text: /*
   * @brief Common ring buffer support functions
   *
   * @note
   * Copyright(C) NXP Semiconductors, 2012
   * All rights reserved.
   *
   * @par
   * Software that is described herein is for illustrative purposes only
   * which provides customers with programming information regarding the
   * LPC products.  This software is supplied "AS IS" without any warranties of
   * any kind, and NXP Semiconductors and its licensor disclaim any and
   * all warranties, express or implied, including all implied warranties of
   * merchantability, fitness for a particular purpose and non-infringement of
   * intellectual property rights.  NXP Semiconductors assumes no responsibility
   * or liability for the use of the software, conveys no license or rights under any
   * patent, copyright, mask work right, or any other intellectual property rights in
   * or to any products. NXP Semiconductors reserves the right to make changes
   * in the software without notification. NXP Semiconductors also makes no
   * representation or warranty that such application will be suitable for the
   * specified use without further testing or modification.
   *
   * @par
   * Permission to use, copy, modify, and distribute this software and its
   * documentation is hereby granted, under NXP Semiconductors' and its
   * licensor's relevant copyrights in the software, without fee, provided that it
   * is used in conjunction with NXP Semiconductors microcontrollers.  This
   * copyright, permission, and disclaimer notice must appear in all copies of
   * this code.
   */
  
  #include <string.h>
  #include "ring_buffer.h"
  
  /*****************************************************************************
   * Private types/enumerations/variables
   ****************************************************************************/
  
  #define RB_INDH(rb)                ((rb)->head & ((rb)->count - 1))
  #define RB_INDT(rb)                ((rb)->tail & ((rb)->count - 1))
  
  /*****************************************************************************
   * Public types/enumerations/variables
   ****************************************************************************/
  
  /*****************************************************************************
   * Private functions
   ****************************************************************************/
  
  /*****************************************************************************
   * Public functions
   ****************************************************************************/
  
  /* Initialize ring buffer */
  int RingBuffer_Init(RINGBUFF_T *RingBuff, void *buffer, int itemSize, int count)
  {
  	RingBuff->data = buffer;
  	RingBuff->count = count;
  	RingBuff->itemSz = itemSize;
  	RingBuff->head = RingBuff->tail = 0;
  
  	return 1;
  }
  
  /* Insert a single item into Ring Buffer */
  int RingBuffer_Insert(RINGBUFF_T *RingBuff, const void *data)
  {
  	uint8_t *ptr = RingBuff->data;
  
  	/* We cannot insert when queue is full */
  	if (RingBuffer_IsFull(RingBuff))
  		return 0;
  
  	ptr += RB_INDH(RingBuff) * RingBuff->itemSz;
  	memcpy(ptr, data, RingBuff->itemSz);
  	RingBuff->head++;
  
  	return 1;
  }
  
  /* Insert multiple items into Ring Buffer */
  int RingBuffer_InsertMult(RINGBUFF_T *RingBuff, const void *data, int num)
  {
  	uint8_t *ptr = RingBuff->data;
  	int cnt1, cnt2;
  
  	/* We cannot insert when queue is full */
  	if (RingBuffer_IsFull(RingBuff))
  		return 0;
  
  	/* Calculate the segment lengths */
  	cnt1 = cnt2 = RingBuffer_GetFree(RingBuff);
  	if (RB_INDH(RingBuff) + cnt1 >= RingBuff->count)
  		cnt1 = RingBuff->count - RB_INDH(RingBuff);
  	cnt2 -= cnt1;
  
  	cnt1 = MIN(cnt1, num);
  	num -= cnt1;
  
  	cnt2 = MIN(cnt2, num);
  	num -= cnt2;
  
  	/* Write segment 1 */
  	ptr += RB_INDH(RingBuff) * RingBuff->itemSz;
  	memcpy(ptr, data, cnt1 * RingBuff->itemSz);
  	RingBuff->head += cnt1;
  
  	/* Write segment 2 */
  	ptr = (uint8_t *) RingBuff->data + RB_INDH(RingBuff) * RingBuff->itemSz;
  	data = (const uint8_t *) data + cnt1 * RingBuff->itemSz;
  	memcpy(ptr, data, cnt2 * RingBuff->itemSz);
  	RingBuff->head += cnt2;
  
  	return cnt1 + cnt2;
  }
  
  /* Pop single item from Ring Buffer */
  int RingBuffer_Pop(RINGBUFF_T *RingBuff, void *data)
  {
  	uint8_t *ptr = RingBuff->data;
  
  	/* We cannot pop when queue is empty */
  	if (RingBuffer_IsEmpty(RingBuff))
  		return 0;
  
  	ptr += RB_INDT(RingBuff) * RingBuff->itemSz;
  	memcpy(data, ptr, RingBuff->itemSz);
  	RingBuff->tail++;
  
  	return 1;
  }
  
  /* Pop multiple items from Ring buffer */
  int RingBuffer_PopMult(RINGBUFF_T *RingBuff, void *data, int num)
  {
  	uint8_t *ptr = RingBuff->data;
  	int cnt1, cnt2;
  
  	/* We cannot insert when queue is empty */
  	if (RingBuffer_IsEmpty(RingBuff))
  		return 0;
  
  	/* Calculate the segment lengths */
  	cnt1 = cnt2 = RingBuffer_GetCount(RingBuff);
  	if (RB_INDT(RingBuff) + cnt1 >= RingBuff->count)
  		cnt1 = RingBuff->count - RB_INDT(RingBuff);
  	cnt2 -= cnt1;
  
  	cnt1 = MIN(cnt1, num);
  	num -= cnt1;
  
  	cnt2 = MIN(cnt2, num);
  	num -= cnt2;
  
  	/* Write segment 1 */
  	ptr += RB_INDT(RingBuff) * RingBuff->itemSz;
  	memcpy(data, ptr, cnt1 * RingBuff->itemSz);
  	RingBuff->tail += cnt1;
  
  	/* Write segment 2 */
  	ptr = (uint8_t *) RingBuff->data + RB_INDT(RingBuff) * RingBuff->itemSz;
  	data = (uint8_t *) data + cnt1 * RingBuff->itemSz;
  	memcpy(data, ptr, cnt2 * RingBuff->itemSz);
  	RingBuff->tail += cnt2;
  
  	return cnt1 + cnt2;
  }
  