LXR uboot/lib/circbuf.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2003
   4 * Gerry Hamel, geh@ti.com, Texas Instruments
   5 */
   6
   7#include <common.h>
   8#include <malloc.h>
   9
  10#include <circbuf.h>
  11
  12
  13int buf_init (circbuf_t * buf, unsigned int size)
  14{
  15        assert (buf != NULL);
  16
  17        buf->size = 0;
  18        buf->totalsize = size;
  19        buf->data = (char *) malloc (sizeof (char) * size);
  20        assert (buf->data != NULL);
  21
  22        buf->top = buf->data;
  23        buf->tail = buf->data;
  24        buf->end = &(buf->data[size]);
  25
  26        return 1;
  27}
  28
  29int buf_free (circbuf_t * buf)
  30{
  31        assert (buf != NULL);
  32        assert (buf->data != NULL);
  33
  34        free (buf->data);
  35        memset (buf, 0, sizeof (circbuf_t));
  36
  37        return 1;
  38}
  39
  40int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
  41{
  42        unsigned int i;
  43        char *p;
  44
  45        assert (buf != NULL);
  46        assert (dest != NULL);
  47
  48        p = buf->top;
  49
  50        /* Cap to number of bytes in buffer */
  51        if (len > buf->size)
  52                len = buf->size;
  53
  54        for (i = 0; i < len; i++) {
  55                dest[i] = *p++;
  56                /* Bounds check. */
  57                if (p == buf->end) {
  58                        p = buf->data;
  59                }
  60        }
  61
  62        /* Update 'top' pointer */
  63        buf->top = p;
  64        buf->size -= len;
  65
  66        return len;
  67}
  68
  69int buf_push (circbuf_t * buf, const char *src, unsigned int len)
  70{
  71        /* NOTE:  this function allows push to overwrite old data. */
  72        unsigned int i;
  73        char *p;
  74
  75        assert (buf != NULL);
  76        assert (src != NULL);
  77
  78        p = buf->tail;
  79
  80        for (i = 0; i < len; i++) {
  81                *p++ = src[i];
  82                if (p == buf->end) {
  83                        p = buf->data;
  84                }
  85                /* Make sure pushing too much data just replaces old data */
  86                if (buf->size < buf->totalsize) {
  87                        buf->size++;
  88                } else {
  89                        buf->top++;
  90                        if (buf->top == buf->end) {
  91                                buf->top = buf->data;
  92                        }
  93                }
  94        }
  95
  96        /* Update 'tail' pointer */
  97        buf->tail = p;
  98
  99        return len;
 100}
 101