/*
   * (C) Copyright 2003
   * Gerry Hamel, geh@ti.com, Texas Instruments
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #include <common.h>
  #include <malloc.h>
  
  #include <circbuf.h>
  
  
  int buf_init (circbuf_t * buf, unsigned int size)
  {
  	assert (buf != NULL);
  
  	buf->size = 0;
  	buf->totalsize = size;
  	buf->data = (char *) malloc (sizeof (char) * size);
  	assert (buf->data != NULL);
  
  	buf->top = buf->data;
  	buf->tail = buf->data;
  	buf->end = &(buf->data[size]);
  
  	return 1;
  }
  
  int buf_free (circbuf_t * buf)
  {
  	assert (buf != NULL);
  	assert (buf->data != NULL);
  
  	free (buf->data);
  	memset (buf, 0, sizeof (circbuf_t));
  
  	return 1;
  }
  
  int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
  {
  	unsigned int i;
  	char *p = buf->top;
  
  	assert (buf != NULL);
  	assert (dest != NULL);
  
  	/* Cap to number of bytes in buffer */
  	if (len > buf->size)
  		len = buf->size;
  
  	for (i = 0; i < len; i++) {
  		dest[i] = *p++;
  		/* Bounds check. */
  		if (p == buf->end) {
  			p = buf->data;
  		}
  	}
  
  	/* Update 'top' pointer */
  	buf->top = p;
  	buf->size -= len;
  
  	return len;
  }
  
  int buf_push (circbuf_t * buf, const char *src, unsigned int len)
  {
  	/* NOTE:  this function allows push to overwrite old data. */
  	unsigned int i;
  	char *p = buf->tail;
  
  	assert (buf != NULL);
  	assert (src != NULL);
  
  	for (i = 0; i < len; i++) {
  		*p++ = src[i];
  		if (p == buf->end) {
  			p = buf->data;
  		}
  		/* Make sure pushing too much data just replaces old data */
  		if (buf->size < buf->totalsize) {
  			buf->size++;
  		} else {
  			buf->top++;
  			if (buf->top == buf->end) {
  				buf->top = buf->data;
  			}
  		}
  	}
  
  	/* Update 'tail' pointer */
  	buf->tail = p;
  
  	return len;
  }