.has
+  //
+  has: function(scheme, host, port)
+  {
+    this._validate(scheme, host, port);
+
+    return "x" + host in this._locations &&
+           scheme === this._locations["x" + host][port];
+  },
+
+  //
+  // see nsIHttpServerIdentity.has
+  //
+  getScheme: function(host, port)
+  {
+    this._validate("http", host, port);
+
+    var entry = this._locations["x" + host];
+    if (!entry)
+      return "";
+
+    return entry[port] || "";
+  },
+
+  //
+  // see nsIHttpServerIdentity.setPrimary
+  //
+  setPrimary: function(scheme, host, port)
+  {
+    this._validate(scheme, host, port);
+
+    this.add(scheme, host, port);
+
+    this._primaryScheme = scheme;
+    this._primaryHost = host;
+    this._primaryPort = port;
+  },
+
+
+  // NSISUPPORTS
+
+  //
+  // see nsISupports.QueryInterface
+  //
+  QueryInterface: function(iid)
+  {
+    if (iid.equals(Ci.nsIHttpServerIdentity) || iid.equals(Ci.nsISupports))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // PRIVATE IMPLEMENTATION
+
+  /**
+* Initializes the primary name for the corresponding server, based on the
+* provided port number.
+*/
+  _initialize: function(port, host, addSecondaryDefault)
+  {
+    this._host = host;
+    if (this._primaryPort !== -1)
+      this.add("http", host, port);
+    else
+      this.setPrimary("http", "localhost", port);
+    this._defaultPort = port;
+
+    // Only add this if we're being called at server startup
+    if (addSecondaryDefault && host != "127.0.0.1")
+      this.add("http", "127.0.0.1", port);
+  },
+
+  /**
+* Called at server shutdown time, unsets the primary location only if it was
+* the default-assigned location and removes the default location from the
+* set of locations used.
+*/
+  _teardown: function()
+  {
+    if (this._host != "127.0.0.1") {
+      // Not the default primary location, nothing special to do here
+      this.remove("http", "127.0.0.1", this._defaultPort);
+    }
+
+    // This is a *very* tricky bit of reasoning here; make absolutely sure the
+    // tests for this code pass before you commit changes to it.
+    if (this._primaryScheme == "http" &&
+        this._primaryHost == this._host &&
+        this._primaryPort == this._defaultPort)
+    {
+      // Make sure we don't trigger the readding logic in .remove(), then remove
+      // the default location.
+      var port = this._defaultPort;
+      this._defaultPort = -1;
+      this.remove("http", this._host, port);
+
+      // Ensure a server start triggers the setPrimary() path in ._initialize()
+      this._primaryPort = -1;
+    }
+    else
+    {
+      // No reason not to remove directly as it's not our primary location
+      this.remove("http", this._host, this._defaultPort);
+    }
+  },
+
+  /**
+* Ensures scheme, host, and port are all valid with respect to RFC 2396.
+*
+* @throws NS_ERROR_ILLEGAL_VALUE
+* if any argument doesn't match the corresponding production
+*/
+  _validate: function(scheme, host, port)
+  {
+    if (scheme !== "http" && scheme !== "https")
+    {
+      dumpn("*** server only supports http/https schemes: '" + scheme + "'");
+      dumpStack();
+      throw Cr.NS_ERROR_ILLEGAL_VALUE;
+    }
+    if (!HOST_REGEX.test(host))
+    {
+      dumpn("*** unexpected host: '" + host + "'");
+      throw Cr.NS_ERROR_ILLEGAL_VALUE;
+    }
+    if (port < 0 || port > 65535)
+    {
+      dumpn("*** unexpected port: '" + port + "'");
+      throw Cr.NS_ERROR_ILLEGAL_VALUE;
+    }
+  }
+};
+
+
+/**
+* Represents a connection to the server (and possibly in the future the thread
+* on which the connection is processed).
+*
+* @param input : nsIInputStream
+* stream from which incoming data on the connection is read
+* @param output : nsIOutputStream
+* stream to write data out the connection
+* @param server : nsHttpServer
+* the server handling the connection
+* @param port : int
+* the port on which the server is running
+* @param outgoingPort : int
+* the outgoing port used by this connection
+* @param number : uint
+* a serial number used to uniquely identify this connection
+*/
+function Connection(input, output, server, port, outgoingPort, number)
+{
+  dumpn("*** opening new connection " + number + " on port " + outgoingPort);
+
+  /** Stream of incoming data. */
+  this.input = input;
+
+  /** Stream for outgoing data. */
+  this.output = output;
+
+  /** The server associated with this request. */
+  this.server = server;
+
+  /** The port on which the server is running. */
+  this.port = port;
+
+  /** The outgoing poort used by this connection. */
+  this._outgoingPort = outgoingPort;
+
+  /** The serial number of this connection. */
+  this.number = number;
+
+  /**
+* The request for which a response is being generated, null if the
+* incoming request has not been fully received or if it had errors.
+*/
+  this.request = null;
+
+  /** State variables for debugging. */
+  this._closed = this._processed = false;
+}
+Connection.prototype =
+{
+  /** Closes this connection's input/output streams. */
+  close: function()
+  {
+    dumpn("*** closing connection " + this.number +
+          " on port " + this._outgoingPort);
+
+    this.input.close();
+    this.output.close();
+    this._closed = true;
+
+    var server = this.server;
+    server._connectionClosed(this);
+
+    // If an error triggered a server shutdown, act on it now
+    if (server._doQuit)
+      server.stop(function() { /* not like we can do anything better */ });
+  },
+
+  /**
+* Initiates processing of this connection, using the data in the given
+* request.
+*
+* @param request : Request
+* the request which should be processed
+*/
+  process: function(request)
+  {
+    NS_ASSERT(!this._closed && !this._processed);
+
+    this._processed = true;
+
+    this.request = request;
+    this.server._handler.handleResponse(this);
+  },
+
+  /**
+* Initiates processing of this connection, generating a response with the
+* given HTTP error code.
+*
+* @param code : uint
+* an HTTP code, so in the range [0, 1000)
+* @param request : Request
+* incomplete data about the incoming request (since there were errors
+* during its processing
+*/
+  processError: function(code, request)
+  {
+    NS_ASSERT(!this._closed && !this._processed);
+
+    this._processed = true;
+    this.request = request;
+    this.server._handler.handleError(code, this);
+  },
+
+  /** Converts this to a string for debugging purposes. */
+  toString: function()
+  {
+    return "<Connection(" + this.number +
+           (this.request ? ", " + this.request.path : "") +"): " +
+           (this._closed ? "closed" : "open") + ">";
+  }
+};
+
+
+
+/** Returns an array of count bytes from the given input stream. */
+function readBytes(inputStream, count)
+{
+  return new BinaryInputStream(inputStream).readByteArray(count);
+}
+
+
+
+/** Request reader processing states; see RequestReader for details. */
+const READER_IN_REQUEST_LINE = 0;
+const READER_IN_HEADERS = 1;
+const READER_IN_BODY = 2;
+const READER_FINISHED = 3;
+
+
+/**
+* Reads incoming request data asynchronously, does any necessary preprocessing,
+* and forwards it to the request handler. Processing occurs in three states:
+*
+* READER_IN_REQUEST_LINE Reading the request's status line
+* READER_IN_HEADERS Reading headers in the request
+* READER_IN_BODY Reading the body of the request
+* READER_FINISHED Entire request has been read and processed
+*
+* During the first two stages, initial metadata about the request is gathered
+* into a Request object. Once the status line and headers have been processed,
+* we start processing the body of the request into the Request. Finally, when
+* the entire body has been read, we create a Response and hand it off to the
+* ServerHandler to be given to the appropriate request handler.
+*
+* @param connection : Connection
+* the connection for the request being read
+*/
+function RequestReader(connection)
+{
+  /** Connection metadata for this request. */
+  this._connection = connection;
+
+  /**
+* A container providing line-by-line access to the raw bytes that make up the
+* data which has been read from the connection but has not yet been acted
+* upon (by passing it to the request handler or by extracting request
+* metadata from it).
+*/
+  this._data = new LineData();
+
+  /**
+* The amount of data remaining to be read from the body of this request.
+* After all headers in the request have been read this is the value in the
+* Content-Length header, but as the body is read its value decreases to zero.
+*/
+  this._contentLength = 0;
+
+  /** The current state of parsing the incoming request. */
+  this._state = READER_IN_REQUEST_LINE;
+
+  /** Metadata constructed from the incoming request for the request handler. */
+  this._metadata = new Request(connection.port);
+
+  /**
+* Used to preserve state if we run out of line data midway through a
+* multi-line header. _lastHeaderName stores the name of the header, while
+* _lastHeaderValue stores the value we've seen so far for the header.
+*
+* These fields are always either both undefined or both strings.
+*/
+  this._lastHeaderName = this._lastHeaderValue = undefined;
+}
+RequestReader.prototype =
+{
+  // NSIINPUTSTREAMCALLBACK
+
+  /**
+* Called when more data from the incoming request is available. This method
+* then reads the available data from input and deals with that data as
+* necessary, depending upon the syntax of already-downloaded data.
+*
+* @param input : nsIAsyncInputStream
+* the stream of incoming data from the connection
+*/
+  onInputStreamReady: function(input)
+  {
+    dumpn("*** onInputStreamReady(input=" + input + ") on thread " +
+          gThreadManager.currentThread + " (main is " +
+          gThreadManager.mainThread + ")");
+    dumpn("*** this._state == " + this._state);
+
+    // Handle cases where we get more data after a request error has been
+    // discovered but *before* we can close the connection.
+    var data = this._data;
+    if (!data)
+      return;
+
+    try
+    {
+      data.appendBytes(readBytes(input, input.available()));
+    }
+    catch (e)
+    {
+      if (streamClosed(e))
+      {
+        dumpn("*** WARNING: unexpected error when reading from socket; will " +
+              "be treated as if the input stream had been closed");
+        dumpn("*** WARNING: actual error was: " + e);
+      }
+
+      // We've lost a race -- input has been closed, but we're still expecting
+      // to read more data. available() will throw in this case, and since
+      // we're dead in the water now, destroy the connection.
+      dumpn("*** onInputStreamReady called on a closed input, destroying " +
+            "connection");
+      this._connection.close();
+      return;
+    }
+
+    switch (this._state)
+    {
+      default:
+        NS_ASSERT(false, "invalid state: " + this._state);
+        break;
+
+      case READER_IN_REQUEST_LINE:
+        if (!this._processRequestLine())
+          break;
+        /* fall through */
+
+      case READER_IN_HEADERS:
+        if (!this._processHeaders())
+          break;
+        /* fall through */
+
+      case READER_IN_BODY:
+        this._processBody();
+    }
+
+    if (this._state != READER_FINISHED)
+      input.asyncWait(this, 0, 0, gThreadManager.currentThread);
+  },
+
+  //
+  // see nsISupports.QueryInterface
+  //
+  QueryInterface: function(aIID)
+  {
+    if (aIID.equals(Ci.nsIInputStreamCallback) ||
+        aIID.equals(Ci.nsISupports))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // PRIVATE API
+
+  /**
+* Processes unprocessed, downloaded data as a request line.
+*
+* @returns boolean
+* true iff the request line has been fully processed
+*/
+  _processRequestLine: function()
+  {
+    NS_ASSERT(this._state == READER_IN_REQUEST_LINE);
+
+    // Servers SHOULD ignore any empty line(s) received where a Request-Line
+    // is expected (section 4.1).
+    var data = this._data;
+    var line = {};
+    var readSuccess;
+    while ((readSuccess = data.readLine(line)) && line.value == "")
+      dumpn("*** ignoring beginning blank line...");
+
+    // if we don't have a full line, wait until we do
+    if (!readSuccess)
+      return false;
+
+    // we have the first non-blank line
+    try
+    {
+      this._parseRequestLine(line.value);
+      this._state = READER_IN_HEADERS;
+      return true;
+    }
+    catch (e)
+    {
+      this._handleError(e);
+      return false;
+    }
+  },
+
+  /**
+* Processes stored data, assuming it is either at the beginning or in
+* the middle of processing request headers.
+*
+* @returns boolean
+* true iff header data in the request has been fully processed
+*/
+  _processHeaders: function()
+  {
+    NS_ASSERT(this._state == READER_IN_HEADERS);
+
+    // XXX things to fix here:
+    //
+    // - need to support RFC 2047-encoded non-US-ASCII characters
+
+    try
+    {
+      var done = this._parseHeaders();
+      if (done)
+      {
+        var request = this._metadata;
+
+        // XXX this is wrong for requests with transfer-encodings applied to
+        // them, particularly chunked (which by its nature can have no
+        // meaningful Content-Length header)!
+        this._contentLength = request.hasHeader("Content-Length")
+                            ? parseInt(request.getHeader("Content-Length"), 10)
+                            : 0;
+        dumpn("_processHeaders, Content-length=" + this._contentLength);
+
+        this._state = READER_IN_BODY;
+      }
+      return done;
+    }
+    catch (e)
+    {
+      this._handleError(e);
+      return false;
+    }
+  },
+
+  /**
+* Processes stored data, assuming it is either at the beginning or in
+* the middle of processing the request body.
+*
+* @returns boolean
+* true iff the request body has been fully processed
+*/
+  _processBody: function()
+  {
+    NS_ASSERT(this._state == READER_IN_BODY);
+
+    // XXX handle chunked transfer-coding request bodies!
+
+    try
+    {
+      if (this._contentLength > 0)
+      {
+        var data = this._data.purge();
+        var count = Math.min(data.length, this._contentLength);
+        dumpn("*** loading data=" + data + " len=" + data.length +
+              " excess=" + (data.length - count));
+
+        var bos = new BinaryOutputStream(this._metadata._bodyOutputStream);
+        bos.writeByteArray(data, count);
+        this._contentLength -= count;
+      }
+
+      dumpn("*** remaining body data len=" + this._contentLength);
+      if (this._contentLength == 0)
+      {
+        this._validateRequest();
+        this._state = READER_FINISHED;
+        this._handleResponse();
+        return true;
+      }
+
+      return false;
+    }
+    catch (e)
+    {
+      this._handleError(e);
+      return false;
+    }
+  },
+
+  /**
+* Does various post-header checks on the data in this request.
+*
+* @throws : HttpError
+* if the request was malformed in some way
+*/
+  _validateRequest: function()
+  {
+    NS_ASSERT(this._state == READER_IN_BODY);
+
+    dumpn("*** _validateRequest");
+
+    var metadata = this._metadata;
+    var headers = metadata._headers;
+
+    // 19.6.1.1 -- servers MUST report 400 to HTTP/1.1 requests w/o Host header
+    var identity = this._connection.server.identity;
+    if (metadata._httpVersion.atLeast(nsHttpVersion.HTTP_1_1))
+    {
+      if (!headers.hasHeader("Host"))
+      {
+        dumpn("*** malformed HTTP/1.1 or greater request with no Host header!");
+        throw HTTP_400;
+      }
+
+      // If the Request-URI wasn't absolute, then we need to determine our host.
+      // We have to determine what scheme was used to access us based on the
+      // server identity data at this point, because the request just doesn't
+      // contain enough data on its own to do this, sadly.
+      if (!metadata._host)
+      {
+        var host, port;
+        var hostPort = headers.getHeader("Host");
+        var colon = hostPort.indexOf(":");
+        if (colon < 0)
+        {
+          host = hostPort;
+          port = "";
+        }
+        else
+        {
+          host = hostPort.substring(0, colon);
+          port = hostPort.substring(colon + 1);
+        }
+
+        // NB: We allow an empty port here because, oddly, a colon may be
+        // present even without a port number, e.g. "example.com:"; in this
+        // case the default port applies.
+        if (!HOST_REGEX.test(host) || !/^\d*$/.test(port))
+        {
+          dumpn("*** malformed hostname (" + hostPort + ") in Host " +
+                "header, 400 time");
+          throw HTTP_400;
+        }
+
+        // If we're not given a port, we're stuck, because we don't know what
+        // scheme to use to look up the correct port here, in general. Since
+        // the HTTPS case requires a tunnel/proxy and thus requires that the
+        // requested URI be absolute (and thus contain the necessary
+        // information), let's assume HTTP will prevail and use that.
+        port = +port || 80;
+
+        var scheme = identity.getScheme(host, port);
+        if (!scheme)
+        {
+          dumpn("*** unrecognized hostname (" + hostPort + ") in Host " +
+                "header, 400 time");
+          throw HTTP_400;
+        }
+
+        metadata._scheme = scheme;
+        metadata._host = host;
+        metadata._port = port;
+      }
+    }
+    else
+    {
+      NS_ASSERT(metadata._host === undefined,
+                "HTTP/1.0 doesn't allow absolute paths in the request line!");
+
+      metadata._scheme = identity.primaryScheme;
+      metadata._host = identity.primaryHost;
+      metadata._port = identity.primaryPort;
+    }
+
+    NS_ASSERT(identity.has(metadata._scheme, metadata._host, metadata._port),
+              "must have a location we recognize by now!");
+  },
+
+  /**
+* Handles responses in case of error, either in the server or in the request.
+*
+* @param e
+* the specific error encountered, which is an HttpError in the case where
+* the request is in some way invalid or cannot be fulfilled; if this isn't
+* an HttpError we're going to be paranoid and shut down, because that
+* shouldn't happen, ever
+*/
+  _handleError: function(e)
+  {
+    // Don't fall back into normal processing!
+    this._state = READER_FINISHED;
+
+    var server = this._connection.server;
+    if (e instanceof HttpError)
+    {
+      var code = e.code;
+    }
+    else
+    {
+      dumpn("!!! UNEXPECTED ERROR: " + e +
+            (e.lineNumber ? ", line " + e.lineNumber : ""));
+
+      // no idea what happened -- be paranoid and shut down
+      code = 500;
+      server._requestQuit();
+    }
+
+    // make attempted reuse of data an error
+    this._data = null;
+
+    this._connection.processError(code, this._metadata);
+  },
+
+  /**
+* Now that we've read the request line and headers, we can actually hand off
+* the request to be handled.
+*
+* This method is called once per request, after the request line and all
+* headers and the body, if any, have been received.
+*/
+  _handleResponse: function()
+  {
+    NS_ASSERT(this._state == READER_FINISHED);
+
+    // We don't need the line-based data any more, so make attempted reuse an
+    // error.
+    this._data = null;
+
+    this._connection.process(this._metadata);
+  },
+
+
+  // PARSING
+
+  /**
+* Parses the request line for the HTTP request associated with this.
+*
+* @param line : string
+* the request line
+*/
+  _parseRequestLine: function(line)
+  {
+    NS_ASSERT(this._state == READER_IN_REQUEST_LINE);
+
+    dumpn("*** _parseRequestLine('" + line + "')");
+
+    var metadata = this._metadata;
+
+    // clients and servers SHOULD accept any amount of SP or HT characters
+    // between fields, even though only a single SP is required (section 19.3)
+    var request = line.split(/[ \t]+/);
+    if (!request || request.length != 3)
+      throw HTTP_400;
+
+    metadata._method = request[0];
+
+    // get the HTTP version
+    var ver = request[2];
+    var match = ver.match(/^HTTP\/(\d+\.\d+)$/);
+    if (!match)
+      throw HTTP_400;
+
+    // determine HTTP version
+    try
+    {
+      metadata._httpVersion = new nsHttpVersion(match[1]);
+      if (!metadata._httpVersion.atLeast(nsHttpVersion.HTTP_1_0))
+        throw "unsupported HTTP version";
+    }
+    catch (e)
+    {
+      // we support HTTP/1.0 and HTTP/1.1 only
+      throw HTTP_501;
+    }
+
+
+    var fullPath = request[1];
+    var serverIdentity = this._connection.server.identity;
+
+    var scheme, host, port;
+
+    if (fullPath.charAt(0) != "/")
+    {
+      // No absolute paths in the request line in HTTP prior to 1.1
+      if (!metadata._httpVersion.atLeast(nsHttpVersion.HTTP_1_1))
+        throw HTTP_400;
+
+      try
+      {
+        var uri = Cc["@mozilla.org/network/io-service;1"]
+                    .getService(Ci.nsIIOService)
+                    .newURI(fullPath, null, null);
+        fullPath = uri.path;
+        scheme = uri.scheme;
+        host = metadata._host = uri.asciiHost;
+        port = uri.port;
+        if (port === -1)
+        {
+          if (scheme === "http")
+            port = 80;
+          else if (scheme === "https")
+            port = 443;
+          else
+            throw HTTP_400;
+        }
+      }
+      catch (e)
+      {
+        // If the host is not a valid host on the server, the response MUST be a
+        // 400 (Bad Request) error message (section 5.2). Alternately, the URI
+        // is malformed.
+        throw HTTP_400;
+      }
+
+      if (!serverIdentity.has(scheme, host, port) || fullPath.charAt(0) != "/")
+        throw HTTP_400;
+    }
+
+    var splitter = fullPath.indexOf("?");
+    if (splitter < 0)
+    {
+      // _queryString already set in ctor
+      metadata._path = fullPath;
+    }
+    else
+    {
+      metadata._path = fullPath.substring(0, splitter);
+      metadata._queryString = fullPath.substring(splitter + 1);
+    }
+
+    metadata._scheme = scheme;
+    metadata._host = host;
+    metadata._port = port;
+  },
+
+  /**
+* Parses all available HTTP headers in this until the header-ending CRLFCRLF,
+* adding them to the store of headers in the request.
+*
+* @throws
+* HTTP_400 if the headers are malformed
+* @returns boolean
+* true if all headers have now been processed, false otherwise
+*/
+  _parseHeaders: function()
+  {
+    NS_ASSERT(this._state == READER_IN_HEADERS);
+
+    dumpn("*** _parseHeaders");
+
+    var data = this._data;
+
+    var headers = this._metadata._headers;
+    var lastName = this._lastHeaderName;
+    var lastVal = this._lastHeaderValue;
+
+    var line = {};
+    while (true)
+    {
+      NS_ASSERT(!((lastVal === undefined) ^ (lastName === undefined)),
+                lastName === undefined ?
+                  "lastVal without lastName? lastVal: '" + lastVal + "'" :
+                  "lastName without lastVal? lastName: '" + lastName + "'");
+
+      if (!data.readLine(line))
+      {
+        // save any data we have from the header we might still be processing
+        this._lastHeaderName = lastName;
+        this._lastHeaderValue = lastVal;
+        return false;
+      }
+
+      var lineText = line.value;
+      var firstChar = lineText.charAt(0);
+
+      // blank line means end of headers
+      if (lineText == "")
+      {
+        // we're finished with the previous header
+        if (lastName)
+        {
+          try
+          {
+            headers.setHeader(lastName, lastVal, true);
+          }
+          catch (e)
+          {
+            dumpn("*** e == " + e);
+            throw HTTP_400;
+          }
+        }
+        else
+        {
+          // no headers in request -- valid for HTTP/1.0 requests
+        }
+
+        // either way, we're done processing headers
+        this._state = READER_IN_BODY;
+        return true;
+      }
+      else if (firstChar == " " || firstChar == "\t")
+      {
+        // multi-line header if we've already seen a header line
+        if (!lastName)
+        {
+          // we don't have a header to continue!
+          throw HTTP_400;
+        }
+
+        // append this line's text to the value; starts with SP/HT, so no need
+        // for separating whitespace
+        lastVal += lineText;
+      }
+      else
+      {
+        // we have a new header, so set the old one (if one existed)
+        if (lastName)
+        {
+          try
+          {
+            headers.setHeader(lastName, lastVal, true);
+          }
+          catch (e)
+          {
+            dumpn("*** e == " + e);
+            throw HTTP_400;
+          }
+        }
+
+        var colon = lineText.indexOf(":"); // first colon must be splitter
+        if (colon < 1)
+        {
+          // no colon or missing header field-name
+          throw HTTP_400;
+        }
+
+        // set header name, value (to be set in the next loop, usually)
+        lastName = lineText.substring(0, colon);
+        lastVal = lineText.substring(colon + 1);
+      } // empty, continuation, start of header
+    } // while (true)
+  }
+};
+
+
+/** The character codes for CR and LF. */
+const CR = 0x0D, LF = 0x0A;
+
+/**
+* Calculates the number of characters before the first CRLF pair in array, or
+* -1 if the array contains no CRLF pair.
+*
+* @param array : Array
+* an array of numbers in the range [0, 256), each representing a single
+* character; the first CRLF is the lowest index i where
+* |array[i] == "\r".charCodeAt(0)| and |array[i+1] == "\n".charCodeAt(0)|,
+* if such an |i| exists, and -1 otherwise
+* @returns int
+* the index of the first CRLF if any were present, -1 otherwise
+*/
+function findCRLF(array)
+{
+  for (var i = array.indexOf(CR); i >= 0; i = array.indexOf(CR, i + 1))
+  {
+    if (array[i + 1] == LF)
+      return i;
+  }
+  return -1;
+}
+
+
+/**
+* A container which provides line-by-line access to the arrays of bytes with
+* which it is seeded.
+*/
+function LineData()
+{
+  /** An array of queued bytes from which to get line-based characters. */
+  this._data = [];
+}
+LineData.prototype =
+{
+  /**
+* Appends the bytes in the given array to the internal data cache maintained
+* by this.
+*/
+  appendBytes: function(bytes)
+  {
+    Array.prototype.push.apply(this._data, bytes);
+  },
+
+  /**
+* Removes and returns a line of data, delimited by CRLF, from this.
+*
+* @param out
+* an object whose "value" property will be set to the first line of text
+* present in this, sans CRLF, if this contains a full CRLF-delimited line
+* of text; if this doesn't contain enough data, the value of the property
+* is undefined
+* @returns boolean
+* true if a full line of data could be read from the data in this, false
+* otherwise
+*/
+  readLine: function(out)
+  {
+    var data = this._data;
+    var length = findCRLF(data);
+    if (length < 0)
+      return false;
+
+    //
+    // We have the index of the CR, so remove all the characters, including
+    // CRLF, from the array with splice, and convert the removed array into the
+    // corresponding string, from which we then strip the trailing CRLF.
+    //
+    // Getting the line in this matter acknowledges that substring is an O(1)
+    // operation in SpiderMonkey because strings are immutable, whereas two
+    // splices, both from the beginning of the data, are less likely to be as
+    // cheap as a single splice plus two extra character conversions.
+    //
+    var line = String.fromCharCode.apply(null, data.splice(0, length + 2));
+    out.value = line.substring(0, length);
+
+    return true;
+  },
+
+  /**
+* Removes the bytes currently within this and returns them in an array.
+*
+* @returns Array
+* the bytes within this when this method is called
+*/
+  purge: function()
+  {
+    var data = this._data;
+    this._data = [];
+    return data;
+  }
+};
+
+
+
+/**
+* Creates a request-handling function for an nsIHttpRequestHandler object.
+*/
+function createHandlerFunc(handler)
+{
+  return function(metadata, response) { handler.handle(metadata, response); };
+}
+
+
+/**
+* The default handler for directories; writes an HTML response containing a
+* slightly-formatted directory listing.
+*/
+function defaultIndexHandler(metadata, response)
+{
+  response.setHeader("Content-Type", "text/html", false);
+
+  var path = htmlEscape(decodeURI(metadata.path));
+
+  //
+  // Just do a very basic bit of directory listings -- no need for too much
+  // fanciness, especially since we don't have a style sheet in which we can
+  // stick rules (don't want to pollute the default path-space).
+  //
+
+  var body = '<html>\
+<head>\
+<title>' + path + '</title>\
+</head>\
+<body>\
+<h1>' + path + '</h1>\
+<ol style="list-style-type: none">';
+
+  var directory = metadata.getProperty("directory").QueryInterface(Ci.nsILocalFile);
+  NS_ASSERT(directory && directory.isDirectory());
+
+  var fileList = [];
+  var files = directory.directoryEntries;
+  while (files.hasMoreElements())
+  {
+    var f = files.getNext().QueryInterface(Ci.nsIFile);
+    var name = f.leafName;
+    if (!f.isHidden() &&
+        (name.charAt(name.length - 1) != HIDDEN_CHAR ||
+         name.charAt(name.length - 2) == HIDDEN_CHAR))
+      fileList.push(f);
+  }
+
+  fileList.sort(fileSort);
+
+  for (var i = 0; i < fileList.length; i++)
+  {
+    var file = fileList[i];
+    try
+    {
+      var name = file.leafName;
+      if (name.charAt(name.length - 1) == HIDDEN_CHAR)
+        name = name.substring(0, name.length - 1);
+      var sep = file.isDirectory() ? "/" : "";
+
+      // Note: using " to delimit the attribute here because encodeURIComponent
+      // passes through '.
+      var item = '<li><a href="' + encodeURIComponent(name) + sep + '">' +
+                   htmlEscape(name) + sep +
+                 '</a></li>';
+
+      body += item;
+    }
+    catch (e) { /* some file system error, ignore the file */ }
+  }
+
+  body += ' </ol>\
+</body>\
+</html>';
+
+  response.bodyOutputStream.write(body, body.length);
+}
+
+/**
+* Sorts a and b (nsIFile objects) into an aesthetically pleasing order.
+*/
+function fileSort(a, b)
+{
+  var dira = a.isDirectory(), dirb = b.isDirectory();
+
+  if (dira && !dirb)
+    return -1;
+  if (dirb && !dira)
+    return 1;
+
+  var namea = a.leafName.toLowerCase(), nameb = b.leafName.toLowerCase();
+  return nameb > namea ? -1 : 1;
+}
+
+
+/**
+* Converts an externally-provided path into an internal path for use in
+* determining file mappings.
+*
+* @param path
+* the path to convert
+* @param encoded
+* true if the given path should be passed through decodeURI prior to
+* conversion
+* @throws URIError
+* if path is incorrectly encoded
+*/
+function toInternalPath(path, encoded)
+{
+  if (encoded)
+    path = decodeURI(path);
+
+  var comps = path.split("/");
+  for (var i = 0, sz = comps.length; i < sz; i++)
+  {
+    var comp = comps[i];
+    if (comp.charAt(comp.length - 1) == HIDDEN_CHAR)
+      comps[i] = comp + HIDDEN_CHAR;
+  }
+  return comps.join("/");
+}
+
+
+/**
+* Adds custom-specified headers for the given file to the given response, if
+* any such headers are specified.
+*
+* @param file
+* the file on the disk which is to be written
+* @param metadata
+* metadata about the incoming request
+* @param response
+* the Response to which any specified headers/data should be written
+* @throws HTTP_500
+* if an error occurred while processing custom-specified headers
+*/
+function maybeAddHeaders(file, metadata, response)
+{
+  var name = file.leafName;
+  if (name.charAt(name.length - 1) == HIDDEN_CHAR)
+    name = name.substring(0, name.length - 1);
+
+  var headerFile = file.parent;
+  headerFile.append(name + HEADERS_SUFFIX);
+
+  if (!headerFile.exists())
+    return;
+
+  const PR_RDONLY = 0x01;
+  var fis = new FileInputStream(headerFile, PR_RDONLY, 0o444,
+                                Ci.nsIFileInputStream.CLOSE_ON_EOF);
+
+  try
+  {
+    var lis = new ConverterInputStream(fis, "UTF-8", 1024, 0x0);
+    lis.QueryInterface(Ci.nsIUnicharLineInputStream);
+
+    var line = {value: ""};
+    var more = lis.readLine(line);
+
+    if (!more && line.value == "")
+      return;
+
+
+    // request line
+
+    var status = line.value;
+    if (status.indexOf("HTTP ") == 0)
+    {
+      status = status.substring(5);
+      var space = status.indexOf(" ");
+      var code, description;
+      if (space < 0)
+      {
+        code = status;
+        description = "";
+      }
+      else
+      {
+        code = status.substring(0, space);
+        description = status.substring(space + 1, status.length);
+      }
+
+      response.setStatusLine(metadata.httpVersion, parseInt(code, 10), description);
+
+      line.value = "";
+      more = lis.readLine(line);
+    }
+
+    // headers
+    while (more || line.value != "")
+    {
+      var header = line.value;
+      var colon = header.indexOf(":");
+
+      response.setHeader(header.substring(0, colon),
+                         header.substring(colon + 1, header.length),
+                         false); // allow overriding server-set headers
+
+      line.value = "";
+      more = lis.readLine(line);
+    }
+  }
+  catch (e)
+  {
+    dumpn("WARNING: error in headers for " + metadata.path + ": " + e);
+    throw HTTP_500;
+  }
+  finally
+  {
+    fis.close();
+  }
+}
+
+
+/**
+* An object which handles requests for a server, executing default and
+* overridden behaviors as instructed by the code which uses and manipulates it.
+* Default behavior includes the paths / and /trace (diagnostics), with some
+* support for HTTP error pages for various codes and fallback to HTTP 500 if
+* those codes fail for any reason.
+*
+* @param server : nsHttpServer
+* the server in which this handler is being used
+*/
+function ServerHandler(server)
+{
+  // FIELDS
+
+  /**
+* The nsHttpServer instance associated with this handler.
+*/
+  this._server = server;
+
+  /**
+* A FileMap object containing the set of path->nsILocalFile mappings for
+* all directory mappings set in the server (e.g., "/" for /var/www/html/,
+* "/foo/bar/" for /local/path/, and "/foo/bar/baz/" for /local/path2).
+*
+* Note carefully: the leading and trailing "/" in each path (not file) are
+* removed before insertion to simplify the code which uses this. You have
+* been warned!
+*/
+  this._pathDirectoryMap = new FileMap();
+
+  /**
+* Custom request handlers for the server in which this resides. Path-handler
+* pairs are stored as property-value pairs in this property.
+*
+* @see ServerHandler.prototype._defaultPaths
+*/
+  this._overridePaths = {};
+
+  /**
+* Custom request handlers for the server in which this resides. Prefix-handler
+* pairs are stored as property-value pairs in this property.
+*/
+  this._overridePrefixes = {};
+
+  /**
+* Custom request handlers for the error handlers in the server in which this
+* resides. Path-handler pairs are stored as property-value pairs in this
+* property.
+*
+* @see ServerHandler.prototype._defaultErrors
+*/
+  this._overrideErrors = {};
+
+  /**
+* Maps file extensions to their MIME types in the server, overriding any
+* mapping that might or might not exist in the MIME service.
+*/
+  this._mimeMappings = {};
+
+  /**
+* The default handler for requests for directories, used to serve directories
+* when no index file is present.
+*/
+  this._indexHandler = defaultIndexHandler;
+
+  /** Per-path state storage for the server. */
+  this._state = {};
+
+  /** Entire-server state storage. */
+  this._sharedState = {};
+
+  /** Entire-server state storage for nsISupports values. */
+  this._objectState = {};
+}
+ServerHandler.prototype =
+{
+  // PUBLIC API
+
+  /**
+* Handles a request to this server, responding to the request appropriately
+* and initiating server shutdown if necessary.
+*
+* This method never throws an exception.
+*
+* @param connection : Connection
+* the connection for this request
+*/
+  handleResponse: function(connection)
+  {
+    var request = connection.request;
+    var response = new Response(connection);
+
+    var path = request.path;
+    dumpn("*** path == " + path);
+
+    try
+    {
+      try
+      {
+        if (path in this._overridePaths)
+        {
+          // explicit paths first, then files based on existing directory mappings,
+          // then (if the file doesn't exist) built-in server default paths
+          dumpn("calling override for " + path);
+          this._overridePaths[path](request, response);
+        }
+        else
+        {
+          let longestPrefix = "";
+          for (let prefix in this._overridePrefixes)
+          {
+            if (prefix.length > longestPrefix.length && path.startsWith(prefix))
+            {
+              longestPrefix = prefix;
+            }
+          }
+          if (longestPrefix.length > 0)
+          {
+            dumpn("calling prefix override for " + longestPrefix);
+            this._overridePrefixes[longestPrefix](request, response);
+          }
+          else
+          {
+            this._handleDefault(request, response);
+          }
+        }
+      }
+      catch (e)
+      {
+        if (response.partiallySent())
+        {
+          response.abort(e);
+          return;
+        }
+
+        if (!(e instanceof HttpError))
+        {
+          dumpn("*** unexpected error: e == " + e);
+          throw HTTP_500;
+        }
+        if (e.code !== 404)
+          throw e;
+
+        dumpn("*** default: " + (path in this._defaultPaths));
+
+        response = new Response(connection);
+        if (path in this._defaultPaths)
+          this._defaultPaths[path](request, response);
+        else
+          throw HTTP_404;
+      }
+    }
+    catch (e)
+    {
+      if (response.partiallySent())
+      {
+        response.abort(e);
+        return;
+      }
+
+      var errorCode = "internal";
+
+      try
+      {
+        if (!(e instanceof HttpError))
+          throw e;
+
+        errorCode = e.code;
+        dumpn("*** errorCode == " + errorCode);
+
+        response = new Response(connection);
+        if (e.customErrorHandling)
+          e.customErrorHandling(response);
+        this._handleError(errorCode, request, response);
+        return;
+      }
+      catch (e2)
+      {
+        dumpn("*** error handling " + errorCode + " error: " +
+              "e2 == " + e2 + ", shutting down server");
+
+        connection.server._requestQuit();
+        response.abort(e2);
+        return;
+      }
+    }
+
+    response.complete();
+  },
+
+  //
+  // see nsIHttpServer.registerFile
+  //
+  registerFile: function(path, file)
+  {
+    if (!file)
+    {
+      dumpn("*** unregistering '" + path + "' mapping");
+      delete this._overridePaths[path];
+      return;
+    }
+
+    dumpn("*** registering '" + path + "' as mapping to " + file.path);
+    file = file.clone();
+
+    var self = this;
+    this._overridePaths[path] =
+      function(request, response)
+      {
+        if (!file.exists())
+          throw HTTP_404;
+
+        response.setStatusLine(request.httpVersion, 200, "OK");
+        self._writeFileResponse(request, file, response, 0, file.fileSize);
+      };
+  },
+
+  //
+  // see nsIHttpServer.registerPathHandler
+  //
+  registerPathHandler: function(path, handler)
+  {
+    // XXX true path validation!
+    if (path.charAt(0) != "/")
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    this._handlerToField(handler, this._overridePaths, path);
+  },
+
+  //
+  // see nsIHttpServer.registerPrefixHandler
+  //
+  registerPrefixHandler: function(prefix, handler)
+  {
+    // XXX true prefix validation!
+    if (!(prefix.startsWith("/") && prefix.endsWith("/")))
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    this._handlerToField(handler, this._overridePrefixes, prefix);
+  },
+
+  //
+  // see nsIHttpServer.registerDirectory
+  //
+  registerDirectory: function(path, directory)
+  {
+    // strip off leading and trailing '/' so that we can use lastIndexOf when
+    // determining exactly how a path maps onto a mapped directory --
+    // conditional is required here to deal with "/".substring(1, 0) being
+    // converted to "/".substring(0, 1) per the JS specification
+    var key = path.length == 1 ? "" : path.substring(1, path.length - 1);
+
+    // the path-to-directory mapping code requires that the first character not
+    // be "/", or it will go into an infinite loop
+    if (key.charAt(0) == "/")
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    key = toInternalPath(key, false);
+
+    if (directory)
+    {
+      dumpn("*** mapping '" + path + "' to the location " + directory.path);
+      this._pathDirectoryMap.put(key, directory);
+    }
+    else
+    {
+      dumpn("*** removing mapping for '" + path + "'");
+      this._pathDirectoryMap.put(key, null);
+    }
+  },
+
+  //
+  // see nsIHttpServer.registerErrorHandler
+  //
+  registerErrorHandler: function(err, handler)
+  {
+    if (!(err in HTTP_ERROR_CODES))
+      dumpn("*** WARNING: registering non-HTTP/1.1 error code " +
+            "(" + err + ") handler -- was this intentional?");
+
+    this._handlerToField(handler, this._overrideErrors, err);
+  },
+
+  //
+  // see nsIHttpServer.setIndexHandler
+  //
+  setIndexHandler: function(handler)
+  {
+    if (!handler)
+      handler = defaultIndexHandler;
+    else if (typeof(handler) != "function")
+      handler = createHandlerFunc(handler);
+
+    this._indexHandler = handler;
+  },
+
+  //
+  // see nsIHttpServer.registerContentType
+  //
+  registerContentType: function(ext, type)
+  {
+    if (!type)
+      delete this._mimeMappings[ext];
+    else
+      this._mimeMappings[ext] = headerUtils.normalizeFieldValue(type);
+  },
+
+  // PRIVATE API
+
+  /**
+* Sets or remove (if handler is null) a handler in an object with a key.
+*
+* @param handler
+* a handler, either function or an nsIHttpRequestHandler
+* @param dict
+* The object to attach the handler to.
+* @param key
+* The field name of the handler.
+*/
+  _handlerToField: function(handler, dict, key)
+  {
+    // for convenience, handler can be a function if this is run from xpcshell
+    if (typeof(handler) == "function")
+      dict[key] = handler;
+    else if (handler)
+      dict[key] = createHandlerFunc(handler);
+    else
+      delete dict[key];
+  },
+
+  /**
+* Handles a request which maps to a file in the local filesystem (if a base
+* path has already been set; otherwise the 404 error is thrown).
+*
+* @param metadata : Request
+* metadata for the incoming request
+* @param response : Response
+* an uninitialized Response to the given request, to be initialized by a
+* request handler
+* @throws HTTP_###
+* if an HTTP error occurred (usually HTTP_404); note that in this case the
+* calling code must handle post-processing of the response
+*/
+  _handleDefault: function(metadata, response)
+  {
+    dumpn("*** _handleDefault()");
+
+    response.setStatusLine(metadata.httpVersion, 200, "OK");
+
+    var path = metadata.path;
+    NS_ASSERT(path.charAt(0) == "/", "invalid path: <" + path + ">");
+
+    // determine the actual on-disk file; this requires finding the deepest
+    // path-to-directory mapping in the requested URL
+    var file = this._getFileForPath(path);
+
+    // the "file" might be a directory, in which case we either serve the
+    // contained index.html or make the index handler write the response
+    if (file.exists() && file.isDirectory())
+    {
+      file.append("index.html"); // make configurable?
+      if (!file.exists() || file.isDirectory())
+      {
+        metadata._ensurePropertyBag();
+        metadata._bag.setPropertyAsInterface("directory", file.parent);
+        this._indexHandler(metadata, response);
+        return;
+      }
+    }
+
+    // alternately, the file might not exist
+    if (!file.exists())
+      throw HTTP_404;
+
+    var start, end;
+    if (metadata._httpVersion.atLeast(nsHttpVersion.HTTP_1_1) &&
+        metadata.hasHeader("Range") &&
+        this._getTypeFromFile(file) !== SJS_TYPE)
+    {
+      var rangeMatch = metadata.getHeader("Range").match(/^bytes=(\d+)?-(\d+)?$/);
+      if (!rangeMatch)
+        throw HTTP_400;
+
+      if (rangeMatch[1] !== undefined)
+        start = parseInt(rangeMatch[1], 10);
+
+      if (rangeMatch[2] !== undefined)
+        end = parseInt(rangeMatch[2], 10);
+
+      if (start === undefined && end === undefined)
+        throw HTTP_400;
+
+      // No start given, so the end is really the count of bytes from the
+      // end of the file.
+      if (start === undefined)
+      {
+        start = Math.max(0, file.fileSize - end);
+        end = file.fileSize - 1;
+      }
+
+      // start and end are inclusive
+      if (end === undefined || end >= file.fileSize)
+        end = file.fileSize - 1;
+
+      if (start !== undefined && start >= file.fileSize) {
+        var HTTP_416 = new HttpError(416, "Requested Range Not Satisfiable");
+        HTTP_416.customErrorHandling = function(errorResponse)
+        {
+          maybeAddHeaders(file, metadata, errorResponse);
+        };
+        throw HTTP_416;
+      }
+
+      if (end < start)
+      {
+        response.setStatusLine(metadata.httpVersion, 200, "OK");
+        start = 0;
+        end = file.fileSize - 1;
+      }
+      else
+      {
+        response.setStatusLine(metadata.httpVersion, 206, "Partial Content");
+        var contentRange = "bytes " + start + "-" + end + "/" + file.fileSize;
+        response.setHeader("Content-Range", contentRange);
+      }
+    }
+    else
+    {
+      start = 0;
+      end = file.fileSize - 1;
+    }
+
+    // finally...
+    dumpn("*** handling '" + path + "' as mapping to " + file.path + " from " +
+          start + " to " + end + " inclusive");
+    this._writeFileResponse(metadata, file, response, start, end - start + 1);
+  },
+
+  /**
+* Writes an HTTP response for the given file, including setting headers for
+* file metadata.
+*
+* @param metadata : Request
+* the Request for which a response is being generated
+* @param file : nsILocalFile
+* the file which is to be sent in the response
+* @param response : Response
+* the response to which the file should be written
+* @param offset: uint
+* the byte offset to skip to when writing
+* @param count: uint
+* the number of bytes to write
+*/
+  _writeFileResponse: function(metadata, file, response, offset, count)
+  {
+    const PR_RDONLY = 0x01;
+
+    var type = this._getTypeFromFile(file);
+    if (type === SJS_TYPE)
+    {
+      var fis = new FileInputStream(file, PR_RDONLY, 0o444,
+                                    Ci.nsIFileInputStream.CLOSE_ON_EOF);
+
+      try
+      {
+        var sis = new ScriptableInputStream(fis);
+        var s = Cu.Sandbox(gGlobalObject);
+        s.importFunction(dump, "dump");
+
+        // Define a basic key-value state-preservation API across requests, with
+        // keys initially corresponding to the empty string.
+        var self = this;
+        var path = metadata.path;
+        s.importFunction(function getState(k)
+        {
+          return self._getState(path, k);
+        });
+        s.importFunction(function setState(k, v)
+        {
+          self._setState(path, k, v);
+        });
+        s.importFunction(function getSharedState(k)
+        {
+          return self._getSharedState(k);
+        });
+        s.importFunction(function setSharedState(k, v)
+        {
+          self._setSharedState(k, v);
+        });
+        s.importFunction(function getObjectState(k, callback)
+        {
+          callback(self._getObjectState(k));
+        });
+        s.importFunction(function setObjectState(k, v)
+        {
+          self._setObjectState(k, v);
+        });
+        s.importFunction(function registerPathHandler(p, h)
+        {
+          self.registerPathHandler(p, h);
+        });
+
+        // Make it possible for sjs files to access their location
+        this._setState(path, "__LOCATION__", file.path);
+
+        try
+        {
+          // Alas, the line number in errors dumped to console when calling the
+          // request handler is simply an offset from where we load the SJS file.
+          // Work around this in a reasonably non-fragile way by dynamically
+          // getting the line number where we evaluate the SJS file. Don't
+          // separate these two lines!
+          var line = new Error().lineNumber;
+          Cu.evalInSandbox(sis.read(file.fileSize), s);
+        }
+        catch (e)
+        {
+          dumpn("*** syntax error in SJS at " + file.path + ": " + e);
+          throw HTTP_500;
+        }
+
+        try
+        {
+          s.handleRequest(metadata, response);
+        }
+        catch (e)
+        {
+          dump("*** error running SJS at " + file.path + ": " +
+               e + " on line " +
+               (e instanceof Error
+               ? e.lineNumber + " in httpd.js"
+               : (e.lineNumber - line)) + "\n");
+          throw HTTP_500;
+        }
+      }
+      finally
+      {
+        fis.close();
+      }
+    }
+    else
+    {
+      try
+      {
+        response.setHeader("Last-Modified",
+                           toDateString(file.lastModifiedTime),
+                           false);
+      }
+      catch (e) { /* lastModifiedTime threw, ignore */ }
+
+      response.setHeader("Content-Type", type, false);
+      maybeAddHeaders(file, metadata, response);
+      response.setHeader("Content-Length", "" + count, false);
+
+      var fis = new FileInputStream(file, PR_RDONLY, 0o444,
+                                    Ci.nsIFileInputStream.CLOSE_ON_EOF);
+
+      offset = offset || 0;
+      count = count || file.fileSize;
+      NS_ASSERT(offset === 0 || offset < file.fileSize, "bad offset");
+      NS_ASSERT(count >= 0, "bad count");
+      NS_ASSERT(offset + count <= file.fileSize, "bad total data size");
+
+      try
+      {
+        if (offset !== 0)
+        {
+          // Seek (or read, if seeking isn't supported) to the correct offset so
+          // the data sent to the client matches the requested range.
+          if (fis instanceof Ci.nsISeekableStream)
+            fis.seek(Ci.nsISeekableStream.NS_SEEK_SET, offset);
+          else
+            new ScriptableInputStream(fis).read(offset);
+        }
+      }
+      catch (e)
+      {
+        fis.close();
+        throw e;
+      }
+
+      let writeMore = function writeMore()
+      {
+        gThreadManager.currentThread
+                      .dispatch(writeData, Ci.nsIThread.DISPATCH_NORMAL);
+      }
+
+      var input = new BinaryInputStream(fis);
+      var output = new BinaryOutputStream(response.bodyOutputStream);
+      var writeData =
+        {
+          run: function()
+          {
+            var chunkSize = Math.min(65536, count);
+            count -= chunkSize;
+            NS_ASSERT(count >= 0, "underflow");
+
+            try
+            {
+              var data = input.readByteArray(chunkSize);
+              NS_ASSERT(data.length === chunkSize,
+                        "incorrect data returned? got " + data.length +
+                        ", expected " + chunkSize);
+              output.writeByteArray(data, data.length);
+              if (count === 0)
+              {
+                fis.close();
+                response.finish();
+              }
+              else
+              {
+                writeMore();
+              }
+            }
+            catch (e)
+            {
+              try
+              {
+                fis.close();
+              }
+              finally
+              {
+                response.finish();
+              }
+              throw e;
+            }
+          }
+        };
+
+      writeMore();
+
+      // Now that we know copying will start, flag the response as async.
+      response.processAsync();
+    }
+  },
+
+  /**
+* Get the value corresponding to a given key for the given path for SJS state
+* preservation across requests.
+*
+* @param path : string
+* the path from which the given state is to be retrieved
+* @param k : string
+* the key whose corresponding value is to be returned
+* @returns string
+* the corresponding value, which is initially the empty string
+*/
+  _getState: function(path, k)
+  {
+    var state = this._state;
+    if (path in state && k in state[path])
+      return state[path][k];
+    return "";
+  },
+
+  /**
+* Set the value corresponding to a given key for the given path for SJS state
+* preservation across requests.
+*
+* @param path : string
+* the path from which the given state is to be retrieved
+* @param k : string
+* the key whose corresponding value is to be set
+* @param v : string
+* the value to be set
+*/
+  _setState: function(path, k, v)
+  {
+    if (typeof v !== "string")
+      throw new Error("non-string value passed");
+    var state = this._state;
+    if (!(path in state))
+      state[path] = {};
+    state[path][k] = v;
+  },
+
+  /**
+* Get the value corresponding to a given key for SJS state preservation
+* across requests.
+*
+* @param k : string
+* the key whose corresponding value is to be returned
+* @returns string
+* the corresponding value, which is initially the empty string
+*/
+  _getSharedState: function(k)
+  {
+    var state = this._sharedState;
+    if (k in state)
+      return state[k];
+    return "";
+  },
+
+  /**
+* Set the value corresponding to a given key for SJS state preservation
+* across requests.
+*
+* @param k : string
+* the key whose corresponding value is to be set
+* @param v : string
+* the value to be set
+*/
+  _setSharedState: function(k, v)
+  {
+    if (typeof v !== "string")
+      throw new Error("non-string value passed");
+    this._sharedState[k] = v;
+  },
+
+  /**
+* Returns the object associated with the given key in the server for SJS
+* state preservation across requests.
+*
+* @param k : string
+* the key whose corresponding object is to be returned
+* @returns nsISupports
+* the corresponding object, or null if none was present
+*/
+  _getObjectState: function(k)
+  {
+    if (typeof k !== "string")
+      throw new Error("non-string key passed");
+    return this._objectState[k] || null;
+  },
+
+  /**
+* Sets the object associated with the given key in the server for SJS
+* state preservation across requests.
+*
+* @param k : string
+* the key whose corresponding object is to be set
+* @param v : nsISupports
+* the object to be associated with the given key; may be null
+*/
+  _setObjectState: function(k, v)
+  {
+    if (typeof k !== "string")
+      throw new Error("non-string key passed");
+    if (typeof v !== "object")
+      throw new Error("non-object value passed");
+    if (v && !("QueryInterface" in v))
+    {
+      throw new Error("must pass an nsISupports; use wrappedJSObject to ease " +
+                      "pain when using the server from JS");
+    }
+
+    this._objectState[k] = v;
+  },
+
+  /**
+* Gets a content-type for the given file, first by checking for any custom
+* MIME-types registered with this handler for the file's extension, second by
+* asking the global MIME service for a content-type, and finally by failing
+* over to application/octet-stream.
+*
+* @param file : nsIFile
+* the nsIFile for which to get a file type
+* @returns string
+* the best content-type which can be determined for the file
+*/
+  _getTypeFromFile: function(file)
+  {
+    try
+    {
+      var name = file.leafName;
+      var dot = name.lastIndexOf(".");
+      if (dot > 0)
+      {
+        var ext = name.slice(dot + 1);
+        if (ext in this._mimeMappings)
+          return this._mimeMappings[ext];
+      }
+      return Cc["@mozilla.org/uriloader/external-helper-app-service;1"]
+               .getService(Ci.nsIMIMEService)
+               .getTypeFromFile(file);
+    }
+    catch (e)
+    {
+      return "application/octet-stream";
+    }
+  },
+
+  /**
+* Returns the nsILocalFile which corresponds to the path, as determined using
+* all registered path->directory mappings and any paths which are explicitly
+* overridden.
+*
+* @param path : string
+* the server path for which a file should be retrieved, e.g. "/foo/bar"
+* @throws HttpError
+* when the correct action is the corresponding HTTP error (i.e., because no
+* mapping was found for a directory in path, the referenced file doesn't
+* exist, etc.)
+* @returns nsILocalFile
+* the file to be sent as the response to a request for the path
+*/
+  _getFileForPath: function(path)
+  {
+    // decode and add underscores as necessary
+    try
+    {
+      path = toInternalPath(path, true);
+    }
+    catch (e)
+    {
+      throw HTTP_400; // malformed path
+    }
+
+    // next, get the directory which contains this path
+    var pathMap = this._pathDirectoryMap;
+
+    // An example progression of tmp for a path "/foo/bar/baz/" might be:
+    // "foo/bar/baz/", "foo/bar/baz", "foo/bar", "foo", ""
+    var tmp = path.substring(1);
+    while (true)
+    {
+      // do we have a match for current head of the path?
+      var file = pathMap.get(tmp);
+      if (file)
+      {
+        // XXX hack; basically disable showing mapping for /foo/bar/ when the
+        // requested path was /foo/bar, because relative links on the page
+        // will all be incorrect -- we really need the ability to easily
+        // redirect here instead
+        if (tmp == path.substring(1) &&
+            tmp.length != 0 &&
+            tmp.charAt(tmp.length - 1) != "/")
+          file = null;
+        else
+          break;
+      }
+
+      // if we've finished trying all prefixes, exit
+      if (tmp == "")
+        break;
+
+      tmp = tmp.substring(0, tmp.lastIndexOf("/"));
+    }
+
+    // no mapping applies, so 404
+    if (!file)
+      throw HTTP_404;
+
+
+    // last, get the file for the path within the determined directory
+    var parentFolder = file.parent;
+    var dirIsRoot = (parentFolder == null);
+
+    // Strategy here is to append components individually, making sure we
+    // never move above the given directory; this allows paths such as
+    // "<file>/foo/../bar" but prevents paths such as "<file>/../base-sibling";
+    // this component-wise approach also means the code works even on platforms
+    // which don't use "/" as the directory separator, such as Windows
+    var leafPath = path.substring(tmp.length + 1);
+    var comps = leafPath.split("/");
+    for (var i = 0, sz = comps.length; i < sz; i++)
+    {
+      var comp = comps[i];
+
+      if (comp == "..")
+        file = file.parent;
+      else if (comp == "." || comp == "")
+        continue;
+      else
+        file.append(comp);
+
+      if (!dirIsRoot && file.equals(parentFolder))
+        throw HTTP_403;
+    }
+
+    return file;
+  },
+
+  /**
+* Writes the error page for the given HTTP error code over the given
+* connection.
+*
+* @param errorCode : uint
+* the HTTP error code to be used
+* @param connection : Connection
+* the connection on which the error occurred
+*/
+  handleError: function(errorCode, connection)
+  {
+    var response = new Response(connection);
+
+    dumpn("*** error in request: " + errorCode);
+
+    this._handleError(errorCode, new Request(connection.port), response);
+  },
+
+  /**
+* Handles a request which generates the given error code, using the
+* user-defined error handler if one has been set, gracefully falling back to
+* the x00 status code if the code has no handler, and failing to status code
+* 500 if all else fails.
+*
+* @param errorCode : uint
+* the HTTP error which is to be returned
+* @param metadata : Request
+* metadata for the request, which will often be incomplete since this is an
+* error
+* @param response : Response
+* an uninitialized Response should be initialized when this method
+* completes with information which represents the desired error code in the
+* ideal case or a fallback code in abnormal circumstances (i.e., 500 is a
+* fallback for 505, per HTTP specs)
+*/
+  _handleError: function(errorCode, metadata, response)
+  {
+    if (!metadata)
+      throw Cr.NS_ERROR_NULL_POINTER;
+
+    var errorX00 = errorCode - (errorCode % 100);
+
+    try
+    {
+      if (!(errorCode in HTTP_ERROR_CODES))
+        dumpn("*** WARNING: requested invalid error: " + errorCode);
+
+      // RFC 2616 says that we should try to handle an error by its class if we
+      // can't otherwise handle it -- if that fails, we revert to handling it as
+      // a 500 internal server error, and if that fails we throw and shut down
+      // the server
+
+      // actually handle the error
+      try
+      {
+        if (errorCode in this._overrideErrors)
+          this._overrideErrors[errorCode](metadata, response);
+        else
+          this._defaultErrors[errorCode](metadata, response);
+      }
+      catch (e)
+      {
+        if (response.partiallySent())
+        {
+          response.abort(e);
+          return;
+        }
+
+        // don't retry the handler that threw
+        if (errorX00 == errorCode)
+          throw HTTP_500;
+
+        dumpn("*** error in handling for error code " + errorCode + ", " +
+              "falling back to " + errorX00 + "...");
+        response = new Response(response._connection);
+        if (errorX00 in this._overrideErrors)
+          this._overrideErrors[errorX00](metadata, response);
+        else if (errorX00 in this._defaultErrors)
+          this._defaultErrors[errorX00](metadata, response);
+        else
+          throw HTTP_500;
+      }
+    }
+    catch (e)
+    {
+      if (response.partiallySent())
+      {
+        response.abort();
+        return;
+      }
+
+      // we've tried everything possible for a meaningful error -- now try 500
+      dumpn("*** error in handling for error code " + errorX00 + ", falling " +
+            "back to 500...");
+
+      try
+      {
+        response = new Response(response._connection);
+        if (500 in this._overrideErrors)
+          this._overrideErrors[500](metadata, response);
+        else
+          this._defaultErrors[500](metadata, response);
+      }
+      catch (e2)
+      {
+        dumpn("*** multiple errors in default error handlers!");
+        dumpn("*** e == " + e + ", e2 == " + e2);
+        response.abort(e2);
+        return;
+      }
+    }
+
+    response.complete();
+  },
+
+  // FIELDS
+
+  /**
+* This object contains the default handlers for the various HTTP error codes.
+*/
+  _defaultErrors:
+  {
+    400: function(metadata, response)
+    {
+      // none of the data in metadata is reliable, so hard-code everything here
+      response.setStatusLine("1.1", 400, "Bad Request");
+      response.setHeader("Content-Type", "text/plain", false);
+
+      var body = "Bad request\n";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    403: function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion, 403, "Forbidden");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>403 Forbidden</title></head>\
+<body>\
+<h1>403 Forbidden</h1>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    404: function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion, 404, "Not Found");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>404 Not Found</title></head>\
+<body>\
+<h1>404 Not Found</h1>\
+<p>\
+<span style='font-family: monospace;'>" +
+                          htmlEscape(metadata.path) +
+                       "</span> was not found.\
+</p>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    416: function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion,
+                            416,
+                            "Requested Range Not Satisfiable");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head>\
+<title>416 Requested Range Not Satisfiable</title></head>\
+<body>\
+<h1>416 Requested Range Not Satisfiable</h1>\
+<p>The byte range was not valid for the\
+requested resource.\
+</p>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    500: function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion,
+                             500,
+                             "Internal Server Error");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>500 Internal Server Error</title></head>\
+<body>\
+<h1>500 Internal Server Error</h1>\
+<p>Something's broken in this server and\
+needs to be fixed.</p>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    501: function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion, 501, "Not Implemented");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>501 Not Implemented</title></head>\
+<body>\
+<h1>501 Not Implemented</h1>\
+<p>This server is not (yet) Apache.</p>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    },
+    505: function(metadata, response)
+    {
+      response.setStatusLine("1.1", 505, "HTTP Version Not Supported");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>505 HTTP Version Not Supported</title></head>\
+<body>\
+<h1>505 HTTP Version Not Supported</h1>\
+<p>This server only supports HTTP/1.0 and HTTP/1.1\
+connections.</p>\
+</body>\
+</html>";
+      response.bodyOutputStream.write(body, body.length);
+    }
+  },
+
+  /**
+* Contains handlers for the default set of URIs contained in this server.
+*/
+  _defaultPaths:
+  {
+    "/": function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion, 200, "OK");
+      response.setHeader("Content-Type", "text/html", false);
+
+      var body = "<html>\
+<head><title>httpd.js</title></head>\
+<body>\
+<h1>httpd.js</h1>\
+<p>If you're seeing this page, httpd.js is up and\
+serving requests! Now set a base path and serve some\
+files!</p>\
+</body>\
+</html>";
+
+      response.bodyOutputStream.write(body, body.length);
+    },
+
+    "/trace": function(metadata, response)
+    {
+      response.setStatusLine(metadata.httpVersion, 200, "OK");
+      response.setHeader("Content-Type", "text/plain", false);
+
+      var body = "Request-URI: " +
+                 metadata.scheme + "://" + metadata.host + ":" + metadata.port +
+                 metadata.path + "\n\n";
+      body += "Request (semantically equivalent, slightly reformatted):\n\n";
+      body += metadata.method + " " + metadata.path;
+
+      if (metadata.queryString)
+        body += "?" + metadata.queryString;
+
+      body += " HTTP/" + metadata.httpVersion + "\r\n";
+
+      var headEnum = metadata.headers;
+      while (headEnum.hasMoreElements())
+      {
+        var fieldName = headEnum.getNext()
+                                .QueryInterface(Ci.nsISupportsString)
+                                .data;
+        body += fieldName + ": " + metadata.getHeader(fieldName) + "\r\n";
+      }
+
+      response.bodyOutputStream.write(body, body.length);
+    }
+  }
+};
+
+
+/**
+* Maps absolute paths to files on the local file system (as nsILocalFiles).
+*/
+function FileMap()
+{
+  /** Hash which will map paths to nsILocalFiles. */
+  this._map = {};
+}
+FileMap.prototype =
+{
+  // PUBLIC API
+
+  /**
+* Maps key to a clone of the nsILocalFile value if value is non-null;
+* otherwise, removes any extant mapping for key.
+*
+* @param key : string
+* string to which a clone of value is mapped
+* @param value : nsILocalFile
+* the file to map to key, or null to remove a mapping
+*/
+  put: function(key, value)
+  {
+    if (value)
+      this._map[key] = value.clone();
+    else
+      delete this._map[key];
+  },
+
+  /**
+* Returns a clone of the nsILocalFile mapped to key, or null if no such
+* mapping exists.
+*
+* @param key : string
+* key to which the returned file maps
+* @returns nsILocalFile
+* a clone of the mapped file, or null if no mapping exists
+*/
+  get: function(key)
+  {
+    var val = this._map[key];
+    return val ? val.clone() : null;
+  }
+};
+
+
+// Response CONSTANTS
+
+// token = *<any CHAR except CTLs or separators>
+// CHAR = <any US-ASCII character (0-127)>
+// CTL = <any US-ASCII control character (0-31) and DEL (127)>
+// separators = "(" | ")" | "<" | ">" | "@"
+// | "," | ";" | ":" | "\" | <">
+// | "/" | "[" | "]" | "?" | "="
+// | "{" | "}" | SP | HT
+const IS_TOKEN_ARRAY =
+  [0, 0, 0, 0, 0, 0, 0, 0, // 0
+   0, 0, 0, 0, 0, 0, 0, 0, // 8
+   0, 0, 0, 0, 0, 0, 0, 0, // 16
+   0, 0, 0, 0, 0, 0, 0, 0, // 24
+
+   0, 1, 0, 1, 1, 1, 1, 1, // 32
+   0, 0, 1, 1, 0, 1, 1, 0, // 40
+   1, 1, 1, 1, 1, 1, 1, 1, // 48
+   1, 1, 0, 0, 0, 0, 0, 0, // 56
+
+   0, 1, 1, 1, 1, 1, 1, 1, // 64
+   1, 1, 1, 1, 1, 1, 1, 1, // 72
+   1, 1, 1, 1, 1, 1, 1, 1, // 80
+   1, 1, 1, 0, 0, 0, 1, 1, // 88
+
+   1, 1, 1, 1, 1, 1, 1, 1, // 96
+   1, 1, 1, 1, 1, 1, 1, 1, // 104
+   1, 1, 1, 1, 1, 1, 1, 1, // 112
+   1, 1, 1, 0, 1, 0, 1]; // 120
+
+
+/**
+* Determines whether the given character code is a CTL.
+*
+* @param code : uint
+* the character code
+* @returns boolean
+* true if code is a CTL, false otherwise
+*/
+function isCTL(code)
+{
+  return (code >= 0 && code <= 31) || (code == 127);
+}
+
+/**
+* Represents a response to an HTTP request, encapsulating all details of that
+* response. This includes all headers, the HTTP version, status code and
+* explanation, and the entity itself.
+*
+* @param connection : Connection
+* the connection over which this response is to be written
+*/
+function Response(connection)
+{
+  /** The connection over which this response will be written. */
+  this._connection = connection;
+
+  /**
+* The HTTP version of this response; defaults to 1.1 if not set by the
+* handler.
+*/
+  this._httpVersion = nsHttpVersion.HTTP_1_1;
+
+  /**
+* The HTTP code of this response; defaults to 200.
+*/
+  this._httpCode = 200;
+
+  /**
+* The description of the HTTP code in this response; defaults to "OK".
+*/
+  this._httpDescription = "OK";
+
+  /**
+* An nsIHttpHeaders object in which the headers in this response should be
+* stored. This property is null after the status line and headers have been
+* written to the network, and it may be modified up until it is cleared,
+* except if this._finished is set first (in which case headers are written
+* asynchronously in response to a finish() call not preceded by
+* flushHeaders()).
+*/
+  this._headers = new nsHttpHeaders();
+
+  /**
+* Set to true when this response is ended (completely constructed if possible
+* and the connection closed); further actions on this will then fail.
+*/
+  this._ended = false;
+
+  /**
+* A stream used to hold data written to the body of this response.
+*/
+  this._bodyOutputStream = null;
+
+  /**
+* A stream containing all data that has been written to the body of this
+* response so far. (Async handlers make the data contained in this
+* unreliable as a way of determining content length in general, but auxiliary
+* saved information can sometimes be used to guarantee reliability.)
+*/
+  this._bodyInputStream = null;
+
+  /**
+* A stream copier which copies data to the network. It is initially null
+* until replaced with a copier for response headers; when headers have been
+* fully sent it is replaced with a copier for the response body, remaining
+* so for the duration of response processing.
+*/
+  this._asyncCopier = null;
+
+  /**
+* True if this response has been designated as being processed
+* asynchronously rather than for the duration of a single call to
+* nsIHttpRequestHandler.handle.
+*/
+  this._processAsync = false;
+
+  /**
+* True iff finish() has been called on this, signaling that no more changes
+* to this may be made.
+*/
+  this._finished = false;
+
+  /**
+* True iff powerSeized() has been called on this, signaling that this
+* response is to be handled manually by the response handler (which may then
+* send arbitrary data in response, even non-HTTP responses).
+*/
+  this._powerSeized = false;
+}
+Response.prototype =
+{
+  // PUBLIC CONSTRUCTION API
+
+  //
+  // see nsIHttpResponse.bodyOutputStream
+  //
+  get bodyOutputStream()
+  {
+    if (this._finished)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+
+    if (!this._bodyOutputStream)
+    {
+      var pipe = new Pipe(true, false, Response.SEGMENT_SIZE, PR_UINT32_MAX,
+                          null);
+      this._bodyOutputStream = pipe.outputStream;
+      this._bodyInputStream = pipe.inputStream;
+      if (this._processAsync || this._powerSeized)
+        this._startAsyncProcessor();
+    }
+
+    return this._bodyOutputStream;
+  },
+
+  //
+  // see nsIHttpResponse.write
+  //
+  write: function(data)
+  {
+    if (this._finished)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+
+    var dataAsString = String(data);
+    this.bodyOutputStream.write(dataAsString, dataAsString.length);
+  },
+
+  //
+  // see nsIHttpResponse.setStatusLine
+  //
+  setStatusLine: function(httpVersion, code, description)
+  {
+    if (!this._headers || this._finished || this._powerSeized)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+    this._ensureAlive();
+
+    if (!(code >= 0 && code < 1000))
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    try
+    {
+      var httpVer;
+      // avoid version construction for the most common cases
+      if (!httpVersion || httpVersion == "1.1")
+        httpVer = nsHttpVersion.HTTP_1_1;
+      else if (httpVersion == "1.0")
+        httpVer = nsHttpVersion.HTTP_1_0;
+      else
+        httpVer = new nsHttpVersion(httpVersion);
+    }
+    catch (e)
+    {
+      throw Cr.NS_ERROR_INVALID_ARG;
+    }
+
+    // Reason-Phrase = *<TEXT, excluding CR, LF>
+    // TEXT = <any OCTET except CTLs, but including LWS>
+    //
+    // XXX this ends up disallowing octets which aren't Unicode, I think -- not
+    // much to do if description is IDL'd as string
+    if (!description)
+      description = "";
+    for (var i = 0; i < description.length; i++)
+      if (isCTL(description.charCodeAt(i)) && description.charAt(i) != "\t")
+        throw Cr.NS_ERROR_INVALID_ARG;
+
+    // set the values only after validation to preserve atomicity
+    this._httpDescription = description;
+    this._httpCode = code;
+    this._httpVersion = httpVer;
+  },
+
+  //
+  // see nsIHttpResponse.setHeader
+  //
+  setHeader: function(name, value, merge)
+  {
+    if (!this._headers || this._finished || this._powerSeized)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+    this._ensureAlive();
+
+    this._headers.setHeader(name, value, merge);
+  },
+
+  //
+  // see nsIHttpResponse.processAsync
+  //
+  processAsync: function()
+  {
+    if (this._finished)
+      throw Cr.NS_ERROR_UNEXPECTED;
+    if (this._powerSeized)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+    if (this._processAsync)
+      return;
+    this._ensureAlive();
+
+    dumpn("*** processing connection " + this._connection.number + " async");
+    this._processAsync = true;
+
+    /*
+* Either the bodyOutputStream getter or this method is responsible for
+* starting the asynchronous processor and catching writes of data to the
+* response body of async responses as they happen, for the purpose of
+* forwarding those writes to the actual connection's output stream.
+* If bodyOutputStream is accessed first, calling this method will create
+* the processor (when it first is clear that body data is to be written
+* immediately, not buffered). If this method is called first, accessing
+* bodyOutputStream will create the processor. If only this method is
+* called, we'll write nothing, neither headers nor the nonexistent body,
+* until finish() is called. Since that delay is easily avoided by simply
+* getting bodyOutputStream or calling write(""), we don't worry about it.
+*/
+    if (this._bodyOutputStream && !this._asyncCopier)
+      this._startAsyncProcessor();
+  },
+
+  //
+  // see nsIHttpResponse.seizePower
+  //
+  seizePower: function()
+  {
+    if (this._processAsync)
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+    if (this._finished)
+      throw Cr.NS_ERROR_UNEXPECTED;
+    if (this._powerSeized)
+      return;
+    this._ensureAlive();
+
+    dumpn("*** forcefully seizing power over connection " +
+          this._connection.number + "...");
+
+    // Purge any already-written data without sending it. We could as easily
+    // swap out the streams entirely, but that makes it possible to acquire and
+    // unknowingly use a stale reference, so we require there only be one of
+    // each stream ever for any response to avoid this complication.
+    if (this._asyncCopier)
+      this._asyncCopier.cancel(Cr.NS_BINDING_ABORTED);
+    this._asyncCopier = null;
+    if (this._bodyOutputStream)
+    {
+      var input = new BinaryInputStream(this._bodyInputStream);
+      var avail;
+      while ((avail = input.available()) > 0)
+        input.readByteArray(avail);
+    }
+
+    this._powerSeized = true;
+    if (this._bodyOutputStream)
+      this._startAsyncProcessor();
+  },
+
+  //
+  // see nsIHttpResponse.finish
+  //
+  finish: function()
+  {
+    if (!this._processAsync && !this._powerSeized)
+      throw Cr.NS_ERROR_UNEXPECTED;
+    if (this._finished)
+      return;
+
+    dumpn("*** finishing connection " + this._connection.number);
+    this._startAsyncProcessor(); // in case bodyOutputStream was never accessed
+    if (this._bodyOutputStream)
+      this._bodyOutputStream.close();
+    this._finished = true;
+  },
+
+
+  // NSISUPPORTS
+
+  //
+  // see nsISupports.QueryInterface
+  //
+  QueryInterface: function(iid)
+  {
+    if (iid.equals(Ci.nsIHttpResponse) || iid.equals(Ci.nsISupports))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // POST-CONSTRUCTION API (not exposed externally)
+
+  /**
+* The HTTP version number of this, as a string (e.g. "1.1").
+*/
+  get httpVersion()
+  {
+    this._ensureAlive();
+    return this._httpVersion.toString();
+  },
+
+  /**
+* The HTTP status code of this response, as a string of three characters per
+* RFC 2616.
+*/
+  get httpCode()
+  {
+    this._ensureAlive();
+
+    var codeString = (this._httpCode < 10 ? "0" : "") +
+                     (this._httpCode < 100 ? "0" : "") +
+                     this._httpCode;
+    return codeString;
+  },
+
+  /**
+* The description of the HTTP status code of this response, or "" if none is
+* set.
+*/
+  get httpDescription()
+  {
+    this._ensureAlive();
+
+    return this._httpDescription;
+  },
+
+  /**
+* The headers in this response, as an nsHttpHeaders object.
+*/
+  get headers()
+  {
+    this._ensureAlive();
+
+    return this._headers;
+  },
+
+  //
+  // see nsHttpHeaders.getHeader
+  //
+  getHeader: function(name)
+  {
+    this._ensureAlive();
+
+    return this._headers.getHeader(name);
+  },
+
+  /**
+* Determines whether this response may be abandoned in favor of a newly
+* constructed response. A response may be abandoned only if it is not being
+* sent asynchronously and if raw control over it has not been taken from the
+* server.
+*
+* @returns boolean
+* true iff no data has been written to the network
+*/
+  partiallySent: function()
+  {
+    dumpn("*** partiallySent()");
+    return this._processAsync || this._powerSeized;
+  },
+
+  /**
+* If necessary, kicks off the remaining request processing needed to be done
+* after a request handler performs its initial work upon this response.
+*/
+  complete: function()
+  {
+    dumpn("*** complete()");
+    if (this._processAsync || this._powerSeized)
+    {
+      NS_ASSERT(this._processAsync ^ this._powerSeized,
+                "can't both send async and relinquish power");
+      return;
+    }
+
+    NS_ASSERT(!this.partiallySent(), "completing a partially-sent response?");
+
+    this._startAsyncProcessor();
+
+    // Now make sure we finish processing this request!
+    if (this._bodyOutputStream)
+      this._bodyOutputStream.close();
+  },
+
+  /**
+* Abruptly ends processing of this response, usually due to an error in an
+* incoming request but potentially due to a bad error handler. Since we
+* cannot handle the error in the usual way (giving an HTTP error page in
+* response) because data may already have been sent (or because the response
+* might be expected to have been generated asynchronously or completely from
+* scratch by the handler), we stop processing this response and abruptly
+* close the connection.
+*
+* @param e : Error
+* the exception which precipitated this abort, or null if no such exception
+* was generated
+*/
+  abort: function(e)
+  {
+    dumpn("*** abort(<" + e + ">)");
+
+    // This response will be ended by the processor if one was created.
+    var copier = this._asyncCopier;
+    if (copier)
+    {
+      // We dispatch asynchronously here so that any pending writes of data to
+      // the connection will be deterministically written. This makes it easier
+      // to specify exact behavior, and it makes observable behavior more
+      // predictable for clients. Note that the correctness of this depends on
+      // callbacks in response to _waitToReadData in WriteThroughCopier
+      // happening asynchronously with respect to the actual writing of data to
+      // bodyOutputStream, as they currently do; if they happened synchronously,
+      // an event which ran before this one could write more data to the
+      // response body before we get around to canceling the copier. We have
+      // tests for this in test_seizepower.js, however, and I can't think of a
+      // way to handle both cases without removing bodyOutputStream access and
+      // moving its effective write(data, length) method onto Response, which
+      // would be slower and require more code than this anyway.
+      gThreadManager.currentThread.dispatch({
+        run: function()
+        {
+          dumpn("*** canceling copy asynchronously...");
+          copier.cancel(Cr.NS_ERROR_UNEXPECTED);
+        }
+      }, Ci.nsIThread.DISPATCH_NORMAL);
+    }
+    else
+    {
+      this.end();
+    }
+  },
+
+  /**
+* Closes this response's network connection, marks the response as finished,
+* and notifies the server handler that the request is done being processed.
+*/
+  end: function()
+  {
+    NS_ASSERT(!this._ended, "ending this response twice?!?!");
+
+    this._connection.close();
+    if (this._bodyOutputStream)
+      this._bodyOutputStream.close();
+
+    this._finished = true;
+    this._ended = true;
+  },
+
+  // PRIVATE IMPLEMENTATION
+
+  /**
+* Sends the status line and headers of this response if they haven't been
+* sent and initiates the process of copying data written to this response's
+* body to the network.
+*/
+  _startAsyncProcessor: function()
+  {
+    dumpn("*** _startAsyncProcessor()");
+
+    // Handle cases where we're being called a second time. The former case
+    // happens when this is triggered both by complete() and by processAsync(),
+    // while the latter happens when processAsync() in conjunction with sent
+    // data causes abort() to be called.
+    if (this._asyncCopier || this._ended)
+    {
+      dumpn("*** ignoring second call to _startAsyncProcessor");
+      return;
+    }
+
+    // Send headers if they haven't been sent already and should be sent, then
+    // asynchronously continue to send the body.
+    if (this._headers && !this._powerSeized)
+    {
+      this._sendHeaders();
+      return;
+    }
+
+    this._headers = null;
+    this._sendBody();
+  },
+
+  /**
+* Signals that all modifications to the response status line and headers are
+* complete and then sends that data over the network to the client. Once
+* this method completes, a different response to the request that resulted
+* in this response cannot be sent -- the only possible action in case of
+* error is to abort the response and close the connection.
+*/
+  _sendHeaders: function()
+  {
+    dumpn("*** _sendHeaders()");
+
+    NS_ASSERT(this._headers);
+    NS_ASSERT(!this._powerSeized);
+
+    // request-line
+    var statusLine = "HTTP/" + this.httpVersion + " " +
+                     this.httpCode + " " +
+                     this.httpDescription + "\r\n";
+
+    // header post-processing
+
+    var headers = this._headers;
+    headers.setHeader("Connection", "close", false);
+    headers.setHeader("Server", "httpd.js", false);
+    if (!headers.hasHeader("Date"))
+      headers.setHeader("Date", toDateString(Date.now()), false);
+
+    // Any response not being processed asynchronously must have an associated
+    // Content-Length header for reasons of backwards compatibility with the
+    // initial server, which fully buffered every response before sending it.
+    // Beyond that, however, it's good to do this anyway because otherwise it's
+    // impossible to test behaviors that depend on the presence or absence of a
+    // Content-Length header.
+    if (!this._processAsync)
+    {
+      dumpn("*** non-async response, set Content-Length");
+
+      var bodyStream = this._bodyInputStream;
+      var avail = bodyStream ? bodyStream.available() : 0;
+
+      // XXX assumes stream will always report the full amount of data available
+      headers.setHeader("Content-Length", "" + avail, false);
+    }
+
+
+    // construct and send response
+    dumpn("*** header post-processing completed, sending response head...");
+
+    // request-line
+    var preambleData = [statusLine];
+
+    // headers
+    var headEnum = headers.enumerator;
+    while (headEnum.hasMoreElements())
+    {
+      var fieldName = headEnum.getNext()
+                              .QueryInterface(Ci.nsISupportsString)
+                              .data;
+      var values = headers.getHeaderValues(fieldName);
+      for (var i = 0, sz = values.length; i < sz; i++)
+        preambleData.push(fieldName + ": " + values[i] + "\r\n");
+    }
+
+    // end request-line/headers
+    preambleData.push("\r\n");
+
+    var preamble = preambleData.join("");
+
+    var responseHeadPipe = new Pipe(true, false, 0, PR_UINT32_MAX, null);
+    responseHeadPipe.outputStream.write(preamble, preamble.length);
+
+    var response = this;
+    var copyObserver =
+      {
+        onStartRequest: function(request, cx)
+        {
+          dumpn("*** preamble copying started");
+        },
+
+        onStopRequest: function(request, cx, statusCode)
+        {
+          dumpn("*** preamble copying complete " +
+                "[status=0x" + statusCode.toString(16) + "]");
+
+          if (!components.isSuccessCode(statusCode))
+          {
+            dumpn("!!! header copying problems: non-success statusCode, " +
+                  "ending response");
+
+            response.end();
+          }
+          else
+          {
+            response._sendBody();
+          }
+        },
+
+        QueryInterface: function(aIID)
+        {
+          if (aIID.equals(Ci.nsIRequestObserver) || aIID.equals(Ci.nsISupports))
+            return this;
+
+          throw Cr.NS_ERROR_NO_INTERFACE;
+        }
+      };
+
+    var headerCopier = this._asyncCopier =
+      new WriteThroughCopier(responseHeadPipe.inputStream,
+                             this._connection.output,
+                             copyObserver, null);
+
+    responseHeadPipe.outputStream.close();
+
+    // Forbid setting any more headers or modifying the request line.
+    this._headers = null;
+  },
+
+  /**
+* Asynchronously writes the body of the response (or the entire response, if
+* seizePower() has been called) to the network.
+*/
+  _sendBody: function()
+  {
+    dumpn("*** _sendBody");
+
+    NS_ASSERT(!this._headers, "still have headers around but sending body?");
+
+    // If no body data was written, we're done
+    if (!this._bodyInputStream)
+    {
+      dumpn("*** empty body, response finished");
+      this.end();
+      return;
+    }
+
+    var response = this;
+    var copyObserver =
+      {
+        onStartRequest: function(request, context)
+        {
+          dumpn("*** onStartRequest");
+        },
+
+        onStopRequest: function(request, cx, statusCode)
+        {
+          dumpn("*** onStopRequest [status=0x" + statusCode.toString(16) + "]");
+
+          if (statusCode === Cr.NS_BINDING_ABORTED)
+          {
+            dumpn("*** terminating copy observer without ending the response");
+          }
+          else
+          {
+            if (!components.isSuccessCode(statusCode))
+              dumpn("*** WARNING: non-success statusCode in onStopRequest");
+
+            response.end();
+          }
+        },
+
+        QueryInterface: function(aIID)
+        {
+          if (aIID.equals(Ci.nsIRequestObserver) || aIID.equals(Ci.nsISupports))
+            return this;
+
+          throw Cr.NS_ERROR_NO_INTERFACE;
+        }
+      };
+
+    dumpn("*** starting async copier of body data...");
+    this._asyncCopier =
+      new WriteThroughCopier(this._bodyInputStream, this._connection.output,
+                            copyObserver, null);
+  },
+
+  /** Ensures that this hasn't been ended. */
+  _ensureAlive: function()
+  {
+    NS_ASSERT(!this._ended, "not handling response lifetime correctly");
+  }
+};
+
+/**
+* Size of the segments in the buffer used in storing response data and writing
+* it to the socket.
+*/
+Response.SEGMENT_SIZE = 8192;
+
+/** Serves double duty in WriteThroughCopier implementation. */
+function notImplemented()
+{
+  throw Cr.NS_ERROR_NOT_IMPLEMENTED;
+}
+
+/** Returns true iff the given exception represents stream closure. */
+function streamClosed(e)
+{
+  return e === Cr.NS_BASE_STREAM_CLOSED ||
+         (typeof e === "object" && e.result === Cr.NS_BASE_STREAM_CLOSED);
+}
+
+/** Returns true iff the given exception represents a blocked stream. */
+function wouldBlock(e)
+{
+  return e === Cr.NS_BASE_STREAM_WOULD_BLOCK ||
+         (typeof e === "object" && e.result === Cr.NS_BASE_STREAM_WOULD_BLOCK);
+}
+
+/**
+* Copies data from source to sink as it becomes available, when that data can
+* be written to sink without blocking.
+*
+* @param source : nsIAsyncInputStream
+* the stream from which data is to be read
+* @param sink : nsIAsyncOutputStream
+* the stream to which data is to be copied
+* @param observer : nsIRequestObserver
+* an observer which will be notified when the copy starts and finishes
+* @param context : nsISupports
+* context passed to observer when notified of start/stop
+* @throws NS_ERROR_NULL_POINTER
+* if source, sink, or observer are null
+*/
+function WriteThroughCopier(source, sink, observer, context)
+{
+  if (!source || !sink || !observer)
+    throw Cr.NS_ERROR_NULL_POINTER;
+
+  /** Stream from which data is being read. */
+  this._source = source;
+
+  /** Stream to which data is being written. */
+  this._sink = sink;
+
+  /** Observer watching this copy. */
+  this._observer = observer;
+
+  /** Context for the observer watching this. */
+  this._context = context;
+
+  /**
+* True iff this is currently being canceled (cancel has been called, the
+* callback may not yet have been made).
+*/
+  this._canceled = false;
+
+  /**
+* False until all data has been read from input and written to output, at
+* which point this copy is completed and cancel() is asynchronously called.
+*/
+  this._completed = false;
+
+  /** Required by nsIRequest, meaningless. */
+  this.loadFlags = 0;
+  /** Required by nsIRequest, meaningless. */
+  this.loadGroup = null;
+  /** Required by nsIRequest, meaningless. */
+  this.name = "response-body-copy";
+
+  /** Status of this request. */
+  this.status = Cr.NS_OK;
+
+  /** Arrays of byte strings waiting to be written to output. */
+  this._pendingData = [];
+
+  // start copying
+  try
+  {
+    observer.onStartRequest(this, context);
+    this._waitToReadData();
+    this._waitForSinkClosure();
+  }
+  catch (e)
+  {
+    dumpn("!!! error starting copy: " + e +
+          ("lineNumber" in e ? ", line " + e.lineNumber : ""));
+    dumpn(e.stack);
+    this.cancel(Cr.NS_ERROR_UNEXPECTED);
+  }
+}
+WriteThroughCopier.prototype =
+{
+  /* nsISupports implementation */
+
+  QueryInterface: function(iid)
+  {
+    if (iid.equals(Ci.nsIInputStreamCallback) ||
+        iid.equals(Ci.nsIOutputStreamCallback) ||
+        iid.equals(Ci.nsIRequest) ||
+        iid.equals(Ci.nsISupports))
+    {
+      return this;
+    }
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // NSIINPUTSTREAMCALLBACK
+
+  /**
+* Receives a more-data-in-input notification and writes the corresponding
+* data to the output.
+*
+* @param input : nsIAsyncInputStream
+* the input stream on whose data we have been waiting
+*/
+  onInputStreamReady: function(input)
+  {
+    if (this._source === null)
+      return;
+
+    dumpn("*** onInputStreamReady");
+
+    //
+    // Ordinarily we'll read a non-zero amount of data from input, queue it up
+    // to be written and then wait for further callbacks. The complications in
+    // this method are the cases where we deviate from that behavior when errors
+    // occur or when copying is drawing to a finish.
+    //
+    // The edge cases when reading data are:
+    //
+    // Zero data is read
+    // If zero data was read, we're at the end of available data, so we can
+    // should stop reading and move on to writing out what we have (or, if
+    // we've already done that, onto notifying of completion).
+    // A stream-closed exception is thrown
+    // This is effectively a less kind version of zero data being read; the
+    // only difference is that we notify of completion with that result
+    // rather than with NS_OK.
+    // Some other exception is thrown
+    // This is the least kind result. We don't know what happened, so we
+    // act as though the stream closed except that we notify of completion
+    // with the result NS_ERROR_UNEXPECTED.
+    //
+
+    var bytesWanted = 0, bytesConsumed = -1;
+    try
+    {
+      input = new BinaryInputStream(input);
+
+      bytesWanted = Math.min(input.available(), Response.SEGMENT_SIZE);
+      dumpn("*** input wanted: " + bytesWanted);
+
+      if (bytesWanted > 0)
+      {
+        var data = input.readByteArray(bytesWanted);
+        bytesConsumed = data.length;
+        this._pendingData.push(String.fromCharCode.apply(String, data));
+      }
+
+      dumpn("*** " + bytesConsumed + " bytes read");
+
+      // Handle the zero-data edge case in the same place as all other edge
+      // cases are handled.
+      if (bytesWanted === 0)
+        throw Cr.NS_BASE_STREAM_CLOSED;
+    }
+    catch (e)
+    {
+      if (streamClosed(e))
+      {
+        dumpn("*** input stream closed");
+        e = bytesWanted === 0 ? Cr.NS_OK : Cr.NS_ERROR_UNEXPECTED;
+      }
+      else
+      {
+        dumpn("!!! unexpected error reading from input, canceling: " + e);
+        e = Cr.NS_ERROR_UNEXPECTED;
+      }
+
+      this._doneReadingSource(e);
+      return;
+    }
+
+    var pendingData = this._pendingData;
+
+    NS_ASSERT(bytesConsumed > 0);
+    NS_ASSERT(pendingData.length > 0, "no pending data somehow?");
+    NS_ASSERT(pendingData[pendingData.length - 1].length > 0,
+              "buffered zero bytes of data?");
+
+    NS_ASSERT(this._source !== null);
+
+    // Reading has gone great, and we've gotten data to write now. What if we
+    // don't have a place to write that data, because output went away just
+    // before this read? Drop everything on the floor, including new data, and
+    // cancel at this point.
+    if (this._sink === null)
+    {
+      pendingData.length = 0;
+      this._doneReadingSource(Cr.NS_ERROR_UNEXPECTED);
+      return;
+    }
+
+    // Okay, we've read the data, and we know we have a place to write it. We
+    // need to queue up the data to be written, but *only* if none is queued
+    // already -- if data's already queued, the code that actually writes the
+    // data will make sure to wait on unconsumed pending data.
+    try
+    {
+      if (pendingData.length === 1)
+        this._waitToWriteData();
+    }
+    catch (e)
+    {
+      dumpn("!!! error waiting to write data just read, swallowing and " +
+            "writing only what we already have: " + e);
+      this._doneWritingToSink(Cr.NS_ERROR_UNEXPECTED);
+      return;
+    }
+
+    // Whee! We successfully read some data, and it's successfully queued up to
+    // be written. All that remains now is to wait for more data to read.
+    try
+    {
+      this._waitToReadData();
+    }
+    catch (e)
+    {
+      dumpn("!!! error waiting to read more data: " + e);
+      this._doneReadingSource(Cr.NS_ERROR_UNEXPECTED);
+    }
+  },
+
+
+  // NSIOUTPUTSTREAMCALLBACK
+
+  /**
+* Callback when data may be written to the output stream without blocking, or
+* when the output stream has been closed.
+*
+* @param output : nsIAsyncOutputStream
+* the output stream on whose writability we've been waiting, also known as
+* this._sink
+*/
+  onOutputStreamReady: function(output)
+  {
+    if (this._sink === null)
+      return;
+
+    dumpn("*** onOutputStreamReady");
+
+    var pendingData = this._pendingData;
+    if (pendingData.length === 0)
+    {
+      // There's no pending data to write. The only way this can happen is if
+      // we're waiting on the output stream's closure, so we can respond to a
+      // copying failure as quickly as possible (rather than waiting for data to
+      // be available to read and then fail to be copied). Therefore, we must
+      // be done now -- don't bother to attempt to write anything and wrap
+      // things up.
+      dumpn("!!! output stream closed prematurely, ending copy");
+
+      this._doneWritingToSink(Cr.NS_ERROR_UNEXPECTED);
+      return;
+    }
+
+
+    NS_ASSERT(pendingData[0].length > 0, "queued up an empty quantum?");
+
+    //
+    // Write out the first pending quantum of data. The possible errors here
+    // are:
+    //
+    // The write might fail because we can't write that much data
+    // Okay, we've written what we can now, so re-queue what's left and
+    // finish writing it out later.
+    // The write failed because the stream was closed
+    // Discard pending data that we can no longer write, stop reading, and
+    // signal that copying finished.
+    // Some other error occurred.
+    // Same as if the stream were closed, but notify with the status
+    // NS_ERROR_UNEXPECTED so the observer knows something was wonky.
+    //
+
+    try
+    {
+      var quantum = pendingData[0];
+
+      // XXX |quantum| isn't guaranteed to be ASCII, so we're relying on
+      // undefined behavior! We're only using this because writeByteArray
+      // is unusably broken for asynchronous output streams; see bug 532834
+      // for details.
+      var bytesWritten = output.write(quantum, quantum.length);
+      if (bytesWritten === quantum.length)
+        pendingData.shift();
+      else
+        pendingData[0] = quantum.substring(bytesWritten);
+
+      dumpn("*** wrote " + bytesWritten + " bytes of data");
+    }
+    catch (e)
+    {
+      if (wouldBlock(e))
+      {
+        NS_ASSERT(pendingData.length > 0,
+                  "stream-blocking exception with no data to write?");
+        NS_ASSERT(pendingData[0].length > 0,
+                  "stream-blocking exception with empty quantum?");
+        this._waitToWriteData();
+        return;
+      }
+
+      if (streamClosed(e))
+        dumpn("!!! output stream prematurely closed, signaling error...");
+      else
+        dumpn("!!! unknown error: " + e + ", quantum=" + quantum);
+
+      this._doneWritingToSink(Cr.NS_ERROR_UNEXPECTED);
+      return;
+    }
+
+    // The day is ours! Quantum written, now let's see if we have more data
+    // still to write.
+    try
+    {
+      if (pendingData.length > 0)
+      {
+        this._waitToWriteData();
+        return;
+      }
+    }
+    catch (e)
+    {
+      dumpn("!!! unexpected error waiting to write pending data: " + e);
+      this._doneWritingToSink(Cr.NS_ERROR_UNEXPECTED);
+      return;
+    }
+
+    // Okay, we have no more pending data to write -- but might we get more in
+    // the future?
+    if (this._source !== null)
+    {
+      /*
+* If we might, then wait for the output stream to be closed. (We wait
+* only for closure because we have no data to write -- and if we waited
+* for a specific amount of data, we would get repeatedly notified for no
+* reason if over time the output stream permitted more and more data to
+* be written to it without blocking.)
+*/
+       this._waitForSinkClosure();
+    }
+    else
+    {
+      /*
+* On the other hand, if we can't have more data because the input
+* stream's gone away, then it's time to notify of copy completion.
+* Victory!
+*/
+      this._sink = null;
+      this._cancelOrDispatchCancelCallback(Cr.NS_OK);
+    }
+  },
+
+
+  // NSIREQUEST
+
+  /** Returns true if the cancel observer hasn't been notified yet. */
+  isPending: function()
+  {
+    return !this._completed;
+  },
+
+  /** Not implemented, don't use! */
+  suspend: notImplemented,
+  /** Not implemented, don't use! */
+  resume: notImplemented,
+
+  /**
+* Cancels data reading from input, asynchronously writes out any pending
+* data, and causes the observer to be notified with the given error code when
+* all writing has finished.
+*
+* @param status : nsresult
+* the status to pass to the observer when data copying has been canceled
+*/
+  cancel: function(status)
+  {
+    dumpn("*** cancel(" + status.toString(16) + ")");
+
+    if (this._canceled)
+    {
+      dumpn("*** suppressing a late cancel");
+      return;
+    }
+
+    this._canceled = true;
+    this.status = status;
+
+    // We could be in the middle of absolutely anything at this point. Both
+    // input and output might still be around, we might have pending data to
+    // write, and in general we know nothing about the state of the world. We
+    // therefore must assume everything's in progress and take everything to its
+    // final steady state (or so far as it can go before we need to finish
+    // writing out remaining data).
+
+    this._doneReadingSource(status);
+  },
+
+
+  // PRIVATE IMPLEMENTATION
+
+  /**
+* Stop reading input if we haven't already done so, passing e as the status
+* when closing the stream, and kick off a copy-completion notice if no more
+* data remains to be written.
+*
+* @param e : nsresult
+* the status to be used when closing the input stream
+*/
+  _doneReadingSource: function(e)
+  {
+    dumpn("*** _doneReadingSource(0x" + e.toString(16) + ")");
+
+    this._finishSource(e);
+    if (this._pendingData.length === 0)
+      this._sink = null;
+    else
+      NS_ASSERT(this._sink !== null, "null output?");
+
+    // If we've written out all data read up to this point, then it's time to
+    // signal completion.
+    if (this._sink === null)
+    {
+      NS_ASSERT(this._pendingData.length === 0, "pending data still?");
+      this._cancelOrDispatchCancelCallback(e);
+    }
+  },
+
+  /**
+* Stop writing output if we haven't already done so, discard any data that
+* remained to be sent, close off input if it wasn't already closed, and kick
+* off a copy-completion notice.
+*
+* @param e : nsresult
+* the status to be used when closing input if it wasn't already closed
+*/
+  _doneWritingToSink: function(e)
+  {
+    dumpn("*** _doneWritingToSink(0x" + e.toString(16) + ")");
+
+    this._pendingData.length = 0;
+    this._sink = null;
+    this._doneReadingSource(e);
+  },
+
+  /**
+* Completes processing of this copy: either by canceling the copy if it
+* hasn't already been canceled using the provided status, or by dispatching
+* the cancel callback event (with the originally provided status, of course)
+* if it already has been canceled.
+*
+* @param status : nsresult
+* the status code to use to cancel this, if this hasn't already been
+* canceled
+*/
+  _cancelOrDispatchCancelCallback: function(status)
+  {
+    dumpn("*** _cancelOrDispatchCancelCallback(" + status + ")");
+
+    NS_ASSERT(this._source === null, "should have finished input");
+    NS_ASSERT(this._sink === null, "should have finished output");
+    NS_ASSERT(this._pendingData.length === 0, "should have no pending data");
+
+    if (!this._canceled)
+    {
+      this.cancel(status);
+      return;
+    }
+
+    var self = this;
+    var event =
+      {
+        run: function()
+        {
+          dumpn("*** onStopRequest async callback");
+
+          self._completed = true;
+          try
+          {
+            self._observer.onStopRequest(self, self._context, self.status);
+          }
+          catch (e)
+          {
+            NS_ASSERT(false,
+                      "how are we throwing an exception here? we control " +
+                      "all the callers! " + e);
+          }
+        }
+      };
+
+    gThreadManager.currentThread.dispatch(event, Ci.nsIThread.DISPATCH_NORMAL);
+  },
+
+  /**
+* Kicks off another wait for more data to be available from the input stream.
+*/
+  _waitToReadData: function()
+  {
+    dumpn("*** _waitToReadData");
+    this._source.asyncWait(this, 0, Response.SEGMENT_SIZE,
+                           gThreadManager.mainThread);
+  },
+
+  /**
+* Kicks off another wait until data can be written to the output stream.
+*/
+  _waitToWriteData: function()
+  {
+    dumpn("*** _waitToWriteData");
+
+    var pendingData = this._pendingData;
+    NS_ASSERT(pendingData.length > 0, "no pending data to write?");
+    NS_ASSERT(pendingData[0].length > 0, "buffered an empty write?");
+
+    this._sink.asyncWait(this, 0, pendingData[0].length,
+                         gThreadManager.mainThread);
+  },
+
+  /**
+* Kicks off a wait for the sink to which data is being copied to be closed.
+* We wait for stream closure when we don't have any data to be copied, rather
+* than waiting to write a specific amount of data. We can't wait to write
+* data because the sink might be infinitely writable, and if no data appears
+* in the source for a long time we might have to spin quite a bit waiting to
+* write, waiting to write again, &c. Waiting on stream closure instead means
+* we'll get just one notification if the sink dies. Note that when data
+* starts arriving from the sink we'll resume waiting for data to be written,
+* dropping this closure-only callback entirely.
+*/
+  _waitForSinkClosure: function()
+  {
+    dumpn("*** _waitForSinkClosure");
+
+    this._sink.asyncWait(this, Ci.nsIAsyncOutputStream.WAIT_CLOSURE_ONLY, 0,
+                         gThreadManager.mainThread);
+  },
+
+  /**
+* Closes input with the given status, if it hasn't already been closed;
+* otherwise a no-op.
+*
+* @param status : nsresult
+* status code use to close the source stream if necessary
+*/
+  _finishSource: function(status)
+  {
+    dumpn("*** _finishSource(" + status.toString(16) + ")");
+
+    if (this._source !== null)
+    {
+      this._source.closeWithStatus(status);
+      this._source = null;
+    }
+  }
+};
+
+
+/**
+* A container for utility functions used with HTTP headers.
+*/
+const headerUtils =
+{
+  /**
+* Normalizes fieldName (by converting it to lowercase) and ensures it is a
+* valid header field name (although not necessarily one specified in RFC
+* 2616).
+*
+* @throws NS_ERROR_INVALID_ARG
+* if fieldName does not match the field-name production in RFC 2616
+* @returns string
+* fieldName converted to lowercase if it is a valid header, for characters
+* where case conversion is possible
+*/
+  normalizeFieldName: function(fieldName)
+  {
+    if (fieldName == "")
+      throw Cr.NS_ERROR_INVALID_ARG;
+
+    for (var i = 0, sz = fieldName.length; i < sz; i++)
+    {
+      if (!IS_TOKEN_ARRAY[fieldName.charCodeAt(i)])
+      {
+        dumpn(fieldName + " is not a valid header field name!");
+        throw Cr.NS_ERROR_INVALID_ARG;
+      }
+    }
+
+    return fieldName.toLowerCase();
+  },
+
+  /**
+* Ensures that fieldValue is a valid header field value (although not
+* necessarily as specified in RFC 2616 if the corresponding field name is
+* part of the HTTP protocol), normalizes the value if it is, and
+* returns the normalized value.
+*
+* @param fieldValue : string
+* a value to be normalized as an HTTP header field value
+* @throws NS_ERROR_INVALID_ARG
+* if fieldValue does not match the field-value production in RFC 2616
+* @returns string
+* fieldValue as a normalized HTTP header field value
+*/
+  normalizeFieldValue: function(fieldValue)
+  {
+    // field-value = *( field-content | LWS )
+    // field-content = <the OCTETs making up the field-value
+    // and consisting of either *TEXT or combinations
+    // of token, separators, and quoted-string>
+    // TEXT = <any OCTET except CTLs,
+    // but including LWS>
+    // LWS = [CRLF] 1*( SP | HT )
+    //
+    // quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
+    // qdtext = <any TEXT except <">>
+    // quoted-pair = "\" CHAR
+    // CHAR = <any US-ASCII character (octets 0 - 127)>
+
+    // Any LWS that occurs between field-content MAY be replaced with a single
+    // SP before interpreting the field value or forwarding the message
+    // downstream (section 4.2); we replace 1*LWS with a single SP
+    var val = fieldValue.replace(/(?:(?:\r\n)?[ \t]+)+/g, " ");
+
+    // remove leading/trailing LWS (which has been converted to SP)
+    val = val.replace(/^ +/, "").replace(/ +$/, "");
+
+    // that should have taken care of all CTLs, so val should contain no CTLs
+    for (var i = 0, len = val.length; i < len; i++)
+      if (isCTL(val.charCodeAt(i)))
+        throw Cr.NS_ERROR_INVALID_ARG;
+
+    // XXX disallows quoted-pair where CHAR is a CTL -- will not invalidly
+    // normalize, however, so this can be construed as a tightening of the
+    // spec and not entirely as a bug
+    return val;
+  }
+};
+
+
+
+/**
+* Converts the given string into a string which is safe for use in an HTML
+* context.
+*
+* @param str : string
+* the string to make HTML-safe
+* @returns string
+* an HTML-safe version of str
+*/
+function htmlEscape(str)
+{
+  // this is naive, but it'll work
+  var s = "";
+  for (var i = 0; i < str.length; i++)
+    s += "&#" + str.charCodeAt(i) + ";";
+  return s;
+}
+
+
+/**
+* Constructs an object representing an HTTP version (see section 3.1).
+*
+* @param versionString
+* a string of the form "#.#", where # is an non-negative decimal integer with
+* or without leading zeros
+* @throws
+* if versionString does not specify a valid HTTP version number
+*/
+function nsHttpVersion(versionString)
+{
+  var matches = /^(\d+)\.(\d+)$/.exec(versionString);
+  if (!matches)
+    throw "Not a valid HTTP version!";
+
+  /** The major version number of this, as a number. */
+  this.major = parseInt(matches[1], 10);
+
+  /** The minor version number of this, as a number. */
+  this.minor = parseInt(matches[2], 10);
+
+  if (isNaN(this.major) || isNaN(this.minor) ||
+      this.major < 0 || this.minor < 0)
+    throw "Not a valid HTTP version!";
+}
+nsHttpVersion.prototype =
+{
+  /**
+* Returns the standard string representation of the HTTP version represented
+* by this (e.g., "1.1").
+*/
+  toString: function ()
+  {
+    return this.major + "." + this.minor;
+  },
+
+  /**
+* Returns true if this represents the same HTTP version as otherVersion,
+* false otherwise.
+*
+* @param otherVersion : nsHttpVersion
+* the version to compare against this
+*/
+  equals: function (otherVersion)
+  {
+    return this.major == otherVersion.major &&
+           this.minor == otherVersion.minor;
+  },
+
+  /** True if this >= otherVersion, false otherwise. */
+  atLeast: function(otherVersion)
+  {
+    return this.major > otherVersion.major ||
+           (this.major == otherVersion.major &&
+            this.minor >= otherVersion.minor);
+  }
+};
+
+nsHttpVersion.HTTP_1_0 = new nsHttpVersion("1.0");
+nsHttpVersion.HTTP_1_1 = new nsHttpVersion("1.1");
+
+
+/**
+* An object which stores HTTP headers for a request or response.
+*
+* Note that since headers are case-insensitive, this object converts headers to
+* lowercase before storing them. This allows the getHeader and hasHeader
+* methods to work correctly for any case of a header, but it means that the
+* values returned by .enumerator may not be equal case-sensitively to the
+* values passed to setHeader when adding headers to this.
+*/
+function nsHttpHeaders()
+{
+  /**
+* A hash of headers, with header field names as the keys and header field
+* values as the values. Header field names are case-insensitive, but upon
+* insertion here they are converted to lowercase. Header field values are
+* normalized upon insertion to contain no leading or trailing whitespace.
+*
+* Note also that per RFC 2616, section 4.2, two headers with the same name in
+* a message may be treated as one header with the same field name and a field
+* value consisting of the separate field values joined together with a "," in
+* their original order. This hash stores multiple headers with the same name
+* in this manner.
+*/
+  this._headers = {};
+}
+nsHttpHeaders.prototype =
+{
+  /**
+* Sets the header represented by name and value in this.
+*
+* @param name : string
+* the header name
+* @param value : string
+* the header value
+* @throws NS_ERROR_INVALID_ARG
+* if name or value is not a valid header component
+*/
+  setHeader: function(fieldName, fieldValue, merge)
+  {
+    var name = headerUtils.normalizeFieldName(fieldName);
+    var value = headerUtils.normalizeFieldValue(fieldValue);
+
+    // The following three headers are stored as arrays because their real-world
+    // syntax prevents joining individual headers into a single header using
+    // ",". See also <http://hg.mozilla.org/mozilla-central/diff/9b2a99adc05e/netwerk/protocol/http/src/nsHttpHeaderArray.cpp#l77>
+    if (merge && name in this._headers)
+    {
+      if (name === "www-authenticate" ||
+          name === "proxy-authenticate" ||
+          name === "set-cookie")
+      {
+        this._headers[name].push(value);
+      }
+      else
+      {
+        this._headers[name][0] += "," + value;
+        NS_ASSERT(this._headers[name].length === 1,
+            "how'd a non-special header have multiple values?")
+      }
+    }
+    else
+    {
+      this._headers[name] = [value];
+    }
+  },
+
+  /**
+* Returns the value for the header specified by this.
+*
+* @throws NS_ERROR_INVALID_ARG
+* if fieldName does not constitute a valid header field name
+* @throws NS_ERROR_NOT_AVAILABLE
+* if the given header does not exist in this
+* @returns string
+* the field value for the given header, possibly with non-semantic changes
+* (i.e., leading/trailing whitespace stripped, whitespace runs replaced
+* with spaces, etc.) at the option of the implementation; multiple
+* instances of the header will be combined with a comma, except for
+* the three headers noted in the description of getHeaderValues
+*/
+  getHeader: function(fieldName)
+  {
+    return this.getHeaderValues(fieldName).join("\n");
+  },
+
+  /**
+* Returns the value for the header specified by fieldName as an array.
+*
+* @throws NS_ERROR_INVALID_ARG
+* if fieldName does not constitute a valid header field name
+* @throws NS_ERROR_NOT_AVAILABLE
+* if the given header does not exist in this
+* @returns [string]
+* an array of all the header values in this for the given
+* header name. Header values will generally be collapsed
+* into a single header by joining all header values together
+* with commas, but certain headers (Proxy-Authenticate,
+* WWW-Authenticate, and Set-Cookie) violate the HTTP spec
+* and cannot be collapsed in this manner. For these headers
+* only, the returned array may contain multiple elements if
+* that header has been added more than once.
+*/
+  getHeaderValues: function(fieldName)
+  {
+    var name = headerUtils.normalizeFieldName(fieldName);
+
+    if (name in this._headers)
+      return this._headers[name];
+    else
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+  },
+
+  /**
+* Returns true if a header with the given field name exists in this, false
+* otherwise.
+*
+* @param fieldName : string
+* the field name whose existence is to be determined in this
+* @throws NS_ERROR_INVALID_ARG
+* if fieldName does not constitute a valid header field name
+* @returns boolean
+* true if the header's present, false otherwise
+*/
+  hasHeader: function(fieldName)
+  {
+    var name = headerUtils.normalizeFieldName(fieldName);
+    return (name in this._headers);
+  },
+
+  /**
+* Returns a new enumerator over the field names of the headers in this, as
+* nsISupportsStrings. The names returned will be in lowercase, regardless of
+* how they were input using setHeader (header names are case-insensitive per
+* RFC 2616).
+*/
+  get enumerator()
+  {
+    var headers = [];
+    for (var i in this._headers)
+    {
+      var supports = new SupportsString();
+      supports.data = i;
+      headers.push(supports);
+    }
+
+    return new nsSimpleEnumerator(headers);
+  }
+};
+
+
+/**
+* Constructs an nsISimpleEnumerator for the given array of items.
+*
+* @param items : Array
+* the items, which must all implement nsISupports
+*/
+function nsSimpleEnumerator(items)
+{
+  this._items = items;
+  this._nextIndex = 0;
+}
+nsSimpleEnumerator.prototype =
+{
+  hasMoreElements: function()
+  {
+    return this._nextIndex < this._items.length;
+  },
+  getNext: function()
+  {
+    if (!this.hasMoreElements())
+      throw Cr.NS_ERROR_NOT_AVAILABLE;
+
+    return this._items[this._nextIndex++];
+  },
+  QueryInterface: function(aIID)
+  {
+    if (Ci.nsISimpleEnumerator.equals(aIID) ||
+        Ci.nsISupports.equals(aIID))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  }
+};
+
+
+/**
+* A representation of the data in an HTTP request.
+*
+* @param port : uint
+* the port on which the server receiving this request runs
+*/
+function Request(port)
+{
+  /** Method of this request, e.g. GET or POST. */
+  this._method = "";
+
+  /** Path of the requested resource; empty paths are converted to '/'. */
+  this._path = "";
+
+  /** Query string, if any, associated with this request (not including '?'). */
+  this._queryString = "";
+
+  /** Scheme of requested resource, usually http, always lowercase. */
+  this._scheme = "http";
+
+  /** Hostname on which the requested resource resides. */
+  this._host = undefined;
+
+  /** Port number over which the request was received. */
+  this._port = port;
+
+  var bodyPipe = new Pipe(false, false, 0, PR_UINT32_MAX, null);
+
+  /** Stream from which data in this request's body may be read. */
+  this._bodyInputStream = bodyPipe.inputStream;
+
+  /** Stream to which data in this request's body is written. */
+  this._bodyOutputStream = bodyPipe.outputStream;
+
+  /**
+* The headers in this request.
+*/
+  this._headers = new nsHttpHeaders();
+
+  /**
+* For the addition of ad-hoc properties and new functionality without having
+* to change nsIHttpRequest every time; currently lazily created, as its only
+* use is in directory listings.
+*/
+  this._bag = null;
+}
+Request.prototype =
+{
+  // SERVER METADATA
+
+  //
+  // see nsIHttpRequest.scheme
+  //
+  get scheme()
+  {
+    return this._scheme;
+  },
+
+  //
+  // see nsIHttpRequest.host
+  //
+  get host()
+  {
+    return this._host;
+  },
+
+  //
+  // see nsIHttpRequest.port
+  //
+  get port()
+  {
+    return this._port;
+  },
+
+  // REQUEST LINE
+
+  //
+  // see nsIHttpRequest.method
+  //
+  get method()
+  {
+    return this._method;
+  },
+
+  //
+  // see nsIHttpRequest.httpVersion
+  //
+  get httpVersion()
+  {
+    return this._httpVersion.toString();
+  },
+
+  //
+  // see nsIHttpRequest.path
+  //
+  get path()
+  {
+    return this._path;
+  },
+
+  //
+  // see nsIHttpRequest.queryString
+  //
+  get queryString()
+  {
+    return this._queryString;
+  },
+
+  // HEADERS
+
+  //
+  // see nsIHttpRequest.getHeader
+  //
+  getHeader: function(name)
+  {
+    return this._headers.getHeader(name);
+  },
+
+  //
+  // see nsIHttpRequest.hasHeader
+  //
+  hasHeader: function(name)
+  {
+    return this._headers.hasHeader(name);
+  },
+
+  //
+  // see nsIHttpRequest.headers
+  //
+  get headers()
+  {
+    return this._headers.enumerator;
+  },
+
+  //
+  // see nsIPropertyBag.enumerator
+  //
+  get enumerator()
+  {
+    this._ensurePropertyBag();
+    return this._bag.enumerator;
+  },
+
+  //
+  // see nsIHttpRequest.headers
+  //
+  get bodyInputStream()
+  {
+    return this._bodyInputStream;
+  },
+
+  //
+  // see nsIPropertyBag.getProperty
+  //
+  getProperty: function(name)
+  {
+    this._ensurePropertyBag();
+    return this._bag.getProperty(name);
+  },
+
+
+  // NSISUPPORTS
+
+  //
+  // see nsISupports.QueryInterface
+  //
+  QueryInterface: function(iid)
+  {
+    if (iid.equals(Ci.nsIHttpRequest) || iid.equals(Ci.nsISupports))
+      return this;
+
+    throw Cr.NS_ERROR_NO_INTERFACE;
+  },
+
+
+  // PRIVATE IMPLEMENTATION
+
+  /** Ensures a property bag has been created for ad-hoc behaviors. */
+  _ensurePropertyBag: function()
+  {
+    if (!this._bag)
+      this._bag = new WritablePropertyBag();
+  }
+};
+
+
+// XPCOM trappings
+if ("XPCOMUtils" in this && // Firefox 3.6 doesn't load XPCOMUtils in this scope for some reason...
+    "generateNSGetFactory" in XPCOMUtils) {
+  var NSGetFactory = XPCOMUtils.generateNSGetFactory([nsHttpServer]);
+}
+
+
+
+/**
+* Creates a new HTTP server listening for loopback traffic on the given port,
+* starts it, and runs the server until the server processes a shutdown request,
+* spinning an event loop so that events posted by the server's socket are
+* processed.
+*
+* This method is primarily intended for use in running this script from within
+* xpcshell and running a functional HTTP server without having to deal with
+* non-essential details.
+*
+* Note that running multiple servers using variants of this method probably
+* doesn't work, simply due to how the internal event loop is spun and stopped.
+*
+* @note
+* This method only works with Mozilla 1.9 (i.e., Firefox 3 or trunk code);
+* you should use this server as a component in Mozilla 1.8.
+* @param port
+* the port on which the server will run, or -1 if there exists no preference
+* for a specific port; note that attempting to use some values for this
+* parameter (particularly those below 1024) may cause this method to throw or
+* may result in the server being prematurely shut down
+* @param basePath
+* a local directory from which requests will be served (i.e., if this is
+* "/home/jwalden/" then a request to /index.html will load
+* /home/jwalden/index.html); if this is omitted, only the default URLs in
+* this server implementation will be functional
+*/
+function server(port, basePath)
+{
+  if (basePath)
+  {
+    var lp = Cc["@mozilla.org/file/local;1"]
+               .createInstance(Ci.nsILocalFile);
+    lp.initWithPath(basePath);
+  }
+
+  // if you're running this, you probably want to see debugging info
+  DEBUG = true;
+
+  var srv = new nsHttpServer();
+  if (lp)
+    srv.registerDirectory("/", lp);
+  srv.registerContentType("sjs", SJS_TYPE);
+  srv.start(port);
+
+  var thread = gThreadManager.currentThread;
+  while (!srv.isStopped())
+    thread.processNextEvent(true);
+
+  // get rid of any pending requests
+  while (thread.hasPendingEvents())
+    thread.processNextEvent(true);
+
+  DEBUG = false;
+}
+
+function startServerAsync(port, basePath)
+{
+  if (basePath)
+  {
+    var lp = Cc["@mozilla.org/file/local;1"]
+               .createInstance(Ci.nsILocalFile);
+    lp.initWithPath(basePath);
+  }
+
+  var srv = new nsHttpServer();
+  if (lp)
+    srv.registerDirectory("/", lp);
+  srv.registerContentType("sjs", "sjs");
+  srv.start(port);
+  return srv;
+}
+
+exports.nsHttpServer = nsHttpServer;
+exports.ScriptableInputStream = ScriptableInputStream;
+exports.server = server;
+exports.startServerAsync = startServerAsync;
new file mode 100644
--- /dev/null
+++ b/addon-sdk/source/test/addons/content-script-messages-latency/main.js
@@ -0,0 +1,90 @@
+/* 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/. */
+"use strict";
+
+const { PageMod } = require("sdk/page-mod");
+const tabs = require("sdk/tabs");
+const { startServerAsync } = require("./httpd");
+const { setTimeout } = require("sdk/timers");
+
+const serverPort = 8099;
+
+exports.testContentScriptLatencyRegression = function*(assert) {
+  let server = startServerAsync(serverPort);
+  server.registerPathHandler("/", function handle(request, response) {
+    response.write(`<html>
+      <head>
+        <link rel="stylesheet" href="/slow.css">
+      </head>
+      <body>
+        slow loading page...
+      </body>
+    </html>`);
+  });
+
+  server.registerPathHandler("/slow.css", function handle(request, response) {
+    response.processAsync();
+    response.setHeader('Content-Type', 'text/css', false);
+    setTimeout(_ => {
+      response.write("body { background: red; }");
+      response.finish();
+    }, 2000);
+  });
+
+
+  let pageMod;
+
+  let worker = yield new Promise((resolve) => {
+    pageMod = PageMod({
+      include: "http://localhost:8099/",
+      attachTo: "top",
+      contentScriptWhen: "start",
+      contentScript: "new " + function ContentScriptScope() {
+        self.port.on("a-port-message", function () {
+          self.port.emit("document-ready-state", document.readyState);
+        });
+      },
+      onAttach: function(w) {
+        resolve(w);
+      }
+    });
+
+    tabs.open({
+      url: "http://localhost:8099/",
+      inBackground: true
+    });
+  });
+
+  worker.port.emit("a-port-message");
+
+  let waitForPortMessage = new Promise((resolve) => {
+    worker.port.once("document-ready-state", (msg) => {
+      resolve(msg);
+    });
+  });
+
+  let documentReadyState = yield waitForPortMessage;
+
+  assert.notEqual(
+    "complete", documentReadyState,
+    "content script received the port message when the page was still loading"
+  );
+
+  assert.notEqual(
+    "uninitialized", documentReadyState,
+    "content script should be frozen if document.readyState is still uninitialized"
+  );
+
+  assert.ok(
+    ["loading", "interactive"].includes(documentReadyState),
+    "content script message received with document.readyState was interactive or loading"
+  );
+
+  // Cleanup.
+  pageMod.destroy();
+  yield new Promise((resolve) => worker.tab.close(resolve));
+  yield new Promise((resolve) => server.stop(resolve));
+};
+
+require("sdk/test/runner").runTestsFromModule(module);
new file mode 100644
--- /dev/null
+++ b/addon-sdk/source/test/addons/content-script-messages-latency/package.json
@@ -0,0 +1,6 @@
+
+{
+  "id": "content-script-messages-latency@jetpack",
+  "main": "./main.js",
+  "version": "0.0.1"
+}
--- a/addon-sdk/source/test/addons/jetpack-addon.ini
+++ b/addon-sdk/source/test/addons/jetpack-addon.ini
@@ -1,13 +1,14 @@
 [addon-manager.xpi]
 [author-email.xpi]
 [child_process.xpi]
 [chrome.xpi]
 [content-permissions.xpi]
+[content-script-messages-latency.xpi]
 [contributors.xpi]
 [curly-id.xpi]
 [developers.xpi]
 [e10s.xpi]
 skip-if = true
 [e10s-content.xpi]
 skip-if = true
 [e10s-l10n.xpi]