Bug 1356546: Part 4 - Use StructuredCloneHolder as transport for proxied method return values. r=aswan

MozReview-Commit-ID: LZ3XkamgkeF

--HG--
extra : rebase_source : 7887bde7e424b35de18ad069161a984c556cc659

toolkit/components/extensions/ExtensionChild.jsm

@@ -48,9 +48,9 @@ const {
 const {
   LocalAPIImplementation,
   LocaleData,
+  NoCloneSpreadArgs,
   SchemaAPIInterface,
   SingletonEventManager,
-  SpreadArgs,
 } = ExtensionCommon;
 
 const isContentProcess = Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_CONTENT;
@@ -773,7 +773,9 @@ class ChildAPIManager {
         if ("error" in data) {
           deferred.reject(data.error);
         } else {
-          deferred.resolve(new SpreadArgs(data.result));
+          let result = data.result.deserialize(this.context.cloneScope);
+
+          deferred.resolve(new NoCloneSpreadArgs(result));
         }
         this.callPromises.delete(data.callId);
         break;

toolkit/components/extensions/ExtensionCommon.jsm

@@ -53,6 +53,11 @@ XPCOMUtils.defineLazyGetter(this, "console", getConsole);
 
 var ExtensionCommon;
 
+/**
+ * A sentinel class to indicate that an array of values should be
+ * treated as an array when used as a promise resolution value, but as a
+ * spread expression (...args) when passed to a callback.
+ */
 class SpreadArgs extends Array {
   constructor(args) {
     super();
@@ -60,6 +65,25 @@ class SpreadArgs extends Array {
   }
 }
 
+/**
+ * Like SpreadArgs, but also indicates that the array values already
+ * belong to the target compartment, and should not be cloned before
+ * being passed.
+ *
+ * The `unwrappedValues` property contains an Array object which belongs
+ * to the target compartment, and contains the same unwrapped values
+ * passed the NoCloneSpreadArgs constructor.
+ */
+class NoCloneSpreadArgs {
+  constructor(args) {
+    this.unwrappedValues = args;
+  }
+
+  [Symbol.iterator]() {
+    return this.unwrappedValues[Symbol.iterator]();
+  }
+}
+
 class BaseContext {
   constructor(envType, extension) {
     this.envType = envType;
@@ -323,6 +347,8 @@ class BaseContext {
             dump(`Promise resolved after context unloaded\n`);
           } else if (!this.active) {
             dump(`Promise resolved while context is inactive\n`);
+          } else if (args instanceof NoCloneSpreadArgs) {
+            this.runSafeWithoutClone(callback, ...args.unwrappedValues);
           } else if (args instanceof SpreadArgs) {
             runSafe(callback, ...args);
           } else {
@@ -348,6 +374,9 @@ class BaseContext {
               dump(`Promise resolved after context unloaded\n`);
             } else if (!this.active) {
               dump(`Promise resolved while context is inactive\n`);
+            } else if (value instanceof NoCloneSpreadArgs) {
+              let values = value.unwrappedValues;
+              this.runSafeWithoutClone(resolve, values.length == 1 ? values[0] : values);
             } else if (value instanceof SpreadArgs) {
               runSafe(resolve, value.length == 1 ? value[0] : value);
             } else {
@@ -1488,6 +1517,7 @@ ExtensionCommon = {
   CanOfAPIs,
   LocalAPIImplementation,
   LocaleData,
+  NoCloneSpreadArgs,
   SchemaAPIInterface,
   SchemaAPIManager,
   SingletonEventManager,

toolkit/components/extensions/ExtensionParent.jsm

@@ -624,7 +624,9 @@ ParentAPIManager = {
         result.then(result => {
           result = result instanceof SpreadArgs ? [...result] : [result];
 
-          reply({result});
+          let holder = new StructuredCloneHolder(result);
+
+          reply({result: holder});
         }, error => {
           error = context.normalizeError(error);
           reply({error: {message: error.message, fileName: error.fileName}});