mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-22 09:49:11 +00:00
3ed4f388d7
svn-id: r42455
305 lines
7.8 KiB
C++
305 lines
7.8 KiB
C++
/* ScummVM - Graphic Adventure Engine
|
|
*
|
|
* ScummVM is the legal property of its developers, whose names
|
|
* are too numerous to list here. Please refer to the COPYRIGHT
|
|
* file distributed with this source distribution.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program 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 for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
* $URL$
|
|
* $Id$
|
|
*/
|
|
|
|
#ifndef COMMON_ARRAY_H
|
|
#define COMMON_ARRAY_H
|
|
|
|
#include "common/scummsys.h"
|
|
#include "common/algorithm.h"
|
|
|
|
namespace Common {
|
|
|
|
/**
|
|
* This class implements a dynamically sized container, which
|
|
* can be accessed similar to a regular C++ array. Accessing
|
|
* elements is performed in constant time (like with plain arrays).
|
|
* In addition, one can append, insert and remove entries (this
|
|
* is the 'dynamic' part). Doing that in general takes time
|
|
* proportional to the number of elements in the array.
|
|
*
|
|
* The container class closest to this in the C++ standard library is
|
|
* std::vector. However, there are some differences. The most important one is
|
|
* that std::vector has a far more sophisticated (and complicated) memory
|
|
* management scheme. There, only elements that 'live' are actually constructed
|
|
* (i.e., have their constructor called), and objects that are removed are
|
|
* immediately destructed (have their destructor called).
|
|
* With Common::Array, this is not the case; instead, it simply uses new[] and
|
|
* delete[] to allocate whole blocks of objects, possibly more than are
|
|
* currently 'alive'. This simplifies memory management, but may have
|
|
* undesirable side effects when one wants to use an Array of complex
|
|
* data types.
|
|
*
|
|
* @todo Improve the storage management of this class.
|
|
* In particular, don't use new[] and delete[], but rather
|
|
* construct/destruct objects manually. This way, we can
|
|
* ensure that storage which is not currently used does not
|
|
* correspond to a live active object.
|
|
* (This is only of interest for array of non-POD objects).
|
|
*/
|
|
template<class T>
|
|
class Array {
|
|
protected:
|
|
uint _capacity;
|
|
uint _size;
|
|
T *_storage;
|
|
|
|
public:
|
|
typedef T *iterator;
|
|
typedef const T *const_iterator;
|
|
|
|
typedef T value_type;
|
|
|
|
public:
|
|
Array() : _capacity(0), _size(0), _storage(0) {}
|
|
|
|
Array(const Array<T> &array) : _capacity(array._size), _size(array._size), _storage(0) {
|
|
if (array._storage) {
|
|
_storage = new T[_capacity];
|
|
assert(_storage);
|
|
copy(array._storage, array._storage + _size, _storage);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Construct an array by copying data from a regular array.
|
|
*/
|
|
template<class T2>
|
|
Array(const T2 *data, int n) {
|
|
_capacity = _size = n;
|
|
_storage = new T[_capacity];
|
|
assert(_storage);
|
|
copy(data, data + _size, _storage);
|
|
}
|
|
|
|
~Array() {
|
|
delete[] _storage;
|
|
_storage = 0;
|
|
_capacity = _size = 0;
|
|
}
|
|
|
|
/** Appends element to the end of the array. */
|
|
void push_back(const T &element) {
|
|
if (_size + 1 <= _capacity)
|
|
_storage[_size++] = element;
|
|
else
|
|
insert_aux(end(), &element, &element + 1);
|
|
}
|
|
|
|
void push_back(const Array<T> &array) {
|
|
if (_size + array.size() <= _capacity) {
|
|
copy(array.begin(), array.end(), end());
|
|
_size += array.size();
|
|
} else
|
|
insert_aux(end(), array.begin(), array.end());
|
|
}
|
|
|
|
/** Removes the last element of the array. */
|
|
void pop_back() {
|
|
assert(_size > 0);
|
|
_size--;
|
|
}
|
|
|
|
/** Returns a reference to the first element of the array. */
|
|
T &front() {
|
|
assert(_size > 0);
|
|
return _storage[0];
|
|
}
|
|
|
|
/** Returns a reference to the first element of the array. */
|
|
const T &front() const {
|
|
assert(_size > 0);
|
|
return _storage[0];
|
|
}
|
|
|
|
/** Returns a reference to the last element of the array. */
|
|
T &back() {
|
|
assert(_size > 0);
|
|
return _storage[_size-1];
|
|
}
|
|
|
|
/** Returns a reference to the last element of the array. */
|
|
const T &back() const {
|
|
assert(_size > 0);
|
|
return _storage[_size-1];
|
|
}
|
|
|
|
|
|
void insert_at(int idx, const T &element) {
|
|
assert(idx >= 0 && (uint)idx <= _size);
|
|
insert_aux(_storage + idx, &element, &element + 1);
|
|
}
|
|
|
|
T remove_at(int idx) {
|
|
assert(idx >= 0 && (uint)idx < _size);
|
|
T tmp = _storage[idx];
|
|
copy(_storage + idx + 1, _storage + _size, _storage + idx);
|
|
_size--;
|
|
return tmp;
|
|
}
|
|
|
|
// TODO: insert, remove, ...
|
|
|
|
T& operator[](int idx) {
|
|
assert(idx >= 0 && (uint)idx < _size);
|
|
return _storage[idx];
|
|
}
|
|
|
|
const T& operator[](int idx) const {
|
|
assert(idx >= 0 && (uint)idx < _size);
|
|
return _storage[idx];
|
|
}
|
|
|
|
Array<T>& operator=(const Array<T> &array) {
|
|
if (this == &array)
|
|
return *this;
|
|
|
|
delete[] _storage;
|
|
_size = array._size;
|
|
_capacity = _size + 32;
|
|
_storage = new T[_capacity];
|
|
assert(_storage);
|
|
copy(array._storage, array._storage + _size, _storage);
|
|
|
|
return *this;
|
|
}
|
|
|
|
uint size() const {
|
|
return _size;
|
|
}
|
|
|
|
void clear() {
|
|
delete[] _storage;
|
|
_storage = 0;
|
|
_size = 0;
|
|
_capacity = 0;
|
|
}
|
|
|
|
bool empty() const {
|
|
return (_size == 0);
|
|
}
|
|
|
|
|
|
iterator begin() {
|
|
return _storage;
|
|
}
|
|
|
|
iterator end() {
|
|
return _storage + _size;
|
|
}
|
|
|
|
const_iterator begin() const {
|
|
return _storage;
|
|
}
|
|
|
|
const_iterator end() const {
|
|
return _storage + _size;
|
|
}
|
|
|
|
void reserve(uint newCapacity) {
|
|
if (newCapacity <= _capacity)
|
|
return;
|
|
|
|
T *old_storage = _storage;
|
|
_capacity = newCapacity;
|
|
_storage = new T[newCapacity];
|
|
assert(_storage);
|
|
|
|
if (old_storage) {
|
|
// Copy old data
|
|
copy(old_storage, old_storage + _size, _storage);
|
|
delete[] old_storage;
|
|
}
|
|
}
|
|
|
|
void resize(uint newSize) {
|
|
reserve(newSize);
|
|
for (uint i = _size; i < newSize; ++i)
|
|
_storage[i] = T();
|
|
_size = newSize;
|
|
}
|
|
|
|
protected:
|
|
static uint roundUpCapacity(uint capacity) {
|
|
// Round up capacity to the next power of 2;
|
|
// we use a minimal capacity of 8.
|
|
uint capa = 8;
|
|
while (capa < capacity)
|
|
capa <<= 1;
|
|
return capa;
|
|
}
|
|
|
|
/**
|
|
* Insert a range of elements coming from this or another array.
|
|
* Unlike std::vector::insert, this method does not accept
|
|
* arbitrary iterators, mainly because our iterator system is
|
|
* seriously limited and does not distinguish between input iterators,
|
|
* output iterators, forward iterators or random access iterators.
|
|
*
|
|
* So, we simply restrict to Array iterators. Extending this to arbitrary
|
|
* random access iterators would be trivial.
|
|
*
|
|
* Moreover, this method does not handle all cases of inserting a subrange
|
|
* of an array into itself; this is why it is private for now.
|
|
*/
|
|
iterator insert_aux(iterator pos, const_iterator first, const_iterator last) {
|
|
assert(_storage <= pos && pos <= _storage + _size);
|
|
assert(first <= last);
|
|
const uint n = last - first;
|
|
if (n) {
|
|
const uint idx = pos - _storage;
|
|
T *newStorage = _storage;
|
|
if (_size + n > _capacity) {
|
|
// If there is not enough space, allocate more and
|
|
// copy old elements over.
|
|
uint newCapacity = roundUpCapacity(_size + n);
|
|
newStorage = new T[newCapacity];
|
|
assert(newStorage);
|
|
copy(_storage, _storage + idx, newStorage);
|
|
pos = newStorage + idx;
|
|
}
|
|
|
|
// Make room for the new elements by shifting back
|
|
// existing ones.
|
|
copy_backward(_storage + idx, _storage + _size, newStorage + _size + n);
|
|
|
|
// Insert the new elements.
|
|
copy(first, last, pos);
|
|
|
|
// Finally, update the internal state
|
|
if (newStorage != _storage) {
|
|
delete[] _storage;
|
|
_capacity = roundUpCapacity(_size + n);
|
|
_storage = newStorage;
|
|
}
|
|
_size += n;
|
|
}
|
|
return pos;
|
|
}
|
|
|
|
};
|
|
|
|
} // End of namespace Common
|
|
|
|
#endif
|