/*
 * ringbuffer.c
 *
 *  Created on: Jul 24, 2012
 *      Author: tkl
 */
#include "irq.h"
#include "ringbuffer.h"

//-----------------------------------------------------------------------------
int ringbuffer_read(struct ringbuffer *this, char *buffer, int size) {
	int i;
	unsigned int irq;
	for(i = 0; i < size; i++) {
		if(this->used > 0) {
			irq = disable_irq();
			buffer[i] = *this->read;
			this->read++;
			this->used--;
			if(this->read >= (this->buffer + this->size)) {
				this->read = this->buffer;
			}
			restore_irq(irq);
		}
		else {
			return i;
		}
	}
	return 0;
}

//-----------------------------------------------------------------------------
int ringbuffer_write(struct ringbuffer *this, const char *buffer,
		int size)
{
	int i = 0;
	unsigned int irq;
	for(i = 0; i < size; i++) {
		if(this->used < this->size) {
			irq = disable_irq();
			*this->write = buffer[i];
			this->write++;
			this->used++;
			if(this->write >= (this->buffer + this->size)) {
				this->write = this->buffer;
			}
			restore_irq(irq);
		}
		else {
			return i;
		}
	}
	return i;
}

//-----------------------------------------------------------------------------
int ringbuffer_is_full(const struct ringbuffer *this) {
	return (this->used == this->size) ? 1 : 0;
}

//-----------------------------------------------------------------------------
int ringbuffer_is_empty(const struct ringbuffer *this) {
	return (this->used == 0) ? 1 : 0;
}