1 files changed, 26 insertions, 0 deletions
diff --git a/dom/media/doctor/DDMessageIndex.h b/dom/media/doctor/DDMessageIndex.h
new file mode 100644
index 0000000000..e2b5c7274c
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+++ b/dom/media/doctor/DDMessageIndex.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 DDMessageIndex_h_
+#define DDMessageIndex_h_
+
+#include "RollingNumber.h"
+
+namespace mozilla {
+
+// Type used to uniquely identify and sort log messages.
+// We assume that a given media element won't live for more than the time taken
+// to log 2^31 messages (per process); for 10,000 messages per seconds, that's
+// about 2.5 days
+using DDMessageIndex = RollingNumber<uint32_t>;
+
+// Printf string constant to use when printing a DDMessageIndex, e.g.:
+// `printf("index=%" PRImi, index);`
+#define PRImi PRIu32
+
+}  // namespace mozilla
+
+#endif  // DDMessageIndex_h_