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/*
* @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 "ring_buffer.h"
int32_t RingBuf_Init(ring_buffer_t* pRB, uint8_t* buffer, uint32_t size )
{
pRB->pBuf = (uint8_t*)buffer;
pRB->size = size;
pRB->rNdx = 0;
pRB->wNdx = 0;
pRB->cnt = 0;
return 0;
}
int32_t RingBuf_Deinit(ring_buffer_t* pRB )
{
pRB = pRB;;
return 0;
}
int32_t RingBuf_GetFreeBytes(ring_buffer_t* pRB )
{
return pRB->size - pRB->cnt;
}
int32_t RingBuf_GetUsedBytes(ring_buffer_t* pRB)
{
return pRB->cnt;
}
int32_t RingBuf_Write(ring_buffer_t* pRB, const uint8_t* data, uint32_t dataBytes)
{
uint32_t writeToEnd, bytesToCopy;
INIT_CRITICAL();
ENTER_CRITICAL();
/* Calculate the maximum amount we can copy */
writeToEnd = pRB->size - pRB->wNdx;
bytesToCopy = MIN(dataBytes, pRB->size - pRB->cnt);
if (bytesToCopy != 0)
{
/* Copy as much as we can until we fall off the end of the buffer */
memcpy(&pRB->pBuf[pRB->wNdx], data, MIN(bytesToCopy, writeToEnd));
/* Check if we have more to copy to the front of the buffer */
if (writeToEnd < bytesToCopy)
{
memcpy(pRB->pBuf, data + writeToEnd, bytesToCopy - writeToEnd);
}
/* Update the wNdx */
pRB->wNdx = (pRB->wNdx + bytesToCopy) % pRB->size;
pRB->cnt += dataBytes;
}
LEAVE_CRITICAL();
return bytesToCopy;
}
int32_t RingBuf_Write1Byte(ring_buffer_t* pRB, const uint8_t *pcData)
{
uint32_t ret = 0;
INIT_CRITICAL();
ENTER_CRITICAL();
if (pRB->cnt < pRB->size)
{
pRB->pBuf[pRB->wNdx] = pcData[0];
pRB->wNdx = (pRB->wNdx + 1) % pRB->size;
pRB->cnt++;
ret = 1;
}
LEAVE_CRITICAL();
return ret;
}
int32_t _prvRingBuf_Read(ring_buffer_t* pRB, uint8_t* data, uint32_t dataBytes, uint32_t isToFree)
{
uint32_t readToEnd, bytesToCopy;
INIT_CRITICAL();
ENTER_CRITICAL();
readToEnd = pRB->size - pRB->rNdx;
bytesToCopy = MIN(dataBytes, pRB->cnt);
if (bytesToCopy != 0)
{
memcpy(data, &pRB->pBuf[pRB->rNdx], MIN(bytesToCopy, readToEnd));
if (readToEnd < bytesToCopy)
memcpy(data + readToEnd, &pRB->pBuf[0], bytesToCopy - readToEnd);
if (isToFree)
{
pRB->rNdx = (pRB->rNdx + bytesToCopy) % pRB->size;
pRB->cnt -= bytesToCopy;
}
}
LEAVE_CRITICAL();
return bytesToCopy;
}
int32_t RingBuf_Read(ring_buffer_t* pRB, uint8_t* data, uint32_t dataBytes)
{
return _prvRingBuf_Read(pRB, data, dataBytes, 1);
}
int32_t RingBuf_Copy(ring_buffer_t* pRB, uint8_t* data, uint32_t dataBytes)
{
return _prvRingBuf_Read(pRB, data, dataBytes, 0);
}
int32_t RingBuf_Read1Byte(ring_buffer_t* pRB, uint8_t *pData)
{
uint32_t ret = 0;
INIT_CRITICAL();
ENTER_CRITICAL();
if (pRB->cnt != 0)
{
pData[0] = pRB->pBuf[pRB->rNdx];
pRB->rNdx = (pRB->rNdx + 1) % pRB->size;
pRB->cnt--;
ret = 1;
}
LEAVE_CRITICAL();
return ret;
}
int32_t RingBuf_Peek(ring_buffer_t* pRB, uint8_t **ppData)
{
uint32_t readToEnd = pRB->size - pRB->rNdx;
uint32_t contiguousBytes;
*ppData = &(pRB->pBuf[pRB->rNdx]);
contiguousBytes = MIN(readToEnd, (readToEnd + pRB->wNdx) % pRB->size);
return contiguousBytes;
}
int32_t RingBuf_Free(ring_buffer_t* pRB, uint32_t bytesToFree)
{
INIT_CRITICAL();
ENTER_CRITICAL();
pRB->rNdx = (pRB->rNdx + bytesToFree) % pRB->size;
pRB->cnt -= bytesToFree;
LEAVE_CRITICAL();
return bytesToFree;
}
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