CircBuffer.h

00001 /* Copyright (c) 2010-2011 mbed.org, MIT License
00002 *
00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004 * and associated documentation files (the "Software"), to deal in the Software without
00005 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00006 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00007 * Software is furnished to do so, subject to the following conditions:
00008 *
00009 * The above copyright notice and this permission notice shall be included in all copies or
00010 * substantial portions of the Software.
00011 *
00012 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 */
00018 
00019 #ifndef CIRCBUFFER_H
00020 #define CIRCBUFFER_H
00021 
00022 template <class T>
00023 class CircBuffer {
00024 public:
00025     CircBuffer(int length) {
00026         write = 0;
00027         read = 0;
00028         size = length + 1;
00029         buf = (T *)malloc(size * sizeof(T));
00030     };
00031 
00032     bool isFull() {
00033         return ((write + 1) % size == read);
00034     };
00035 
00036     bool isEmpty() {
00037         return (read == write);
00038     };
00039 
00040     void queue(T k) {
00041         if (isFull()) {
00042             read++;
00043             read %= size;
00044         }
00045         buf[write++] = k;
00046         write %= size;
00047     }
00048 
00049     uint16_t available() {
00050         return (write >= read) ? write - read : size - read + write;
00051     };
00052 
00053     bool dequeue(T * c) {
00054         bool empty = isEmpty();
00055         if (!empty) {
00056             *c = buf[read++];
00057             read %= size;
00058         }
00059         return(!empty);
00060     };
00061 
00062 private:
00063     volatile uint16_t write;
00064     volatile uint16_t read;
00065     uint16_t size;
00066     T * buf;
00067 };
00068 
00069 #endif