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Diffstat (limited to 'engines/titanic/support/fixed_queue.h')
-rw-r--r-- | engines/titanic/support/fixed_queue.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/engines/titanic/support/fixed_queue.h b/engines/titanic/support/fixed_queue.h new file mode 100644 index 0000000000..a7ba6eac2c --- /dev/null +++ b/engines/titanic/support/fixed_queue.h @@ -0,0 +1,142 @@ +/* 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. + * + */ + +#ifndef TITANIC_FIXED_QUEUE_H +#define TITANIC_FIXED_QUEUE_H + +#include "common/scummsys.h" +#include "common/array.h" + +namespace Titanic { + +/** + * Extremly simple fixed size queue class. + */ +template<class T, uint MAX_SIZE = 10> +class FixedQueue { + typedef uint size_type; +protected: + Common::Array<T> _data; + size_type _topIndex; +public: + FixedQueue<T, MAX_SIZE>() : _topIndex(0) { + _data.reserve(MAX_SIZE); + } + + /** + * Returns the size of the queue in use + */ + size_type size() const { return _data.size() - _topIndex; } + + /** + * Returns the amount of free remaining space in the queue + */ + size_type freeSize() const { return MAX_SIZE - size(); } + + /** + * Returns true if the queue is empty + */ + bool empty() const { + return size() == 0; + } + + /** + * Returns true if the queue is full + */ + bool full() const { + return freeSize() == 0; + } + + /** + * Clears the queue + */ + void clear() { + _data.clear(); + _topIndex = 0; + } + + /** + * If the tail of the queue in use has reached the end of the internal + * array, pushes all pending data back to the start of the array + */ + void compact() { + if (_data.size() == MAX_SIZE && _topIndex > 0) { + Common::copy(&_data[_topIndex], &_data[0] + MAX_SIZE, &_data[0]); + _data.resize(size()); + _topIndex = 0; + } + } + + /** + * Adds a value to the end of the queue + */ + void push(const T &v) { + assert(size() < MAX_SIZE); + compact(); + _data.push_back(v); + } + + /** + * Returns the top value on the queue + */ + const T &top() const { + assert(size() > 0); + return _data[_topIndex]; + } + + /** + * Returns the top value on the queue + */ + T &top() { + assert(size() > 0); + return _data[_topIndex]; + } + + /** + * Pops the top value off the queue + */ + T pop() { + T tmp = top(); + ++_topIndex; + return tmp; + } + + /** + * Returns values from within the queue without popping them + */ + T &operator[](size_type i) { + assert(i < size()); + return _data[_topIndex + i]; + } + + /** + * Returns values from within the queue without popping them + */ + const T &operator[](size_type i) const { + assert(i < size()); + return _data[_topIndex + i]; + } +}; + +} // End of namespace Titanic + +#endif |