flow_meter/src/fifo.c

51 lines
1.5 KiB
C

/* Copyright (c) 2016, Jan Wiśniewski <vuko@hackerspace.pl>
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*/
#include"fifo.h"
void fifoInit(fifo *f, uint8_t *addr, uint16_t size){
f->first = 0;
f->last = 0;
f->size = size;
f->data = addr;
};
inline uint8_t fifoEmpty(fifo *f){
return f->first == f->last;
}
inline uint8_t fifoFull(fifo *f){
return f->first == (f->last+1)%f->size;
}
void fifoPush(fifo *f, uint8_t d){
if(!fifoFull(f)){
f->data[f->last] = d;
f->last = (f->last + 1)%f->size;
}
}
uint8_t fifoPop(fifo *f){
uint16_t first = f->first;
if(!fifoEmpty(f)){
f->first = (f->first + 1)%f->size;
return f->data[first];
} else {
return 0x00;
}
}