HamShield/SimpleFIFO.h

90 lines
2.5 KiB
C++

#ifndef SimpleFIFO_h
#define SimpleFIFO_h
/*
||
|| @file SimpleFIFO.h
|| @version 1.2
|| @author Alexander Brevig
|| @contact alexanderbrevig@gmail.com
||
|| @description
|| | A simple FIFO class, mostly for primitive types but can be used with classes if assignment to int is allowed
|| | This FIFO is not dynamic, so be sure to choose an appropriate size for it
|| #
||
|| @license
|| | Copyright (c) 2010 Alexander Brevig
|| | This library is free software; you can redistribute it and/or
|| | modify it under the terms of the GNU Lesser General Public
|| | License as published by the Free Software Foundation; version
|| | 2.1 of the License.
|| |
|| | This library is distributed in the hope that it will be useful,
|| | but WITHOUT ANY WARRANTY; without even the implied warranty of
|| | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|| | Lesser General Public License for more details.
|| |
|| | You should have received a copy of the GNU Lesser General Public
|| | License along with this library; if not, write to the Free Software
|| | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|| #
||
*/
template<typename T, int rawSize>
class SimpleFIFO {
public:
const int size; //speculative feature, in case it's needed
SimpleFIFO();
T dequeue(); //get next element
bool enqueue( T element ); //add an element
T peek() const; //get the next element without releasing it from the FIFO
void flush(); //[1.1] reset to default state
//how many elements are currently in the FIFO?
unsigned char count() { return numberOfElements; }
private:
#ifndef SimpleFIFO_NONVOLATILE
volatile unsigned char numberOfElements;
volatile unsigned char nextIn;
volatile unsigned char nextOut;
volatile T raw[rawSize];
#else
unsigned char numberOfElements;
unsigned char nextIn;
unsigned char nextOut;
T raw[rawSize];
#endif
};
template<typename T, int rawSize>
SimpleFIFO<T,rawSize>::SimpleFIFO() : size(rawSize) {
flush();
}
template<typename T, int rawSize>
bool SimpleFIFO<T,rawSize>::enqueue( T element ) {
if ( count() >= rawSize ) { return false; }
numberOfElements++;
nextIn %= size;
raw[nextIn] = element;
nextIn++; //advance to next index
return true;
}
template<typename T, int rawSize>
T SimpleFIFO<T,rawSize>::dequeue() {
numberOfElements--;
nextOut %= size;
return raw[ nextOut++];
}
template<typename T, int rawSize>
T SimpleFIFO<T,rawSize>::peek() const {
return raw[ nextOut % size];
}
template<typename T, int rawSize>
void SimpleFIFO<T,rawSize>::flush() {
nextIn = nextOut = numberOfElements = 0;
}
#endif