diff -r 000000000000 -r 6474c204b198 rdf/base/src/nsNameSpaceMap.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rdf/base/src/nsNameSpaceMap.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,64 @@
+/* -*- 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 "nsNameSpaceMap.h"
+#include "nsReadableUtils.h"
+
+nsNameSpaceMap::nsNameSpaceMap()
+    : mEntries(nullptr)
+{
+    MOZ_COUNT_CTOR(nsNameSpaceMap);
+}
+
+nsNameSpaceMap::~nsNameSpaceMap()
+{
+    MOZ_COUNT_DTOR(nsNameSpaceMap);
+
+    while (mEntries) {
+        Entry* doomed = mEntries;
+        mEntries = mEntries->mNext;
+        delete doomed;
+    }
+}
+
+nsresult
+nsNameSpaceMap::Put(const nsAString& aURI, nsIAtom* aPrefix)
+{
+    nsCString uriUTF8;
+    AppendUTF16toUTF8(aURI, uriUTF8);
+    return Put(uriUTF8, aPrefix);
+}
+
+nsresult
+nsNameSpaceMap::Put(const nsCSubstring& aURI, nsIAtom* aPrefix)
+{
+    Entry* entry;
+
+    // Make sure we're not adding a duplicate
+    for (entry = mEntries; entry != nullptr; entry = entry->mNext) {
+        if (entry->mURI == aURI || entry->mPrefix == aPrefix)
+            return NS_ERROR_FAILURE;
+    }
+
+    entry = new Entry(aURI, aPrefix);
+    if (! entry)
+        return NS_ERROR_OUT_OF_MEMORY;
+
+    entry->mNext = mEntries;
+    mEntries = entry;
+    return NS_OK;
+}
+
+nsNameSpaceMap::const_iterator
+nsNameSpaceMap::GetNameSpaceOf(const nsCSubstring& aURI) const
+{
+    for (Entry* entry = mEntries; entry != nullptr; entry = entry->mNext) {
+        if (StringBeginsWith(aURI, entry->mURI))
+            return const_iterator(entry);
+    }
+
+    return last();
+}