openflow/lib/dynamic-string.c

/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
 * Junior University
 * 
 * We are making the OpenFlow specification and associated documentation
 * (Software) available for public use and benefit with the expectation
 * that others will use, modify and enhance the Software and contribute
 * those enhancements back to the community. However, since we would
 * like to make the Software available for broadest use, with as few
 * restrictions as possible permission is hereby granted, free of
 * charge, to any person obtaining a copy of this Software to deal in
 * the Software under the copyrights without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * 
 * The name and trademarks of copyright holder(s) may NOT be used in
 * advertising or publicity pertaining to the Software or any
 * derivatives without specific, written prior permission.
 */

#include <config.h>
#include "dynamic-string.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"

void
ds_init(struct ds *ds)
{
    ds->string = NULL;
    ds->length = 0;
    ds->allocated = 0;
}

void
ds_clear(struct ds *ds) 
{
    ds->length = 0;
}

void
ds_reserve(struct ds *ds, size_t min_length)
{
    if (min_length > ds->allocated || !ds->string) {
        ds->allocated += MAX(min_length, ds->allocated);
        ds->allocated = MAX(8, ds->allocated);
        ds->string = xrealloc(ds->string, ds->allocated + 1);
    }
}

void
ds_put_char(struct ds *ds, char c)
{
    ds_reserve(ds, ds->length + 1);
    ds->string[ds->length++] = c;
    ds->string[ds->length] = '\0';
}

void
ds_put_cstr(struct ds *ds, const char *s)
{
    size_t s_len = strlen(s);
    ds_reserve(ds, ds->length + s_len);
    memcpy(&ds->string[ds->length], s, s_len + 1);
    ds->length += s_len;
}

void
ds_put_format(struct ds *ds, const char *format, ...)
{
    va_list args;

    va_start(args, format);
    ds_put_format_valist(ds, format, args);
    va_end(args);
}

void
ds_put_format_valist(struct ds *ds, const char *format, va_list args_)
{
    va_list args;
    size_t available;
    int needed;

    va_copy(args, args_);
    available = ds->string ? ds->allocated - ds->length + 1 : 0;
    needed = vsnprintf(&ds->string[ds->length], available, format, args);
    va_end(args);

    if (needed < available) {
        ds->length += needed;
    } else {
        size_t available;

        ds_reserve(ds, ds->length + needed);

        va_copy(args, args_);
        available = ds->allocated - ds->length + 1;
        needed = vsnprintf(&ds->string[ds->length], available, format, args);
        va_end(args);

        assert(needed < available);
        ds->length += needed;
    }
}

char *
ds_cstr(struct ds *ds)
{
    if (!ds->string) {
        ds_reserve(ds, 0);
        ds->string[0] = '\0';
    }
    return ds->string;
}

void
ds_destroy(struct ds *ds)
{
    free(ds->string);
}

/* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
 * line.  Numeric offsets are also included, starting at 'ofs' for the first
 * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters
 * are also rendered alongside. */
void
ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
                uintptr_t ofs, bool ascii)
{
  const uint8_t *buf = buf_;
  const size_t per_line = 16; /* Maximum bytes per line. */

  while (size > 0)
    {
      size_t start, end, n;
      size_t i;

      /* Number of bytes on this line. */
      start = ofs % per_line;
      end = per_line;
      if (end - start > size)
        end = start + size;
      n = end - start;

      /* Print line. */
      ds_put_format(ds, "%08jx  ", (uintmax_t) ROUND_DOWN(ofs, per_line));
      for (i = 0; i < start; i++)
        ds_put_format(ds, "   ");
      for (; i < end; i++)
        ds_put_format(ds, "%02hhx%c",
                buf[i - start], i == per_line / 2 - 1? '-' : ' ');
      if (ascii)
        {
          for (; i < per_line; i++)
            ds_put_format(ds, "   ");
          ds_put_format(ds, "|");
          for (i = 0; i < start; i++)
            ds_put_format(ds, " ");
          for (; i < end; i++) {
              int c = buf[i - start];
              ds_put_char(ds, c >= 32 && c < 127 ? c : '.');
          }
          for (; i < per_line; i++)
            ds_put_format(ds, " ");
          ds_put_format(ds, "|");
        }
      ds_put_format(ds, "\n");

      ofs += n;
      buf += n;
      size -= n;
    }
}