1 files changed, 53 insertions, 0 deletions
diff --git a/xpcom/ds/nsStaticAtom.h b/xpcom/ds/nsStaticAtom.h
new file mode 100644
index 000000000..7e31623db
--- /dev/null
+++ b/xpcom/ds/nsStaticAtom.h
@@ -0,0 +1,53 @@
+/* -*- 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/. */
+
+#ifndef nsStaticAtom_h__
+#define nsStaticAtom_h__
+
+#include "nsIAtom.h"
+#include "nsStringBuffer.h"
+
+#define NS_STATIC_ATOM(buffer_name, atom_ptr) \
+  { (nsStringBuffer*) &buffer_name, atom_ptr }
+
+#define NS_STATIC_ATOM_BUFFER(buffer_name, str_data) \
+  static nsFakeStringBuffer<sizeof(str_data)> buffer_name = \
+    { 1, sizeof(str_data) * sizeof(char16_t), (u"" str_data) };
+
+/**
+ * Holds data used to initialize large number of atoms during startup. Use
+ * the above macros to initialize these structs. They should never be accessed
+ * directly other than from AtomTable.cpp
+ */
+struct nsStaticAtom
+{
+  // mStringBuffer points to the string buffer for a permanent atom, and is
+  // therefore safe as a non-owning reference.
+  nsStringBuffer* MOZ_NON_OWNING_REF mStringBuffer;
+  nsIAtom** mAtom;
+};
+
+/**
+ * This is a struct with the same binary layout as a nsStringBuffer.
+ */
+template<uint32_t size>
+struct nsFakeStringBuffer
+{
+  int32_t mRefCnt;
+  uint32_t mSize;
+  char16_t mStringData[size];
+};
+
+// Register an array of static atoms with the atom table
+template<uint32_t N>
+void
+NS_RegisterStaticAtoms(const nsStaticAtom (&aAtoms)[N])
+{
+  extern void RegisterStaticAtoms(const nsStaticAtom*, uint32_t aAtomCount);
+  RegisterStaticAtoms(aAtoms, N);
+}
+
+#endif