1 files changed, 61 insertions, 0 deletions
diff --git a/intl/locale/nsLanguageAtomService.h b/intl/locale/nsLanguageAtomService.h
new file mode 100644
index 0000000000..521ead4e87
--- /dev/null
+++ b/intl/locale/nsLanguageAtomService.h
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/*
+ * The nsILanguageAtomService provides a mapping from languages or charsets
+ * to language groups, and access to the system locale language.
+ */
+
+#ifndef nsLanguageAtomService_h_
+#define nsLanguageAtomService_h_
+
+#include "mozilla/NotNull.h"
+#include "nsCOMPtr.h"
+#include "nsAtomHashKeys.h"
+#include "nsTHashMap.h"
+
+namespace mozilla {
+class Encoding;
+}
+
+class nsLanguageAtomService final {
+  using Encoding = mozilla::Encoding;
+  template <typename T>
+  using NotNull = mozilla::NotNull<T>;
+
+ public:
+  static nsLanguageAtomService* GetService();
+
+  static void Shutdown();
+
+  nsStaticAtom* LookupLanguage(const nsACString& aLanguage);
+  already_AddRefed<nsAtom> LookupCharSet(NotNull<const Encoding*> aCharSet);
+  nsAtom* GetLocaleLanguage();
+
+  // Returns the language group that the specified language is a part of.
+  //
+  // aNeedsToCache is used for two things.  If null, it indicates that
+  // the nsLanguageAtomService is safe to cache the result of the
+  // language group lookup, either because we're on the main thread,
+  // or because we're on a style worker thread but the font lock has
+  // been acquired.  If non-null, it indicates that it's not safe to
+  // cache the result of the language group lookup (because we're on
+  // a style worker thread without the lock acquired).  In this case,
+  // GetLanguageGroup will store true in *aNeedsToCache true if we
+  // would have cached the result of a new lookup, and false if we
+  // were able to use an existing cached result.  Thus, callers that
+  // get a true *aNeedsToCache outparam value should make an effort
+  // to re-call GetLanguageGroup when it is safe to cache, to avoid
+  // recomputing the language group again later.
+  nsStaticAtom* GetLanguageGroup(nsAtom* aLanguage,
+                                 bool* aNeedsToCache = nullptr);
+  nsStaticAtom* GetUncachedLanguageGroup(nsAtom* aLanguage) const;
+
+ private:
+  nsTHashMap<RefPtr<nsAtom>, nsStaticAtom*> mLangToGroup;
+  RefPtr<nsAtom> mLocaleLanguage;
+};
+
+#endif