Mercurial > vba-clojure

     1 /***************************************************************************

     2  *   Copyright (C) 2008 by Sindre Aamås                                    *

     3  *   aamas@stud.ntnu.no                                                    *

     4  *                                                                         *

     5  *   This program is free software; you can redistribute it and/or modify  *

     6  *   it under the terms of the GNU General Public License version 2 as     *

     7  *   published by the Free Software Foundation.                            *

     8  *                                                                         *

     9  *   This program is distributed in the hope that it will be useful,       *

    10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *

    11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *

    12  *   GNU General Public License version 2 for more details.                *

    13  *                                                                         *

    14  *   You should have received a copy of the GNU General Public License     *

    15  *   version 2 along with this program; if not, write to the               *

    16  *   Free Software Foundation, Inc.,                                       *

    17  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *

    18  ***************************************************************************/

    19 #ifndef RINGBUFFER_H

    20 #define RINGBUFFER_H

    21 

    22 #include "Array.h"

    23 #include <cstddef>

    24 #include <algorithm>

    25 #include <cstring>

    26 

    27 template<typename T>

    28 class RingBuffer {

    29 	Array<T> buf;

    30 	std::size_t sz;

    31 	std::size_t rpos;

    32 	std::size_t wpos;

    33 

    34 public:

    35 	RingBuffer(const std::size_t sz_in = 0) : sz(0), rpos(0), wpos(0) { reset(sz_in); }

    36 

    37 	std::size_t avail() const {

    38 		return (wpos < rpos ? 0 : sz) + rpos - wpos - 1;

    39 	}

    40 

    41 	void clear() {

    42 		wpos = rpos = 0;

    43 	}

    44 

    45 	void fill(T value);

    46 

    47 	void read(T *out, std::size_t num);

    48 

    49 	void reset(std::size_t sz_in);

    50 

    51 	std::size_t size() const {

    52 		return sz - 1;

    53 	}

    54 

    55 	std::size_t used() const {

    56 		return (wpos < rpos ? sz : 0) + wpos - rpos;

    57 	}

    58 

    59 	void write(const T *in, std::size_t num);

    60 };

    61 

    62 template<typename T>

    63 void RingBuffer<T>::fill(const T value) {

    64 	std::fill(buf + 0, buf + sz, value);

    65 	rpos = 0;

    66 	wpos = sz - 1;

    67 }

    68 

    69 template<typename T>

    70 void RingBuffer<T>::read(T *out, std::size_t num) {

    71 	if (rpos + num > sz) {

    72 		const std::size_t n = sz - rpos;

    73 

    74 		std::memcpy(out, buf + rpos, n * sizeof(T));

    75 

    76 		rpos = 0;

    77 		num -= n;

    78 		out += n;

    79 	}

    80 

    81 	std::memcpy(out, buf + rpos, num * sizeof(T));

    82 

    83 	if ((rpos += num) == sz)

    84 		rpos = 0;

    85 }

    86 

    87 template<typename T>

    88 void RingBuffer<T>::reset(const std::size_t sz_in) {

    89 	sz = sz_in + 1;

    90 	rpos = wpos = 0;

    91 	buf.reset(sz_in ? sz : 0);

    92 }

    93 

    94 template<typename T>

    95 void RingBuffer<T>::write(const T *in, std::size_t num) {

    96 	if (wpos + num > sz) {

    97 		const std::size_t n = sz - wpos;

    98 

    99 		std::memcpy(buf + wpos, in, n * sizeof(T));

   100 

   101 		wpos = 0;

   102 		num -= n;

   103 		in += n;

   104 	}

   105 

   106 	std::memcpy(buf + wpos, in, num * sizeof(T));

   107 

   108 	if ((wpos += num) == sz)

   109 		wpos = 0;

   110 }

   111 

   112 #endif
author	Robert McIntyre <rlm@mit.edu>
date	Tue, 20 Mar 2012 18:07:42 -0500
parents	f9f4f1b99eed
children