rlm@1: /***************************************************************************
rlm@1:  *   Copyright (C) 2008 by Sindre Aamås                                    *
rlm@1:  *   aamas@stud.ntnu.no                                                    *
rlm@1:  *                                                                         *
rlm@1:  *   This program is free software; you can redistribute it and/or modify  *
rlm@1:  *   it under the terms of the GNU General Public License version 2 as     *
rlm@1:  *   published by the Free Software Foundation.                            *
rlm@1:  *                                                                         *
rlm@1:  *   This program is distributed in the hope that it will be useful,       *
rlm@1:  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
rlm@1:  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
rlm@1:  *   GNU General Public License version 2 for more details.                *
rlm@1:  *                                                                         *
rlm@1:  *   You should have received a copy of the GNU General Public License     *
rlm@1:  *   version 2 along with this program; if not, write to the               *
rlm@1:  *   Free Software Foundation, Inc.,                                       *
rlm@1:  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
rlm@1:  ***************************************************************************/
rlm@1: #ifndef RINGBUFFER_H
rlm@1: #define RINGBUFFER_H
rlm@1: 
rlm@1: #include "Array.h"
rlm@1: #include <cstddef>
rlm@1: #include <algorithm>
rlm@1: #include <cstring>
rlm@1: 
rlm@1: template<typename T>
rlm@1: class RingBuffer {
rlm@1: 	Array<T> buf;
rlm@1: 	std::size_t sz;
rlm@1: 	std::size_t rpos;
rlm@1: 	std::size_t wpos;
rlm@1: 
rlm@1: public:
rlm@1: 	RingBuffer(const std::size_t sz_in = 0) : sz(0), rpos(0), wpos(0) { reset(sz_in); }
rlm@1: 
rlm@1: 	std::size_t avail() const {
rlm@1: 		return (wpos < rpos ? 0 : sz) + rpos - wpos - 1;
rlm@1: 	}
rlm@1: 
rlm@1: 	void clear() {
rlm@1: 		wpos = rpos = 0;
rlm@1: 	}
rlm@1: 
rlm@1: 	void fill(T value);
rlm@1: 
rlm@1: 	void read(T *out, std::size_t num);
rlm@1: 
rlm@1: 	void reset(std::size_t sz_in);
rlm@1: 
rlm@1: 	std::size_t size() const {
rlm@1: 		return sz - 1;
rlm@1: 	}
rlm@1: 
rlm@1: 	std::size_t used() const {
rlm@1: 		return (wpos < rpos ? sz : 0) + wpos - rpos;
rlm@1: 	}
rlm@1: 
rlm@1: 	void write(const T *in, std::size_t num);
rlm@1: };
rlm@1: 
rlm@1: template<typename T>
rlm@1: void RingBuffer<T>::fill(const T value) {
rlm@1: 	std::fill(buf + 0, buf + sz, value);
rlm@1: 	rpos = 0;
rlm@1: 	wpos = sz - 1;
rlm@1: }
rlm@1: 
rlm@1: template<typename T>
rlm@1: void RingBuffer<T>::read(T *out, std::size_t num) {
rlm@1: 	if (rpos + num > sz) {
rlm@1: 		const std::size_t n = sz - rpos;
rlm@1: 
rlm@1: 		std::memcpy(out, buf + rpos, n * sizeof(T));
rlm@1: 
rlm@1: 		rpos = 0;
rlm@1: 		num -= n;
rlm@1: 		out += n;
rlm@1: 	}
rlm@1: 
rlm@1: 	std::memcpy(out, buf + rpos, num * sizeof(T));
rlm@1: 
rlm@1: 	if ((rpos += num) == sz)
rlm@1: 		rpos = 0;
rlm@1: }
rlm@1: 
rlm@1: template<typename T>
rlm@1: void RingBuffer<T>::reset(const std::size_t sz_in) {
rlm@1: 	sz = sz_in + 1;
rlm@1: 	rpos = wpos = 0;
rlm@1: 	buf.reset(sz_in ? sz : 0);
rlm@1: }
rlm@1: 
rlm@1: template<typename T>
rlm@1: void RingBuffer<T>::write(const T *in, std::size_t num) {
rlm@1: 	if (wpos + num > sz) {
rlm@1: 		const std::size_t n = sz - wpos;
rlm@1: 
rlm@1: 		std::memcpy(buf + wpos, in, n * sizeof(T));
rlm@1: 
rlm@1: 		wpos = 0;
rlm@1: 		num -= n;
rlm@1: 		in += n;
rlm@1: 	}
rlm@1: 
rlm@1: 	std::memcpy(buf + wpos, in, num * sizeof(T));
rlm@1: 
rlm@1: 	if ((wpos += num) == sz)
rlm@1: 		wpos = 0;
rlm@1: }
rlm@1: 
rlm@1: #endif