66 lines
2.2 KiB
C
66 lines
2.2 KiB
C
|
//this is a single reader [maybe multiple writer?] byte queue
|
||
|
|
//Copyright 2008 Alex Norman
|
||
|
|
//writen by Alex Norman
|
||
|
|
//
|
||
|
|
//This file is part of avr-bytequeue.
|
||
|
|
//
|
||
|
|
//avr-bytequeue is free software: you can redistribute it and/or modify
|
||
|
|
//it under the terms of the GNU General Public License as published by
|
||
|
|
//the Free Software Foundation, either version 3 of the License, or
|
||
|
|
//(at your option) any later version.
|
||
|
|
//
|
||
|
|
//avr-bytequeue 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 General Public License for more details.
|
||
|
|
//
|
||
|
|
//You should have received a copy of the GNU General Public License
|
||
|
|
//along with avr-bytequeue. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
#include "bytequeue.h"
|
||
|
|
#include "interrupt_setting.h"
|
||
|
|
|
||
|
|
void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen){
|
||
|
|
queue->length = arrayLen;
|
||
|
|
queue->data = dataArray;
|
||
|
|
queue->start = queue->end = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item){
|
||
|
|
interrupt_setting_t setting = store_and_clear_interrupt();
|
||
|
|
//full
|
||
|
|
if(((queue->end + 1) % queue->length) == queue->start){
|
||
|
|
restore_interrupt_setting(setting);
|
||
|
|
return false;
|
||
|
|
} else {
|
||
|
|
queue->data[queue->end] = item;
|
||
|
|
queue->end = (queue->end + 1) % queue->length;
|
||
|
|
restore_interrupt_setting(setting);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
byteQueueIndex_t bytequeue_length(byteQueue_t * queue){
|
||
|
|
byteQueueIndex_t len;
|
||
|
|
interrupt_setting_t setting = store_and_clear_interrupt();
|
||
|
|
if(queue->end >= queue->start)
|
||
|
|
len = queue->end - queue->start;
|
||
|
|
else
|
||
|
|
len = (queue->length - queue->start) + queue->end;
|
||
|
|
restore_interrupt_setting(setting);
|
||
|
|
return len;
|
||
|
|
}
|
||
|
|
|
||
|
|
//we don't need to avoid interrupts if there is only one reader
|
||
|
|
uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index){
|
||
|
|
return queue->data[(queue->start + index) % queue->length];
|
||
|
|
}
|
||
|
|
|
||
|
|
//we just update the start index to remove elements
|
||
|
|
void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove){
|
||
|
|
interrupt_setting_t setting = store_and_clear_interrupt();
|
||
|
|
queue->start = (queue->start + numToRemove) % queue->length;
|
||
|
|
restore_interrupt_setting(setting);
|
||
|
|
}
|
||
|
|
|