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RIOT/sys/tsrb/tsrb.c 1.21 KB
a752c7ab   elopes   add first test an...
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  /*
   * Copyright (C) 2015 Kaspar Schleiser <kaspar@schleiser.de>
   *
   * This file is subject to the terms and conditions of the GNU Lesser
   * General Public License v2.1. See the file LICENSE in the top level
   * directory for more details.
   */
  
  /**
   * @ingroup sys
   * @{
   * @file
   * @brief       thread-safe ringbuffer implementation
   *
   * @author      Kaspar Schleiser <kaspar@schleiser.de>
   *
   * @}
   */
  
  #include "tsrb.h"
  
  static void _push(tsrb_t *rb, char c)
  {
      rb->buf[rb->writes++ & (rb->size - 1)] = c;
  }
  
  static char _pop(tsrb_t *rb)
  {
      return rb->buf[rb->reads++ & (rb->size - 1)];
  }
  
  int tsrb_get_one(tsrb_t *rb)
  {
      if (!tsrb_empty(rb)) {
          return _pop(rb);
      }
      else {
          return -1;
      }
  }
  
  int tsrb_get(tsrb_t *rb, char *dst, size_t n)
  {
      size_t tmp = n;
      while (tmp && !tsrb_empty(rb)) {
          *dst++ = _pop(rb);
          tmp--;
      }
      return (n - tmp);
  }
  
  int tsrb_add_one(tsrb_t *rb, char c)
  {
      if (!tsrb_full(rb)) {
          _push(rb, c);
          return 0;
      }
      else {
          return -1;
      }
  }
  
  int tsrb_add(tsrb_t *rb, const char *src, size_t n)
  {
      size_t tmp = n;
      while (tmp && !tsrb_full(rb)) {
          _push(rb, *src++);
          tmp--;
      }
      return (n - tmp);
  }