/*

 * 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

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 */

#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