/*********************************************************************************
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* Copyright: (C) 2023 LingYun IoT System Studio.
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* All rights reserved.
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*
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* Filename: ringbuf.c
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* Description: This file is common ring buffer API functions
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*
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* Version: 1.0.0(11/08/23)
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* Author: Guo Wenxue <guowenxue@gmail.com>
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* ChangeLog: 1, Release initial version on "11/08/23 16:18:43"
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*
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********************************************************************************/
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#include <string.h>
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#include <assert.h>
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#include "ringbuf.h"
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void rb_init(struct ring_buffer *rb, unsigned char *buf, int size)
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{
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memset(rb, 0, sizeof (struct ring_buffer));
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rb->rd_pointer = 0;
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rb->wr_pointer = 0;
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rb->buffer= buf;
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rb->size = size;
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}
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void rb_clear(struct ring_buffer *rb)
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{
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memset(rb->buffer, 0, rb->size);
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rb->rd_pointer=0;
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rb->wr_pointer=0;
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}
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int rb_data_size(struct ring_buffer *rb)
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{
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return ((rb->wr_pointer - rb->rd_pointer) & (rb->size-1));
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}
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int rb_free_size(struct ring_buffer *rb)
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{
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return (rb->size - 1 - rb_data_size(rb));
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}
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unsigned char rb_peek(struct ring_buffer *rb, int index)
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{
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assert(index < rb_data_size(rb));
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return rb->buffer[((rb->rd_pointer + index) % rb->size)];
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}
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int rb_write(struct ring_buffer *rb, unsigned char *buf, int len)
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{
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int total;
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int i;
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/* total = len = min(space, len) */
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total = rb_free_size(rb);
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if(len > total)
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len = total;
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else
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total = len;
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i = rb->wr_pointer;
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if(i + len > rb->size)
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{
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memcpy(rb->buffer + i, buf, rb->size - i);
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buf += rb->size - i;
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len -= rb->size - i;
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i = 0;
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}
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memcpy(rb->buffer + i, buf, len);
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rb->wr_pointer = i + len;
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return total;
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}
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int rb_read(struct ring_buffer *rb, unsigned char *buf, int bytes)
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{
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int total;
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int i;
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total = rb_data_size(rb);
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if(bytes > total)
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bytes = total;
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i = rb->rd_pointer;
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if(i + bytes > rb->size)
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{
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memcpy(buf, rb->buffer + i, rb->size - i);
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buf += rb->size - i;
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bytes -= rb->size - i;
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i = 0;
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}
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memcpy(buf, rb->buffer + i, bytes);
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rb->rd_pointer = i + bytes;
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return total;
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}
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int rb_copy(struct ring_buffer *rb, unsigned char *buf, int bytes)
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{
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int total;
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int i;
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total = rb_data_size(rb);
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if(bytes > total)
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bytes = total;
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i = rb->rd_pointer;
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if(i + bytes > rb->size)
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{
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memcpy(buf, rb->buffer + i, rb->size - i);
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buf += rb->size - i;
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bytes -= rb->size - i;
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i = 0;
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}
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memcpy(buf, rb->buffer + i, bytes);
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return total;
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}
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