linfifo.c

#include "linfifo/linfifo.h"
#include "linfifo_os.h"

size_t linfifo_mem_page_size(void) { return linfifo_os_mem_page_size(); }

linfifo_retval_t linfifo_create(size_t len, linfifo_t *out_lf) {
  size_t const ps = linfifo_mem_page_size();
  if (LINFIFO_UNLIKELY(!out_lf || !len)) { return LINFIFO_RETVAL_ERR_ARG; }
  if (LINFIFO_UNLIKELY(((len / ps) * ps) != len)) { return LINFIFO_RETVAL_ERR_ARG; }
  if (LINFIFO_UNLIKELY((len & (len - 1)) != 0)) { return LINFIFO_RETVAL_ERR_ARG; }
  out_lf->head = out_lf->tail = 0;
  out_lf->capacity = len;
  out_lf->seat = NULL;
  return linfifo_os_mbuf_create(out_lf);
}

linfifo_retval_t linfifo_destroy(linfifo_t *lf) {
  if (LINFIFO_UNLIKELY(!lf)) { return LINFIFO_RETVAL_ERR_ARG; }
  linfifo_retval_t const rv = linfifo_os_mbuf_free(lf);
  lf->head = lf->tail = lf->capacity = 0;
  lf->seat = NULL;
  return rv;
}

linfifo_retval_t linfifo_put_acquire(linfifo_t *lf, void **out_buf, size_t *out_avail) {
  if (LINFIFO_UNLIKELY(!lf || !out_buf || !out_avail)) { return LINFIFO_RETVAL_ERR_ARG; }
  *out_buf = &((char *)lf->seat)[lf->head & (lf->capacity - 1)];
  *out_avail = lf->capacity - (lf->head - lf->tail);
  return *out_avail ? LINFIFO_RETVAL_SUCCESS : LINFIFO_RETVAL_ERR_NO_MEM;
}

linfifo_retval_t linfifo_put_commit(linfifo_t *lf, size_t len) {
  if (LINFIFO_UNLIKELY(!lf)) { return LINFIFO_RETVAL_ERR_ARG; }
  if (LINFIFO_UNLIKELY(len > (lf->capacity - (lf->head - lf->tail)))) {
    return LINFIFO_RETVAL_ERR_NO_MEM;
  }
  lf->head += len;
  return LINFIFO_RETVAL_SUCCESS;
}

linfifo_retval_t linfifo_get_acquire(linfifo_t *lf, void **out_buf, size_t *out_avail) {
  if (LINFIFO_UNLIKELY(!lf || !out_buf || !out_avail)) { return LINFIFO_RETVAL_ERR_ARG; }
  *out_buf = &((char *)lf->seat)[lf->tail & (lf->capacity - 1)];
  *out_avail = lf->head - lf->tail;
  return *out_avail ? LINFIFO_RETVAL_SUCCESS : LINFIFO_RETVAL_ERR_NO_MEM;
}

linfifo_retval_t linfifo_get_commit(linfifo_t *lf, size_t len) {
  if (LINFIFO_UNLIKELY(!lf)) { return LINFIFO_RETVAL_ERR_ARG; }
  if (LINFIFO_UNLIKELY(len > (lf->head - lf->tail))) { return LINFIFO_RETVAL_ERR_NO_MEM; }
  lf->tail += len;
  return LINFIFO_RETVAL_SUCCESS;
}