1 files changed, 67 insertions, 0 deletions
diff --git a/ipc/glue/IPCMessageUtilsSpecializations.cpp b/ipc/glue/IPCMessageUtilsSpecializations.cpp
new file mode 100644
index 0000000000..410b1e730f
--- /dev/null
+++ b/ipc/glue/IPCMessageUtilsSpecializations.cpp
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "IPCMessageUtilsSpecializations.h"
+#include "nsGkAtoms.h"
+
+namespace IPC {
+
+static const uint16_t kDynamicAtomToken = 0xffff;
+static const uint16_t kAtomsCount =
+    static_cast<uint16_t>(mozilla::detail::GkAtoms::Atoms::AtomsCount);
+
+static_assert(static_cast<size_t>(
+                  mozilla::detail::GkAtoms::Atoms::AtomsCount) == kAtomsCount,
+              "Number of static atoms must fit in a uint16_t");
+
+static_assert(kDynamicAtomToken >= kAtomsCount,
+              "Exceeded supported number of static atoms");
+
+/* static */
+void ParamTraits<nsAtom*>::Write(MessageWriter* aWriter, const nsAtom* aParam) {
+  MOZ_ASSERT(aParam);
+
+  if (aParam->IsStatic()) {
+    const nsStaticAtom* atom = aParam->AsStatic();
+    uint16_t index = static_cast<uint16_t>(nsGkAtoms::IndexOf(atom));
+    MOZ_ASSERT(index < kAtomsCount);
+    WriteParam(aWriter, index);
+    return;
+  }
+  WriteParam(aWriter, kDynamicAtomToken);
+  nsDependentAtomString atomStr(aParam);
+  // nsDependentAtomString is serialized as its base, nsString, but we
+  // can be explicit about it.
+  nsString& str = atomStr;
+  WriteParam(aWriter, str);
+}
+
+/* static */
+bool ParamTraits<nsAtom*>::Read(MessageReader* aReader,
+                                RefPtr<nsAtom>* aResult) {
+  uint16_t token;
+  if (!ReadParam(aReader, &token)) {
+    return false;
+  }
+  if (token != kDynamicAtomToken) {
+    if (token >= kAtomsCount) {
+      return false;
+    }
+    *aResult = nsGkAtoms::GetAtomByIndex(token);
+    return true;
+  }
+
+  nsAutoString str;
+  if (!ReadParam(aReader, static_cast<nsString*>(&str))) {
+    return false;
+  }
+
+  *aResult = NS_Atomize(str);
+  MOZ_ASSERT(*aResult);
+  return true;
+}
+
+}  // namespace IPC