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 #include <stdlib.h>
00023 #include "sLPC17xx.h"
00024 #include "platform_memory.h"
00025 
00026 template <class T>
00027 class CircBuffer {
00028 public:
00029     CircBuffer(int length) {
00030         write = 0;
00031         read = 0;
00032         size = length;
00033         buf = (uint8_t*) AHB0.alloc(size * sizeof(T));
00034     };
00035 
00036     bool isFull() {
00037         __disable_irq();
00038         bool b= ((write + 1) % size == read);
00039         __enable_irq();
00040         return b;
00041     };
00042 
00043     bool isEmpty() {
00044         return (read == write);
00045     };
00046 
00047     void queue(T k) {
00048         __disable_irq();
00049         if (isFull()) {
00050             read++;
00051             read %= size;
00052         }
00053         buf[write++] = k;
00054         write %= size;
00055         __enable_irq();
00056     }
00057 
00058     uint16_t available() {
00059         __disable_irq();
00060         uint16_t i= (write >= read) ? write - read : (size - read) + write;
00061         __enable_irq();
00062         return i;
00063     };
00064     uint16_t free() {
00065         return size - available() - 1;
00066     };
00067 
00068     void dump() {
00069         iprintf("[RingBuffer Sz:%2d Rd:%2d Wr:%2d Av:%2d Fr:%2d]\n", size, read, write, available(), free());
00070     }
00071 
00072     bool dequeue(T * c) {
00073         bool empty = isEmpty();
00074         if (!empty) {
00075             *c = buf[read++];
00076             read %= size;
00077         }
00078         return(!empty);
00079     };
00080 
00081     void peek(T * c, int offset) {
00082         int h = (read + offset) % size;
00083         *c = buf[h];
00084     };
00085 
00086     void flush() {
00087         read = write;
00088     }
00089 
00090 private:
00091     volatile uint16_t write;
00092     volatile uint16_t read;
00093     uint16_t size;
00094     T * buf;
00095 };
00096 
00097 #endif