src/libs/USBDevice/USBSerial/CircBuffer.h

   1 /* Copyright (c) 2010-2011 mbed.org, MIT License
   2 *
   3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
   4 * and associated documentation files (the "Software"), to deal in the Software without
   5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
   6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
   7 * Software is furnished to do so, subject to the following conditions:
   8 *
   9 * The above copyright notice and this permission notice shall be included in all copies or
  10 * substantial portions of the Software.
  11 *
  12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
  13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  17 */
  18
  19 #ifndef CIRCBUFFER_H
  20 #define CIRCBUFFER_H
  21
  22 #include <stdlib.h>
  23 #include "sLPC17xx.h"
  24 #include <ahbmalloc.h>
  25
  26 template <class T>
  27 class CircBuffer {
  28 public:
  29     CircBuffer(int length) {
  30         write = 0;
  31         read = 0;
  32         size = length;
  33         buf = (T *)ahbmalloc(size * sizeof(T), AHB_BANK_0);
  34     };
  35
  36         bool isFull() {
  37                 __disable_irq();
  38                 bool b= ((write + 1) % size == read);
  39                 __enable_irq();
  40                 return b;
  41     };
  42
  43     bool isEmpty() {
  44         return (read == write);
  45     };
  46
  47     void queue(T k) {
  48                 __disable_irq();
  49         if (isFull()) {
  50             read++;
  51             read %= size;
  52         }
  53         buf[write++] = k;
  54         write %= size;
  55                 __enable_irq();
  56     }
  57
  58     uint16_t available() {
  59                 __disable_irq();
  60                 uint16_t i= (write >= read) ? write - read : (size - read) + write;
  61                 __enable_irq();
  62                 return i;
  63     };
  64     uint16_t free() {
  65         return size - available() - 1;
  66     };
  67
  68     void dump() {
  69         iprintf("[RingBuffer Sz:%2d Rd:%2d Wr:%2d Av:%2d Fr:%2d]\n", size, read, write, available(), free());
  70     }
  71
  72     bool dequeue(T * c) {
  73         bool empty = isEmpty();
  74         if (!empty) {
  75             *c = buf[read++];
  76             read %= size;
  77         }
  78         return(!empty);
  79     };
  80
  81     void peek(T * c, int offset) {
  82         int h = (read + offset) % size;
  83         *c = buf[h];
  84     };
  85
  86     void flush() {
  87         read = write;
  88     }
  89
  90 private:
  91     volatile uint16_t write;
  92     volatile uint16_t read;
  93     uint16_t size;
  94     T * buf;
  95 };
  96
  97 #endif