1 files changed, 52 insertions, 0 deletions
diff --git a/xpcom/io/nsNativeCharsetUtils.h b/xpcom/io/nsNativeCharsetUtils.h
new file mode 100644
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+++ b/xpcom/io/nsNativeCharsetUtils.h
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+/* -*- 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 nsNativeCharsetUtils_h__
+#define nsNativeCharsetUtils_h__
+
+/*****************************************************************************\
+ *                                                                           *
+ *                             **** NOTICE ****                              *
+ *                                                                           *
+ *             *** THESE ARE NOT GENERAL PURPOSE CONVERTERS ***              *
+ *                                                                           *
+ *    NS_CopyNativeToUnicode / NS_CopyUnicodeToNative should only be used    *
+ *    for converting *FILENAMES* between bytes and UTF-16. They are not      *
+ *    designed or tested for general encoding converter use.                 *
+ *                                                                           *
+ *    On Windows, these functions convert to and from the system's legacy    *
+ *    code page, which cannot represent all of Unicode. Elsewhere, these     *
+ *    convert to and from UTF-8.                                             *
+ *                                                                           *
+\*****************************************************************************/
+
+#include "nsError.h"
+#include "nsStringFwd.h"
+
+/**
+ * thread-safe conversion routines that do not depend on uconv libraries.
+ */
+nsresult NS_CopyNativeToUnicode(const nsACString& aInput, nsAString& aOutput);
+nsresult NS_CopyUnicodeToNative(const nsAString& aInput, nsACString& aOutput);
+
+/*
+ * This function indicates whether the character encoding used in the file
+ * system (more exactly what's used for |GetNativeFoo| and |SetNativeFoo|
+ * of |nsIFile|) is UTF-8 or not. Knowing that helps us avoid an
+ * unncessary encoding conversion in some cases. For instance, to get the leaf
+ * name in UTF-8 out of nsIFile, we can just use |GetNativeLeafName| rather
+ * than using |GetLeafName| and converting the result to UTF-8 if the file
+ * system  encoding is UTF-8.
+ */
+inline constexpr bool NS_IsNativeUTF8() {
+#ifdef XP_WIN
+  return false;
+#else
+  return true;
+#endif
+}
+
+#endif  // nsNativeCharsetUtils_h__