diff -r 000000000000 -r 6474c204b198 xpcom/ds/nsArray.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/ds/nsArray.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,208 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "nsArray.h"
+#include "nsArrayEnumerator.h"
+#include "nsIWeakReference.h"
+#include "nsIWeakReferenceUtils.h"
+#include "nsThreadUtils.h"
+
+// used by IndexOf()
+struct findIndexOfClosure
+{
+    nsISupports *targetElement;
+    uint32_t startIndex;
+    uint32_t resultIndex;
+};
+
+static bool FindElementCallback(void* aElement, void* aClosure);
+
+NS_INTERFACE_MAP_BEGIN(nsArray)
+  NS_INTERFACE_MAP_ENTRY(nsIArray)
+  NS_INTERFACE_MAP_ENTRY(nsIMutableArray)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMutableArray)
+NS_INTERFACE_MAP_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsArrayCC)
+  NS_INTERFACE_MAP_ENTRY(nsIArray)
+  NS_INTERFACE_MAP_ENTRY(nsIMutableArray)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMutableArray)
+NS_INTERFACE_MAP_END
+
+nsArray::~nsArray()
+{
+    Clear();
+}
+
+
+NS_IMPL_ADDREF(nsArray)
+NS_IMPL_RELEASE(nsArray)
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsArrayCC)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsArrayCC)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsArrayCC)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsArrayCC)
+    tmp->Clear();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsArrayCC)
+    NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mArray)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMETHODIMP
+nsArray::GetLength(uint32_t* aLength)
+{
+    *aLength = mArray.Count();
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsArray::QueryElementAt(uint32_t aIndex,
+                        const nsIID& aIID,
+                        void ** aResult)
+{
+    nsISupports * obj = mArray.SafeObjectAt(aIndex);
+    if (!obj) return NS_ERROR_ILLEGAL_VALUE;
+
+    // no need to worry about a leak here, because SafeObjectAt() 
+    // doesn't addref its result
+    return obj->QueryInterface(aIID, aResult);
+}
+
+NS_IMETHODIMP
+nsArray::IndexOf(uint32_t aStartIndex, nsISupports* aElement,
+                 uint32_t* aResult)
+{
+    // optimize for the common case by forwarding to mArray
+    if (aStartIndex == 0) {
+        uint32_t idx = mArray.IndexOf(aElement);
+        if (idx == UINT32_MAX)
+            return NS_ERROR_FAILURE;
+
+        *aResult = idx;
+        return NS_OK;
+    }
+
+    findIndexOfClosure closure = { aElement, aStartIndex, 0 };
+    bool notFound = mArray.EnumerateForwards(FindElementCallback, &closure);
+    if (notFound)
+        return NS_ERROR_FAILURE;
+
+    *aResult = closure.resultIndex;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsArray::Enumerate(nsISimpleEnumerator **aResult)
+{
+    return NS_NewArrayEnumerator(aResult, static_cast<nsIArray*>(this));
+}
+
+// nsIMutableArray implementation
+
+NS_IMETHODIMP
+nsArray::AppendElement(nsISupports* aElement, bool aWeak)
+{
+    bool result;
+    if (aWeak) {
+        nsCOMPtr<nsIWeakReference> elementRef = do_GetWeakReference(aElement);
+        NS_ASSERTION(elementRef, "AppendElement: Trying to use weak references on an object that doesn't support it");
+        if (!elementRef)
+            return NS_ERROR_FAILURE;
+        result = mArray.AppendObject(elementRef);
+    }
+
+    else {
+        // add the object directly
+        result = mArray.AppendObject(aElement);
+    }
+    return result ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsArray::RemoveElementAt(uint32_t aIndex)
+{
+    bool result = mArray.RemoveObjectAt(aIndex);
+    return result ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsArray::InsertElementAt(nsISupports* aElement, uint32_t aIndex, bool aWeak)
+{
+    nsCOMPtr<nsISupports> elementRef;
+    if (aWeak) {
+        elementRef = do_GetWeakReference(aElement);
+        NS_ASSERTION(elementRef, "InsertElementAt: Trying to use weak references on an object that doesn't support it");
+        if (!elementRef)
+            return NS_ERROR_FAILURE;
+    } else {
+        elementRef = aElement;
+    }
+    bool result = mArray.InsertObjectAt(elementRef, aIndex);
+    return result ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsArray::ReplaceElementAt(nsISupports* aElement, uint32_t aIndex, bool aWeak)
+{
+    nsCOMPtr<nsISupports> elementRef;
+    if (aWeak) {
+        elementRef = do_GetWeakReference(aElement);
+        NS_ASSERTION(elementRef, "ReplaceElementAt: Trying to use weak references on an object that doesn't support it");
+        if (!elementRef)
+            return NS_ERROR_FAILURE;
+    } else {
+        elementRef = aElement;
+    }
+    bool result = mArray.ReplaceObjectAt(elementRef, aIndex);
+    return result ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsArray::Clear()
+{
+    mArray.Clear();
+    return NS_OK;
+}
+
+//
+// static helper routines
+//
+bool
+FindElementCallback(void *aElement, void* aClosure)
+{
+    findIndexOfClosure* closure =
+        static_cast<findIndexOfClosure*>(aClosure);
+
+    nsISupports* element =
+        static_cast<nsISupports*>(aElement);
+    
+    // don't start searching until we're past the startIndex
+    if (closure->resultIndex >= closure->startIndex &&
+        element == closure->targetElement) {
+        return false;    // stop! We found it
+    }
+    closure->resultIndex++;
+
+    return true;
+}
+
+nsresult
+nsArray::XPCOMConstructor(nsISupports *aOuter, const nsIID& aIID, void **aResult)
+{
+    if (aOuter)
+        return NS_ERROR_NO_AGGREGATION;
+
+    nsCOMPtr<nsIMutableArray> inst = Create();
+    return inst->QueryInterface(aIID, aResult); 
+}
+
+already_AddRefed<nsIMutableArray>
+nsArray::Create()
+{
+    nsCOMPtr<nsIMutableArray> inst = NS_IsMainThread() ? new nsArrayCC : new nsArray;
+    return inst.forget();
+}