lwm2m-plain-text.c

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/*
 * Copyright (c) 2015, Yanzi Networks AB.
 * 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 HOLDER 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.
 */

/**
 * \addtogroup oma-lwm2m
 * @{
 */

/**
 * \file
 *         Implementation of the Contiki OMA LWM2M plain text reader / writer
 * \author
 *         Joakim Eriksson <joakime@sics.se>
 *         Niclas Finne <nfi@sics.se>
 */

#include "lwm2m-object.h"
#include "lwm2m-plain-text.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define DEBUG 0
#if DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif

/*---------------------------------------------------------------------------*/
size_t
lwm2m_plain_text_read_int(const uint8_t *inbuf, size_t len, int32_t *value)
{
  int i, neg = 0;
  *value = 0;
  for(i = 0; i < len; i++) {
    if(inbuf[i] >= '0' && inbuf[i] <= '9') {
      *value = *value * 10 + (inbuf[i] - '0');
    } else if(inbuf[i] == '-' && i == 0) {
      neg = 1;
    } else {
      break;
    }
  }
  if(neg) {
    *value = -*value;
  }
  return i;
}
/*---------------------------------------------------------------------------*/
size_t
lwm2m_plain_text_read_float32fix(const uint8_t *inbuf, size_t len,
                                 int32_t *value, int bits)
{
  int i, dot = 0, neg = 0;
  int32_t counter, integerpart, frac;

  integerpart = 0;
  counter = 0;
  frac = 0;
  for(i = 0; i < len; i++) {
    if(inbuf[i] >= '0' && inbuf[i] <= '9') {
      counter = counter * 10 + (inbuf[i] - '0');
      frac = frac * 10;
    } else if(inbuf[i] == '.' && dot == 0) {
      integerpart = counter;
      counter = 0;
      frac = 1;
      dot = 1;
    } else if(inbuf[i] == '-' && i == 0) {
      neg = 1;
    } else {
      break;
    }
  }
  if(dot == 0) {
    integerpart = counter;
    counter = 0;
    frac = 1;
  }
  *value = integerpart << bits;
  if(frac > 1) {
    *value += ((counter << bits) / frac);
  }
  PRINTF("READ FLOATFIX: \"%.*s\" => int(%ld) frac(%ld) f=%ld Value=%ld\n",
         (int)len, (char *)inbuf,
         (long)integerpart,
         (long)counter,
         (long)frac,
         (long)*value);
  if(neg) {
    *value = -*value;
  }
  return i;
}
/*---------------------------------------------------------------------------*/
size_t
lwm2m_plain_text_write_float32fix(uint8_t *outbuf, size_t outlen,
                                  int32_t value, int bits)
{
  int64_t v;
  unsigned long integer_part;
  unsigned long frac_part;
  int n, o = 0;

  if(outlen == 0) {
    return 0;
  }
  if(value < 0) {
    *outbuf++ = '-';
    outlen--;
    o = 1;
    value = -value;
  }

  integer_part = (unsigned long)(value >> bits);
  v = value - (integer_part << bits);
  v = (v * 100) >> bits;
  frac_part = (unsigned long)v;

  n = snprintf((char *)outbuf, outlen, "%lu.%02lu", integer_part, frac_part);
  if(n < 0 || n >= outlen) {
    return 0;
  }
  return n + o;
}
/*---------------------------------------------------------------------------*/
static size_t
write_boolean(const lwm2m_context_t *ctx, uint8_t *outbuf, size_t outlen,
              int value)
{
  if(outlen > 0) {
    if(value) {
      *outbuf = '1';
    } else {
      *outbuf = '0';
    }
    return 1;
  }
  return 0;
}
/*---------------------------------------------------------------------------*/
static size_t
write_int(const lwm2m_context_t *ctx, uint8_t *outbuf, size_t outlen,
          int32_t value)
{
  int n = snprintf((char *)outbuf, outlen, "%ld", (long)value);
  if(n < 0 || n >= outlen) {
    return 0;
  }
  return n;
}
/*---------------------------------------------------------------------------*/
static size_t
write_float32fix(const lwm2m_context_t *ctx, uint8_t *outbuf, size_t outlen,
                 int32_t value, int bits)
{
  return lwm2m_plain_text_write_float32fix(outbuf, outlen, value, bits);
}
/*---------------------------------------------------------------------------*/
static size_t
write_string(const lwm2m_context_t *ctx, uint8_t *outbuf, size_t outlen,
             const char *value, size_t stringlen)
{
  int n = snprintf((char *)outbuf, outlen, "%.*s", (int) stringlen, value);
  if(n < 0 || n >= outlen) {
    return 0;
  }
  return n;
}
/*---------------------------------------------------------------------------*/
const lwm2m_writer_t lwm2m_plain_text_writer = {
  write_int,
  write_string,
  write_float32fix,
  write_boolean
};
/*---------------------------------------------------------------------------*/
static size_t
read_int(const lwm2m_context_t *ctx, const uint8_t *inbuf, size_t len,
         int32_t *value)
{
  return lwm2m_plain_text_read_int(inbuf, len, value);
}
/*---------------------------------------------------------------------------*/
static size_t
read_string(const lwm2m_context_t *ctx, const uint8_t *inbuf, size_t len,
            uint8_t *value, size_t stringlen)
{
  if(stringlen <= len) {
    /* The outbuffer can not contain the full string including ending zero */
    return 0;
  }
  memcpy(value, inbuf, len);
  value[len] = '\0';
  return len;
}
/*---------------------------------------------------------------------------*/
static size_t
read_float32fix(const lwm2m_context_t *ctx, const uint8_t *inbuf, size_t len,
                int32_t *value, int bits)
{
  return lwm2m_plain_text_read_float32fix(inbuf, len, value, bits);
}
/*---------------------------------------------------------------------------*/
static size_t
read_boolean(const lwm2m_context_t *ctx, const uint8_t *inbuf, size_t len,
             int *value)
{
  if(len > 0) {
    if(*inbuf == '1' || *inbuf == '0') {
      *value = *inbuf == '1' ? 1 : 0;
      return 1;
    }
  }
  return 0;
}
/*---------------------------------------------------------------------------*/
const lwm2m_reader_t lwm2m_plain_text_reader = {
  read_int,
  read_string,
  read_float32fix,
  read_boolean
};
/*---------------------------------------------------------------------------*/
/** @} */