1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/sdl/RingBuffer.h	Sun Mar 04 21:06:50 2012 -0600
     1.3 @@ -0,0 +1,112 @@
     1.4 +/***************************************************************************
     1.5 + *   Copyright (C) 2008 by Sindre Aamås                                    *
     1.6 + *   aamas@stud.ntnu.no                                                    *
     1.7 + *                                                                         *
     1.8 + *   This program is free software; you can redistribute it and/or modify  *
     1.9 + *   it under the terms of the GNU General Public License version 2 as     *
    1.10 + *   published by the Free Software Foundation.                            *
    1.11 + *                                                                         *
    1.12 + *   This program is distributed in the hope that it will be useful,       *
    1.13 + *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
    1.14 + *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
    1.15 + *   GNU General Public License version 2 for more details.                *
    1.16 + *                                                                         *
    1.17 + *   You should have received a copy of the GNU General Public License     *
    1.18 + *   version 2 along with this program; if not, write to the               *
    1.19 + *   Free Software Foundation, Inc.,                                       *
    1.20 + *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
    1.21 + ***************************************************************************/
    1.22 +#ifndef RINGBUFFER_H
    1.23 +#define RINGBUFFER_H
    1.24 +
    1.25 +#include "Array.h"
    1.26 +#include <cstddef>
    1.27 +#include <algorithm>
    1.28 +#include <cstring>
    1.29 +
    1.30 +template<typename T>
    1.31 +class RingBuffer {
    1.32 +	Array<T> buf;
    1.33 +	std::size_t sz;
    1.34 +	std::size_t rpos;
    1.35 +	std::size_t wpos;
    1.36 +
    1.37 +public:
    1.38 +	RingBuffer(const std::size_t sz_in = 0) : sz(0), rpos(0), wpos(0) { reset(sz_in); }
    1.39 +
    1.40 +	std::size_t avail() const {
    1.41 +		return (wpos < rpos ? 0 : sz) + rpos - wpos - 1;
    1.42 +	}
    1.43 +
    1.44 +	void clear() {
    1.45 +		wpos = rpos = 0;
    1.46 +	}
    1.47 +
    1.48 +	void fill(T value);
    1.49 +
    1.50 +	void read(T *out, std::size_t num);
    1.51 +
    1.52 +	void reset(std::size_t sz_in);
    1.53 +
    1.54 +	std::size_t size() const {
    1.55 +		return sz - 1;
    1.56 +	}
    1.57 +
    1.58 +	std::size_t used() const {
    1.59 +		return (wpos < rpos ? sz : 0) + wpos - rpos;
    1.60 +	}
    1.61 +
    1.62 +	void write(const T *in, std::size_t num);
    1.63 +};
    1.64 +
    1.65 +template<typename T>
    1.66 +void RingBuffer<T>::fill(const T value) {
    1.67 +	std::fill(buf + 0, buf + sz, value);
    1.68 +	rpos = 0;
    1.69 +	wpos = sz - 1;
    1.70 +}
    1.71 +
    1.72 +template<typename T>
    1.73 +void RingBuffer<T>::read(T *out, std::size_t num) {
    1.74 +	if (rpos + num > sz) {
    1.75 +		const std::size_t n = sz - rpos;
    1.76 +
    1.77 +		std::memcpy(out, buf + rpos, n * sizeof(T));
    1.78 +
    1.79 +		rpos = 0;
    1.80 +		num -= n;
    1.81 +		out += n;
    1.82 +	}
    1.83 +
    1.84 +	std::memcpy(out, buf + rpos, num * sizeof(T));
    1.85 +
    1.86 +	if ((rpos += num) == sz)
    1.87 +		rpos = 0;
    1.88 +}
    1.89 +
    1.90 +template<typename T>
    1.91 +void RingBuffer<T>::reset(const std::size_t sz_in) {
    1.92 +	sz = sz_in + 1;
    1.93 +	rpos = wpos = 0;
    1.94 +	buf.reset(sz_in ? sz : 0);
    1.95 +}
    1.96 +
    1.97 +template<typename T>
    1.98 +void RingBuffer<T>::write(const T *in, std::size_t num) {
    1.99 +	if (wpos + num > sz) {
   1.100 +		const std::size_t n = sz - wpos;
   1.101 +
   1.102 +		std::memcpy(buf + wpos, in, n * sizeof(T));
   1.103 +
   1.104 +		wpos = 0;
   1.105 +		num -= n;
   1.106 +		in += n;
   1.107 +	}
   1.108 +
   1.109 +	std::memcpy(buf + wpos, in, num * sizeof(T));
   1.110 +
   1.111 +	if ((wpos += num) == sz)
   1.112 +		wpos = 0;
   1.113 +}
   1.114 +
   1.115 +#endif