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#include "fifo.h"
void fifo_init(FIFO *fifo, uint8_t *buffer, uint16_t bufferlength)
{
fifo->buffer_ptr = buffer;
fifo->bufferlength = bufferlength;
fifo->read_index = 0;
fifo->write_index = 0;
}
uint16_t fifo_get_buffersize(FIFO *fifo)
{
return fifo->bufferlength;
}
uint16_t fifo_bytes_available(FIFO *fifo)
{
if (fifo->write_index > fifo->read_index){
return (fifo->write_index - fifo->read_index);
}
else if (fifo->write_index < fifo->read_index){
return (fifo_get_buffersize(fifo) - (fifo->read_index - fifo->write_index));
}
else { // read_index == write_index
return 0;
}
}
//uint16_t fifo_lines_available(FIFO *fifo){}
void fifo_move_read_index(FIFO *fifo)
{
fifo->read_index++;
fifo->read_index %= fifo_get_buffersize(fifo);
}
void fifo_move_write_index(FIFO *fifo)
{
fifo->write_index++;
fifo->write_index %= fifo_get_buffersize(fifo);
}
void fifo_get_byte(FIFO *fifo, uint8_t *data_sink)
{
if(fifo_bytes_available(fifo)){
*data_sink = fifo->buffer_ptr[fifo->read_index];
fifo_move_read_index(fifo);
}
}
void fifo_put_byte(FIFO *fifo, uint8_t *data_source)
{
fifo->buffer_ptr[fifo->write_index] = *data_source;
fifo_move_write_index(fifo);
if(fifo->read_index == fifo->write_index){ // buffer overflow case
fifo_move_read_index(fifo);
}
}
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