/*

 * Copyright (c) 1997, 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.

 *

 */

#include "precompiled.hpp"

#include "libadt/vectset.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/arena.hpp"

#include "utilities/count_leading_zeros.hpp"

VectorSet::VectorSet(Arena *arena) : _size(2),

    _data(NEW_ARENA_ARRAY(arena, uint32_t, 2)),

    _set_arena(arena) {

  _data[0] = 0;

  _data[1] = 0;

}

// Expand the existing set to a bigger size

void VectorSet::grow(uint new_size) {

  new_size = (new_size + bit_mask) >> word_bits;

  assert(new_size != 0 && new_size < (1U << 31), "");

  uint x = (1U << 31) >> (count_leading_zeros(new_size) - 1);

  _data = REALLOC_ARENA_ARRAY(_set_arena, uint32_t, _data, _size, x);

  Copy::zero_to_bytes(_data + _size, (x - _size) * sizeof(uint32_t));

  _size = x;

}

// Insert a member into an existing Set.

void VectorSet::insert(uint elem) {

  uint32_t word = elem >> word_bits;

  uint32_t mask = 1U << (elem & bit_mask);

  if (word >= _size) {

    grow(elem + 1);

  }

  _data[word] |= mask;

}

// Resets the storage

void VectorSet::reset_memory() {

  assert(_size >= 2, "_size can never be less than 2");

  _data = REALLOC_ARENA_ARRAY(_set_arena, uint32_t, _data, _size, 2);

  _size = 2;

  _data[0] = 0;

  _data[1] = 0;

}

// Return true if the set is empty

bool VectorSet::is_empty() const {

  for (uint32_t i = 0; i < _size; i++) {

    if (_data[i] != 0) {

      return false;

    }

  }

  return true;

}