/*

 * Copyright (c) 1997, 2013, 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_UTILITIES_GROWABLEARRAY_HPP

#define SHARE_VM_UTILITIES_GROWABLEARRAY_HPP

#include "memory/allocation.hpp"

#include "memory/allocation.inline.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

#include "utilities/top.hpp"

// A growable array.

/*************************************************************************/

/*                                                                       */

/*     WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING   */

/*                                                                       */

/* Should you use GrowableArrays to contain handles you must be certain  */

/* the the GrowableArray does not outlive the HandleMark that contains   */

/* the handles. Since GrowableArrays are typically resource allocated    */

/* the following is an example of INCORRECT CODE,                        */

/*                                                                       */

/* ResourceMark rm;                                                      */

/* GrowableArray<Handle>* arr = new GrowableArray<Handle>(size);         */

/* if (blah) {                                                           */

/*    while (...) {                                                      */

/*      HandleMark hm;                                                   */

/*      ...                                                              */

/*      Handle h(THREAD, some_oop);                                      */

/*      arr->append(h);                                                  */

/*    }                                                                  */

/* }                                                                     */

/* if (arr->length() != 0 ) {                                            */

/*    oop bad_oop = arr->at(0)(); // Handle is BAD HERE.                 */

/*    ...                                                                */

/* }                                                                     */

/*                                                                       */

/* If the GrowableArrays you are creating is C_Heap allocated then it    */

/* hould not old handles since the handles could trivially try and       */

/* outlive their HandleMark. In some situations you might need to do     */

/* this and it would be legal but be very careful and see if you can do  */

/* the code in some other manner.                                        */

/*                                                                       */

/*************************************************************************/

// To call default constructor the placement operator new() is used.

// It should be empty (it only returns the passed void* pointer).

// The definition of placement operator new(size_t, void*) in the <new>.

#include <new>

// Need the correct linkage to call qsort without warnings

extern "C" {

  typedef int (*_sort_Fn)(const void *, const void *);

}

class GenericGrowableArray : public ResourceObj {

  friend class VMStructs;

 protected:

  int    _len;          // current length

  int    _max;          // maximum length

  Arena* _arena;        // Indicates where allocation occurs:

                        //   0 means default ResourceArea

                        //   1 means on C heap

                        //   otherwise, allocate in _arena

  MEMFLAGS   _memflags;   // memory type if allocation in C heap

#ifdef ASSERT

  int    _nesting;      // resource area nesting at creation

  void   set_nesting();

  void   check_nesting();

#else

#define  set_nesting();

#define  check_nesting();

#endif

  // Where are we going to allocate memory?

  bool on_C_heap() { return _arena == (Arena*)1; }

  bool on_stack () { return _arena == NULL;      }

  bool on_arena () { return _arena >  (Arena*)1;  }

  // This GA will use the resource stack for storage if c_heap==false,

  // Else it will use the C heap.  Use clear_and_deallocate to avoid leaks.

  GenericGrowableArray(int initial_size, int initial_len, bool c_heap, MEMFLAGS flags = mtNone) {

    _len = initial_len;

    _max = initial_size;

    _memflags = flags;

    // memory type has to be specified for C heap allocation

    assert(!(c_heap && flags == mtNone), "memory type not specified for C heap object");

    assert(_len >= 0 && _len <= _max, "initial_len too big");

    _arena = (c_heap ? (Arena*)1 : NULL);

    set_nesting();

    assert(!on_C_heap() || allocated_on_C_heap(), "growable array must be on C heap if elements are");

    assert(!on_stack() ||

           (allocated_on_res_area() || allocated_on_stack()),

           "growable array must be on stack if elements are not on arena and not on C heap");

  }

  // This GA will use the given arena for storage.

  // Consider using new(arena) GrowableArray<T> to allocate the header.

  GenericGrowableArray(Arena* arena, int initial_size, int initial_len) {

    _len = initial_len;

    _max = initial_size;

    assert(_len >= 0 && _len <= _max, "initial_len too big");

    _arena = arena;

    _memflags = mtNone;

    assert(on_arena(), "arena has taken on reserved value 0 or 1");

    // Relax next assert to allow object allocation on resource area,

    // on stack or embedded into an other object.

    assert(allocated_on_arena() || allocated_on_stack(),

           "growable array must be on arena or on stack if elements are on arena");

  }

  void* raw_allocate(int elementSize);

  // some uses pass the Thread explicitly for speed (4990299 tuning)

  void* raw_allocate(Thread* thread, int elementSize) {

    assert(on_stack(), "fast ResourceObj path only");

    return (void*)resource_allocate_bytes(thread, elementSize * _max);

  }

};

template<class E> class GrowableArrayIterator;

template<class E, class UnaryPredicate> class GrowableArrayFilterIterator;

template<class E> class GrowableArray : public GenericGrowableArray {

  friend class VMStructs;

 private:

  E*     _data;         // data array

  void grow(int j);

  void raw_at_put_grow(int i, const E& p, const E& fill);

  void  clear_and_deallocate();

 public:

  GrowableArray(Thread* thread, int initial_size) : GenericGrowableArray(initial_size, 0, false) {

    _data = (E*)raw_allocate(thread, sizeof(E));

    for (int i = 0; i < _max; i++) ::new ((void*)&_data[i]) E();

  }

  GrowableArray(int initial_size, bool C_heap = false, MEMFLAGS F = mtInternal)

    : GenericGrowableArray(initial_size, 0, C_heap, F) {

    _data = (E*)raw_allocate(sizeof(E));

    for (int i = 0; i < _max; i++) ::new ((void*)&_data[i]) E();

  }

  GrowableArray(int initial_size, int initial_len, const E& filler, bool C_heap = false, MEMFLAGS memflags = mtInternal)

    : GenericGrowableArray(initial_size, initial_len, C_heap, memflags) {

    _data = (E*)raw_allocate(sizeof(E));

    int i = 0;

    for (; i < _len; i++) ::new ((void*)&_data[i]) E(filler);

    for (; i < _max; i++) ::new ((void*)&_data[i]) E();

  }

  GrowableArray(Arena* arena, int initial_size, int initial_len, const E& filler) : GenericGrowableArray(arena, initial_size, initial_len) {

    _data = (E*)raw_allocate(sizeof(E));

    int i = 0;

    for (; i < _len; i++) ::new ((void*)&_data[i]) E(filler);

    for (; i < _max; i++) ::new ((void*)&_data[i]) E();

  }

  GrowableArray() : GenericGrowableArray(2, 0, false) {

    _data = (E*)raw_allocate(sizeof(E));

    ::new ((void*)&_data[0]) E();

    ::new ((void*)&_data[1]) E();

  }

                                // Does nothing for resource and arena objects

  ~GrowableArray()              { if (on_C_heap()) clear_and_deallocate(); }

  void  clear()                 { _len = 0; }

  int   length() const          { return _len; }

  int   max_length() const      { return _max; }

  void  trunc_to(int l)         { assert(l <= _len,"cannot increase length"); _len = l; }

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

  bool  is_nonempty() const     { return _len != 0; }

  bool  is_full() const         { return _len == _max; }

  DEBUG_ONLY(E* data_addr() const      { return _data; })

  void print();

  int append(const E& elem) {

    check_nesting();

    if (_len == _max) grow(_len);

    int idx = _len++;

    _data[idx] = elem;

    return idx;

  }

  bool append_if_missing(const E& elem) {

    // Returns TRUE if elem is added.

    bool missed = !contains(elem);

    if (missed) append(elem);

    return missed;

  }

  E& at(int i) {

    assert(0 <= i && i < _len, "illegal index");

    return _data[i];

  }

  E const& at(int i) const {

    assert(0 <= i && i < _len, "illegal index");

    return _data[i];

  }

  E* adr_at(int i) const {

    assert(0 <= i && i < _len, "illegal index");

    return &_data[i];

  }

  E first() const {

    assert(_len > 0, "empty list");

    return _data[0];

  }

  E top() const {

    assert(_len > 0, "empty list");

    return _data[_len-1];

  }

  GrowableArrayIterator<E> begin() const {

    return GrowableArrayIterator<E>(this, 0);

  }

  GrowableArrayIterator<E> end() const {

    return GrowableArrayIterator<E>(this, length());

  }

  void push(const E& elem) { append(elem); }

  E pop() {

    assert(_len > 0, "empty list");

    return _data[--_len];

  }

  void at_put(int i, const E& elem) {

    assert(0 <= i && i < _len, "illegal index");

    _data[i] = elem;

  }

  E at_grow(int i, const E& fill = E()) {

    assert(0 <= i, "negative index");

    check_nesting();

    if (i >= _len) {

      if (i >= _max) grow(i);

      for (int j = _len; j <= i; j++)

        _data[j] = fill;

      _len = i+1;

    }

    return _data[i];

  }

  void at_put_grow(int i, const E& elem, const E& fill = E()) {

    assert(0 <= i, "negative index");

    check_nesting();

    raw_at_put_grow(i, elem, fill);

  }

  bool contains(const E& elem) const {

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

      if (_data[i] == elem) return true;

    }

    return false;

  }

  int  find(const E& elem) const {

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

      if (_data[i] == elem) return i;

    }

    return -1;

  }

  int  find_from_end(const E& elem) const {

    for (int i = _len-1; i >= 0; i--) {

      if (_data[i] == elem) return i;

    }

    return -1;

  }

  int  find(void* token, bool f(void*, E)) const {

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

      if (f(token, _data[i])) return i;

    }

    return -1;

  }

  int  find_from_end(void* token, bool f(void*, E)) const {

    // start at the end of the array

    for (int i = _len-1; i >= 0; i--) {

      if (f(token, _data[i])) return i;

    }

    return -1;

  }

  void remove(const E& elem) {

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

      if (_data[i] == elem) {

        for (int j = i + 1; j < _len; j++) _data[j-1] = _data[j];

        _len--;

        return;

      }

    }

    ShouldNotReachHere();

  }

  // The order is preserved.

  void remove_at(int index) {

    assert(0 <= index && index < _len, "illegal index");

    for (int j = index + 1; j < _len; j++) _data[j-1] = _data[j];

    _len--;

  }

  // The order is changed.

  void delete_at(int index) {

    assert(0 <= index && index < _len, "illegal index");

    if (index < --_len) {

      // Replace removed element with last one.

      _data[index] = _data[_len];

    }

  }

  // inserts the given element before the element at index i

  void insert_before(const int idx, const E& elem) {

    assert(0 <= idx && idx <= _len, "illegal index");

    check_nesting();

    if (_len == _max) grow(_len);

    for (int j = _len - 1; j >= idx; j--) {

      _data[j + 1] = _data[j];

    }

    _len++;

    _data[idx] = elem;

  }

  void appendAll(const GrowableArray<E>* l) {

    for (int i = 0; i < l->_len; i++) {

      raw_at_put_grow(_len, l->_data[i], E());

    }

  }

  void sort(int f(E*,E*)) {

    qsort(_data, length(), sizeof(E), (_sort_Fn)f);

  }

  // sort by fixed-stride sub arrays:

  void sort(int f(E*,E*), int stride) {

    qsort(_data, length() / stride, sizeof(E) * stride, (_sort_Fn)f);

  }

};

// Global GrowableArray methods (one instance in the library per each 'E' type).

template<class E> void GrowableArray<E>::grow(int j) {

    // grow the array by doubling its size (amortized growth)

    int old_max = _max;

    if (_max == 0) _max = 1; // prevent endless loop

    while (j >= _max) _max = _max*2;

    // j < _max

    E* newData = (E*)raw_allocate(sizeof(E));

    int i = 0;

    for (     ; i < _len; i++) ::new ((void*)&newData[i]) E(_data[i]);

    for (     ; i < _max; i++) ::new ((void*)&newData[i]) E();

    for (i = 0; i < old_max; i++) _data[i].~E();

    if (on_C_heap() && _data != NULL) {

      FreeHeap(_data);

    }

    _data = newData;

}

template<class E> void GrowableArray<E>::raw_at_put_grow(int i, const E& p, const E& fill) {

    if (i >= _len) {

      if (i >= _max) grow(i);

      for (int j = _len; j < i; j++)

        _data[j] = fill;

      _len = i+1;

    }

    _data[i] = p;

}

// This function clears and deallocate the data in the growable array that

// has been allocated on the C heap.  It's not public - called by the

// destructor.

template<class E> void GrowableArray<E>::clear_and_deallocate() {

    assert(on_C_heap(),

           "clear_and_deallocate should only be called when on C heap");

    clear();

    if (_data != NULL) {

      for (int i = 0; i < _max; i++) _data[i].~E();

      FreeHeap(_data);

      _data = NULL;

    }

}

template<class E> void GrowableArray<E>::print() {

    tty->print("Growable Array " INTPTR_FORMAT, this);

    tty->print(": length %ld (_max %ld) { ", _len, _max);

    for (int i = 0; i < _len; i++) tty->print(INTPTR_FORMAT " ", *(intptr_t*)&(_data[i]));

    tty->print("}\n");

}

// Custom STL-style iterator to iterate over GrowableArrays

// It is constructed by invoking GrowableArray::begin() and GrowableArray::end()

template<class E> class GrowableArrayIterator : public StackObj {

  friend class GrowableArray<E>;

  template<class F, class UnaryPredicate> friend class GrowableArrayFilterIterator;

 private:

  const GrowableArray<E>* _array; // GrowableArray we iterate over

  int _position;                  // The current position in the GrowableArray

  // Private constructor used in GrowableArray::begin() and GrowableArray::end()

  GrowableArrayIterator(const GrowableArray<E>* array, int position) : _array(array), _position(position) {

    assert(0 <= position && position <= _array->length(), "illegal position");

  }

 public:

  GrowableArrayIterator<E>& operator++()  { ++_position; return *this; }

  E operator*()                           { return _array->at(_position); }

  bool operator==(const GrowableArrayIterator<E>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position == rhs._position;

  }

  bool operator!=(const GrowableArrayIterator<E>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position != rhs._position;

  }

};

// Custom STL-style iterator to iterate over elements of a GrowableArray that satisfy a given predicate

template<class E, class UnaryPredicate> class GrowableArrayFilterIterator : public StackObj {

  friend class GrowableArray<E>;

 private:

  const GrowableArray<E>* _array;   // GrowableArray we iterate over

  int _position;                    // Current position in the GrowableArray

  UnaryPredicate _predicate;        // Unary predicate the elements of the GrowableArray should satisfy

 public:

  GrowableArrayFilterIterator(const GrowableArrayIterator<E>& begin, UnaryPredicate filter_predicate)

   : _array(begin._array), _position(begin._position), _predicate(filter_predicate) {

    // Advance to first element satisfying the predicate

    while(_position != _array->length() && !_predicate(_array->at(_position))) {

      ++_position;

    }

  }

  GrowableArrayFilterIterator<E, UnaryPredicate>& operator++() {

    do {

      // Advance to next element satisfying the predicate

      ++_position;

    } while(_position != _array->length() && !_predicate(_array->at(_position)));

    return *this;

  }

  E operator*()   { return _array->at(_position); }

  bool operator==(const GrowableArrayIterator<E>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position == rhs._position;

  }

  bool operator!=(const GrowableArrayIterator<E>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position != rhs._position;

  }

  bool operator==(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position == rhs._position;

  }

  bool operator!=(const GrowableArrayFilterIterator<E, UnaryPredicate>& rhs)  {

    assert(_array == rhs._array, "iterator belongs to different array");

    return _position != rhs._position;

  }

};

#endif // SHARE_VM_UTILITIES_GROWABLEARRAY_HPP