qmk_firmware/tmk_core/protocol/midi/bytequeue/bytequeue.h

//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/>.

#ifndef BYTEQUEUE_H
#define BYTEQUEUE_H

#ifdef __cplusplus
extern "C" {
#endif 

#include <inttypes.h>
#include <stdbool.h>

typedef uint8_t byteQueueIndex_t;

typedef struct {
	byteQueueIndex_t start;
	byteQueueIndex_t end;
	byteQueueIndex_t length;
	uint8_t * data;
} byteQueue_t;

//you must have a queue, an array of data which the queue will use, and the length of that array
void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen);

//add an item to the queue, returns false if the queue is full
bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item);

//get the length of the queue
byteQueueIndex_t bytequeue_length(byteQueue_t * queue);

//this grabs data at the index given [starting at queue->start]
uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index);

//update the index in the queue to reflect data that has been dealt with 
void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove);

#ifdef __cplusplus
}
#endif 

#endif