Bug 481603: Add a way to unload JS modules loaded with Components.utils.import. r=mrbkap

js/src/xpconnect/idl/xpcIJSModuleLoader.idl

@@ -48,14 +48,14 @@ struct JSObject;
 
 [ptr] native JSObjectPtr(JSObject);
 
-[scriptable, uuid(89da3673-e699-4f26-9ed7-11a528011434)]
+[scriptable, uuid(3f945a8e-58ca-47ba-a789-82d022e837fd)]
 interface xpcIJSModuleLoader : nsISupports
 {
   /**
    * To be called from JavaScript only.
    *
    * Synchronously loads and evaluates the js file located at
-   * 'registryLocation' with a new, fully privileged global object.
+   * aResourceURI with a new, fully privileged global object.
    *
    * If 'targetObj' is specified and equal to null, returns the
    * module's global object. Otherwise (if 'targetObj' is not
@@ -85,11 +85,19 @@ interface xpcIJSModuleLoader : nsISupports
                              /* , [optional] in JSObject targetObj */);
 
   /**
-   * Imports the JS module at 'registryLocation' to the JS object
+   * Imports the JS module at aResourceURI to the JS object
    * 'targetObj' (if != null) as described for importModule() and
    * returns the module's global object.
    */
   [noscript] JSObjectPtr importInto(in AUTF8String aResourceURI,
                                     in JSObjectPtr targetObj,
                                     in nsAXPCNativeCallContextPtr cc);
+
+  /**
+   * Unloads the JS module at aResourceURI. Existing references to the module
+   * will continue to work but any subsequent import of the module will
+   * reload it and give new reference. If the JS module hasn't yet been imported
+   * then this method will do nothing.
+   */
+  void unload(in AUTF8String aResourceURI);
 };

js/src/xpconnect/idl/xpccomponents.idl

@@ -123,7 +123,7 @@ interface nsIXPCComponents_utils_Sandbox : nsISupports
 /**
 * interface of Components.utils
 */
-[scriptable, uuid(c1d616fa-1875-49ba-b7b8-5861dab31a42)]
+[scriptable, uuid(5f0acf45-135a-48d1-976c-082ce3b24ead)]
 interface nsIXPCComponents_Utils : nsISupports
 {
 
@@ -204,6 +204,16 @@ interface nsIXPCComponents_Utils : nsISupports
     void /* JSObject */ import(in AUTF8String registryLocation
                                /*, [optional] in JSObject targetObj */);
 
+    /*
+     * Unloads the JS module at 'registryLocation'. Existing references to the
+     * module will continue to work but any subsequent import of the module will
+     * reload it and give new reference. If the JS module hasn't yet been
+     * imported then this method will do nothing.
+     *
+     * @param resourceURI A resource:// URI string to unload the module from.
+     */
+    void unload(in AUTF8String registryLocation);
+
     /*
      * To be called from JS only.
      *

js/src/xpconnect/loader/mozJSComponentLoader.cpp

@@ -1601,6 +1601,76 @@ mozJSComponentLoader::ImportInto(const nsACString & aLocation,
     return NS_OK;
 }
 
+NS_IMETHODIMP
+mozJSComponentLoader::Unload(const nsACString & aLocation)
+{
+    nsresult rv;
+
+    if (!mInitialized) {
+        return NS_OK;
+    }
+
+    nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Get the URI.
+    nsCOMPtr<nsIURI> resURI;
+    rv = ioService->NewURI(aLocation, nsnull, nsnull, getter_AddRefs(resURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // figure out the resolved URI
+    nsCOMPtr<nsIChannel> scriptChannel;
+    rv = ioService->NewChannelFromURI(resURI, getter_AddRefs(scriptChannel));
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
+
+    nsCOMPtr<nsIURI> resolvedURI;
+    rv = scriptChannel->GetURI(getter_AddRefs(resolvedURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // get the JAR if there is one
+    nsCOMPtr<nsIJARURI> jarURI;
+    jarURI = do_QueryInterface(resolvedURI, &rv);
+    nsCOMPtr<nsIFileURL> baseFileURL;
+    nsCAutoString jarEntry;
+    if (NS_SUCCEEDED(rv)) {
+        nsCOMPtr<nsIURI> baseURI;
+        rv = jarURI->GetJARFile(getter_AddRefs(baseURI));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        baseFileURL = do_QueryInterface(baseURI, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        jarURI->GetJAREntry(jarEntry);
+        NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+        baseFileURL = do_QueryInterface(resolvedURI, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    nsCOMPtr<nsIFile> sourceFile;
+    rv = baseFileURL->GetFile(getter_AddRefs(sourceFile));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsILocalFile> sourceLocalFile;
+    sourceLocalFile = do_QueryInterface(sourceFile, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoString key;
+    if (jarEntry.IsEmpty()) {
+        rv = FileKey(sourceLocalFile, key);
+    } else {
+        rv = JarKey(sourceLocalFile, jarEntry, key);
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    ModuleEntry* mod;
+    if (mImports.Get(key, &mod)) {
+        mImports.Remove(key);
+    }
+
+    return NS_OK;
+}
+
 NS_IMETHODIMP
 mozJSComponentLoader::Observe(nsISupports *subject, const char *topic,
                               const PRUnichar *data)

js/src/xpconnect/src/xpccomponents.cpp

@@ -3725,6 +3725,18 @@ nsXPCComponents_Utils::Import(const nsACString & registryLocation)
     return moduleloader->Import(registryLocation);
 }
 
+/* unload (in AUTF8String registryLocation);
+ */
+NS_IMETHODIMP
+nsXPCComponents_Utils::Unload(const nsACString & registryLocation)
+{
+    nsCOMPtr<xpcIJSModuleLoader> moduleloader =
+        do_GetService(MOZJSCOMPONENTLOADER_CONTRACTID);
+    if (!moduleloader)
+        return NS_ERROR_FAILURE;
+    return moduleloader->Unload(registryLocation);
+}
+
 /* xpcIJSWeakReference getWeakReference (); */
 NS_IMETHODIMP
 nsXPCComponents_Utils::GetWeakReference(xpcIJSWeakReference **_retval)

js/src/xpconnect/tests/unit/test_unload.js

@@ -0,0 +1,65 @@
+/*
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *    Dave Townsend <dtownsend@oxymoronical.com> (original author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+ 
+function run_test() {
+  var scope1 = {};
+  var global1 = Components.utils.import("resource://gre/modules/NetUtil.jsm", scope1);
+
+  var scope2 = {};
+  var global2 = Components.utils.import("resource://gre/modules/NetUtil.jsm", scope2);
+
+  do_check_true(global1 === global2);
+  do_check_true(scope1.NetUtil === scope2.NetUtil);
+
+  Components.utils.unload("resource://gre/modules/NetUtil.jsm");
+
+  var scope3 = {};
+  var global3 = Components.utils.import("resource://gre/modules/NetUtil.jsm", scope3);
+
+  do_check_false(global1 === global3);
+  do_check_false(scope1.NetUtil === scope3.NetUtil);
+
+  // Both instances should work
+  uri1 = scope1.NetUtil.newURI("http://www.example.com");
+  do_check_true(uri1 instanceof Components.interfaces.nsIURL);
+
+  var uri3 = scope3.NetUtil.newURI("http://www.example.com");
+  do_check_true(uri3 instanceof Components.interfaces.nsIURL);
+
+  do_check_true(uri1.equals(uri3));
+}

js/src/xpconnect/tests/unit/xpcshell.ini

@@ -15,3 +15,4 @@ tail =
 [test_localeCompare.js]
 [test_recursive_import.js]
 [test_xpcomutils.js]
+[test_unload.js]