diff -r 2c3cc4b01880 -r c16ac7a2eba4 src/hotspot/share/jfr/recorder/repository/jfrChunk.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/recorder/repository/jfrChunk.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP
+#define SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP
+
+#include "jfr/utilities/jfrAllocation.hpp"
+
+const u1 COMPLETE = 0;
+const u1 GUARD = 0xff;
+const u1 PAD = 0;
+
+class JfrChunk : public JfrCHeapObj {
+  friend class JfrChunkWriter;
+  friend class JfrChunkHeadWriter;
+ private:
+  char* _path;
+  int64_t _start_ticks;
+  int64_t _previous_start_ticks;
+  int64_t _start_nanos;
+  int64_t _previous_start_nanos;
+  int64_t _last_update_nanos;
+  int64_t _last_checkpoint_offset;
+  int64_t _last_metadata_offset;
+  mutable u1 _generation;
+
+  JfrChunk();
+  ~JfrChunk();
+  void reset();
+
+  const char* magic() const;
+  u2 major_version() const;
+  u2 minor_version() const;
+  int64_t cpu_frequency() const;
+  u2 capabilities() const;
+
+  void update_start_ticks();
+  void update_start_nanos();
+  void save_current_and_update_start_ticks();
+  void save_current_and_update_start_nanos();
+
+  int64_t last_checkpoint_offset() const;
+  void set_last_checkpoint_offset(int64_t offset);
+
+  int64_t last_metadata_offset() const;
+  void set_last_metadata_offset(int64_t offset);
+  bool has_metadata() const;
+
+  int64_t start_ticks() const;
+  int64_t start_nanos() const;
+
+  int64_t previous_start_ticks() const;
+  int64_t previous_start_nanos() const;
+  int64_t last_chunk_duration() const;
+
+  void set_time_stamp();
+  void update_current_nanos();
+
+  void set_path(const char* path);
+  const char* path() const;
+
+  bool is_started() const;
+  bool is_finished() const;
+
+  int64_t duration() const;
+  u1 generation() const;
+  u1 next_generation() const;
+};
+
+#endif // SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP