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 <log.h>
   9#include <malloc.h>
  10
  11#include <circbuf.h>
  12
  13
  14int buf_init (circbuf_t * buf, unsigned int size)
  15{
  16        assert (buf != NULL);
  17
  18        buf->size = 0;
  19        buf->totalsize = size;
  20        buf->data = (char *) malloc (sizeof (char) * size);
  21        assert (buf->data != NULL);
  22
  23        buf->top = buf->data;
  24        buf->tail = buf->data;
  25        buf->end = &(buf->data[size]);
  26
  27        return 1;
  28}
  29
  30int buf_free (circbuf_t * buf)
  31{
  32        assert (buf != NULL);
  33        assert (buf->data != NULL);
  34
  35        free (buf->data);
  36        memset (buf, 0, sizeof (circbuf_t));
  37
  38        return 1;
  39}
  40
  41int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
  42{
  43        unsigned int i;
  44        char *p;
  45
  46        assert (buf != NULL);
  47        assert (dest != NULL);
  48
  49        p = buf->top;
  50
  51        /* Cap to number of bytes in buffer */
  52        if (len > buf->size)
  53                len = buf->size;
  54
  55        for (i = 0; i < len; i++) {
  56                dest[i] = *p++;
  57                /* Bounds check. */
  58                if (p == buf->end) {
  59                        p = buf->data;
  60                }
  61        }
  62
  63        /* Update 'top' pointer */
  64        buf->top = p;
  65        buf->size -= len;
  66
  67        return len;
  68}
  69
  70int buf_push (circbuf_t * buf, const char *src, unsigned int len)
  71{
  72        /* NOTE:  this function allows push to overwrite old data. */
  73        unsigned int i;
  74        char *p;
  75
  76        assert (buf != NULL);
  77        assert (src != NULL);
  78
  79        p = buf->tail;
  80
  81        for (i = 0; i < len; i++) {
  82                *p++ = src[i];
  83                if (p == buf->end) {
  84                        p = buf->data;
  85                }
  86                /* Make sure pushing too much data just replaces old data */
  87                if (buf->size < buf->totalsize) {
  88                        buf->size++;
  89                } else {
  90                        buf->top++;
  91                        if (buf->top == buf->end) {
  92                                buf->top = buf->data;
  93                        }
  94                }
  95        }
  96
  97        /* Update 'tail' pointer */
  98        buf->tail = p;
  99
 100        return len;
 101}
 102