Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

features/unsupported/USBDevice/USBSerial/CircBuffer.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
elessair 0:f269e3021894 2 *
elessair 0:f269e3021894 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
elessair 0:f269e3021894 4 * and associated documentation files (the "Software"), to deal in the Software without
elessair 0:f269e3021894 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
elessair 0:f269e3021894 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
elessair 0:f269e3021894 7 * Software is furnished to do so, subject to the following conditions:
elessair 0:f269e3021894 8 *
elessair 0:f269e3021894 9 * The above copyright notice and this permission notice shall be included in all copies or
elessair 0:f269e3021894 10 * substantial portions of the Software.
elessair 0:f269e3021894 11 *
elessair 0:f269e3021894 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
elessair 0:f269e3021894 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
elessair 0:f269e3021894 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
elessair 0:f269e3021894 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
elessair 0:f269e3021894 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
elessair 0:f269e3021894 17 */
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #ifndef CIRCBUFFER_H
elessair 0:f269e3021894 20 #define CIRCBUFFER_H
elessair 0:f269e3021894 21
elessair 0:f269e3021894 22 template <class T, int Size>
elessair 0:f269e3021894 23 class CircBuffer {
elessair 0:f269e3021894 24 public:
elessair 0:f269e3021894 25 CircBuffer():write(0), read(0){}
elessair 0:f269e3021894 26 bool isFull() {
elessair 0:f269e3021894 27 return ((write + 1) % size == read);
elessair 0:f269e3021894 28 };
elessair 0:f269e3021894 29
elessair 0:f269e3021894 30 bool isEmpty() {
elessair 0:f269e3021894 31 return (read == write);
elessair 0:f269e3021894 32 };
elessair 0:f269e3021894 33
elessair 0:f269e3021894 34 void queue(T k) {
elessair 0:f269e3021894 35 if (isFull()) {
elessair 0:f269e3021894 36 read++;
elessair 0:f269e3021894 37 read %= size;
elessair 0:f269e3021894 38 }
elessair 0:f269e3021894 39 buf[write++] = k;
elessair 0:f269e3021894 40 write %= size;
elessair 0:f269e3021894 41 }
elessair 0:f269e3021894 42
elessair 0:f269e3021894 43 uint16_t available() {
elessair 0:f269e3021894 44 return (write >= read) ? write - read : size - read + write;
elessair 0:f269e3021894 45 };
elessair 0:f269e3021894 46
elessair 0:f269e3021894 47 bool dequeue(T * c) {
elessair 0:f269e3021894 48 bool empty = isEmpty();
elessair 0:f269e3021894 49 if (!empty) {
elessair 0:f269e3021894 50 *c = buf[read++];
elessair 0:f269e3021894 51 read %= size;
elessair 0:f269e3021894 52 }
elessair 0:f269e3021894 53 return(!empty);
elessair 0:f269e3021894 54 };
elessair 0:f269e3021894 55
elessair 0:f269e3021894 56 private:
elessair 0:f269e3021894 57 volatile uint16_t write;
elessair 0:f269e3021894 58 volatile uint16_t read;
elessair 0:f269e3021894 59 static const int size = Size+1; //a modern optimizer should be able to remove this so it uses no ram.
elessair 0:f269e3021894 60 T buf[Size+1];
elessair 0:f269e3021894 61 };
elessair 0:f269e3021894 62
elessair 0:f269e3021894 63 #endif