/*----------------------------------------------------------------------------
* Copyright (c) <2018>, <Huawei Technologies Co., Ltd>
* All rights reserved.
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
* 3. Neither the name of the copyright holder nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific prior written
* permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*---------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
* Notice of Export Control Law
* ===============================================
* Huawei LiteOS may be subject to applicable export control laws and regulations, which might
* include those applicable to Huawei LiteOS of U.S. and the country in which you are located.
* Import, export and usage of Huawei LiteOS in any manner by you shall be in compliance with such
* applicable export control laws and regulations.
*---------------------------------------------------------------------------*/
/**
* DATE AUTHOR INSTRUCTION
* 2019-04-29 10:34 zhangqianfu The first version
*
*/
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <link_misc.h>
int ring_buffer_init(tag_ring_buffer_t *ring,unsigned char *buf, int buflen,int offset,int datalen)
{
int ret = -1;
if((NULL == ring))
{
return ret;
}
ring->buf = buf;
ring->buflen = buflen;
ring->datalen = datalen;
ring->dataoff = offset;
ret = 0;
return ret;
}
int ring_buffer_write(tag_ring_buffer_t *ring,unsigned char *buf, int len)
{
int ret = -1;
int cpylen; //the current time we should move
int lenleft; //and how many data still left to move
int offset;
unsigned char *src;
unsigned char *dst;
if((NULL == ring)||(NULL == buf)||(0 == len))
{
return ret;//which means parameters error
}
if((ring->datalen == ring->buflen)|| (ring->buflen <= 0))
{
ret = 0;
return ret;//which means you could copy nothing here
}
ret = len > (ring->buflen-ring->datalen)?(ring->buflen-ring->datalen):len;
//now let us think the method to fill the data,take care of the roll back
lenleft = ret;
src = buf;
if((ring->dataoff+ring->datalen)>ring->buflen) //which means the data has roll back
{
offset = (ring->dataoff+ring->datalen)%ring->buflen; //we could move it one time
cpylen = lenleft;
dst = ring->buf + offset;
if(cpylen > 0)
{
(void) memcpy(dst,src,cpylen);
ring->datalen += cpylen;
lenleft -= cpylen;
}
}
else if((ring->dataoff+ring->datalen + lenleft)>ring->buflen) //which means the data will be roll back
{
//which means roll back,we should copy some here to the tail
offset = ring->dataoff + ring->datalen;
cpylen = ring->buflen - offset;
dst = ring->buf + offset;
(void) memcpy(dst,src,cpylen);
src += cpylen;
ring->datalen += cpylen;
lenleft -= cpylen;
}
//here means we could move it by one time
if(lenleft > 0)
{
offset = (ring->dataoff+ring->datalen)%ring->buflen; //we could move it one time
cpylen = lenleft;
dst = ring->buf + offset;
(void) memcpy(dst,src,cpylen);
ring->datalen += cpylen;
}
return ret;
}
int ring_buffer_read(tag_ring_buffer_t *ring,unsigned char *buf, int len)
{
int ret = -1;
int cpylen; //the current time we should move
int lenleft; //and how many data still left to move
int offset;
unsigned char *src;
unsigned char *dst;
if((NULL == ring)||(NULL == buf)||(0 == len))
{
return ret;//which means parameters error
}
if((ring->datalen == 0) || (ring->buflen <= 0))
{
ret = 0;
return ret;//which means you could copy nothing here
}
ret = len > ring->datalen?ring->datalen:len;
//now let us think the method to fill the data,take care of the roll back
lenleft = ret;
dst = buf;
if(ring->dataoff >= (ring->buflen - lenleft)) //which means the data has roll back
{
offset =ring->dataoff; //we cpy part
cpylen = ring->buflen - ring->dataoff;
src = ring->buf + offset;
if(cpylen > 0)
{
(void) memcpy(dst,src,cpylen);
ring->dataoff = (ring->dataoff + cpylen)%ring->buflen;
ring->datalen -= cpylen;
lenleft -= cpylen;
dst += cpylen;
}
}
//here means we could move it by one time
if(lenleft > 0)
{
offset =ring->dataoff; //we cpy part
cpylen = lenleft;
src = ring->buf + offset;
(void) memcpy(dst,src,cpylen);
ring->dataoff = ring->dataoff + cpylen;
ring->datalen -= cpylen;
}
return ret;
}
int ring_buffer_datalen(tag_ring_buffer_t *ring)
{
int ret = -1;
if(NULL != ring)
{
ret = ring->datalen;
}
return ret;
}
int ring_buffer_freespace(tag_ring_buffer_t *ring)
{
int ret = -1;
if(NULL != ring)
{
ret = ring->buflen-ring->datalen;
}
return ret;
}
int ring_buffer_reset(tag_ring_buffer_t *ring)
{
int ret = -1;
if(NULL != ring)
{
ring->datalen = 0;
ring->dataoff = 0;
ret = 0;
}
return ret;
}
int ring_buffer_deinit(tag_ring_buffer_t *ring)
{
int ret = -1;
if(NULL != ring)
{
(void) memset(ring,0,sizeof(tag_ring_buffer_t));
ret = 0;
}
return ret;
}