--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/leakprofiler/chains/edgeStore.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2014, 2018, 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_LEAKPROFILER_CHAINS_EDGESTORE_HPP
+#define SHARE_VM_LEAKPROFILER_CHAINS_EDGESTORE_HPP
+
+#include "jfr/utilities/jfrHashtable.hpp"
+#include "jfr/leakprofiler/chains/edge.hpp"
+#include "memory/allocation.hpp"
+
+typedef u8 traceid;
+
+class RoutableEdge : public Edge {
+ private:
+  mutable const RoutableEdge* _skip_edge;
+  mutable size_t _skip_length;
+  mutable bool _processed;
+
+ public:
+  RoutableEdge();
+  RoutableEdge(const Edge* parent, const oop* reference);
+  RoutableEdge(const Edge& edge);
+  RoutableEdge(const RoutableEdge& edge);
+  void operator=(const RoutableEdge& edge);
+
+  const RoutableEdge* skip_edge() const { return _skip_edge; }
+  size_t skip_length() const { return _skip_length; }
+
+  bool is_skip_edge() const { return _skip_edge != NULL; }
+  bool processed() const { return _processed; }
+  bool is_sentinel() const {
+    return _skip_edge == NULL && _skip_length == 1;
+  }
+
+  void set_skip_edge(const RoutableEdge* edge) const {
+    assert(!is_skip_edge(), "invariant");
+    assert(edge != this, "invariant");
+    _skip_edge = edge;
+  }
+
+  void set_skip_length(size_t length) const {
+    _skip_length = length;
+  }
+
+  void set_processed() const {
+    assert(!_processed, "invariant");
+    _processed = true;
+  }
+
+  // true navigation according to physical tree representation
+  const RoutableEdge* physical_parent() const {
+    return static_cast<const RoutableEdge*>(parent());
+  }
+
+  // logical navigation taking skip levels into account
+  const RoutableEdge* logical_parent() const {
+    return is_skip_edge() ? skip_edge() : physical_parent();
+  }
+
+  size_t logical_distance_to_root() const;
+};
+
+class EdgeStore : public CHeapObj<mtTracing> {
+  typedef HashTableHost<RoutableEdge, traceid, Entry, EdgeStore> EdgeHashTable;
+  typedef EdgeHashTable::HashEntry EdgeEntry;
+  template <typename,
+            typename,
+            template<typename, typename> class,
+            typename,
+            size_t>
+  friend class HashTableHost;
+ private:
+  static traceid _edge_id_counter;
+  EdgeHashTable* _edges;
+
+  // Hash table callbacks
+  void assign_id(EdgeEntry* entry);
+  bool equals(const Edge& query, uintptr_t hash, const EdgeEntry* entry);
+
+  const Edge* get_edge(const Edge* edge) const;
+  const Edge* put(const Edge* edge);
+
+ public:
+  EdgeStore();
+  ~EdgeStore();
+
+  void add_chain(const Edge* chain, size_t length);
+  bool is_empty() const;
+  size_t number_of_entries() const;
+
+  traceid get_id(const Edge* edge) const;
+  traceid get_root_id(const Edge* edge) const;
+
+  template <typename T>
+  void iterate_edges(T& functor) const { _edges->iterate_value<T>(functor); }
+};
+
+#endif // SHARE_VM_LEAKPROFILER_CHAINS_EDGESTORE_HPP