/**
* Push into fifo
* @param fifo - fifo descriptor
* @param item - pointer to item
* @return 0 - ok, 1 - item pushed and buffer is full
*/
int fifo_push(struct fifo_buffer *fifo, void *item)
{
memcpy(fifo->buf + fifo->write_pointer, item, fifo->item_size);
inc_pointer(&fifo->write_pointer, fifo->item_size, fifo->count);
if(fifo->write_pointer == fifo->read_pointer) { // If fifo is full
inc_pointer(&fifo->read_pointer, fifo->item_size, fifo->count);
return 1;
}
return 0;
}
size_t cbuf_read_char(cbuf_t* cbuf, char* c, bool block) {
DEBUG_ASSERT(cbuf);
DEBUG_ASSERT(c);
retry:
if (block) {
event_wait(&cbuf->event);
}
size_t ret = 0;
{
AutoSpinLock guard(&cbuf->lock);
// see if there's data available
if (cbuf->tail != cbuf->head) {
*c = cbuf->buf[cbuf->tail];
cbuf->tail = inc_pointer(cbuf, cbuf->tail, 1);
if (cbuf->tail == cbuf->head) {
// we've emptied the buffer, unsignal the event
event_unsignal(&cbuf->event);
}
ret = 1;
}
}
if (block && ret == 0) {
goto retry;
}
return ret;
}
/**
* Pop from fifo buffer
* @param fifo - fifo descriptor
* @param item - pointer to poped item
* @return 0 - ok, 1 - buffer is empty
*/
int fifo_pop(struct fifo_buffer *fifo, void *item)
{
if(fifo->read_pointer == fifo->write_pointer)
return 1;
memcpy(item, fifo->buf + fifo->read_pointer, fifo->item_size);
inc_pointer(&fifo->read_pointer, fifo->item_size, fifo->count);
return 0;
}
/**
* Check fifo buffer is full
* @param fifo - fifo descriptor
* @return 1 - buffer is full
*/
int fifo_is_full(struct fifo_buffer *fifo)
{
int p;
p = fifo->write_pointer;
inc_pointer(&p, fifo->item_size, fifo->count);
if(p == fifo->read_pointer)
return 1;
return 0;
}
size_t cbuf_write_char(cbuf_t* cbuf, char c) {
DEBUG_ASSERT(cbuf);
size_t ret = 0;
{
AutoSpinLock guard(&cbuf->lock);
if (cbuf_space_avail(cbuf) > 0) {
cbuf->buf[cbuf->head] = c;
cbuf->head = inc_pointer(cbuf, cbuf->head, 1);
ret = 1;
}
}
if (ret > 0) {
event_signal(&cbuf->event, true);
}
return ret;
}
