1
0
tmk_keyboard/tmk_core/tool/mbed/mbed-sdk/libraries/USBDevice/USBSerial/CircBuffer.h

64 lines
2.0 KiB
C
Raw Normal View 히스토리

/* Copyright (c) 2010-2011 mbed.org, MIT License
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
* and associated documentation files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef CIRCBUFFER_H
#define CIRCBUFFER_H
template <class T, int Size>
class CircBuffer {
public:
CircBuffer():write(0), read(0){}
bool isFull() {
return ((write + 1) % size == read);
};
bool isEmpty() {
return (read == write);
};
void queue(T k) {
if (isFull()) {
read++;
read %= size;
}
buf[write++] = k;
write %= size;
}
uint16_t available() {
return (write >= read) ? write - read : size - read + write;
};
bool dequeue(T * c) {
bool empty = isEmpty();
if (!empty) {
*c = buf[read++];
read %= size;
}
return(!empty);
};
private:
volatile uint16_t write;
volatile uint16_t read;
static const int size = Size+1; //a modern optimizer should be able to remove this so it uses no ram.
T buf[Size];
};
#endif