/*

 * Copyright (c) 2000, 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_OOPS_ARRAY_HPP

#define SHARE_OOPS_ARRAY_HPP

#include "memory/allocation.hpp"

#include "memory/metaspace.hpp"

#include "runtime/orderAccess.hpp"

#include "utilities/align.hpp"

// Array for metadata allocation

template <typename T>

class Array: public MetaspaceObj {

  friend class MetadataFactory;

  friend class MetaspaceShared;

  friend class VMStructs;

  friend class JVMCIVMStructs;

  friend class MethodHandleCompiler;           // special case

  friend class WhiteBox;

protected:

  int _length;                                 // the number of array elements

  T   _data[1];                                // the array memory

  void initialize(int length) {

    _length = length;

  }

 private:

  // Turn off copy constructor and assignment operator.

  Array(const Array<T>&);

  void operator=(const Array<T>&);

  void* operator new(size_t size, ClassLoaderData* loader_data, int length, TRAPS) throw() {

    size_t word_size = Array::size(length);

    return (void*) Metaspace::allocate(loader_data, word_size,

                                       MetaspaceObj::array_type(sizeof(T)), THREAD);

  }

  static size_t byte_sizeof(int length, size_t elm_byte_size) {

    return sizeof(Array<T>) + MAX2(length - 1, 0) * elm_byte_size;

  }

  static size_t byte_sizeof(int length) { return byte_sizeof(length, sizeof(T)); }

  // WhiteBox API helper.

  // Can't distinguish between array of length 0 and length 1,

  // will always return 0 in those cases.

  static int bytes_to_length(size_t bytes)       {

    assert(is_aligned(bytes, BytesPerWord), "Must be, for now");

    if (sizeof(Array<T>) >= bytes) {

      return 0;

    }

    size_t left = bytes - sizeof(Array<T>);

    assert(is_aligned(left, sizeof(T)), "Must be");

    size_t elements = left / sizeof(T);

    assert(elements <= (size_t)INT_MAX, "number of elements " SIZE_FORMAT "doesn't fit into an int.", elements);

    int length = (int)elements;

    assert((size_t)size(length) * BytesPerWord == (size_t)bytes,

           "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT,

           bytes, (size_t)size(length) * BytesPerWord);

    return length;

  }

  explicit Array(int length) : _length(length) {

    assert(length >= 0, "illegal length");

  }

  Array(int length, T init) : _length(length) {

    assert(length >= 0, "illegal length");

    for (int i = 0; i < length; i++) {

      _data[i] = init;

    }

  }

 public:

  // standard operations

  int  length() const                 { return _length; }

  T* data()                           { return _data; }

  bool is_empty() const               { return length() == 0; }

  int index_of(const T& x) const {

    int i = length();

    while (i-- > 0 && _data[i] != x) ;

    return i;

  }

  // sort the array.

  bool contains(const T& x) const      { return index_of(x) >= 0; }

  T    at(int i) const                 { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return _data[i]; }

  void at_put(const int i, const T& x) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); _data[i] = x; }

  T*   adr_at(const int i)             { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return &_data[i]; }

  int  find(const T& x)                { return index_of(x); }

  T at_acquire(const int i)            { return OrderAccess::load_acquire(adr_at(i)); }

  void release_at_put(int i, T x)      { OrderAccess::release_store(adr_at(i), x); }

  static int size(int length) {

    size_t bytes = align_up(byte_sizeof(length), BytesPerWord);

    size_t words = bytes / BytesPerWord;

    assert(words <= INT_MAX, "Overflow: " SIZE_FORMAT, words);

    return (int)words;

  }

  int size() {

    return size(_length);

  }

  static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }

  // Note, this offset don't have to be wordSize aligned.

  static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };

  // FIXME: How to handle this?

  void print_value_on(outputStream* st) const {

    st->print("Array<T>(" INTPTR_FORMAT ")", p2i(this));

  }

#ifndef PRODUCT

  void print(outputStream* st) {

     for (int i = 0; i< _length; i++) {

       st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));

     }

  }

  void print() { print(tty); }

#endif // PRODUCT

};

#endif // SHARE_OOPS_ARRAY_HPP