/*

 * Copyright (c) 2017, 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

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 */

#ifndef SHARE_JFR_WRITERS_JFRTYPEWRITERHOST_HPP

#define SHARE_JFR_WRITERS_JFRTYPEWRITERHOST_HPP

#include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"

#include "jfr/utilities/jfrTypes.hpp"

#include "memory/allocation.hpp"

template <typename WriterImpl, u4 ID>

class JfrTypeWriterHost : public StackObj {

 private:

  WriterImpl _impl;

  JfrCheckpointWriter* _writer;

  JfrCheckpointContext _ctx;

  int64_t _count_offset;

  int _count;

  bool _skip_header;

 public:

  JfrTypeWriterHost(JfrCheckpointWriter* writer,

                    bool class_unload = false,

                    bool skip_header = false) : _impl(writer, class_unload),

                                                _writer(writer),

                                                _ctx(writer->context()),

                                                _count(0),

                                                _skip_header(skip_header) {

    assert(_writer != NULL, "invariant");

    if (!_skip_header) {

      _writer->write_type((JfrTypeId)ID);

      _count_offset = _writer->reserve(sizeof(u4)); // Don't know how many yet

    }

  }

  ~JfrTypeWriterHost() {

    if (_count == 0) {

      // nothing written, restore context for rewind

      _writer->set_context(_ctx);

      return;

    }

    assert(_count > 0, "invariant");

    if (!_skip_header) {

      _writer->write_count(_count, _count_offset);

    }

  }

  bool operator()(typename WriterImpl::Type const & value) {

    this->_count += _impl(value);

    return true;

  }

  int count() const   { return _count; }

  void add(int count) { _count += count; }

};

typedef int(*type_write_operation)(JfrCheckpointWriter*, const void*);

template <typename T, type_write_operation op>

class JfrTypeWriterImplHost {

 private:

  JfrCheckpointWriter* _writer;

 public:

  typedef T Type;

  JfrTypeWriterImplHost(JfrCheckpointWriter* writer, bool class_unload = false) : _writer(writer) {}

  int operator()(T const& value) {

    return op(this->_writer, value);

  }

};

template <typename T, typename Predicate, type_write_operation op>

class JfrPredicatedTypeWriterImplHost : public JfrTypeWriterImplHost<T, op> {

 private:

  Predicate _predicate;

  typedef JfrTypeWriterImplHost<T, op> Parent;

 public:

  JfrPredicatedTypeWriterImplHost(JfrCheckpointWriter* writer, bool class_unload = false) :

    Parent(writer), _predicate(class_unload) {}

  int operator()(T const& value) {

    return _predicate(value) ? Parent::operator()(value) : 0;

  }

};

#endif // SHARE_JFR_WRITERS_JFRTYPEWRITERHOST_HPP